chore: Release lemur version 0.15.0

- Support WGPU_FORCE_FALLBACK to run on CPU
 - Pass display when creating wgpu instance
 - Pass compatible surface when constructing adapter
 - Log some settings (at debug level)

.gitattributes

@@ -4,6 +4,7 @@
 *.html  text eol=lf diff=html
 *.java  text eol=lf diff=java
 *.js    text eol=lf diff=js
+*.sh    text eol=lf
 *.txt   text eol=lf
 
 *.class binary

.gitignore

@@ -1,4 +1,5 @@
-/shrooms-vb
-/shrooms-vb.exe
+/lemur
+/lemur.exe
 .vscode
 output
+/target

Cargo.toml

@@ -0,0 +1,67 @@
+[package]
+name = "lemur"
+description = "An emulator for the Virtual Boy."
+repository = "https://git.virtual-boy.com/PVB/lemur"
+publish = false
+license = "MIT"
+version = "0.15.0"
+edition = "2024"
+
+[dependencies]
+anyhow = "1"
+atoi = "3"
+audioadapter-buffers = "4"
+atomic = "0.6"
+bitflags = { version = "2", features = ["serde"] }
+bytemuck = { version = "1", features = ["derive"] }
+clap = { version = "4", features = ["derive"] }
+cpal = "0.18"
+directories = "6"
+egui = { version = "0.34", features = ["persistence", "serde"] }
+egui_extras = { version = "0.34", features = ["image"] }
+egui-notify = "0.22"
+egui-winit = "0.34"
+egui-wgpu = { version = "0.34", features = ["winit"] }
+fxprof-processed-profile = "0.8"
+fixed = { version = "1.28", features = ["num-traits"] }
+gilrs = { version = "0.11", features = ["serde-serialize"] }
+gimli = "0.34"
+hex = "0.4"
+image = { version = "0.25", default-features = false, features = ["png"] }
+itertools = "0.15"
+normpath = "1"
+notify = "8"
+num-derive = "0.4"
+num-traits = "0.2"
+object = "0.39"
+oneshot = { version = "0.2", features = ["async", "std"] }
+pollster = "1"
+rand = "0.10"
+rfd = "0.17"
+rtrb = "0.3"
+rubato = "4"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+thread-priority = "3"
+tokio = { version = "1", features = ["io-util", "macros", "net", "rt", "sync", "time"] }
+tracing = { version = "0.1", features = ["release_max_level_debug"] }
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }
+wgpu = { version = "29", features = ["serde"] }
+wholesym = "0.8"
+winit = { version = "0.30", features = ["serde"] }
+
+[target.'cfg(windows)'.dependencies]
+windows = { version = "0.62", features = ["Win32_System_Threading"] }
+
+[build-dependencies]
+cc = "1"
+winresource = "0.1"
+
+[profile.release]
+lto = true
+
+[package.metadata.bundle]
+name = "Lemur"
+identifier = "com.virtual-boy.Lemur"
+icon = ["assets/lemur-256x256.png"]
+category = "games"

README.md

@@ -1,19 +1,27 @@
-# Shrooms VB (native)
+# Lemur
 
-An SDL-based implementation of shrooms-vb.
+A Virtual Boy emulator built around the shrooms-vb core. Written in Rust, using winit, wgpu, and egui. Should run on any major OS.
 
 ## Setup
 
 Install the following dependencies:
- - `gcc` (or MinGW on Windows) (or whatever, just set `CC`)
- - `pkg-config`
- - sdl2
+ - `cargo` (via [rustup](https://rustup.rs/), the version from your package manager is too old)
+ - a C compiler (any will do, [the build script](https://docs.rs/cc/latest/cc/#compile-time-requirements) will find it automatically)
+ - (on linux) `libasound2-dev` and `libudev-dev`
 
 Run
 ```sh
-make build
+cargo build --release
 ```
 
-## Dependencies
+The executable will be in `target/release/lemur[.exe]`
 
-This program uses a vendored version of [nuklear](https://github.com/Immediate-Mode-UI/Nuklear/tree/6566d9075d5fed48af014c93f87c4aed8c4bd21c) for GUIs.
+## Release
+
+Bump the version number in `Cargo.toml`, then run this script:
+
+```sh
+./scripts/release.sh
+```
+
+It uses docker to cross compile for Windows, MacOS, and Linux. All binaries are left in the `output` directory.

assets.h

@@ -1,17 +0,0 @@
-#ifndef SHROOMS_VB_NATIVE_ASSETS_
-#define SHROOMS_VB_NATIVE_ASSETS_
-
-#include <stdint.h>
-
-extern const uint8_t _binary_assets_lefteye_bin_start;
-const uint8_t *LEFT_EYE_DEFAULT = &_binary_assets_lefteye_bin_start; 
-
-extern const uint8_t _binary_assets_righteye_bin_start;
-const uint8_t *RIGHT_EYE_DEFAULT = &_binary_assets_righteye_bin_start; 
-
-extern const uint8_t _binary_assets_selawk_bin_start;
-extern const uint8_t _binary_assets_selawk_bin_end;
-const uint8_t *SELAWIK = &_binary_assets_selawk_bin_start;
-#define SELAWIK_LEN (&_binary_assets_selawk_bin_end - &_binary_assets_selawk_bin_start)
-
-#endif

audio.c

@@ -1,69 +0,0 @@
-#include <audio.h>
-#include <stdio.h>
-
-void audioCallback(void *userdata, uint8_t *stream, int len) {
-    AudioContext *aud;
-    SDL_assert(len == 834 * 4);
-
-    aud = userdata;
-    if (!aud->filled) {
-        /* too little data, play silence */
-        SDL_memset4(stream, 0, 834);
-        return;
-    }
-    SDL_memcpy4(stream, aud->buffers[aud->current], 834);
-    ++aud->current;
-    aud->current %= 2;
-    aud->filled -= 1;
-} 
-
-int audioInit(AudioContext *aud) {
-    SDL_AudioSpec spec;
-    spec.freq = 41700;
-    spec.format = AUDIO_S16;
-    spec.channels = 2;
-    spec.samples = 834;
-    spec.callback = &audioCallback;
-    spec.userdata = aud;
-
-    aud->id = SDL_OpenAudioDevice(NULL, 0, &spec, NULL, 0);
-    aud->paused = true;
-    if (!aud->id) {
-        fprintf(stderr, "could not open audio device: %s\n", SDL_GetError());
-        return -1;
-    }
-    aud->current = 0;
-    aud->filled = 0;
-    return 0;
-}
-
-void audioDestroy(AudioContext *aud) {
-    SDL_CloseAudioDevice(aud->id);
-}
-
-int audioUpdate(AudioContext *aud, void *data, uint32_t bytes) {
-    int filled;
-    if (!aud->id) return -1;
-    SDL_assert(bytes == 834 * 4);
-
-    SDL_LockAudioDevice(aud->id);
-    if (aud->filled < 2) {
-        int next = (aud->current + aud->filled) % 2;
-        SDL_memcpy4(aud->buffers[next], data, bytes / 4);
-        aud->filled += 1;
-    }
-    filled = aud->filled;
-    SDL_UnlockAudioDevice(aud->id);
-
-    if (aud->paused) {
-        SDL_PauseAudioDevice(aud->id, false);
-        aud->paused = false;
-    }
-
-    while (filled > 1) {
-        SDL_Delay(0);
-        filled = aud->filled;
-    }
-
-    return 0;
-}

audio.h

@@ -1,19 +0,0 @@
-#ifndef SHROOMS_VB_NATIVE_AUDIO_
-#define SHROOMS_VB_NATIVE_AUDIO_
-
-#include <SDL2/SDL.h>
-#include <stdbool.h>
-
-typedef struct {
-    SDL_AudioDeviceID id;
-    bool paused;
-    uint32_t buffers[2][834];
-    int current;
-    int filled;
-} AudioContext;
-
-int audioInit(AudioContext *aud);
-void audioDestroy(AudioContext *aud);
-int audioUpdate(AudioContext *aud, void *data, uint32_t bytes);
-
-#endif

build.Dockerfile

@@ -0,0 +1,53 @@
+# This Dockerfile produces a base image for builds.
+# It includes all dependencies necessary to cross-compile for Windows/MacOS/Linux.
+
+FROM debian:trixie AS osxcross
+ADD --chmod=644 "https://apt.llvm.org/llvm-snapshot.gpg.key" /etc/apt/trusted.gpg.d/apt.llvm.org.asc
+WORKDIR /build/osxcross
+ADD "https://github.com/tpoechtrager/osxcross.git#47936a512273bb3b414b5a2e83043c92eabc7ae7" .
+ADD "https://github.com/joseluisq/macosx-sdks/releases/download/14.5/MacOSX14.5.sdk.tar.xz" ./tarballs/MacOSX14.5.sdk.tar.xz
+RUN apt-get update && \
+    apt-get install -y ca-certificates
+COPY llvm.sources /etc/apt/sources.list.d/llvm.sources
+RUN apt-get update && \
+    apt-get install -y bash bzip2 clang-22 git lld-22 llvm-22 make patch xz-utils && \
+    ln -s $(which clang-22) /usr/bin/clang && \
+    ln -s $(which clang++-22) /usr/bin/clang++ && \
+    ln -s $(which ld64.lld-22) /usr/bin/ld64.lld && \
+    SDK_VERSION=14.5 UNATTENDED=1 ENABLE_COMPILER_RT_INSTALL=1 TARGET_DIR=/osxcross ./build.sh
+
+FROM rust:1.97-trixie
+ADD --chmod=644 "https://apt.llvm.org/llvm-snapshot.gpg.key" /etc/apt/trusted.gpg.d/apt.llvm.org.asc
+COPY llvm.sources /etc/apt/sources.list.d/llvm.sources
+RUN rustup target add x86_64-pc-windows-msvc && \
+    rustup target add x86_64-apple-darwin && \
+    rustup target add aarch64-apple-darwin && \
+    apt-get update && \
+    apt-get install -y clang-22 lld-22 libc6-dev libasound2-dev libudev-dev genisoimage mingw-w64 && \
+    cargo install cargo-bundle xwin && \
+    xwin --accept-license splat --output xwin && \
+    rm -rf .xwin-cache && \
+    ln -s $(which clang-22) /usr/bin/clang && \
+    ln -s $(which clang++-22) /usr/bin/clang++
+COPY --from=osxcross /osxcross /osxcross
+
+ENV PATH="/osxcross/bin:$PATH" \
+    LD_LIBRARY_PATH="/osxcross/lib" \
+    CC="clang-22" CXX="clang++-22" AR="llvm-ar-22" \
+    CC_x86_64-apple-darwin="o64-clang" \
+    CXX_x86_64-apple-darwin="o64-clang++" \
+    CC_aarch64-apple-darwin="oa64-clang" \
+    CXX_aarch64-apple-darwin="o6a4-clang++" \
+    SHROOMS_CFLAGS_x86_64-unknown-linux-gnu="-flto" \
+    CARGO_TARGET_X86_64_UNKNOWN_LINUX_GNU_RUSTFLAGS="-Clinker-plugin-lto -Clinker=clang -Clink-arg=-fuse-ld=lld" \
+    SHROOMS_CFLAGS_x86_64-pc-windows-msvc="-flto" \
+    CFLAGS_x86_64-pc-windows-msvc="-I/xwin/crt/include -I/xwin/sdk/include/ucrt -I/xwin/sdk/include/um -I/xwin/sdk/include/shared" \
+    CARGO_TARGET_X86_64_PC_WINDOWS_MSVC_RUSTFLAGS="-Lnative=/xwin/crt/lib/x86_64 -Lnative=/xwin/sdk/lib/um/x86_64 -Lnative=/xwin/sdk/lib/ucrt/x86_64 -Clinker-plugin-lto -Clink-arg=-fuse-ld=lld" \
+    CARGO_TARGET_X86_64_PC_WINDOWS_MSVC_LINKER="lld-link-22" \
+    CARGO_TARGET_X86_64_APPLE_DARWIN_LINKER="o64-clang" \
+    CARGO_TARGET_X86_64_APPLE_DARWIN_AR="llvm-ar-22" \
+    CARGO_TARGET_AARCH64_APPLE_DARWIN_LINKER="oa64-clang" \
+    CARGO_TARGET_AARCH64_APPLE_DARWIN_AR="llvm-ar-22" \
+    RC_PATH="llvm-rc-22" \
+    MACOSX_DEPLOYMENT_TARGET="14.5"
+ENTRYPOINT ["bash"]

build.rs

@@ -0,0 +1,41 @@
+use std::{error::Error, path::Path};
+
+fn main() -> Result<(), Box<dyn Error>> {
+    if std::env::var("CARGO_CFG_TARGET_OS")? == "windows" {
+        let mut res = winresource::WindowsResource::new();
+        res.set_icon("assets/lemur.ico");
+        res.compile()?;
+    }
+
+    println!("cargo::rerun-if-changed=shrooms-vb-core");
+
+    let mut builder = cc::Build::new();
+    let _ = builder.try_flags_from_environment("SHROOMS_CFLAGS");
+    let opt_level = if builder.get_compiler().is_like_msvc() {
+        2
+    } else {
+        3
+    };
+    builder
+        .include(Path::new("shrooms-vb-core/core"))
+        .include(Path::new("shrooms-vb-core/util"))
+        .opt_level(opt_level)
+        .flag_if_supported("-fno-strict-aliasing")
+        .define("_CRT_SECURE_NO_WARNINGS", None)
+        .define("VB_LITTLE_ENDIAN", None)
+        .define("VB_SIGNED_PROPAGATE", None)
+        .define("VB_DIV_GENERIC", None)
+        .define("VB_DIRECT_EXCEPTION", "on_exception")
+        .define("VB_DIRECT_EXECUTE", "on_execute")
+        .define("VB_DIRECT_FETCH", "on_fetch")
+        .define("VB_DIRECT_FRAME", "on_frame")
+        .define("VB_DIRECT_READ", "on_read")
+        .define("VB_DIRECT_WRITE", "on_write")
+        .define("VBU_REALLOC", "vbu_realloc_shim")
+        .file(Path::new("shrooms-vb-core/core/vb.c"))
+        .file(Path::new("shrooms-vb-core/util/isx.c"))
+        .file(Path::new("shrooms-vb-core/util/vbu.c"))
+        .compile("vb");
+
+    Ok(())
+}

cli.c

@@ -1,16 +0,0 @@
-#include <cli.h>
-#include <stdio.h>
-
-int parseCLIArgs(int argc, char **argv, CLIArgs *args) {
-    int arg;
-
-    args->filename = NULL;
-    for (arg = 1; arg < argc; ++arg) {
-        if (args->filename) {
-            fprintf(stderr, "usage: %s /path/to/rom.vb\n", argv[0]);
-            return 1;
-        }
-        args->filename = argv[arg];
-    }
-    return 0;
-}

cli.h

@@ -1,10 +0,0 @@
-#ifndef SHROOMS_VB_NATIVE_CLI_
-#define SHROOMS_VB_NATIVE_CLI_
-
-typedef struct {
-    char *filename;
-} CLIArgs;
-
-int parseCLIArgs(int argc, char **argv, CLIArgs *args);
-
-#endif

controller.c

@@ -1,65 +0,0 @@
-#include <controller.h>
-
-#define VB_PWR 0x0001
-#define VB_SGN 0x0002
-#define VB_A   0x0004
-#define VB_B   0x0008
-#define VB_RT  0x0010
-#define VB_LT  0x0020
-#define VB_RU  0x0040
-#define VB_RR  0x0080
-#define VB_LR  0x0100
-#define VB_LL  0x0200
-#define VB_LD  0x0400
-#define VB_LU  0x0800
-#define VB_STA 0x1000
-#define VB_SEL 0x2000
-#define VB_RL  0x4000
-#define VB_RD  0x8000
-
-static uint16_t symToMask(SDL_KeyCode sym) {
-    switch (sym) {
-    default: return 0;
-    case SDLK_a:
-        return VB_SEL;
-    case SDLK_s:
-        return VB_STA;
-    case SDLK_d:
-        return VB_B;
-    case SDLK_f:
-        return VB_A;
-    case SDLK_e:
-        return VB_LT;
-    case SDLK_r:
-        return VB_RT;
-    case SDLK_i:
-        return VB_RU;
-    case SDLK_j:
-        return VB_RL;
-    case SDLK_k:
-        return VB_RD;
-    case SDLK_l:
-        return VB_RR;
-    case SDLK_UP:
-        return VB_LU;
-    case SDLK_LEFT:
-        return VB_LL;
-    case SDLK_DOWN:
-        return VB_LD;
-    case SDLK_RIGHT:
-        return VB_LR;
-    }
-}
-
-void ctrlInit(ControllerState *ctrl) {
-    ctrl->keys = VB_SGN;
-}
-void ctrlKeyDown(ControllerState *ctrl, SDL_Keycode sym) {
-    ctrl->keys |= symToMask(sym);
-}
-void ctrlKeyUp(ControllerState *ctrl, SDL_Keycode sym) {
-    ctrl->keys &= ~symToMask(sym);
-}
-uint16_t ctrlKeys(ControllerState *ctrl) {
-    return ctrl->keys;
-}

controller.h

@@ -1,16 +0,0 @@
-#ifndef SHROOMS_VB_NATIVE_CONTROLLER_
-#define SHROOMS_VB_NATIVE_CONTROLLER_
-
-#include <SDL2/SDL.h>
-#include <stdint.h>
-
-typedef struct {
-    uint16_t keys;
-} ControllerState;
-
-void ctrlInit(ControllerState *ctrl);
-void ctrlKeyDown(ControllerState *ctrl, SDL_Keycode sym);
-void ctrlKeyUp(ControllerState *ctrl, SDL_Keycode sym);
-uint16_t ctrlKeys(ControllerState *ctrl);
-
-#endif

emulation.c

@@ -1,75 +0,0 @@
-#include "emulation.h"
-#include <stdlib.h>
-
-static int onFrame(VB *sim) {
-    SimContext *ctx = vbGetUserData(sim);
-    ctx->hasFrame = true;
-    return 1;
-}
-
-int emuInit(EmulationContext *emu) {
-    emu->sim = malloc(vbSizeOf());
-    vbInit(emu->sim);
-
-    emu->ctx = malloc(sizeof(SimContext));
-    emu->ctx->hasFrame = false;
-    emu->ctx->currentSample = 0;
-    vbSetSamples(emu->sim, emu->ctx->samples[emu->ctx->currentSample], VB_S16, 834);
-    vbSetUserData(emu->sim, emu->ctx);
-    vbSetFrameCallback(emu->sim, &onFrame);
-
-    return 0;
-}
-
-void emuDestroy(EmulationContext *emu) {
-    uint8_t *rom = vbGetCartROM(emu->sim, NULL);
-    SimContext *ctx = vbGetUserData(emu->sim);
-
-    if (rom) free(rom);
-    if (ctx) free(ctx);
-    free(emu->sim);
-}
-
-void emuLoadGame(EmulationContext *emu, uint8_t *rom, uint32_t romSize) {
-    uint8_t *oldRom = vbGetCartROM(emu->sim, NULL);
-    if (oldRom) free(oldRom);
-    vbSetCartROM(emu->sim, rom, romSize);
-    vbReset(emu->sim);
-}
-
-void emuReset(EmulationContext *emu) {
-    vbReset(emu->sim);
-}
-
-bool emuIsGameLoaded(EmulationContext *emu) {
-    return vbGetCartROM(emu->sim, NULL) != NULL;
-}
-
-#define MAX_STEP_CLOCKS 20000000
-void emuTick(EmulationContext *emu) {
-    uint32_t clocks = MAX_STEP_CLOCKS;
-    vbEmulate(emu->sim, &clocks);
-}
-
-bool emuReadPixels(EmulationContext *emu, uint8_t *left, uint8_t *right) {
-    if (!emu->ctx->hasFrame) {
-        return false;
-    }
-    emu->ctx->hasFrame = false;
-    vbGetPixels(emu->sim, left, 1, 384, right, 1, 384);
-    return true;
-}
-
-void emuReadSamples(EmulationContext *emu, void **data, uint32_t *bytes) {
-    uint32_t samplePairs;
-
-    *data = vbGetSamples(emu->sim, NULL, NULL, &samplePairs);
-    *bytes = samplePairs * 4;
-    emu->ctx->currentSample += 1;
-    emu->ctx->currentSample %= 2;
-    vbSetSamples(emu->sim, emu->ctx->samples[emu->ctx->currentSample], VB_S16, 834);
-}
-
-void emuSetKeys(EmulationContext *emu, uint16_t keys) {
-    vbSetKeys(emu->sim, keys);
-}

emulation.h

@@ -1,30 +0,0 @@
-#ifndef SHROOMS_VB_NATIVE_EMULATION_
-#define SHROOMS_VB_NATIVE_EMULATION_
-
-#include "shrooms-vb-core/core/vb.h"
-#include <stdbool.h>
-#include <stdint.h>
-
-typedef struct SimContext {
-    bool hasFrame;
-    uint32_t samples[2][834];
-    uint32_t currentSample;
-} SimContext;
-
-typedef struct EmulationContext {
-    VB *sim;
-    SimContext *ctx;
-} EmulationContext;
-
-int emuInit(EmulationContext *emu);
-void emuDestroy(EmulationContext *emu);
-void emuLoadGame(EmulationContext *emu, uint8_t *rom, uint32_t romSize);
-void emuReset(EmulationContext *emu);
-bool emuIsGameLoaded(EmulationContext *emu);
-
-void emuTick(EmulationContext *emu);
-bool emuReadPixels(EmulationContext *emu, uint8_t *left, uint8_t *right);
-void emuReadSamples(EmulationContext *emu, void **data, uint32_t *bytes);
-void emuSetKeys(EmulationContext *emu, uint16_t keys);
-
-#endif

external/nuklear_sdl_renderer.h

@@ -1,393 +0,0 @@
-/*
- * Nuklear - 4.9.4 - public domain
- */
-/*
- * ==============================================================
- *
- *                              API
- *
- * ===============================================================
- */
-#ifndef NK_SDL_RENDERER_H_
-#define NK_SDL_RENDERER_H_
-
-#ifndef NK_SDL_RENDERER_SDL_H
-#define NK_SDL_RENDERER_SDL_H <SDL.h>
-#endif
-#include NK_SDL_RENDERER_SDL_H
-NK_API struct nk_context*   nk_sdl_init(SDL_Window *win, SDL_Renderer *renderer);
-NK_API void                 nk_sdl_font_stash_begin(struct nk_font_atlas **atlas);
-NK_API void                 nk_sdl_font_stash_end(void);
-NK_API int                  nk_sdl_handle_event(SDL_Event *evt);
-NK_API void                 nk_sdl_render(enum nk_anti_aliasing);
-NK_API void                 nk_sdl_shutdown(void);
-NK_API void                 nk_sdl_handle_grab(void);
-
-#if SDL_COMPILEDVERSION < SDL_VERSIONNUM(2, 0, 22)
-/* Metal API does not support cliprects with negative coordinates or large
- * dimensions. The issue is fixed in SDL2 with version 2.0.22 but until
- * that version is released, the NK_SDL_CLAMP_CLIP_RECT flag can be used to
- * ensure the cliprect is itself clipped to the viewport.
- * See discussion at https://discourse.libsdl.org/t/rendergeometryraw-producing-different-results-in-metal-vs-opengl/34953
- */
-#define NK_SDL_CLAMP_CLIP_RECT
-#endif
-
-#endif /* NK_SDL_RENDERER_H_ */
-
-/*
- * ==============================================================
- *
- *                          IMPLEMENTATION
- *
- * ===============================================================
- */
-#ifdef NK_SDL_RENDERER_IMPLEMENTATION
-#include <string.h>
-#include <stdlib.h>
-
-struct nk_sdl_device {
-    struct nk_buffer cmds;
-    struct nk_draw_null_texture tex_null;
-    SDL_Texture *font_tex;
-};
-
-struct nk_sdl_vertex {
-    float position[2];
-    float uv[2];
-    nk_byte col[4];
-};
-
-static struct nk_sdl {
-    SDL_Window *win;
-    SDL_Renderer *renderer;
-    struct nk_sdl_device ogl;
-    struct nk_context ctx;
-    struct nk_font_atlas atlas;
-    Uint64 time_of_last_frame;
-} sdl;
-
-NK_INTERN void
-nk_sdl_device_upload_atlas(const void *image, int width, int height)
-{
-    struct nk_sdl_device *dev = &sdl.ogl;
-
-    SDL_Texture *g_SDLFontTexture = SDL_CreateTexture(sdl.renderer, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_STATIC, width, height);
-    if (g_SDLFontTexture == NULL) {
-        SDL_Log("error creating texture");
-        return;
-    }
-    SDL_UpdateTexture(g_SDLFontTexture, NULL, image, 4 * width);
-    SDL_SetTextureBlendMode(g_SDLFontTexture, SDL_BLENDMODE_BLEND);
-    dev->font_tex = g_SDLFontTexture;
-}
-
-NK_API void
-nk_sdl_render(enum nk_anti_aliasing AA)
-{
-    /* setup global state */
-    struct nk_sdl_device *dev = &sdl.ogl;
-
-    {
-        SDL_Rect saved_clip;
-#ifdef NK_SDL_CLAMP_CLIP_RECT
-        SDL_Rect viewport;
-#endif
-        SDL_bool clipping_enabled;
-        int vs = sizeof(struct nk_sdl_vertex);
-        size_t vp = offsetof(struct nk_sdl_vertex, position);
-        size_t vt = offsetof(struct nk_sdl_vertex, uv);
-        size_t vc = offsetof(struct nk_sdl_vertex, col);
-
-        /* convert from command queue into draw list and draw to screen */
-        const struct nk_draw_command *cmd;
-        const nk_draw_index *offset = NULL;
-        struct nk_buffer vbuf, ebuf;
-
-        /* fill converting configuration */
-        struct nk_convert_config config;
-        static const struct nk_draw_vertex_layout_element vertex_layout[] = {
-            {NK_VERTEX_POSITION, NK_FORMAT_FLOAT, NK_OFFSETOF(struct nk_sdl_vertex, position)},
-            {NK_VERTEX_TEXCOORD, NK_FORMAT_FLOAT, NK_OFFSETOF(struct nk_sdl_vertex, uv)},
-            {NK_VERTEX_COLOR, NK_FORMAT_R8G8B8A8, NK_OFFSETOF(struct nk_sdl_vertex, col)},
-            {NK_VERTEX_LAYOUT_END}
-        };
-
-        Uint64 now = SDL_GetTicks64();
-        sdl.ctx.delta_time_seconds = (float)(now - sdl.time_of_last_frame) / 1000;
-        sdl.time_of_last_frame = now;
-
-        NK_MEMSET(&config, 0, sizeof(config));
-        config.vertex_layout = vertex_layout;
-        config.vertex_size = sizeof(struct nk_sdl_vertex);
-        config.vertex_alignment = NK_ALIGNOF(struct nk_sdl_vertex);
-        config.tex_null = dev->tex_null;
-        config.circle_segment_count = 22;
-        config.curve_segment_count = 22;
-        config.arc_segment_count = 22;
-        config.global_alpha = 1.0f;
-        config.shape_AA = AA;
-        config.line_AA = AA;
-
-        /* convert shapes into vertexes */
-        nk_buffer_init_default(&vbuf);
-        nk_buffer_init_default(&ebuf);
-        nk_convert(&sdl.ctx, &dev->cmds, &vbuf, &ebuf, &config);
-
-        /* iterate over and execute each draw command */
-        offset = (const nk_draw_index*)nk_buffer_memory_const(&ebuf);
-
-        clipping_enabled = SDL_RenderIsClipEnabled(sdl.renderer);
-        SDL_RenderGetClipRect(sdl.renderer, &saved_clip);
-#ifdef NK_SDL_CLAMP_CLIP_RECT
-        SDL_RenderGetViewport(sdl.renderer, &viewport);
-#endif
-
-        nk_draw_foreach(cmd, &sdl.ctx, &dev->cmds)
-        {
-            if (!cmd->elem_count) continue;
-
-            {
-                SDL_Rect r;
-                r.x = cmd->clip_rect.x;
-                r.y = cmd->clip_rect.y;
-                r.w = cmd->clip_rect.w;
-                r.h = cmd->clip_rect.h;
-#ifdef NK_SDL_CLAMP_CLIP_RECT
-                if (r.x < 0) {
-                    r.w += r.x;
-                    r.x = 0;
-                }
-                if (r.y < 0) {
-                    r.h += r.y;
-                    r.y = 0;
-                }
-                if (r.h > viewport.h) {
-                    r.h = viewport.h;
-                }
-                if (r.w > viewport.w) {
-                    r.w = viewport.w;
-                }
-#endif
-                SDL_RenderSetClipRect(sdl.renderer, &r);
-            }
-
-            {
-                const void *vertices = nk_buffer_memory_const(&vbuf);
-
-                SDL_RenderGeometryRaw(sdl.renderer,
-                        (SDL_Texture *)cmd->texture.ptr,
-                        (const float*)((const nk_byte*)vertices + vp), vs,
-                        (const SDL_Color*)((const nk_byte*)vertices + vc), vs,
-                        (const float*)((const nk_byte*)vertices + vt), vs,
-                        (vbuf.needed / vs),
-                        (void *) offset, cmd->elem_count, 2);
-
-                offset += cmd->elem_count;
-            }
-        }
-
-        SDL_RenderSetClipRect(sdl.renderer, &saved_clip);
-        if (!clipping_enabled) {
-            SDL_RenderSetClipRect(sdl.renderer, NULL);
-        }
-
-        nk_clear(&sdl.ctx);
-        nk_buffer_clear(&dev->cmds);
-        nk_buffer_free(&vbuf);
-        nk_buffer_free(&ebuf);
-    }
-}
-
-static void
-nk_sdl_clipboard_paste(nk_handle usr, struct nk_text_edit *edit)
-{
-    const char *text = SDL_GetClipboardText();
-    if (text) nk_textedit_paste(edit, text, nk_strlen(text));
-    (void)usr;
-}
-
-static void
-nk_sdl_clipboard_copy(nk_handle usr, const char *text, int len)
-{
-    char *str = 0;
-    (void)usr;
-    if (!len) return;
-    str = (char*)malloc((size_t)len+1);
-    if (!str) return;
-    memcpy(str, text, (size_t)len);
-    str[len] = '\0';
-    SDL_SetClipboardText(str);
-    free(str);
-}
-
-NK_API struct nk_context*
-nk_sdl_init(SDL_Window *win, SDL_Renderer *renderer)
-{
-#ifndef NK_SDL_CLAMP_CLIP_RECT
-    SDL_RendererInfo info;
-    SDL_version runtimeVer;
-
-    /* warn for cases where NK_SDL_CLAMP_CLIP_RECT should have been set but isn't */
-    SDL_GetRendererInfo(renderer, &info);
-    SDL_GetVersion(&runtimeVer);
-    if (strncmp("metal", info.name, 5) == 0 &&
-        SDL_VERSIONNUM(runtimeVer.major, runtimeVer.minor, runtimeVer.patch) < SDL_VERSIONNUM(2, 0, 22))
-    {
-        SDL_LogWarn(
-            SDL_LOG_CATEGORY_APPLICATION,
-            "renderer is using Metal API but runtime SDL version %d.%d.%d is older than compiled version %d.%d.%d, "
-            "which may cause issues with rendering",
-            runtimeVer.major, runtimeVer.minor, runtimeVer.patch,
-            SDL_MAJOR_VERSION, SDL_MINOR_VERSION, SDL_PATCHLEVEL
-        );
-    }
-#endif
-    sdl.win = win;
-    sdl.renderer = renderer;
-    sdl.time_of_last_frame = SDL_GetTicks64();
-    nk_init_default(&sdl.ctx, 0);
-    sdl.ctx.clip.copy = nk_sdl_clipboard_copy;
-    sdl.ctx.clip.paste = nk_sdl_clipboard_paste;
-    sdl.ctx.clip.userdata = nk_handle_ptr(0);
-    nk_buffer_init_default(&sdl.ogl.cmds);
-    return &sdl.ctx;
-}
-
-NK_API void
-nk_sdl_font_stash_begin(struct nk_font_atlas **atlas)
-{
-    nk_font_atlas_init_default(&sdl.atlas);
-    nk_font_atlas_begin(&sdl.atlas);
-    *atlas = &sdl.atlas;
-}
-
-NK_API void
-nk_sdl_font_stash_end(void)
-{
-    const void *image; int w, h;
-    image = nk_font_atlas_bake(&sdl.atlas, &w, &h, NK_FONT_ATLAS_RGBA32);
-    nk_sdl_device_upload_atlas(image, w, h);
-    nk_font_atlas_end(&sdl.atlas, nk_handle_ptr(sdl.ogl.font_tex), &sdl.ogl.tex_null);
-    if (sdl.atlas.default_font)
-        nk_style_set_font(&sdl.ctx, &sdl.atlas.default_font->handle);
-}
-
-NK_API void
-nk_sdl_handle_grab(void)
-{
-    struct nk_context *ctx = &sdl.ctx;
-    if (ctx->input.mouse.grab) {
-        SDL_SetRelativeMouseMode(SDL_TRUE);
-    } else if (ctx->input.mouse.ungrab) {
-        /* better support for older SDL by setting mode first; causes an extra mouse motion event */
-        SDL_SetRelativeMouseMode(SDL_FALSE);
-        SDL_WarpMouseInWindow(sdl.win, (int)ctx->input.mouse.prev.x, (int)ctx->input.mouse.prev.y);
-    } else if (ctx->input.mouse.grabbed) {
-        ctx->input.mouse.pos.x = ctx->input.mouse.prev.x;
-        ctx->input.mouse.pos.y = ctx->input.mouse.prev.y;
-    }
-}
-
-NK_API int
-nk_sdl_handle_event(SDL_Event *evt)
-{
-    struct nk_context *ctx = &sdl.ctx;
-
-    switch(evt->type)
-    {
-        case SDL_KEYUP: /* KEYUP & KEYDOWN share same routine */
-        case SDL_KEYDOWN:
-            {
-                int down = evt->type == SDL_KEYDOWN;
-                const Uint8* state = SDL_GetKeyboardState(0);
-                switch(evt->key.keysym.sym)
-                {
-                    case SDLK_RSHIFT: /* RSHIFT & LSHIFT share same routine */
-                    case SDLK_LSHIFT:    nk_input_key(ctx, NK_KEY_SHIFT, down); break;
-                    case SDLK_DELETE:    nk_input_key(ctx, NK_KEY_DEL, down); break;
-                    case SDLK_RETURN:    nk_input_key(ctx, NK_KEY_ENTER, down); break;
-                    case SDLK_TAB:       nk_input_key(ctx, NK_KEY_TAB, down); break;
-                    case SDLK_BACKSPACE: nk_input_key(ctx, NK_KEY_BACKSPACE, down); break;
-                    case SDLK_HOME:      nk_input_key(ctx, NK_KEY_TEXT_START, down);
-                                         nk_input_key(ctx, NK_KEY_SCROLL_START, down); break;
-                    case SDLK_END:       nk_input_key(ctx, NK_KEY_TEXT_END, down);
-                                         nk_input_key(ctx, NK_KEY_SCROLL_END, down); break;
-                    case SDLK_PAGEDOWN:  nk_input_key(ctx, NK_KEY_SCROLL_DOWN, down); break;
-                    case SDLK_PAGEUP:    nk_input_key(ctx, NK_KEY_SCROLL_UP, down); break;
-                    case SDLK_z:         nk_input_key(ctx, NK_KEY_TEXT_UNDO, down && state[SDL_SCANCODE_LCTRL]); break;
-                    case SDLK_r:         nk_input_key(ctx, NK_KEY_TEXT_REDO, down && state[SDL_SCANCODE_LCTRL]); break;
-                    case SDLK_c:         nk_input_key(ctx, NK_KEY_COPY, down && state[SDL_SCANCODE_LCTRL]); break;
-                    case SDLK_v:         nk_input_key(ctx, NK_KEY_PASTE, down && state[SDL_SCANCODE_LCTRL]); break;
-                    case SDLK_x:         nk_input_key(ctx, NK_KEY_CUT, down && state[SDL_SCANCODE_LCTRL]); break;
-                    case SDLK_b:         nk_input_key(ctx, NK_KEY_TEXT_LINE_START, down && state[SDL_SCANCODE_LCTRL]); break;
-                    case SDLK_e:         nk_input_key(ctx, NK_KEY_TEXT_LINE_END, down && state[SDL_SCANCODE_LCTRL]); break;
-                    case SDLK_UP:        nk_input_key(ctx, NK_KEY_UP, down); break;
-                    case SDLK_DOWN:      nk_input_key(ctx, NK_KEY_DOWN, down); break;
-                    case SDLK_LEFT:
-                        if (state[SDL_SCANCODE_LCTRL])
-                            nk_input_key(ctx, NK_KEY_TEXT_WORD_LEFT, down);
-                        else nk_input_key(ctx, NK_KEY_LEFT, down);
-                        break;
-                    case SDLK_RIGHT:
-                        if (state[SDL_SCANCODE_LCTRL])
-                            nk_input_key(ctx, NK_KEY_TEXT_WORD_RIGHT, down);
-                        else nk_input_key(ctx, NK_KEY_RIGHT, down);
-                        break;
-                }
-            }
-            return 1;
-
-        case SDL_MOUSEBUTTONUP: /* MOUSEBUTTONUP & MOUSEBUTTONDOWN share same routine */
-        case SDL_MOUSEBUTTONDOWN:
-            {
-                int down = evt->type == SDL_MOUSEBUTTONDOWN;
-                const int x = evt->button.x, y = evt->button.y;
-                switch(evt->button.button)
-                {
-                    case SDL_BUTTON_LEFT:
-                        if (evt->button.clicks > 1)
-                            nk_input_button(ctx, NK_BUTTON_DOUBLE, x, y, down);
-                        nk_input_button(ctx, NK_BUTTON_LEFT, x, y, down); break;
-                    case SDL_BUTTON_MIDDLE: nk_input_button(ctx, NK_BUTTON_MIDDLE, x, y, down); break;
-                    case SDL_BUTTON_RIGHT:  nk_input_button(ctx, NK_BUTTON_RIGHT, x, y, down); break;
-                }
-            }
-            return 1;
-
-        case SDL_MOUSEMOTION:
-            if (ctx->input.mouse.grabbed) {
-                int x = (int)ctx->input.mouse.prev.x, y = (int)ctx->input.mouse.prev.y;
-                nk_input_motion(ctx, x + evt->motion.xrel, y + evt->motion.yrel);
-            }
-            else nk_input_motion(ctx, evt->motion.x, evt->motion.y);
-            return 1;
-
-        case SDL_TEXTINPUT:
-            {
-                nk_glyph glyph;
-                memcpy(glyph, evt->text.text, NK_UTF_SIZE);
-                nk_input_glyph(ctx, glyph);
-            }
-            return 1;
-
-        case SDL_MOUSEWHEEL:
-            nk_input_scroll(ctx,nk_vec2((float)evt->wheel.x,(float)evt->wheel.y));
-            return 1;
-    }
-    return 0;
-}
-
-NK_API
-void nk_sdl_shutdown(void)
-{
-    struct nk_sdl_device *dev = &sdl.ogl;
-    nk_font_atlas_clear(&sdl.atlas);
-    nk_free(&sdl.ctx);
-    SDL_DestroyTexture(dev->font_tex);
-    /* glDeleteTextures(1, &dev->font_tex); */
-    nk_buffer_free(&dev->cmds);
-    memset(&sdl, 0, sizeof(sdl));
-}
-
-#endif /* NK_SDL_RENDERER_IMPLEMENTATION */

external/tinyfiledialogs.h

@@ -1,314 +0,0 @@
-/* SPDX-License-Identifier: Zlib
-Copyright (c) 2014 - 2024 Guillaume Vareille http://ysengrin.com
-	 ____________________________________________________________________
-	|                                                                    |
-	| 100% compatible C C++  ->  You can rename tinfiledialogs.c as .cpp |
-	|____________________________________________________________________|
-
-********* TINY FILE DIALOGS OFFICIAL WEBSITE IS ON SOURCEFORGE *********
-  _________
- /         \ tinyfiledialogs.h v3.18.2 [Jun 8, 2024]
- |tiny file| Unique header file created [November 9, 2014]
- | dialogs |
- \____  ___/ http://tinyfiledialogs.sourceforge.net
-      \|     git clone http://git.code.sf.net/p/tinyfiledialogs/code tinyfd
- ____________________________________________
-|                                            |
-|   email: tinyfiledialogs at ysengrin.com   |
-|____________________________________________|
- ________________________________________________________________________________
-|  ____________________________________________________________________________  |
-| |                                                                            | |
-| |  - in tinyfiledialogs, char is UTF-8 by default (since v3.6)               | |
-| |                                                                            | |
-| | on windows:                                                                | |
-| |  - for UTF-16, use the wchar_t functions at the bottom of the header file  | |
-| |                                                                            | |
-| |  - _wfopen() requires wchar_t                                              | |
-| |  - fopen() uses char but expects ASCII or MBCS (not UTF-8)                 | |
-| |  - if you want char to be MBCS: set tinyfd_winUtf8 to 0                    | |
-| |                                                                            | |
-| |  - alternatively, tinyfiledialogs provides                                 | |
-| |                        functions to convert between UTF-8, UTF-16 and MBCS | |
-| |____________________________________________________________________________| |
-|________________________________________________________________________________|
-
-If you like tinyfiledialogs, please upvote my stackoverflow answer
-https://stackoverflow.com/a/47651444
-
-- License -
-This software is provided 'as-is', without any express or implied
-warranty.  In no event will the authors be held liable for any damages
-arising from the use of this software.
-Permission is granted to anyone to use this software for any purpose,
-including commercial applications, and to alter it and redistribute it
-freely, subject to the following restrictions:
-1. The origin of this software must not be misrepresented; you must not
-claim that you wrote the original software.  If you use this software
-in a product, an acknowledgment in the product documentation would be
-appreciated but is not required.
-2. Altered source versions must be plainly marked as such, and must not be
-misrepresented as being the original software.
-3. This notice may not be removed or altered from any source distribution.
-
-     __________________________________________
-    |  ______________________________________  |
-    | |                                      | |
-    | | DO NOT USE USER INPUT IN THE DIALOGS | |
-    | |______________________________________| |
-    |__________________________________________|
-*/
-
-#ifndef TINYFILEDIALOGS_H
-#define TINYFILEDIALOGS_H
-
-#ifdef	__cplusplus
-extern "C" {
-#endif
-
-/******************************************************************************************************/
-/**************************************** UTF-8 on Windows ********************************************/
-/******************************************************************************************************/
-#ifdef _WIN32
-/* On windows, if you want to use UTF-8 ( instead of the UTF-16/wchar_t functions at the end of this file )
-Make sure your code is really prepared for UTF-8 (on windows, functions like fopen() expect MBCS and not UTF-8) */
-extern int tinyfd_winUtf8; /* on windows char strings can be 1:UTF-8(default) or 0:MBCS */
-/* for MBCS change this to 0, in tinyfiledialogs.c or in your code */
-
-/* Here are some functions to help you convert between UTF-16 UTF-8 MBSC */
-char * tinyfd_utf8toMbcs(char const * aUtf8string);
-char * tinyfd_utf16toMbcs(wchar_t const * aUtf16string);
-wchar_t * tinyfd_mbcsTo16(char const * aMbcsString);
-char * tinyfd_mbcsTo8(char const * aMbcsString);
-wchar_t * tinyfd_utf8to16(char const * aUtf8string);
-char * tinyfd_utf16to8(wchar_t const * aUtf16string);
-#endif
-/******************************************************************************************************/
-/******************************************************************************************************/
-/******************************************************************************************************/
-
-/************* 3 funtions for C# (you don't need this in C or C++) : */
-char const * tinyfd_getGlobalChar(char const * aCharVariableName); /* returns NULL on error */
-int tinyfd_getGlobalInt(char const * aIntVariableName); /* returns -1 on error */
-int tinyfd_setGlobalInt(char const * aIntVariableName, int aValue); /* returns -1 on error */
-/* aCharVariableName: "tinyfd_version" "tinyfd_needs" "tinyfd_response"
-   aIntVariableName : "tinyfd_verbose" "tinyfd_silent" "tinyfd_allowCursesDialogs"
-				      "tinyfd_forceConsole" "tinyfd_assumeGraphicDisplay" "tinyfd_winUtf8"
-**************/
-
-extern char tinyfd_version[8]; /* contains tinyfd current version number */
-extern char tinyfd_needs[]; /* info about requirements */
-extern int tinyfd_verbose; /* 0 (default) or 1 : on unix, prints the command line calls */
-extern int tinyfd_silent; /* 1 (default) or 0 : on unix, hide errors and warnings from called dialogs */
-
-/** Curses dialogs are difficult to use and counter-intuitive.
-On windows they are only ascii and still uses the unix backslash ! **/
-extern int tinyfd_allowCursesDialogs; /* 0 (default) or 1 */
-
-extern int tinyfd_forceConsole;  /* 0 (default) or 1 */
-/* for unix & windows: 0 (graphic mode) or 1 (console mode).
-0: try to use a graphic solution, if it fails then it uses console mode.
-1: forces all dialogs into console mode even when an X server is present.
-   if enabled, it can use the package Dialog or dialog.exe.
-   on windows it only make sense for console applications */
-
-extern int tinyfd_assumeGraphicDisplay; /* 0 (default) or 1  */
-/* some systems don't set the environment variable DISPLAY even when a graphic display is present.
-set this to 1 to tell tinyfiledialogs to assume the existence of a graphic display */
-
-extern char tinyfd_response[1024];
-/* if you pass "tinyfd_query" as aTitle,
-the functions will not display the dialogs
-but will return 0 for console mode, 1 for graphic mode.
-tinyfd_response is then filled with the retain solution.
-possible values for tinyfd_response are (all lowercase)
-for graphic mode:
-  windows_wchar windows applescript kdialog zenity zenity3 yad matedialog
-  shellementary qarma python2-tkinter python3-tkinter python-dbus
-  perl-dbus gxmessage gmessage xmessage xdialog gdialog dunst
-for console mode:
-  dialog whiptail basicinput no_solution */
-
-void tinyfd_beep(void);
-
-int tinyfd_notifyPopup(
-	char const * aTitle, /* NULL or "" */
-	char const * aMessage, /* NULL or "" may contain \n \t */
-	char const * aIconType); /* "info" "warning" "error" */
-		/* return has only meaning for tinyfd_query */
-
-int tinyfd_messageBox(
-	char const * aTitle , /* NULL or "" */
-	char const * aMessage , /* NULL or "" may contain \n \t */
-	char const * aDialogType , /* "ok" "okcancel" "yesno" "yesnocancel" */
-	char const * aIconType , /* "info" "warning" "error" "question" */
-	int aDefaultButton ) ;
-		/* 0 for cancel/no , 1 for ok/yes , 2 for no in yesnocancel */
-
-char * tinyfd_inputBox(
-	char const * aTitle , /* NULL or "" */
-	char const * aMessage , /* NULL or "" (\n and \t have no effect) */
-	char const * aDefaultInput ) ;  /* NULL = passwordBox, "" = inputbox */
-		/* returns NULL on cancel */
-
-char * tinyfd_saveFileDialog(
-	char const * aTitle , /* NULL or "" */
-	char const * aDefaultPathAndOrFile , /* NULL or "" , ends with / to set only a directory */
-	int aNumOfFilterPatterns , /* 0  (1 in the following example) */
-	char const * const * aFilterPatterns , /* NULL or char const * lFilterPatterns[1]={"*.txt"} */
-	char const * aSingleFilterDescription ) ; /* NULL or "text files" */
-		/* returns NULL on cancel */
-
-char * tinyfd_openFileDialog(
-	char const * aTitle, /* NULL or "" */
-	char const * aDefaultPathAndOrFile, /* NULL or "" , ends with / to set only a directory */
-	int aNumOfFilterPatterns , /* 0 (2 in the following example) */
-	char const * const * aFilterPatterns, /* NULL or char const * lFilterPatterns[2]={"*.png","*.jpg"}; */
-	char const * aSingleFilterDescription, /* NULL or "image files" */
-	int aAllowMultipleSelects ) ; /* 0 or 1 */
-		/* in case of multiple files, the separator is | */
-		/* returns NULL on cancel */
-
-char * tinyfd_selectFolderDialog(
-	char const * aTitle, /* NULL or "" */
-	char const * aDefaultPath); /* NULL or "" */
-		/* returns NULL on cancel */
-
-char * tinyfd_colorChooser(
-	char const * aTitle, /* NULL or "" */
-	char const * aDefaultHexRGB, /* NULL or "" or "#FF0000" */
-	unsigned char const aDefaultRGB[3] , /* unsigned char lDefaultRGB[3] = { 0 , 128 , 255 }; */
-	unsigned char aoResultRGB[3] ) ; /* unsigned char lResultRGB[3]; */
-		/* aDefaultRGB is used only if aDefaultHexRGB is absent */
-		/* aDefaultRGB and aoResultRGB can be the same array */
-		/* returns NULL on cancel */
-		/* returns the hexcolor as a string "#FF0000" */
-		/* aoResultRGB also contains the result */
-
-
-/************ WINDOWS ONLY SECTION ************************/
-#ifdef _WIN32
-
-/* windows only - utf-16 version */
-int tinyfd_notifyPopupW(
-	wchar_t const * aTitle, /* NULL or L"" */
-	wchar_t const * aMessage, /* NULL or L"" may contain \n \t */
-	wchar_t const * aIconType); /* L"info" L"warning" L"error" */
-
-/* windows only - utf-16 version */
-int tinyfd_messageBoxW(
-	wchar_t const * aTitle, /* NULL or L"" */
-	wchar_t const * aMessage, /* NULL or L"" may contain \n \t */
-	wchar_t const * aDialogType, /* L"ok" L"okcancel" L"yesno" */
-	wchar_t const * aIconType, /* L"info" L"warning" L"error" L"question" */
-	int aDefaultButton ); /* 0 for cancel/no , 1 for ok/yes */
-		/* returns 0 for cancel/no , 1 for ok/yes */
-
-/* windows only - utf-16 version */
-wchar_t * tinyfd_inputBoxW(
-	wchar_t const * aTitle, /* NULL or L"" */
-	wchar_t const * aMessage, /* NULL or L"" (\n nor \t not respected) */
-	wchar_t const * aDefaultInput); /* NULL passwordBox, L"" inputbox */
-
-/* windows only - utf-16 version */
-wchar_t * tinyfd_saveFileDialogW(
-	wchar_t const * aTitle, /* NULL or L"" */
-	wchar_t const * aDefaultPathAndOrFile, /* NULL or L"" , ends with / to set only a directory */
-	int aNumOfFilterPatterns, /* 0 (1 in the following example) */
-	wchar_t const * const * aFilterPatterns, /* NULL or wchar_t const * lFilterPatterns[1]={L"*.txt"} */
-	wchar_t const * aSingleFilterDescription); /* NULL or L"text files" */
-		/* returns NULL on cancel */
-
-/* windows only - utf-16 version */
-wchar_t * tinyfd_openFileDialogW(
-	wchar_t const * aTitle, /* NULL or L"" */
-	wchar_t const * aDefaultPathAndOrFile, /* NULL or L"" , ends with / to set only a directory */
-	int aNumOfFilterPatterns , /* 0 (2 in the following example) */
-	wchar_t const * const * aFilterPatterns, /* NULL or wchar_t const * lFilterPatterns[2]={L"*.png","*.jpg"} */
-	wchar_t const * aSingleFilterDescription, /* NULL or L"image files" */
-	int aAllowMultipleSelects ) ; /* 0 or 1 */
-		/* in case of multiple files, the separator is | */
-		/* returns NULL on cancel */
-
-/* windows only - utf-16 version */
-wchar_t * tinyfd_selectFolderDialogW(
-	wchar_t const * aTitle, /* NULL or L"" */
-	wchar_t const * aDefaultPath); /* NULL or L"" */
-		/* returns NULL on cancel */
-
-/* windows only - utf-16 version */
-wchar_t * tinyfd_colorChooserW(
-	wchar_t const * aTitle, /* NULL or L"" */
-	wchar_t const * aDefaultHexRGB, /* NULL or L"#FF0000" */
-	unsigned char const aDefaultRGB[3], /* unsigned char lDefaultRGB[3] = { 0 , 128 , 255 }; */
-	unsigned char aoResultRGB[3]); /* unsigned char lResultRGB[3]; */
-		/* returns the hexcolor as a string L"#FF0000" */
-		/* aoResultRGB also contains the result */
-		/* aDefaultRGB is used only if aDefaultHexRGB is NULL */
-		/* aDefaultRGB and aoResultRGB can be the same array */
-		/* returns NULL on cancel */
-
-#endif /*_WIN32 */
-
-#ifdef	__cplusplus
-} /*extern "C"*/
-#endif
-
-#endif /* TINYFILEDIALOGS_H */
-
-/*
- ________________________________________________________________________________
-|  ____________________________________________________________________________  |
-| |                                                                            | |
-| | on windows:                                                                | |
-| |  - for UTF-16, use the wchar_t functions at the bottom of the header file  | |
-| |  - _wfopen() requires wchar_t                                              | |
-| |                                                                            | |
-| |  - in tinyfiledialogs, char is UTF-8 by default (since v3.6)               | |
-| |  - but fopen() expects MBCS (not UTF-8)                                    | |
-| |  - if you want char to be MBCS: set tinyfd_winUtf8 to 0                    | |
-| |                                                                            | |
-| |  - alternatively, tinyfiledialogs provides                                 | |
-| |                        functions to convert between UTF-8, UTF-16 and MBCS | |
-| |____________________________________________________________________________| |
-|________________________________________________________________________________|
-
-- This is not for ios nor android (it works in termux though).
-- The files can be renamed with extension ".cpp" as the code is 100% compatible C C++
-  (just comment out << extern "C" >> in the header file)
-- Windows is fully supported from XP to 10 (maybe even older versions)
-- C# & LUA via dll, see files in the folder EXTRAS
-- OSX supported from 10.4 to latest (maybe even older versions)
-- Do not use " and ' as the dialogs will be displayed with a warning
-  instead of the title, message, etc...
-- There's one file filter only, it may contain several patterns.
-- If no filter description is provided,
-  the list of patterns will become the description.
-- On windows link against Comdlg32.lib and Ole32.lib
-  (on windows the no linking claim is a lie)
-- On unix: it tries command line calls, so no such need (NO LINKING).
-- On unix you need one of the following:
-  applescript, kdialog, zenity, matedialog, shellementary, qarma, yad,
-  python (2 or 3)/tkinter/python-dbus (optional), Xdialog
-  or curses dialogs (opens terminal if running without console).
-- One of those is already included on most (if not all) desktops.
-- In the absence of those it will use gdialog, gxmessage or whiptail
-  with a textinputbox. If nothing is found, it switches to basic console input,
-  it opens a console if needed (requires xterm + bash).
-- for curses dialogs you must set tinyfd_allowCursesDialogs=1
-- You can query the type of dialog that will be used (pass "tinyfd_query" as aTitle)
-- String memory is preallocated statically for all the returned values.
-- File and path names are tested before return, they should be valid.
-- tinyfd_forceConsole=1; at run time, forces dialogs into console mode.
-- On windows, console mode only make sense for console applications.
-- On windows, console mode is not implemented for wchar_T UTF-16.
-- Mutiple selects are not possible in console mode.
-- The package dialog must be installed to run in curses dialogs in console mode.
-  It is already installed on most unix systems.
-- On osx, the package dialog can be installed via
-  http://macappstore.org/dialog or http://macports.org
-- On windows, for curses dialogs console mode,
-  dialog.exe should be copied somewhere on your executable path.
-  It can be found at the bottom of the following page:
-  http://andrear.altervista.org/home/cdialog.php
-*/

llvm.sources

@@ -0,0 +1,4 @@
+Types: deb deb-src
+URIs: http://apt.llvm.org/trixie/
+Suites: llvm-toolchain-trixie-22
+Components: main

main.c

@@ -1,41 +0,0 @@
-#include "cli.h"
-#include <SDL2/SDL.h>
-#include <stdbool.h>
-#include <stdio.h>
-#include "ui.h"
-
-int main(int argc, char **argv) {
-    CLIArgs args;
-    UIContext *ui;
-    int status;
-    bool running = false;
-
-    if (parseCLIArgs(argc, argv, &args)) {
-        return 1;
-    }
-
-    SDL_SetHint(SDL_HINT_VIDEO_HIGHDPI_DISABLED, "0");
-    SDL_SetHint(SDL_HINT_WINDOWS_DPI_AWARENESS, "system");
-    if (SDL_Init(SDL_INIT_EVERYTHING)) {
-        fprintf(stderr, "Error initializing SDL: %s\n", SDL_GetError());
-        return 1;
-    }
-
-    ui = uiInit();
-    if (!ui) {
-        SDL_Quit();
-        return 1;
-    }
-
-    if (args.filename) {
-        if (uiLoadGame(ui, args.filename)) {
-            return 1;
-        }
-        running = true;
-    }
-
-    status = uiRun(ui, running);
-    uiDestroy(ui);
-    SDL_Quit();
-    return status;
-}

makefile

@@ -1,54 +0,0 @@
-CC?=gcc
-LD?=ld
-msys_version := $(if $(findstring Msys, $(shell uname -o)),$(word 1, $(subst ., ,$(shell uname -r))),0)
-
-ifeq ($(msys_version), 0)
-PKGFLAGS=$(shell pkg-config sdl2 --cflags --libs)
-BINLINKFLAGS=-z noexecstack
-else
-PKGFLAGS=$(shell pkg-config sdl2 --cflags --libs) -mwindows -mconsole -lcomdlg32 -lole32
-BINLINKFLAGS=
-endif
-
-.PHONY: clean build
-clean:
-	@rm -rf shrooms-vb output
-
-CFILES := $(foreach dir,./,$(notdir $(wildcard $(dir)/*.c)))
-BINFILES := $(foreach dir,assets/,$(notdir $(wildcard $(dir)/*.bin)))
-
-COBJS := $(CFILES:%.c=output/%.o)
-EXTOBJS = output/vb.o output/tinyfiledialogs.o
-BINOBJS := $(BINFILES:%.bin=output/%.o)
-
-OFILES := $(COBJS) $(EXTOBJS) $(BINOBJS)
-
-output/%.o: %.c
-	@mkdir -p output
-	@$(CC) -c -o $@ $< -I . \
-		-I shrooms-vb-core/core $(PKGFLAGS) \
-		-O3 -flto=auto -Wno-long-long \
-		-Werror -std=c90 -Wall -Wextra -Wpedantic
-
-output/vb.o: shrooms-vb-core/core/vb.c
-	@mkdir -p output
-	@$(CC) -c -o $@ $< -I . \
-		-I shrooms-vb-core/core \
-		-O3 -flto=auto -fno-strict-aliasing \
-		-Werror -std=c90 -Wall -Wextra -Wpedantic
-
-output/tinyfiledialogs.o: external/tinyfiledialogs.c
-	@mkdir -p output
-	@$(CC) -c -o $@ $< -I . \
-		-I external \
-		-O3 -flto=auto -fno-strict-aliasing -Wno-cast-function-type \
-		-Werror -std=c90 -Wall -Wextra -Wpedantic
-
-output/%.o: assets/%.bin
-	@mkdir -p output
-	@$(LD) -r -b binary $(BINLINKFLAGS) -o $@ $<
-
-shrooms-vb: $(OFILES)
-	@$(CC) -o $@ $(OFILES) $(PKGFLAGS) -lm -flto=auto
-
-build: shrooms-vb

nuklear.c

@@ -1,3 +0,0 @@
-#define NK_IMPLEMENTATION
-#define NK_SDL_RENDERER_IMPLEMENTATION
-#include "nuklear.h"

nuklear.h

@@ -1,17 +0,0 @@
-#ifndef SHROOMS_VB_NATIVE_NUKLEAR_
-#define SHROOMS_VB_NATIVE_NUKLEAR_
-
-#define NK_INCLUDE_FIXED_TYPES
-#define NK_INCLUDE_STANDARD_BOOL
-#define NK_INCLUDE_STANDARD_IO
-#define NK_INCLUDE_STANDARD_VARARGS
-#define NK_INCLUDE_DEFAULT_ALLOCATOR
-#define NK_INCLUDE_VERTEX_BUFFER_OUTPUT
-#define NK_INCLUDE_FONT_BAKING
-#define NK_INCLUDE_DEFAULT_FONT
-#include "external/nuklear.h"
-
-#define NK_SDL_RENDERER_SDL_H <SDL2/SDL.h>
-#include "external/nuklear_sdl_renderer.h"
-
-#endif

scripts/bundle.sh

@@ -0,0 +1,4 @@
+set -e
+
+docker build --pull -f build.Dockerfile -t lemur-build .
+MSYS_NO_PATHCONV=1 docker run -it --rm -v .:/app -w /app lemur-build /app/scripts/do-bundle.sh

scripts/do-bundle.sh

@@ -0,0 +1,35 @@
+# Set everything up
+rm -rf output
+mkdir -p output
+cargo clean
+
+# Build for linux
+cargo build --release
+cp target/release/lemur output/lemur-linux
+
+# Bundle for Linux
+cargo bundle --release --format deb
+cp target/release/bundle/deb/*.deb output
+
+# Build for Windows
+cargo build --release --target x86_64-pc-windows-msvc
+cp target/x86_64-pc-windows-msvc/release/lemur.exe output
+
+# Build for MacOS Intel
+cargo build --release --target x86_64-apple-darwin
+cp target/x86_64-apple-darwin/release/lemur output/lemur-osx-intel
+
+# Bundle for MacOS Intel
+cargo bundle --release --target x86_64-apple-darwin --format osx
+genisoimage -V lemur -D -R -apple -no-pad -o output/Lemur-Intel.dmg target/x86_64-apple-darwin/release/bundle/osx
+
+# Build for MacOS Apple Silicon
+cargo build --release --target aarch64-apple-darwin
+cp target/aarch64-apple-darwin/release/lemur output/lemur-osx-apple-silicon
+
+# Bundle for MacOS Apple Silicon
+cargo bundle --release --target aarch64-apple-darwin --format osx
+genisoimage -V lemur -D -R -apple -no-pad -o output/Lemur-Apple-Silicon.dmg target/aarch64-apple-darwin/release/bundle/osx
+
+# Clean up after ourselves
+cargo clean

scripts/release.sh

@@ -0,0 +1,71 @@
+set -e
+version=$(cat Cargo.toml | sed -n -e '/version/ {s/.* = *//p;q}' | tr -d '"')
+
+read -p "You wanted to release $version, right? [Y/n] " -n 1 -r
+echo
+case "$REPLY" in
+    n|N ) exit 1;;
+esac
+
+if [ -z "${RELEASE_TOKEN}" ]; then
+    echo "Please set the RELEASE_TOKEN env var."
+    exit 1
+fi
+if ! command -v curl 2>&1 >/dev/null; then
+    echo "Please install curl."
+    exit 1
+fi
+if ! command -v jq 2>&1 >/dev/null; then
+    echo "Please install jq."
+    exit 1
+fi
+if ! command -v docker 2>&1 >/dev/null; then
+    echo "Please install docker."
+    exit 1
+fi
+
+./scripts/bundle.sh
+
+body=$(cat <<EOF
+## How to install
+
+The emulator can be found in the "Downloads" section of this release.
+
+### Windows users
+
+Download \`lemur.exe\`.
+
+### MacOS users
+
+If your Mac uses an Intel processor, download and install \`Lemur-Intel.dmg\`.
+
+If it uses Apple Silicon, download and install \`Lemur-Apple-Silicon.dmg\`.
+
+If you're not sure which to choose, use [this guide](https://support.apple.com/en-us/116943) to find out.
+
+### Linux users
+
+You can either download and run \`lemur-linux\`, or download and install the attached .deb file.
+EOF
+)
+
+payload=$(cat <<EOF
+{
+  "body": $(echo "$body" | jq -Rsa .),
+  "draft": false,
+  "name": "v${version}",
+  "prerelease": false,
+  "tag_name": "v${version}"
+}
+EOF
+)
+
+echo "Creating release..."
+response=$(curl -s --json "$payload" "https://git.virtual-boy.com/api/v1/repos/PVB/lemur/releases?token=$RELEASE_TOKEN")
+echo "$response"
+upload_url=$(echo "$response" | jq -r '.upload_url')
+for file in output/*; do
+    echo "Uploading $(basename "$file")..."
+    upload_res=$(curl -s -F "attachment=@$file" "$upload_url?name=$(basename "$file")&token=$RELEASE_TOKEN")
+    echo "$upload_res"
+done

src/app.rs

@@ -0,0 +1,706 @@
+use std::{
+    collections::hash_map::Entry,
+    num::NonZero,
+    sync::Arc,
+    thread,
+    time::{Duration, Instant},
+};
+
+use egui::{
+    Context, FontData, FontDefinitions, FontFamily, IconData, PlatformOutput, RawInput,
+    TextWrapMode, ViewportBuilder, ViewportCommand, ViewportEvent, ViewportId, ViewportIdMap,
+    ViewportIdSet, ViewportInfo, style::ScrollStyle,
+};
+use egui_wgpu::winit::Painter;
+use egui_winit::EventResponse;
+use gilrs::{EventType, Gilrs};
+use tracing::{debug, error, warn};
+use winit::{
+    application::ApplicationHandler,
+    event::WindowEvent,
+    event_loop::{ActiveEventLoop, ControlFlow, EventLoopProxy, OwnedDisplayHandle},
+    window::{Window, WindowId},
+};
+
+use crate::{
+    config::{AppConfig, CliArgs},
+    controller::ControllerManager,
+    emulator::{EmulatorClient, EmulatorCommand, SimId},
+    images::ImageTextureLoader,
+    input::{MappingProvider, ShortcutProvider},
+    memory::MemoryClient,
+    persistence::Persistence,
+    window::{AppWindow, ChildWindow, GameScreen, GameWindow, InitArgs},
+};
+
+const EGUI_FILENAME: &str = "egui";
+
+fn load_icon() -> anyhow::Result<IconData> {
+    let bytes = include_bytes!("../assets/lemur-256x256.png");
+    let img = image::load_from_memory_with_format(bytes, image::ImageFormat::Png)?;
+    let rgba = img.into_rgba8();
+    Ok(IconData {
+        width: rgba.width(),
+        height: rgba.height(),
+        rgba: rgba.into_vec(),
+    })
+}
+
+struct SharedViewportState {
+    viewport_info: ViewportIdMap<ViewportInfo>,
+    wgpu: WgpuState,
+    painter: Option<Painter>,
+    resized_viewport: Option<ViewportId>,
+}
+impl SharedViewportState {
+    fn init_painter(&mut self, ctx: &Context, window: &Window) -> &mut Painter {
+        if self.painter.is_none() {
+            let wgpu_config = egui_wgpu::WgpuConfiguration {
+                present_mode: wgpu::PresentMode::AutoVsync,
+                wgpu_setup: egui_wgpu::WgpuSetup::Existing(self.wgpu.init(window)),
+                ..egui_wgpu::WgpuConfiguration::default()
+            };
+
+            let options = egui_wgpu::RendererOptions::default();
+            let painter =
+                pollster::block_on(Painter::new(ctx.clone(), wgpu_config, false, options));
+            self.painter = Some(painter);
+        }
+        self.painter.as_mut().unwrap()
+    }
+    fn get_painter(&mut self) -> &mut Painter {
+        self.painter.as_mut().unwrap()
+    }
+}
+
+pub struct Application {
+    client: EmulatorClient,
+    persistence: Persistence,
+    ctx: Context,
+    shared: SharedViewportState,
+    icon: Option<Arc<IconData>>,
+    app: GameWindow,
+    controllers: ControllerManager,
+    viewports: ViewportIdMap<ViewportManager>,
+    focused: Option<ViewportId>,
+    redraw_times: ViewportIdMap<Instant>,
+    initial_windows: Vec<ChildWindow>,
+}
+
+impl Application {
+    pub fn new(
+        client: EmulatorClient,
+        proxy: EventLoopProxy<UserEvent>,
+        handle: OwnedDisplayHandle,
+        persistence: Persistence,
+        args: CliArgs,
+        config: AppConfig,
+    ) -> Self {
+        let wgpu = WgpuState::new(handle, config);
+        let icon = load_icon().ok().map(Arc::new);
+        let mappings = MappingProvider::new(persistence.clone(), args.player2_controller);
+        let shortcuts = ShortcutProvider::new(persistence.clone());
+        let controllers = ControllerManager::new(client.clone(), &mappings);
+        let memory = Arc::new(MemoryClient::new(client.clone()));
+        let images = Arc::new(ImageTextureLoader::new());
+        {
+            let mappings = mappings.clone();
+            let proxy = proxy.clone();
+            thread::spawn(|| process_gamepad_input(mappings, proxy));
+        }
+        let app = GameWindow::new(
+            ViewportId::ROOT,
+            client.clone(),
+            proxy.clone(),
+            persistence.clone(),
+            shortcuts.clone(),
+            &memory,
+            &images,
+            mappings.clone(),
+            SimId::Player1,
+        );
+
+        let ctx = Context::default();
+        let data = persistence.load_config(EGUI_FILENAME).unwrap_or_default();
+        ctx.data_mut(|d| *d = data);
+        let mut fonts = FontDefinitions::default();
+        fonts.font_data.insert(
+            "Selawik".into(),
+            Arc::new(FontData::from_static(include_bytes!(
+                "../assets/selawik.ttf"
+            ))),
+        );
+        fonts
+            .families
+            .get_mut(&FontFamily::Proportional)
+            .unwrap()
+            .insert(0, "Selawik".into());
+        ctx.set_fonts(fonts);
+        ctx.global_style_mut(|s| {
+            s.wrap_mode = Some(TextWrapMode::Extend);
+            s.visuals.menu_corner_radius = Default::default();
+            s.spacing.scroll = ScrollStyle::thin();
+        });
+        egui_extras::install_image_loaders(&ctx);
+        ctx.add_texture_loader(images.clone());
+        ctx.set_embed_viewports(false);
+        {
+            let proxy = proxy.clone();
+            ctx.set_request_repaint_callback(move |info| {
+                let _ = proxy.send_event(UserEvent::RequestRedraw(
+                    info.viewport_id,
+                    Instant::now() + info.delay,
+                ));
+            });
+        }
+
+        let mut initial_windows = vec![];
+        if let Some(port) = args.debug_port {
+            initial_windows.push(ChildWindow::Debugger { port: Some(port) });
+        }
+        if args.profile {
+            initial_windows.push(ChildWindow::Profiler { launch: true });
+        }
+        if args.character_data {
+            initial_windows.push(ChildWindow::CharacterData);
+        }
+        if args.bgmap_data {
+            initial_windows.push(ChildWindow::BgMap);
+        }
+        if args.object_data {
+            initial_windows.push(ChildWindow::Objects);
+        }
+        if args.worlds {
+            initial_windows.push(ChildWindow::Worlds);
+        }
+        if args.frame_buffers {
+            initial_windows.push(ChildWindow::FrameBuffers);
+        }
+        if args.registers {
+            initial_windows.push(ChildWindow::Registers);
+        }
+        if args.terminal {
+            initial_windows.push(ChildWindow::Terminal);
+        }
+        if args.player2 {
+            client.send_command(EmulatorCommand::StartSecondSim(args.rom.clone()));
+            initial_windows.push(ChildWindow::Player2);
+        }
+
+        Self {
+            client,
+            persistence,
+            ctx,
+            shared: SharedViewportState {
+                viewport_info: ViewportIdMap::default(),
+                wgpu,
+                painter: None,
+                resized_viewport: None,
+            },
+            icon,
+            app,
+            controllers,
+            viewports: ViewportIdMap::default(),
+            focused: None,
+            redraw_times: ViewportIdMap::default(),
+            initial_windows,
+        }
+    }
+
+    fn check_repaint(&mut self, event_loop: &ActiveEventLoop) {
+        let now = Instant::now();
+        self.redraw_times.retain(|viewport_id, time| {
+            if *time > now {
+                return true;
+            }
+            if let Some(viewport) = self.viewports.get(viewport_id) {
+                viewport.window.request_redraw();
+            }
+            false
+        });
+        if let Some(next_repaint_time) = self.redraw_times.values().min().copied() {
+            event_loop.set_control_flow(ControlFlow::WaitUntil(next_repaint_time));
+        }
+    }
+
+    fn repaint_all(&mut self, event_loop: &ActiveEventLoop) {
+        enum ViewportUpdate {
+            Keep {
+                recreate: bool,
+                builder: ViewportBuilder,
+                parent: ViewportId,
+                commands: Vec<ViewportCommand>,
+            },
+            Remove,
+        }
+        let mut updates = ViewportIdMap::<ViewportUpdate>::default();
+        for viewport in self.viewports.values() {
+            updates.insert(
+                viewport.id,
+                ViewportUpdate::Keep {
+                    recreate: false,
+                    builder: viewport.builder.clone(),
+                    parent: self
+                        .shared
+                        .viewport_info
+                        .get(&viewport.id)
+                        .and_then(|vp| vp.parent)
+                        .unwrap_or(ViewportId::ROOT),
+                    commands: vec![],
+                },
+            );
+        }
+
+        for viewport in self.viewports.values_mut() {
+            let mut input = viewport.take_egui_input();
+            if !self.shared.viewport_info.contains_key(&viewport.id) {
+                continue;
+            }
+            input.viewports = self.shared.viewport_info.clone();
+            let output = self.ctx.run_ui(input, |ui| {
+                if viewport.id == ViewportId::ROOT {
+                    self.app.show(ui);
+                } else if let Some(cb) = ui.viewport(|v| v.viewport_ui_cb.clone()) {
+                    cb(ui);
+                }
+            });
+            viewport.handle_platform_output(output.platform_output);
+            for (id, update) in updates.iter_mut() {
+                if !output.viewport_output.contains_key(id) {
+                    self.shared.viewport_info.remove(id);
+                    *update = ViewportUpdate::Remove;
+                }
+            }
+            for (id, mut vp) in output.viewport_output {
+                match updates.entry(id) {
+                    Entry::Vacant(e) => {
+                        e.insert(ViewportUpdate::Keep {
+                            recreate: true,
+                            builder: vp.builder,
+                            parent: vp.parent,
+                            commands: vp.commands,
+                        });
+                    }
+                    Entry::Occupied(e) => {
+                        let ViewportUpdate::Keep {
+                            recreate,
+                            builder,
+                            commands,
+                            ..
+                        } = e.into_mut()
+                        else {
+                            continue;
+                        };
+                        let (_, should_recreate) = builder.patch(vp.builder);
+                        *recreate |= should_recreate;
+                        commands.append(&mut vp.commands);
+                    }
+                }
+            }
+            let clipped_primitives = self.ctx.tessellate(output.shapes, output.pixels_per_point);
+            viewport.window.pre_present_notify();
+            self.shared.get_painter().paint_and_update_textures(
+                viewport.id,
+                output.pixels_per_point,
+                [0.0, 0.0, 0.0, 0.0],
+                &clipped_primitives,
+                &output.textures_delta,
+                vec![],
+            );
+        }
+        let mut active_viewports = ViewportIdSet::default();
+        for (id, update) in updates {
+            match update {
+                ViewportUpdate::Keep {
+                    recreate,
+                    builder,
+                    parent,
+                    commands,
+                } => {
+                    active_viewports.insert(id);
+                    let manager = self
+                        .viewports
+                        .remove(&id)
+                        .filter(|_| !recreate)
+                        .unwrap_or_else(|| {
+                            let manager = ViewportManager::new(
+                                &self.ctx,
+                                id,
+                                parent,
+                                event_loop,
+                                builder,
+                                &mut self.shared,
+                            );
+                            self.app.handle_init(
+                                id,
+                                InitArgs {
+                                    window: &manager.window,
+                                    render_state: &self
+                                        .shared
+                                        .get_painter()
+                                        .render_state()
+                                        .unwrap(),
+                                },
+                            );
+                            manager
+                        });
+                    manager.process_viewport_commands(commands, &mut self.shared);
+                    self.viewports.insert(id, manager);
+                }
+                ViewportUpdate::Remove => {
+                    self.viewports.remove(&id);
+                }
+            }
+        }
+        if !active_viewports.contains(&ViewportId::ROOT) {
+            event_loop.exit();
+        }
+        if let Some(painter) = self.shared.painter.as_mut() {
+            painter.gc_viewports(&active_viewports);
+        }
+    }
+}
+
+impl ApplicationHandler<UserEvent> for Application {
+    fn resumed(&mut self, event_loop: &ActiveEventLoop) {
+        let mut viewport_builder = self.app.initial_viewport();
+        if let Some(icon) = &self.icon {
+            viewport_builder = viewport_builder.with_icon(icon.clone());
+        }
+        let manager = ViewportManager::new(
+            &self.ctx,
+            ViewportId::ROOT,
+            ViewportId::ROOT,
+            event_loop,
+            viewport_builder,
+            &mut self.shared,
+        );
+        let render_state = self.shared.get_painter().render_state().unwrap();
+        GameScreen::init_pipeline(&render_state);
+        self.app.handle_init(
+            ViewportId::ROOT,
+            InitArgs {
+                window: &manager.window,
+                render_state: &render_state,
+            },
+        );
+        self.viewports.insert(ViewportId::ROOT, manager);
+        for window in std::mem::take(&mut self.initial_windows) {
+            self.app.open(window);
+        }
+    }
+
+    fn about_to_wait(&mut self, _event_loop: &ActiveEventLoop) {
+        if let Some(viewport) = self.viewports.get(&ViewportId::ROOT) {
+            viewport.window.request_redraw();
+        }
+    }
+
+    fn window_event(
+        &mut self,
+        event_loop: &ActiveEventLoop,
+        window_id: WindowId,
+        event: WindowEvent,
+    ) {
+        let Some(viewport) = self
+            .viewports
+            .values_mut()
+            .find(|v| v.has_window_id(window_id))
+        else {
+            return;
+        };
+        let viewport_id = viewport.id;
+        let (response, close_requested) = viewport.on_window_event(&event, &mut self.shared);
+        if close_requested && viewport_id == ViewportId::ROOT {
+            event_loop.exit();
+        }
+        if response.repaint {
+            viewport.window.request_redraw();
+        }
+        if !response.consumed {
+            match event {
+                WindowEvent::KeyboardInput { event, .. }
+                    if !self.app.handle_key_event(viewport_id, &event) =>
+                {
+                    self.controllers.handle_key_event(&event);
+                }
+                WindowEvent::DroppedFile(path) => {
+                    self.app.handle_dropped_file(viewport_id, path);
+                }
+                WindowEvent::Focused(new_focused) => {
+                    self.focused = new_focused.then_some(viewport_id);
+                }
+                WindowEvent::RedrawRequested => {
+                    self.repaint_all(event_loop);
+                }
+                _ => {}
+            }
+        }
+        self.check_repaint(event_loop);
+    }
+
+    fn device_event(
+        &mut self,
+        _event_loop: &ActiveEventLoop,
+        _device_id: winit::event::DeviceId,
+        event: winit::event::DeviceEvent,
+    ) {
+        if let winit::event::DeviceEvent::MouseMotion { delta } = event {
+            let Some(viewport) = self
+                .focused
+                .as_ref()
+                .and_then(|id| self.viewports.get_mut(id))
+            else {
+                return;
+            };
+            viewport.on_mouse_motion(delta);
+        }
+    }
+
+    fn user_event(&mut self, event_loop: &ActiveEventLoop, event: UserEvent) {
+        match event {
+            UserEvent::GamepadEvent(event) => {
+                if !self
+                    .focused
+                    .is_some_and(|id| self.app.handle_gamepad_event(id, &event))
+                {
+                    self.controllers.handle_gamepad_event(&event);
+                }
+            }
+            UserEvent::LowBattery(sim_id, pwr) => {
+                self.controllers.handle_low_battery(sim_id, pwr);
+            }
+            UserEvent::Quit(sim_id) => match sim_id {
+                SimId::Player1 => event_loop.exit(),
+                SimId::Player2 => self.app.close(ChildWindow::Player2),
+            },
+            UserEvent::RequestRedraw(viewport, when) => {
+                let scheduled = self.redraw_times.entry(viewport).or_insert(when);
+                if *scheduled > when {
+                    *scheduled = when;
+                }
+            }
+        }
+        self.check_repaint(event_loop);
+    }
+
+    fn exiting(&mut self, _event_loop: &ActiveEventLoop) {
+        if let Err(error) = self
+            .ctx
+            .data(|d| self.persistence.save_config(EGUI_FILENAME, d))
+        {
+            error!(%error, "could not save egui state.");
+        }
+        let (sender, receiver) = oneshot::channel();
+        if self.client.send_command(EmulatorCommand::Exit(sender))
+            && let Err(error) = receiver.recv_timeout(Duration::from_secs(5))
+        {
+            error!(%error, "could not gracefully exit.");
+        }
+    }
+}
+
+struct WgpuState {
+    instance: wgpu::Instance,
+    device_descriptor: Arc<dyn Fn(&wgpu::Adapter) -> wgpu::DeviceDescriptor<'static> + Send + Sync>,
+    config: AppConfig,
+}
+
+impl WgpuState {
+    fn new(handle: OwnedDisplayHandle, config: AppConfig) -> Self {
+        #[allow(unused_variables)]
+        let egui_wgpu::WgpuSetupCreateNew {
+            instance_descriptor: wgpu::InstanceDescriptor { backends, .. },
+            device_descriptor,
+            ..
+        } = egui_wgpu::WgpuSetupCreateNew::without_display_handle();
+        #[cfg(windows)]
+        let backends = wgpu::Backends::from_env()
+            .unwrap_or((wgpu::Backends::PRIMARY | wgpu::Backends::GL) - wgpu::Backends::VULKAN);
+        let instance = wgpu::Instance::new(wgpu::InstanceDescriptor {
+            backends,
+            ..wgpu::InstanceDescriptor::new_with_display_handle_from_env(Box::new(handle))
+        });
+
+        Self {
+            instance,
+            device_descriptor,
+            config,
+        }
+    }
+
+    fn init(&mut self, window: &Window) -> egui_wgpu::WgpuSetupExisting {
+        let power_preference =
+            wgpu::PowerPreference::from_env().unwrap_or(self.config.power_preference);
+        debug!("power preference: {power_preference:?}");
+
+        let force_fallback_adapter = std::env::var("WGPU_FORCE_FALLBACK")
+            .map_or(self.config.force_fallback, |f| {
+                f.eq_ignore_ascii_case("true") || f.eq_ignore_ascii_case("1")
+            });
+        debug!("force fallback: {force_fallback_adapter}");
+
+        let surface = self
+            .instance
+            .create_surface(window)
+            .expect("could not create surface");
+
+        let adapter =
+            pollster::block_on(self.instance.request_adapter(&wgpu::RequestAdapterOptions {
+                power_preference,
+                compatible_surface: Some(&surface),
+                force_fallback_adapter,
+            }))
+            .expect("could not create adapter");
+        debug!("selected adapter: {:?}", adapter.get_info());
+
+        drop(surface);
+
+        let (device, queue) =
+            pollster::block_on(adapter.request_device(&(*self.device_descriptor)(&adapter)))
+                .expect("could not request device");
+
+        egui_wgpu::WgpuSetupExisting {
+            instance: self.instance.clone(),
+            adapter,
+            device,
+            queue,
+        }
+    }
+}
+
+struct ViewportManager {
+    id: ViewportId,
+    window: Arc<Window>,
+    state: egui_winit::State,
+    builder: ViewportBuilder,
+}
+impl ViewportManager {
+    fn new(
+        ctx: &Context,
+        viewport_id: ViewportId,
+        parent_id: ViewportId,
+        event_loop: &ActiveEventLoop,
+        builder: ViewportBuilder,
+        shared: &mut SharedViewportState,
+    ) -> Self {
+        let window = Arc::new(egui_winit::create_window(ctx, event_loop, &builder).unwrap());
+        let painter = shared.init_painter(ctx, &window);
+        pollster::block_on(painter.set_window(viewport_id, Some(window.clone()))).unwrap();
+        let state = egui_winit::State::new(
+            ctx.clone(),
+            viewport_id,
+            event_loop,
+            Some(window.scale_factor() as f32),
+            event_loop.system_theme(),
+            painter.max_texture_side(),
+        );
+
+        let mut info = ViewportInfo {
+            parent: Some(parent_id),
+            ..ViewportInfo::default()
+        };
+        egui_winit::update_viewport_info(&mut info, ctx, &window, true);
+        shared.viewport_info.insert(viewport_id, info);
+
+        Self {
+            id: viewport_id,
+            window,
+            state,
+            builder,
+        }
+    }
+
+    fn has_window_id(&self, window_id: WindowId) -> bool {
+        self.window.id() == window_id
+    }
+
+    fn on_mouse_motion(&mut self, delta: (f64, f64)) {
+        self.state.on_mouse_motion(delta);
+    }
+
+    fn on_window_event(
+        &mut self,
+        event: &WindowEvent,
+        shared: &mut SharedViewportState,
+    ) -> (EventResponse, bool) {
+        if let WindowEvent::Resized(size) = event
+            && let (Some(width), Some(height)) =
+                (NonZero::new(size.width), NonZero::new(size.height))
+        {
+            if shared.resized_viewport != Some(self.id) {
+                shared.resized_viewport = Some(self.id);
+                shared
+                    .get_painter()
+                    .on_window_resize_state_change(self.id, true);
+            }
+            shared
+                .get_painter()
+                .on_window_resized(self.id, width, height);
+        }
+        let response = self.state.on_window_event(&self.window, event);
+        let info = shared.viewport_info.get_mut(&self.id).unwrap();
+        if let WindowEvent::CloseRequested = event {
+            info.events.push(ViewportEvent::Close);
+        }
+        egui_winit::update_viewport_info(info, self.state.egui_ctx(), &self.window, false);
+        (response, info.close_requested())
+    }
+
+    fn take_egui_input(&mut self) -> RawInput {
+        self.state.take_egui_input(&self.window)
+    }
+
+    fn handle_platform_output(&mut self, platform_output: PlatformOutput) {
+        self.state
+            .handle_platform_output(&self.window, platform_output);
+    }
+
+    fn process_viewport_commands(
+        &self,
+        commands: Vec<ViewportCommand>,
+        shared: &mut SharedViewportState,
+    ) {
+        let info = shared.viewport_info.get_mut(&self.id).unwrap();
+        egui_winit::process_viewport_commands(
+            self.state.egui_ctx(),
+            info,
+            commands,
+            &self.window,
+            &mut vec![],
+        );
+    }
+}
+
+#[derive(Debug)]
+pub enum UserEvent {
+    GamepadEvent(gilrs::Event),
+    Quit(SimId),
+    LowBattery(SimId, bool),
+    RequestRedraw(ViewportId, Instant),
+}
+
+fn process_gamepad_input(mappings: MappingProvider, proxy: EventLoopProxy<UserEvent>) {
+    let mut gilrs = match Gilrs::new() {
+        Ok(gilrs) => gilrs,
+        Err(error) => {
+            warn!(%error, "could not connect gamepad listener");
+            return;
+        }
+    };
+    while let Some(event) = gilrs.next_event_blocking(None) {
+        if event.event == EventType::Connected {
+            let Some(gamepad) = gilrs.connected_gamepad(event.id) else {
+                continue;
+            };
+            mappings.handle_gamepad_connect(&gamepad);
+        }
+        if event.event == EventType::Disconnected {
+            mappings.handle_gamepad_disconnect(event.id);
+        }
+        if proxy.send_event(UserEvent::GamepadEvent(event)).is_err() {
+            // main thread has closed! we done
+            return;
+        }
+    }
+}

src/audio.rs

@@ -0,0 +1,266 @@
+use std::time::Duration;
+
+use anyhow::{Context, Result, bail};
+use audioadapter_buffers::direct::InterleavedSlice;
+use cpal::{
+    Device, FromSample, Sample, SampleFormat, SizedSample, StreamConfig,
+    traits::{DeviceTrait, HostTrait, StreamTrait},
+};
+use itertools::Itertools;
+use rubato::{Adjustable as _, Resampler};
+use tracing::warn;
+
+struct CpalAudio {
+    #[allow(unused)]
+    stream: cpal::Stream,
+    sampler: rubato::Async<f32>,
+    input_buffer: Vec<f32>,
+    output_buffer: Vec<f32>,
+    sample_sink: rtrb::Producer<f32>,
+}
+
+const VB_FREQUENCY: usize = 41700;
+
+impl CpalAudio {
+    fn init() -> Result<Self> {
+        let host = cpal::default_host();
+        let device = host
+            .default_output_device()
+            .context("no output device available")?;
+        let default_rate = device.default_output_config()?.sample_rate();
+
+        let supported_config = device
+            .supported_output_configs()?
+            .filter(|c| {
+                c.contains_rate(default_rate)
+                    && matches!(
+                        c.sample_format(),
+                        SampleFormat::F32
+                            | SampleFormat::F64
+                            | SampleFormat::I32
+                            | SampleFormat::I16
+                    )
+            })
+            .max_by(|a, b| a.cmp_default_heuristics(b))
+            .context("no suitable output config available")?
+            .with_sample_rate(default_rate);
+        let mut config = supported_config.config();
+
+        let resample_ratio = config.sample_rate as f64 / VB_FREQUENCY as f64;
+        let chunk_size = (834.0 * resample_ratio) as usize;
+        let sampler = rubato::Async::new_poly(
+            resample_ratio,
+            64.0,
+            rubato::PolynomialDegree::Cubic,
+            chunk_size,
+            2,
+            rubato::FixedAsync::Output,
+        )?;
+        config.buffer_size = cpal::BufferSize::Fixed(sampler.output_frames_max() as u32);
+
+        match supported_config.sample_format() {
+            SampleFormat::F32 if config.channels == 2 => {
+                Self::new_f32_stereo(device, config, sampler)
+            }
+            SampleFormat::F32 => Self::new::<f32>(device, config, sampler),
+            SampleFormat::F64 => Self::new::<f64>(device, config, sampler),
+            SampleFormat::I32 => Self::new::<i32>(device, config, sampler),
+            SampleFormat::I16 => Self::new::<i16>(device, config, sampler),
+            _ => bail!("unsupported sample format"),
+        }
+    }
+
+    fn new_f32_stereo(
+        device: Device,
+        config: StreamConfig,
+        sampler: rubato::Async<f32>,
+    ) -> Result<Self> {
+        let input_buffer = Vec::with_capacity(sampler.nbr_channels() * sampler.input_frames_max());
+        let output_buffer = vec![0.0; sampler.nbr_channels() * sampler.output_frames_max()];
+        let (sample_sink, mut sample_source) =
+            rtrb::RingBuffer::new(sampler.output_frames_max() * 4);
+
+        let stream = device.build_output_stream(
+            config,
+            move |data: &mut [f32], _| {
+                let requested = data.len();
+                let chunk = match sample_source.read_chunk(data.len()) {
+                    Ok(c) => c,
+                    Err(rtrb::chunks::ChunkError::TooFewSlots(n)) => {
+                        sample_source.read_chunk(n).unwrap()
+                    }
+                };
+                let len = chunk.len();
+                let (first, second) = chunk.as_slices();
+                data[0..first.len()].copy_from_slice(first);
+                data[first.len()..len].copy_from_slice(second);
+                for rest in &mut data[len..requested] {
+                    *rest = 0.0;
+                }
+                chunk.commit_all();
+            },
+            move |error| warn!(%error, "stream error"),
+            None,
+        )?;
+        stream.play()?;
+        Ok(Self {
+            stream,
+            sampler,
+            input_buffer,
+            output_buffer,
+            sample_sink,
+        })
+    }
+
+    fn new<S: SizedSample + FromSample<f32>>(
+        device: Device,
+        config: StreamConfig,
+        sampler: rubato::Async<f32>,
+    ) -> Result<Self> {
+        let input_buffer = Vec::with_capacity(sampler.nbr_channels() * sampler.input_frames_max());
+        let output_buffer = vec![0.0; sampler.nbr_channels() * sampler.output_frames_max()];
+        let (sample_sink, mut sample_source) =
+            rtrb::RingBuffer::new(sampler.output_frames_max() * 4);
+
+        let channels = config.channels as usize;
+
+        let stream = device.build_output_stream(
+            config,
+            move |data: &mut [S], _| {
+                let requested = data.len() * 2 / channels;
+                let chunk = match sample_source.read_chunk(requested) {
+                    Ok(c) => c,
+                    Err(rtrb::chunks::ChunkError::TooFewSlots(n)) => {
+                        sample_source.read_chunk(n).unwrap()
+                    }
+                };
+                let (first, second) = chunk.as_slices();
+
+                let new_samples = first
+                    .iter()
+                    .chain(second)
+                    .map(|s: &f32| (*s).to_sample())
+                    .chunks(2);
+                let buffer = data.iter_mut().chunks(channels);
+                for (dst, samples) in buffer.into_iter().zip(&new_samples) {
+                    // channels beyond the first two are zeroed
+                    let src = samples.chain(std::iter::repeat(S::EQUILIBRIUM));
+                    for (d, s) in dst.zip(src) {
+                        *d = s;
+                    }
+                }
+
+                chunk.commit_all();
+            },
+            move |error| warn!(%error, "stream error"),
+            None,
+        )?;
+        stream.play()?;
+        Ok(Self {
+            stream,
+            sampler,
+            input_buffer,
+            output_buffer,
+            sample_sink,
+        })
+    }
+
+    fn update(&mut self, mut samples: &[f32]) {
+        while self.input_buffer.len() + samples.len() >= self.sampler.input_frames_next() * 2 {
+            let samples_needed =
+                (self.sampler.input_frames_next() * 2).saturating_sub(self.input_buffer.len());
+            let (current_samples, future_samples) = samples.split_at(samples_needed);
+            self.input_buffer.extend_from_slice(current_samples);
+            samples = future_samples;
+
+            let buffer_in =
+                InterleavedSlice::new(&self.input_buffer, 2, self.sampler.input_frames_next())
+                    .unwrap();
+            let mut buffer_out = InterleavedSlice::new_mut(
+                &mut self.output_buffer,
+                2,
+                self.sampler.output_frames_next(),
+            )
+            .unwrap();
+            let (_, output_samples) = self
+                .sampler
+                .process_into_buffer(&buffer_in, &mut buffer_out, None)
+                .unwrap();
+            let chunk = match self.sample_sink.write_chunk_uninit(output_samples * 2) {
+                Ok(c) => c,
+                Err(rtrb::chunks::ChunkError::TooFewSlots(n)) => {
+                    self.sample_sink.write_chunk_uninit(n).unwrap()
+                }
+            };
+            chunk.fill_from_iter(self.output_buffer[..output_samples * 2].iter().copied());
+
+            self.input_buffer.clear();
+        }
+        self.input_buffer.extend_from_slice(samples);
+
+        while self.sample_sink.slots() < self.sampler.output_frames_max() * 2 {
+            std::thread::sleep(Duration::from_micros(500));
+        }
+    }
+
+    fn set_speed(&mut self, speed: f64) -> Result<()> {
+        self.sampler
+            .set_resample_ratio_relative(1.0 / speed, false)?;
+        Ok(())
+    }
+}
+
+struct NoAudio {
+    speed: f64,
+}
+
+impl NoAudio {
+    fn new() -> Self {
+        Self { speed: 1.0 }
+    }
+
+    fn update(&mut self, samples: &[f32]) {
+        let samples = (samples.len() / 2) as f64;
+        let elapsed = Duration::from_secs_f64(samples / (VB_FREQUENCY as f64 * self.speed));
+        std::thread::sleep(elapsed);
+    }
+
+    fn set_speed(&mut self, speed: f64) -> Result<()> {
+        self.speed = speed;
+        Ok(())
+    }
+}
+
+#[allow(clippy::large_enum_variant)]
+enum AudioInner {
+    Cpal(CpalAudio),
+    None(NoAudio),
+}
+
+pub struct Audio(AudioInner);
+
+impl Audio {
+    pub fn init() -> Self {
+        match CpalAudio::init() {
+            Ok(a) => Self(AudioInner::Cpal(a)),
+            Err(e) => {
+                warn!("could not play audio: {e}");
+                Self(AudioInner::None(NoAudio::new()))
+            }
+        }
+    }
+
+    pub fn update(&mut self, samples: &[f32]) {
+        match &mut self.0 {
+            AudioInner::Cpal(a) => a.update(samples),
+            AudioInner::None(a) => a.update(samples),
+        }
+    }
+
+    pub fn set_speed(&mut self, speed: f64) -> Result<()> {
+        match &mut self.0 {
+            AudioInner::Cpal(a) => a.set_speed(speed),
+            AudioInner::None(a) => a.set_speed(speed),
+        }
+    }
+}

src/config.rs

@@ -0,0 +1,177 @@
+use anyhow::Result;
+use clap::{Parser, ValueEnum};
+use egui::{Color32, Pos2, Vec2};
+use serde::{Deserialize, Serialize};
+
+use crate::{emulator::SimId, persistence::Persistence, window::DisplayMode};
+use std::path::PathBuf;
+
+#[derive(Parser)]
+#[command(version, long_version = env!("CARGO_PKG_VERSION"))]
+pub struct CliArgs {
+    /// The path to a virtual boy ROM to run.
+    pub rom: Option<PathBuf>,
+    /// Start a GDB/LLDB debug server on this port.
+    #[arg(short, long)]
+    pub debug_port: Option<u16>,
+    /// Enable profiling a game
+    #[arg(short, long)]
+    pub profile: bool,
+    /// Open character data window
+    #[arg(short, long)]
+    pub character_data: bool,
+    /// Open bgmap data window
+    #[arg(short, long)]
+    pub bgmap_data: bool,
+    /// Open object data window
+    #[arg(short, long)]
+    pub object_data: bool,
+    /// Open worlds window
+    #[arg(long)]
+    pub worlds: bool,
+    /// Open frame buffers window
+    #[arg(short, long)]
+    pub frame_buffers: bool,
+    /// Open registers window
+    #[arg(short, long)]
+    pub registers: bool,
+    /// Open terminal
+    #[arg(short, long)]
+    pub terminal: bool,
+    /// Watch ROM files for changes, automatically reload
+    #[arg(short, long)]
+    pub watch: bool,
+    /// Automatically open Player 2 for multiplayer
+    #[arg(long)]
+    pub player2: bool,
+    /// Map the first connected controller to Player 2
+    #[arg(long)]
+    pub player2_controller: bool,
+    /// Force the application to render with CPU, rather than GPU.
+    #[arg(long)]
+    pub wgpu_force_fallback: Option<bool>,
+    /// Set a preference for whether to use a low-power or high-performance GPU adapter
+    #[arg(long)]
+    pub wgpu_power_preference: Option<PowerPreferenceWrapper>,
+}
+
+#[derive(ValueEnum, Clone, Copy)]
+pub enum PowerPreferenceWrapper {
+    Low,
+    High,
+    None,
+}
+impl From<PowerPreferenceWrapper> for wgpu::PowerPreference {
+    fn from(value: PowerPreferenceWrapper) -> Self {
+        match value {
+            PowerPreferenceWrapper::Low => wgpu::PowerPreference::LowPower,
+            PowerPreferenceWrapper::High => wgpu::PowerPreference::HighPerformance,
+            PowerPreferenceWrapper::None => wgpu::PowerPreference::None,
+        }
+    }
+}
+
+pub const COLOR_PRESETS: [[Color32; 2]; 3] = [
+    [
+        Color32::from_rgb(0xff, 0x00, 0x00),
+        Color32::from_rgb(0x00, 0xc6, 0xf0),
+    ],
+    [
+        Color32::from_rgb(0x00, 0xb4, 0x00),
+        Color32::from_rgb(0xc8, 0x00, 0xff),
+    ],
+    [
+        Color32::from_rgb(0xb4, 0x9b, 0x00),
+        Color32::from_rgb(0x00, 0x00, 0xff),
+    ],
+];
+
+const fn default_power_preference() -> wgpu::PowerPreference {
+    wgpu::PowerPreference::LowPower
+}
+
+#[derive(Serialize, Deserialize, Clone, PartialEq, Eq)]
+pub struct AppConfig {
+    #[serde(default = "default_power_preference")]
+    pub power_preference: wgpu::PowerPreference,
+    #[serde(default)]
+    pub force_fallback: bool,
+}
+
+impl AppConfig {
+    pub fn load(persistence: &Persistence) -> Self {
+        if let Ok(config) = persistence.load_config(APP_CONFIG_FILENAME) {
+            return config;
+        }
+        Self {
+            power_preference: default_power_preference(),
+            force_fallback: false,
+        }
+    }
+
+    pub fn save(&self, persistence: &Persistence) -> Result<()> {
+        persistence.save_config(APP_CONFIG_FILENAME, &self)
+    }
+
+    pub fn update(&mut self, args: &CliArgs) -> bool {
+        let mut updated = false;
+        if let Some(pref) = args.wgpu_power_preference {
+            self.power_preference = pref.into();
+            updated = true;
+        }
+        if let Some(force_fallback) = args.wgpu_force_fallback {
+            self.force_fallback = force_fallback;
+            updated = true;
+        }
+        updated
+    }
+}
+
+const APP_CONFIG_FILENAME: &str = "config";
+
+const fn default_audio_enabled() -> bool {
+    true
+}
+
+#[derive(Serialize, Deserialize, Clone, PartialEq, Eq)]
+pub struct SimConfig {
+    pub display_mode: DisplayMode,
+    pub colors: [Color32; 2],
+    pub dimensions: Vec2,
+    #[serde(default = "default_audio_enabled")]
+    pub audio_enabled: bool,
+    #[serde(default)]
+    pub low_battery: bool,
+    #[serde(default)]
+    pub watch_rom: bool,
+    #[serde(default)]
+    pub position: Option<Pos2>,
+}
+
+impl SimConfig {
+    pub fn load(persistence: &Persistence, sim_id: SimId) -> Self {
+        if let Ok(config) = persistence.load_config(sim_config_filename(sim_id)) {
+            return config;
+        }
+        Self {
+            display_mode: DisplayMode::Anaglyph,
+            colors: COLOR_PRESETS[0],
+            dimensions: DisplayMode::Anaglyph.proportions() + Vec2::new(0.0, 22.0),
+            audio_enabled: true,
+            low_battery: false,
+            watch_rom: false,
+            position: None,
+        }
+    }
+
+    pub fn save(&self, persistence: &Persistence, sim_id: SimId) -> Result<()> {
+        persistence.save_config(sim_config_filename(sim_id), self)
+    }
+}
+
+fn sim_config_filename(sim_id: SimId) -> &'static str {
+    match sim_id {
+        SimId::Player1 => "config_p1",
+        SimId::Player2 => "config_p2",
+    }
+}

src/controller.rs

@@ -0,0 +1,245 @@
+use std::{
+    collections::HashMap,
+    sync::{Arc, RwLock},
+};
+
+use gilrs::{Event as GamepadEvent, EventType, GamepadId, ev::Code};
+use winit::{
+    event::{ElementState, KeyEvent},
+    keyboard::PhysicalKey,
+};
+
+use crate::{
+    emulator::{EmulatorClient, EmulatorCommand, SimId, VBKey},
+    input::{AxisMapping, InputMapping, MappingProvider},
+};
+
+pub struct Controller {
+    pub sim_id: SimId,
+    state: VBKey,
+    axis_values: HashMap<(GamepadId, Code), f32>,
+    mapping: Arc<RwLock<InputMapping>>,
+}
+
+impl Controller {
+    pub fn new(sim_id: SimId, mappings: &MappingProvider) -> Self {
+        Self {
+            sim_id,
+            state: VBKey::SGN,
+            axis_values: HashMap::new(),
+            mapping: mappings.for_sim(sim_id).clone(),
+        }
+    }
+
+    pub fn key_event(&mut self, event: &KeyEvent) -> Option<VBKey> {
+        let keys = self.map_keys(&event.physical_key)?;
+        match event.state {
+            ElementState::Pressed => self.update_state(keys, VBKey::empty()),
+            ElementState::Released => self.update_state(VBKey::empty(), keys),
+        }
+    }
+
+    pub fn gamepad_event(&mut self, event: &GamepadEvent) -> Option<VBKey> {
+        let (pressed, released) = match event.event {
+            EventType::ButtonPressed(_, code) => {
+                let mappings = self.map_button(&event.id, &code)?;
+                (mappings, VBKey::empty())
+            }
+            EventType::ButtonReleased(_, code) => {
+                let mappings = self.map_button(&event.id, &code)?;
+                (VBKey::empty(), mappings)
+            }
+            EventType::AxisChanged(_, value, code) => {
+                let mapping = self.map_axis(&event.id, &code)?;
+                self.axis_values.insert((event.id, code), value);
+
+                let pair_value = mapping
+                    .pair
+                    .and_then(|p| self.axis_values.get(&(event.id, p)))
+                    .copied()
+                    .unwrap_or_default();
+                let neg = mapping.neg;
+                let pos = mapping.pos;
+
+                let (mut pressed, mut released) = axis_presses(value, pair_value, neg, pos);
+                if let Some(other) = mapping.pair.and_then(|p| self.map_axis(&event.id, &p)) {
+                    let (other_pressed, other_released) =
+                        axis_presses(pair_value, value, other.neg, other.pos);
+                    pressed = pressed.union(other_pressed);
+                    released = released.union(other_released);
+                }
+                (pressed, released)
+            }
+            _ => {
+                return None;
+            }
+        };
+        self.update_state(pressed, released)
+    }
+
+    pub fn low_battery(&mut self, pwr: bool) -> Option<VBKey> {
+        let (pressed, released) = if pwr {
+            (VBKey::PWR, VBKey::empty())
+        } else {
+            (VBKey::empty(), VBKey::PWR)
+        };
+        self.update_state(pressed, released)
+    }
+
+    fn update_state(&mut self, pressed: VBKey, released: VBKey) -> Option<VBKey> {
+        let old_state = self.state;
+        self.state = self.state.union(pressed).difference(released);
+        if self.state != old_state {
+            Some(self.state)
+        } else {
+            None
+        }
+    }
+
+    fn map_keys(&self, key: &PhysicalKey) -> Option<VBKey> {
+        self.mapping.read().unwrap().map_keyboard(key)
+    }
+
+    fn map_button(&self, id: &GamepadId, code: &Code) -> Option<VBKey> {
+        self.mapping.read().unwrap().map_button(id, code)
+    }
+
+    fn map_axis(&self, id: &GamepadId, code: &Code) -> Option<AxisMapping> {
+        self.mapping.read().unwrap().map_axis(id, code)
+    }
+}
+
+pub struct ControllerManager {
+    client: EmulatorClient,
+    controllers: [Controller; 2],
+}
+
+impl ControllerManager {
+    pub fn new(client: EmulatorClient, mappings: &MappingProvider) -> Self {
+        Self {
+            client,
+            controllers: [
+                Controller::new(SimId::Player1, mappings),
+                Controller::new(SimId::Player2, mappings),
+            ],
+        }
+    }
+
+    pub fn handle_key_event(&mut self, event: &KeyEvent) {
+        for controller in &mut self.controllers {
+            if let Some(pressed) = controller.key_event(event) {
+                self.client
+                    .send_command(EmulatorCommand::SetKeys(controller.sim_id, pressed));
+            }
+        }
+    }
+
+    pub fn handle_gamepad_event(&mut self, event: &GamepadEvent) {
+        for controller in &mut self.controllers {
+            if let Some(pressed) = controller.gamepad_event(event) {
+                self.client
+                    .send_command(EmulatorCommand::SetKeys(controller.sim_id, pressed));
+            }
+        }
+    }
+
+    pub fn handle_low_battery(&mut self, sim_id: SimId, pwr: bool) {
+        let controller = &mut self.controllers[sim_id.to_index()];
+        if let Some(pressed) = controller.low_battery(pwr) {
+            self.client
+                .send_command(EmulatorCommand::SetKeys(controller.sim_id, pressed));
+        }
+    }
+}
+
+fn axis_presses(value: f32, pair_value: f32, neg: VBKey, pos: VBKey) -> (VBKey, VBKey) {
+    use std::f32::consts::FRAC_PI_3;
+
+    let mut pressed = VBKey::empty();
+    let mut released = VBKey::empty();
+
+    let magnitude = value.hypot(pair_value);
+    let abs_angle = pair_value.atan2(value).abs();
+
+    if magnitude < 0.65 {
+        released = released.union(neg).union(pos);
+    } else if abs_angle <= FRAC_PI_3 {
+        // stick tilted towards positive
+        released = released.union(neg);
+
+        if magnitude >= 0.75 {
+            pressed = pressed.union(pos);
+        }
+    } else if abs_angle >= 2.0 * FRAC_PI_3 {
+        // stick tilted towards negative
+        released = released.union(pos);
+
+        if magnitude >= 0.75 {
+            pressed = pressed.union(neg);
+        }
+    } else {
+        released = released.union(neg).union(pos);
+    }
+
+    (pressed, released)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{VBKey, axis_presses};
+
+    const NEG: VBKey = VBKey::LL;
+    const POS: VBKey = VBKey::LR;
+
+    const NONE: VBKey = VBKey::empty();
+    const BOTH: VBKey = NEG.union(POS);
+
+    #[test]
+    fn detects_no_input() {
+        let (pressed, released) = axis_presses(0.0, 0.0, NEG, POS);
+        assert_eq!(pressed, NONE);
+        assert_eq!(released, BOTH);
+    }
+
+    #[test]
+    fn detects_pos_input() {
+        let (pressed, released) = axis_presses(1.0, 0.0, NEG, POS);
+        assert_eq!(pressed, POS);
+        assert_eq!(released, NEG);
+    }
+
+    #[test]
+    fn detects_neg_input() {
+        let (pressed, released) = axis_presses(-1.0, 0.0, NEG, POS);
+        assert_eq!(pressed, NEG);
+        assert_eq!(released, POS);
+    }
+
+    #[test]
+    fn respects_dead_zone() {
+        let (pressed, released) = axis_presses(0.70, 0.0, NEG, POS);
+        assert_eq!(pressed, NONE);
+        assert_eq!(released, NEG);
+    }
+
+    #[test]
+    fn handles_diagonals_ok() {
+        let (pressed, released) = axis_presses(0.6, 0.6, NEG, POS);
+        assert_eq!(pressed, POS);
+        assert_eq!(released, NEG);
+    }
+
+    #[test]
+    fn ignores_diagonal_noise() {
+        let (pressed, released) = axis_presses(-1.0, -0.1484245, NEG, POS);
+        assert_eq!(pressed, NEG);
+        assert_eq!(released, POS);
+    }
+
+    #[test]
+    fn ignores_small_values() {
+        let (pressed, released) = axis_presses(-0.1484245, -1.0, NEG, POS);
+        assert_eq!(pressed, NONE);
+        assert_eq!(released, BOTH);
+    }
+}

src/emulator.rs

@@ -0,0 +1,977 @@
+use std::{
+    collections::HashMap,
+    fmt::Display,
+    path::{Path, PathBuf},
+    sync::{
+        Arc, Weak,
+        atomic::{AtomicBool, Ordering},
+        mpsc::{self, RecvTimeoutError, TryRecvError},
+    },
+    time::Duration,
+};
+
+use anyhow::Result;
+use atomic::Atomic;
+use bytemuck::NoUninit;
+use egui_notify::Toast;
+use tracing::{error, warn};
+
+use crate::{
+    audio::Audio,
+    graphics::TextureSink,
+    memory::{MemoryRange, MemoryRegion},
+};
+use cart::Cart;
+pub use game_info::GameInfo;
+pub use inline_stack_map::InlineStack;
+use inline_stack_map::InlineStackMap;
+use shrooms_vb_core::{EXPECTED_FRAME_SIZE, Sim, StopReason};
+pub use shrooms_vb_core::{SimEvent, VBKey, VBRegister, VBWatchpointType};
+
+mod address_set;
+mod cart;
+mod game_info;
+mod inline_stack_map;
+mod shrooms_vb_core;
+mod shrooms_vb_util;
+
+#[derive(PartialEq, Eq, Hash, Clone, Copy, Debug)]
+pub enum SimId {
+    Player1,
+    Player2,
+}
+impl SimId {
+    pub const fn values() -> [Self; 2] {
+        [Self::Player1, Self::Player2]
+    }
+    pub const fn to_index(self) -> usize {
+        match self {
+            Self::Player1 => 0,
+            Self::Player2 => 1,
+        }
+    }
+    pub const fn from_index(index: usize) -> Option<Self> {
+        match index {
+            0 => Some(Self::Player1),
+            1 => Some(Self::Player2),
+            _ => None,
+        }
+    }
+}
+impl Display for SimId {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(match self {
+            Self::Player1 => "Player 1",
+            Self::Player2 => "Player 2",
+        })
+    }
+}
+
+pub struct EmulatorBuilder {
+    rom: Option<PathBuf>,
+    commands: mpsc::Receiver<EmulatorCommand>,
+    sim_state: Arc<[Atomic<SimState>; 2]>,
+    state: Arc<Atomic<EmulatorState>>,
+    audio_on: Arc<[AtomicBool; 2]>,
+    linked: Arc<AtomicBool>,
+    start_paused: bool,
+    watch_rom: Arc<[AtomicBool; 2]>,
+}
+
+impl EmulatorBuilder {
+    pub fn new() -> (Self, EmulatorClient) {
+        let (queue, commands) = mpsc::channel();
+        let builder = Self {
+            rom: None,
+            commands,
+            sim_state: Arc::new([
+                Atomic::new(SimState::Uninitialized),
+                Atomic::new(SimState::Uninitialized),
+            ]),
+            state: Arc::new(Atomic::new(EmulatorState::Paused)),
+            audio_on: Arc::new([AtomicBool::new(true), AtomicBool::new(true)]),
+            linked: Arc::new(AtomicBool::new(false)),
+            start_paused: false,
+            watch_rom: Arc::new([AtomicBool::new(false), AtomicBool::new(false)]),
+        };
+        let client = EmulatorClient {
+            queue,
+            sim_state: builder.sim_state.clone(),
+            state: builder.state.clone(),
+            watch_rom: builder.watch_rom.clone(),
+            linked: builder.linked.clone(),
+        };
+        (builder, client)
+    }
+
+    pub fn with_rom(self, path: &Path) -> Self {
+        Self {
+            rom: Some(path.into()),
+            ..self
+        }
+    }
+
+    pub fn start_paused(self, paused: bool) -> Self {
+        Self {
+            start_paused: paused,
+            ..self
+        }
+    }
+
+    pub fn with_audio_on(self, p1: bool, p2: bool) -> Self {
+        self.audio_on[0].store(p1, Ordering::Relaxed);
+        self.audio_on[1].store(p2, Ordering::Relaxed);
+        self
+    }
+
+    pub fn with_watch_rom(self, p1: bool, p2: bool) -> Self {
+        self.watch_rom[0].store(p1, Ordering::Relaxed);
+        self.watch_rom[1].store(p2, Ordering::Relaxed);
+        self
+    }
+
+    pub fn build(self) -> Result<Emulator> {
+        let mut emulator = Emulator::new(
+            self.commands,
+            self.sim_state,
+            self.state,
+            self.audio_on,
+            self.watch_rom,
+            self.linked,
+        );
+        if let Some(path) = self.rom {
+            emulator.load_cart(SimId::Player1, &path)?;
+        }
+        if self.start_paused {
+            emulator.pause_sims()?;
+        }
+        Ok(emulator)
+    }
+}
+
+pub struct Emulator {
+    sims: Vec<Sim>,
+    carts: [Option<Cart>; 2],
+    audio: Audio,
+    commands: mpsc::Receiver<EmulatorCommand>,
+    sim_state: Arc<[Atomic<SimState>; 2]>,
+    state: Arc<Atomic<EmulatorState>>,
+    audio_on: Arc<[AtomicBool; 2]>,
+    watch_rom: Arc<[AtomicBool; 2]>,
+    linked: Arc<AtomicBool>,
+    profilers: [Option<ProfileSender>; 2],
+    renderers: HashMap<SimId, TextureSink>,
+    messages: HashMap<SimId, mpsc::Sender<Toast>>,
+    debuggers: HashMap<SimId, DebugInfo>,
+    stdouts: HashMap<SimId, mpsc::Sender<String>>,
+    watched_regions: HashMap<MemoryRange, Weak<MemoryRegion>>,
+    eye_contents: [Vec<u8>; 2],
+    audio_samples: Vec<f32>,
+    buffer: Vec<u8>,
+}
+
+impl Emulator {
+    fn new(
+        commands: mpsc::Receiver<EmulatorCommand>,
+        sim_state: Arc<[Atomic<SimState>; 2]>,
+        state: Arc<Atomic<EmulatorState>>,
+        audio_on: Arc<[AtomicBool; 2]>,
+        watch_rom: Arc<[AtomicBool; 2]>,
+        linked: Arc<AtomicBool>,
+    ) -> Self {
+        Self {
+            sims: vec![],
+            carts: [None, None],
+            audio: Audio::init(),
+            commands,
+            sim_state,
+            state,
+            audio_on,
+            watch_rom,
+            linked,
+            profilers: [None, None],
+            renderers: HashMap::new(),
+            messages: HashMap::new(),
+            debuggers: HashMap::new(),
+            stdouts: HashMap::new(),
+            watched_regions: HashMap::new(),
+            eye_contents: [vec![0u8; 384 * 224 * 2], vec![0u8; 384 * 224 * 2]],
+            audio_samples: Vec::with_capacity(EXPECTED_FRAME_SIZE),
+            buffer: vec![],
+        }
+    }
+
+    pub fn reload_cart(&mut self, sim_id: SimId) -> Result<()> {
+        let Some(cart) = &self.carts[sim_id.to_index()] else {
+            return Ok(());
+        };
+        let path = cart.file_path.clone();
+        self.load_cart(sim_id, &path)
+    }
+
+    pub fn load_cart(&mut self, sim_id: SimId, path: &Path) -> Result<()> {
+        let watch = self.watch_rom[sim_id.to_index()].load(Ordering::Acquire);
+        let cart = Cart::load(path, sim_id, watch)?;
+        self.try_reset_sim(sim_id, Some(cart))?;
+        Ok(())
+    }
+
+    pub fn start_second_sim(&mut self, rom: Option<PathBuf>) -> Result<()> {
+        let file_path = if let Some(path) = rom {
+            Some(path)
+        } else {
+            self.carts[0].as_ref().map(|c| c.file_path.clone())
+        };
+        let watch = self.watch_rom[SimId::Player2.to_index()].load(Ordering::Acquire);
+        let cart = match file_path {
+            Some(rom_path) => Some(Cart::load(&rom_path, SimId::Player2, watch)?),
+            None => None,
+        };
+        self.try_reset_sim(SimId::Player2, cart)?;
+        self.link_sims();
+        Ok(())
+    }
+
+    fn reset_sim(&mut self, sim_id: SimId, new_cart: Option<Cart>) -> bool {
+        if let Err(error) = self.try_reset_sim(sim_id, new_cart) {
+            self.report_error(sim_id, format!("Error resetting sim: {error}"));
+            false
+        } else {
+            true
+        }
+    }
+
+    fn try_reset_sim(&mut self, sim_id: SimId, new_cart: Option<Cart>) -> Result<()> {
+        self.save_sram(sim_id)?;
+
+        let index = sim_id.to_index();
+        while self.sims.len() <= index {
+            let new_index = self.sims.len();
+            self.sims.push(Sim::new());
+            if self
+                .stdouts
+                .contains_key(&SimId::from_index(new_index).unwrap())
+            {
+                self.sims[new_index].watch_stdout(true);
+            }
+            self.sim_state[new_index].store(SimState::NoGame, Ordering::Release);
+        }
+        let sim = &mut self.sims[index];
+        sim.reset();
+        if let Some(cart) = new_cart {
+            sim.load_cart(cart.rom.clone(), cart.sram.clone())?;
+            self.carts[index] = Some(cart);
+            self.sim_state[index].store(SimState::Ready, Ordering::Release);
+        } else if let Some(cart) = self.carts[index].as_mut()
+            && cart.is_watching()
+        {
+            cart.reload()?;
+            sim.load_cart(cart.rom.clone(), cart.sram.clone())?;
+        }
+        let mut profiling = false;
+        if let Some(profiler) = self.profilers[sim_id.to_index()].as_ref()
+            && let Some(cart) = self.carts[index].as_ref()
+            && profiler
+                .send(ProfileEvent::Start {
+                    info: cart.info.clone(),
+                })
+                .is_ok()
+        {
+            sim.monitor_events(true, cart.info.inline_stack_map().clone());
+            profiling = true;
+        }
+        if !profiling {
+            sim.monitor_events(false, InlineStackMap::empty());
+        }
+
+        if self.sim_state[index].load(Ordering::Acquire) == SimState::Ready {
+            self.resume_sims();
+        }
+        Ok(())
+    }
+
+    fn link_sims(&mut self) {
+        let (first, second) = self.sims.split_at_mut(1);
+        let Some(first) = first.first_mut() else {
+            return;
+        };
+        let Some(second) = second.first_mut() else {
+            return;
+        };
+        first.link(second);
+        self.linked.store(true, Ordering::Release);
+    }
+
+    fn unlink_sims(&mut self) {
+        let Some(first) = self.sims.first_mut() else {
+            return;
+        };
+        first.unlink();
+        self.linked.store(false, Ordering::Release);
+    }
+
+    fn pause_sims(&mut self) -> Result<()> {
+        if self
+            .state
+            .compare_exchange(
+                EmulatorState::Running,
+                EmulatorState::Paused,
+                Ordering::AcqRel,
+                Ordering::Relaxed,
+            )
+            .is_ok()
+        {
+            for sim_id in SimId::values() {
+                self.save_sram(sim_id)?;
+            }
+        }
+        Ok(())
+    }
+
+    fn resume_sims(&mut self) {
+        let _ = self.state.compare_exchange(
+            EmulatorState::Paused,
+            EmulatorState::Running,
+            Ordering::AcqRel,
+            Ordering::Relaxed,
+        );
+    }
+
+    fn frame_advance(&mut self) {
+        if self
+            .state
+            .compare_exchange(
+                EmulatorState::Paused,
+                EmulatorState::Stepping,
+                Ordering::AcqRel,
+                Ordering::Acquire,
+            )
+            .is_err_and(|s| s == EmulatorState::Running)
+        {
+            let _ = self.state.compare_exchange(
+                EmulatorState::Running,
+                EmulatorState::Stepping,
+                Ordering::AcqRel,
+                Ordering::Relaxed,
+            );
+        }
+    }
+
+    fn set_speed(&mut self, speed: f64) -> Result<()> {
+        self.audio.set_speed(speed)
+    }
+
+    fn save_sram(&mut self, sim_id: SimId) -> Result<()> {
+        let sim = self.sims.get_mut(sim_id.to_index());
+        let cart = self.carts[sim_id.to_index()].as_mut();
+        if let (Some(sim), Some(cart)) = (sim, cart) {
+            sim.read_sram(&mut cart.sram);
+            cart.save_sram()?;
+        }
+        Ok(())
+    }
+
+    pub fn stop_second_sim(&mut self) -> Result<()> {
+        self.save_sram(SimId::Player2)?;
+        self.renderers.remove(&SimId::Player2);
+        self.sims.truncate(1);
+        self.sim_state[SimId::Player2.to_index()].store(SimState::Uninitialized, Ordering::Release);
+        self.stop_debugging(SimId::Player2);
+        self.linked.store(false, Ordering::Release);
+        Ok(())
+    }
+
+    fn start_profiling(&mut self, sim_id: SimId, sender: ProfileSender) -> Result<()> {
+        self.profilers[sim_id.to_index()] = Some(sender);
+        self.try_reset_sim(sim_id, None)
+    }
+
+    fn start_debugging(&mut self, sim_id: SimId, sender: DebugSender) {
+        if self.sim_state[sim_id.to_index()].load(Ordering::Acquire) != SimState::Ready {
+            // Can't debug unless a game is connected
+            return;
+        }
+        let debug = DebugInfo {
+            sender,
+            stop_reason: Some(DebugStopReason::Paused),
+        };
+        self.debuggers.insert(sim_id, debug);
+        self.state
+            .store(EmulatorState::Debugging, Ordering::Release);
+    }
+
+    fn stop_debugging(&mut self, sim_id: SimId) {
+        if let Some(sim) = self.sims.get_mut(sim_id.to_index()) {
+            sim.clear_debug_state();
+        }
+        self.debuggers.remove(&sim_id);
+        if self.debuggers.is_empty() {
+            let _ = self.state.compare_exchange(
+                EmulatorState::Debugging,
+                EmulatorState::Running,
+                Ordering::AcqRel,
+                Ordering::Relaxed,
+            );
+        }
+    }
+
+    fn debug_interrupt(&mut self, sim_id: SimId) {
+        self.debug_stop(sim_id, DebugStopReason::Paused);
+    }
+
+    fn debug_stop(&mut self, sim_id: SimId, reason: DebugStopReason) {
+        let Some(debugger) = self.debuggers.get_mut(&sim_id) else {
+            self.stop_debugging(sim_id);
+            return;
+        };
+        if debugger.stop_reason != Some(reason) {
+            debugger.stop_reason = Some(reason);
+            if debugger.sender.send(DebugEvent::Stopped(reason)).is_err() {
+                self.stop_debugging(sim_id);
+            }
+        }
+    }
+
+    fn debug_continue(&mut self, sim_id: SimId) -> bool {
+        let Some(debugger) = self.debuggers.get_mut(&sim_id) else {
+            self.stop_debugging(sim_id);
+            return false;
+        };
+        debugger.stop_reason = None;
+        true
+    }
+
+    fn debug_step(&mut self, sim_id: SimId) {
+        if self.debug_continue(sim_id) {
+            let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
+                return;
+            };
+            sim.step();
+        }
+    }
+
+    fn watch_memory(&mut self, range: MemoryRange, region: Weak<MemoryRegion>) {
+        self.watched_regions.insert(range, region);
+    }
+
+    pub fn run(&mut self) {
+        loop {
+            let idle = self.tick();
+            if idle {
+                // The game is paused, and we have output all the video/audio we have.
+                // Block the thread until a new command comes in, or a ROM changes.
+                loop {
+                    match self.commands.recv_timeout(Duration::from_millis(250)) {
+                        Ok(command) => {
+                            self.handle_command(command);
+                            break;
+                        }
+                        Err(RecvTimeoutError::Timeout) => {
+                            let mut changed = false;
+                            for sim_id in SimId::values() {
+                                let Some(cart) = self.carts[sim_id.to_index()].as_ref() else {
+                                    continue;
+                                };
+                                if cart.changed() {
+                                    changed |= self.reset_sim(sim_id, None);
+                                }
+                            }
+                            if changed {
+                                break;
+                            }
+                        }
+                        Err(RecvTimeoutError::Disconnected) => {
+                            return;
+                        }
+                    }
+                }
+            }
+            loop {
+                match self.commands.try_recv() {
+                    Ok(command) => self.handle_command(command),
+                    Err(TryRecvError::Empty) => {
+                        break;
+                    }
+                    Err(TryRecvError::Disconnected) => {
+                        return;
+                    }
+                }
+            }
+            for sim_id in SimId::values() {
+                let Some(cart) = self.carts[sim_id.to_index()].as_ref() else {
+                    continue;
+                };
+                if cart.changed() {
+                    self.reset_sim(sim_id, None);
+                }
+            }
+            self.watched_regions.retain(|range, region| {
+                let Some(region) = region.upgrade() else {
+                    return false;
+                };
+                let Some(sim) = self.sims.get_mut(range.sim.to_index()) else {
+                    return false;
+                };
+                self.buffer.clear();
+                sim.read_memory(range.start, range.length, &mut self.buffer);
+                region.update(&self.buffer);
+                true
+            });
+        }
+    }
+
+    // returns true if the emulator is "idle" (i.e. this didn't output anything)
+    pub fn tick(&mut self) -> bool {
+        let p1_state = self.sim_state[SimId::Player1.to_index()].load(Ordering::Acquire);
+        let p2_state = self.sim_state[SimId::Player2.to_index()].load(Ordering::Acquire);
+        let state = self.state.load(Ordering::Acquire);
+
+        // Emulation
+        // Don't emulate if the state is "paused", or if any sim is paused in the debugger
+        let running = match state {
+            EmulatorState::Paused => false,
+            EmulatorState::Running | EmulatorState::Stepping => true,
+            EmulatorState::Debugging => self.debuggers.values().all(|d| d.stop_reason.is_none()),
+        };
+        let p1_running = running && p1_state == SimState::Ready;
+        let p2_running = running && p2_state == SimState::Ready;
+        let mut idle = !p1_running && !p2_running;
+
+        let cycles = self.emulate(p1_running, p2_running);
+
+        // if we're profiling, track events
+        for ((sim, profiler), running) in self
+            .sims
+            .iter_mut()
+            .zip(self.profilers.iter_mut())
+            .zip([p1_running, p2_running])
+        {
+            if !running {
+                continue;
+            }
+            if let Some(p) = profiler {
+                let (event, inline_stack) = sim.take_profiler_updates();
+                if p.send(ProfileEvent::Update {
+                    cycles,
+                    event,
+                    inline_stack,
+                })
+                .is_err()
+                {
+                    sim.monitor_events(false, InlineStackMap::empty());
+                    *profiler = None;
+                }
+            }
+        }
+
+        if state == EmulatorState::Stepping {
+            self.state.store(EmulatorState::Paused, Ordering::Release);
+        }
+
+        // stdout
+        self.stdouts.retain(|sim_id, stdout| {
+            let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
+                return true;
+            };
+            if let Some(text) = sim.take_stdout()
+                && stdout.send(text).is_err()
+            {
+                sim.watch_stdout(false);
+                return false;
+            }
+            true
+        });
+
+        // Debug state
+        if state == EmulatorState::Debugging {
+            for sim_id in SimId::values() {
+                let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
+                    continue;
+                };
+                if let Some(reason) = sim.take_stop_reason() {
+                    let stop_reason = match reason {
+                        StopReason::Stepped => DebugStopReason::Trace,
+                        StopReason::Watchpoint(watch, address) => {
+                            DebugStopReason::Watchpoint(watch, address)
+                        }
+                        StopReason::Breakpoint => DebugStopReason::Breakpoint,
+                    };
+                    self.debug_stop(sim_id, stop_reason);
+                }
+            }
+        }
+
+        // Video
+        for sim_id in SimId::values() {
+            let Some(renderer) = self.renderers.get_mut(&sim_id) else {
+                continue;
+            };
+            let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
+                continue;
+            };
+            if sim.read_pixels(&mut self.eye_contents[sim_id.to_index()]) {
+                idle = false;
+                if renderer
+                    .queue_render(&self.eye_contents[sim_id.to_index()])
+                    .is_err()
+                {
+                    self.renderers.remove(&sim_id);
+                }
+            }
+        }
+
+        // Audio
+        // Audio playback speed is how we keep the emulator running in real time.
+        // Even if we're muted, call `read_samples` to know how many frames of silence to play.
+        let p1_audio =
+            p1_running && self.audio_on[SimId::Player1.to_index()].load(Ordering::Acquire);
+        let p2_audio =
+            p2_running && self.audio_on[SimId::Player2.to_index()].load(Ordering::Acquire);
+        let (p1_weight, p2_weight) = match (p1_audio, p2_audio) {
+            (true, true) => (0.5, 0.5),
+            (true, false) => (1.0, 0.0),
+            (false, true) => (0.0, 1.0),
+            (false, false) => (0.0, 0.0),
+        };
+        if let Some(sim) = self.sims.get_mut(SimId::Player1.to_index()) {
+            sim.read_samples(&mut self.audio_samples, p1_weight);
+        }
+        if let Some(sim) = self.sims.get_mut(SimId::Player2.to_index()) {
+            sim.read_samples(&mut self.audio_samples, p2_weight);
+        }
+        if !self.audio_samples.is_empty() {
+            idle = false;
+        }
+        self.audio.update(&self.audio_samples);
+        self.audio_samples.clear();
+        idle
+    }
+
+    fn emulate(&mut self, p1_running: bool, p2_running: bool) -> u32 {
+        const MAX_CYCLES: u32 = 20_000_000;
+        let mut cycles = MAX_CYCLES;
+        if p1_running && p2_running {
+            Sim::emulate_many(&mut self.sims, &mut cycles);
+        } else if p1_running {
+            self.sims[SimId::Player1.to_index()].emulate(&mut cycles);
+        } else if p2_running {
+            self.sims[SimId::Player2.to_index()].emulate(&mut cycles);
+        }
+        MAX_CYCLES - cycles
+    }
+
+    fn handle_command(&mut self, command: EmulatorCommand) {
+        match command {
+            EmulatorCommand::ConnectToSim(sim_id, renderer, messages) => {
+                self.renderers.insert(sim_id, renderer);
+                self.messages.insert(sim_id, messages);
+            }
+            EmulatorCommand::LoadGame(sim_id, path) => {
+                if let Err(error) = self.load_cart(sim_id, &path) {
+                    self.report_error(sim_id, format!("Error loading rom: {error}"));
+                }
+            }
+            EmulatorCommand::ReloadRom(sim_id) => {
+                if let Err(error) = self.reload_cart(sim_id) {
+                    self.report_error(sim_id, format!("Error loading rom: {error}"));
+                }
+            }
+            EmulatorCommand::WatchRom(sim_id, watch) => {
+                self.watch_rom[sim_id.to_index()].store(watch, Ordering::Release);
+                let Some(cart) = self.carts[sim_id.to_index()].as_mut() else {
+                    return;
+                };
+                if watch {
+                    cart.restart_watching();
+                } else {
+                    cart.stop_watching();
+                }
+            }
+            EmulatorCommand::StartSecondSim(path) => {
+                if let Err(error) = self.start_second_sim(path) {
+                    self.report_error(
+                        SimId::Player2,
+                        format!("Error starting second sim: {error}"),
+                    );
+                }
+            }
+            EmulatorCommand::StopSecondSim => {
+                if let Err(error) = self.stop_second_sim() {
+                    self.report_error(
+                        SimId::Player2,
+                        format!("Error stopping second sim: {error}"),
+                    );
+                }
+            }
+            EmulatorCommand::Pause => {
+                if let Err(error) = self.pause_sims() {
+                    self.report_error(SimId::Player1, format!("Error pausing: {error}"));
+                }
+            }
+            EmulatorCommand::Resume => {
+                self.resume_sims();
+            }
+            EmulatorCommand::FrameAdvance => {
+                self.frame_advance();
+            }
+            EmulatorCommand::SetSpeed(speed) => {
+                if let Err(error) = self.set_speed(speed) {
+                    self.report_error(SimId::Player1, format!("Error setting speed: {error}"));
+                }
+            }
+            EmulatorCommand::StartProfiling(sim_id, profiler) => {
+                if let Err(error) = self.start_profiling(sim_id, profiler) {
+                    self.report_error(SimId::Player1, format!("Error enaling profiler: {error}"));
+                }
+            }
+            EmulatorCommand::StartDebugging(sim_id, debugger) => {
+                self.start_debugging(sim_id, debugger);
+            }
+            EmulatorCommand::StopDebugging(sim_id) => {
+                self.stop_debugging(sim_id);
+            }
+            EmulatorCommand::DebugInterrupt(sim_id) => {
+                self.debug_interrupt(sim_id);
+            }
+            EmulatorCommand::DebugContinue(sim_id) => {
+                self.debug_continue(sim_id);
+            }
+            EmulatorCommand::DebugStep(sim_id) => {
+                self.debug_step(sim_id);
+            }
+            EmulatorCommand::ReadRegister(sim_id, register, done) => {
+                let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
+                    return;
+                };
+                let value = sim.read_register(register);
+                let _ = done.send(value);
+            }
+            EmulatorCommand::WriteRegister(sim_id, register, value) => {
+                let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
+                    return;
+                };
+                sim.write_register(register, value);
+            }
+            EmulatorCommand::ReadMemory(sim_id, start, length, mut buffer, done) => {
+                let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
+                    return;
+                };
+                sim.read_memory(start, length, &mut buffer);
+                let _ = done.send(buffer);
+            }
+            EmulatorCommand::WriteMemory(sim_id, start, buffer, done) => {
+                let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
+                    return;
+                };
+                sim.write_memory(start, &buffer);
+                let _ = done.send(buffer);
+            }
+            EmulatorCommand::WatchMemory(range, region) => {
+                self.watch_memory(range, region);
+            }
+            EmulatorCommand::AddBreakpoint(sim_id, address) => {
+                let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
+                    return;
+                };
+                sim.add_breakpoint(address);
+            }
+            EmulatorCommand::RemoveBreakpoint(sim_id, address) => {
+                let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
+                    return;
+                };
+                sim.remove_breakpoint(address);
+            }
+            EmulatorCommand::AddWatchpoint(sim_id, address, length, watch) => {
+                let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
+                    return;
+                };
+                sim.add_watchpoint(address, length, watch);
+            }
+            EmulatorCommand::RemoveWatchpoint(sim_id, address, length, watch) => {
+                let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
+                    return;
+                };
+                sim.remove_watchpoint(address, length, watch);
+            }
+            EmulatorCommand::WatchStdout(sim_id, stdout_sink) => {
+                self.stdouts.insert(sim_id, stdout_sink);
+                let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
+                    return;
+                };
+                sim.watch_stdout(true);
+            }
+            EmulatorCommand::SetAudioEnabled(sim_id, enabled) => {
+                self.audio_on[sim_id.to_index()].store(enabled, Ordering::Release);
+            }
+            EmulatorCommand::Link => {
+                self.link_sims();
+            }
+            EmulatorCommand::Unlink => {
+                self.unlink_sims();
+            }
+            EmulatorCommand::Reset(sim_id) => {
+                self.reset_sim(sim_id, None);
+            }
+            EmulatorCommand::SetKeys(sim_id, keys) => {
+                if let Some(sim) = self.sims.get_mut(sim_id.to_index()) {
+                    sim.set_keys(keys);
+                }
+            }
+            EmulatorCommand::Screenshot(sim_id, sender) => {
+                let contents = self.eye_contents[sim_id.to_index()].clone();
+                let _ = sender.send(contents);
+            }
+            EmulatorCommand::Exit(done) => {
+                for sim_id in SimId::values() {
+                    if let Err(error) = self.save_sram(sim_id) {
+                        self.report_error(sim_id, format!("Error saving sram on exit: {error}"));
+                    }
+                }
+                let _ = done.send(());
+            }
+        }
+    }
+
+    fn report_error(&self, sim_id: SimId, message: String) {
+        let messages = self
+            .messages
+            .get(&sim_id)
+            .or_else(|| self.messages.get(&SimId::Player1));
+        if let Some(msg) = messages {
+            let mut toast = Toast::error(&message);
+            toast.duration(Some(Duration::from_secs(5)));
+            if msg.send(toast).is_ok() {
+                return;
+            }
+        }
+        error!("{}", message);
+    }
+}
+
+#[derive(Debug)]
+pub enum EmulatorCommand {
+    ConnectToSim(SimId, TextureSink, mpsc::Sender<Toast>),
+    LoadGame(SimId, PathBuf),
+    ReloadRom(SimId),
+    WatchRom(SimId, bool),
+    StartSecondSim(Option<PathBuf>),
+    StopSecondSim,
+    Pause,
+    Resume,
+    FrameAdvance,
+    SetSpeed(f64),
+    StartProfiling(SimId, ProfileSender),
+    StartDebugging(SimId, DebugSender),
+    StopDebugging(SimId),
+    DebugInterrupt(SimId),
+    DebugContinue(SimId),
+    DebugStep(SimId),
+    ReadRegister(SimId, VBRegister, oneshot::Sender<u32>),
+    WriteRegister(SimId, VBRegister, u32),
+    ReadMemory(SimId, u32, usize, Vec<u8>, oneshot::Sender<Vec<u8>>),
+    WriteMemory(SimId, u32, Vec<u8>, oneshot::Sender<Vec<u8>>),
+    WatchMemory(MemoryRange, Weak<MemoryRegion>),
+    AddBreakpoint(SimId, u32),
+    RemoveBreakpoint(SimId, u32),
+    AddWatchpoint(SimId, u32, usize, VBWatchpointType),
+    RemoveWatchpoint(SimId, u32, usize, VBWatchpointType),
+    WatchStdout(SimId, mpsc::Sender<String>),
+    SetAudioEnabled(SimId, bool),
+    Link,
+    Unlink,
+    Reset(SimId),
+    SetKeys(SimId, VBKey),
+    Screenshot(SimId, oneshot::Sender<Vec<u8>>),
+    Exit(oneshot::Sender<()>),
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, NoUninit)]
+#[repr(usize)]
+pub enum SimState {
+    Uninitialized,
+    NoGame,
+    Ready,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, NoUninit)]
+#[repr(usize)]
+pub enum EmulatorState {
+    Paused,
+    Running,
+    Stepping,
+    Debugging,
+}
+
+type ProfileSender = tokio::sync::mpsc::UnboundedSender<ProfileEvent>;
+type DebugSender = tokio::sync::mpsc::UnboundedSender<DebugEvent>;
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum DebugStopReason {
+    // We are stepping
+    Trace,
+    // We hit a breakpoint
+    Breakpoint,
+    // We hit a watchpoint
+    Watchpoint(VBWatchpointType, u32),
+    // The debugger told us to pause
+    Paused,
+}
+
+struct DebugInfo {
+    sender: DebugSender,
+    stop_reason: Option<DebugStopReason>,
+}
+
+pub enum DebugEvent {
+    Stopped(DebugStopReason),
+}
+
+pub enum ProfileEvent {
+    Start {
+        info: Arc<GameInfo>,
+    },
+    Update {
+        cycles: u32,
+        event: Option<SimEvent>,
+        inline_stack: Option<InlineStack>,
+    },
+}
+
+#[derive(Clone)]
+pub struct EmulatorClient {
+    queue: mpsc::Sender<EmulatorCommand>,
+    sim_state: Arc<[Atomic<SimState>; 2]>,
+    state: Arc<Atomic<EmulatorState>>,
+    linked: Arc<AtomicBool>,
+    watch_rom: Arc<[AtomicBool; 2]>,
+}
+
+impl EmulatorClient {
+    pub fn has_player_2(&self) -> bool {
+        self.sim_state(SimId::Player2) != SimState::Uninitialized
+    }
+    pub fn sim_state(&self, sim_id: SimId) -> SimState {
+        self.sim_state[sim_id.to_index()].load(Ordering::Acquire)
+    }
+    pub fn emulator_state(&self) -> EmulatorState {
+        self.state.load(Ordering::Acquire)
+    }
+    pub fn are_sims_linked(&self) -> bool {
+        self.linked.load(Ordering::Acquire)
+    }
+    pub fn is_rom_watched(&self, sim_id: SimId) -> bool {
+        self.watch_rom[sim_id.to_index()].load(Ordering::Acquire)
+    }
+    pub fn send_command(&self, command: EmulatorCommand) -> bool {
+        match self.queue.send(command) {
+            Ok(()) => true,
+            Err(err) => {
+                warn!(
+                    "could not send command {:?} as emulator is shut down",
+                    err.0
+                );
+                false
+            }
+        }
+    }
+}

src/emulator/address_set.rs

@@ -0,0 +1,270 @@
+use std::{
+    collections::{BTreeMap, BTreeSet},
+    ops::Bound,
+};
+
+#[derive(Debug, Default)]
+pub struct AddressSet {
+    ranges: BTreeSet<(u32, usize)>,
+    bounds: BTreeMap<u32, usize>,
+}
+
+impl AddressSet {
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    pub fn add(&mut self, address: u32, length: usize) {
+        if length == 0 || !self.ranges.insert((address, length)) {
+            return;
+        }
+        let end = (address as usize)
+            .checked_add(length)
+            .and_then(|e| u32::try_from(e).ok());
+
+        if let Some(end) = end {
+            let val_before = self.bounds.range(..=end).next_back().map_or(0, |(_, &v)| v);
+            self.bounds.insert(end, val_before);
+        }
+
+        let val_before = self
+            .bounds
+            .range(..address)
+            .next_back()
+            .map_or(0, |(_, &v)| v);
+        if let Some(&val_at) = self.bounds.get(&address) {
+            if val_before == val_at + 1 {
+                self.bounds.remove(&address);
+            }
+        } else {
+            self.bounds.insert(address, val_before);
+        }
+
+        let start_bound = Bound::Included(address);
+        let end_bound = match end {
+            Some(e) => Bound::Excluded(e),
+            None => Bound::Unbounded,
+        };
+
+        for (_, val) in self.bounds.range_mut((start_bound, end_bound)) {
+            *val += 1;
+        }
+    }
+
+    pub fn remove(&mut self, address: u32, length: usize) {
+        if !self.ranges.remove(&(address, length)) {
+            return;
+        }
+        let end = (address as usize)
+            .checked_add(length)
+            .and_then(|e| u32::try_from(e).ok());
+
+        if let Some(end) = end {
+            let val_before = self.bounds.range(..end).next_back().map_or(0, |(_, &v)| v);
+            if let Some(&val_at) = self.bounds.get(&end) {
+                if val_at + 1 == val_before {
+                    self.bounds.remove(&end);
+                }
+            } else {
+                self.bounds.insert(end, val_before);
+            }
+        }
+
+        let val_before = self
+            .bounds
+            .range(..address)
+            .next_back()
+            .map_or(0, |(_, &v)| v);
+        if let Some(&val_at) = self.bounds.get(&address) {
+            if val_before + 1 == val_at {
+                self.bounds.remove(&address);
+            }
+        } else {
+            self.bounds.insert(address, val_before);
+        }
+
+        let start_bound = Bound::Included(address);
+        let end_bound = match end {
+            Some(e) => Bound::Excluded(e),
+            None => Bound::Unbounded,
+        };
+
+        for (_, val) in self.bounds.range_mut((start_bound, end_bound)) {
+            *val -= 1;
+        }
+    }
+
+    pub fn clear(&mut self) {
+        self.ranges.clear();
+        self.bounds.clear();
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.bounds.is_empty()
+    }
+
+    pub fn contains(&self, address: u32) -> bool {
+        self.bounds
+            .range(..=address)
+            .next_back()
+            .is_some_and(|(_, &val)| val > 0)
+    }
+
+    pub fn start_of_range_containing(&self, address: u32) -> Option<u32> {
+        if !self.contains(address) {
+            return None;
+        }
+        self.ranges
+            .range(..=(address, usize::MAX))
+            .rev()
+            .find_map(|&(start, length)| {
+                let contains = start <= address
+                    && (start as usize)
+                        .checked_add(length)
+                        .is_none_or(|end| end > address as usize);
+                contains.then_some(start)
+            })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::AddressSet;
+
+    #[test]
+    fn should_not_include_addresses_when_empty() {
+        let set = AddressSet::new();
+        assert!(set.is_empty());
+        assert!(!set.contains(0x13374200));
+        assert_eq!(set.start_of_range_containing(0x13374200), None);
+    }
+
+    #[test]
+    fn should_include_addresses_when_full() {
+        let mut set = AddressSet::new();
+        set.add(0x00000000, 0x100000000);
+        assert!(set.contains(0x13374200));
+        assert_eq!(set.start_of_range_containing(0x13374200), Some(0x00000000));
+    }
+
+    #[test]
+    fn should_ignore_empty_address_ranges() {
+        let mut set = AddressSet::new();
+        set.add(0x13374200, 0);
+        assert!(set.is_empty());
+        assert!(!set.contains(0x13374200));
+    }
+
+    #[test]
+    fn should_add_addresses_idempotently() {
+        let mut set = AddressSet::new();
+        set.add(0x13374200, 1);
+        set.add(0x13374200, 1);
+        set.remove(0x13374200, 1);
+        assert!(set.is_empty());
+        assert!(!set.contains(0x13374200));
+    }
+
+    #[test]
+    fn should_remove_addresses_idempotently() {
+        let mut set = AddressSet::new();
+        set.add(0x13374200, 1);
+        set.remove(0x13374200, 1);
+        set.remove(0x13374200, 1);
+        assert!(set.is_empty());
+        assert!(!set.contains(0x13374200));
+    }
+
+    #[test]
+    fn should_report_address_in_range() {
+        let mut set = AddressSet::new();
+        set.add(0x13374200, 4);
+        assert!(!set.contains(0x133741ff));
+        for address in 0x13374200..0x13374204 {
+            assert!(set.contains(address));
+        }
+        assert!(!set.contains(0x13374204));
+    }
+
+    #[test]
+    fn should_allow_overlapping_addresses() {
+        let mut set = AddressSet::new();
+        set.add(0x13374200, 4);
+        set.add(0x13374201, 1);
+        set.add(0x13374202, 2);
+
+        assert!(!set.contains(0x133741ff));
+        for address in 0x13374200..0x13374204 {
+            assert!(set.contains(address));
+        }
+        assert!(!set.contains(0x13374204));
+
+        set.remove(0x13374200, 4);
+        assert!(!set.contains(0x13374200));
+        for address in 0x13374201..0x13374204 {
+            assert!(set.contains(address));
+        }
+        assert!(!set.contains(0x13374204));
+    }
+
+    #[test]
+    fn should_allow_removing_overlapped_address_ranges() {
+        let mut set = AddressSet::new();
+        set.add(0x13374200, 8);
+        set.add(0x13374204, 8);
+        set.remove(0x13374204, 8);
+
+        for address in 0x13374200..0x13374208 {
+            assert!(set.contains(address));
+        }
+        for address in 0x13374208..0x1337420c {
+            assert!(!set.contains(address));
+        }
+    }
+
+    #[test]
+    fn should_merge_adjacent_ranges() {
+        let mut set = AddressSet::new();
+        set.add(0x13374200, 4);
+        set.add(0x13374204, 4);
+        set.add(0x13374208, 4);
+        set.add(0x1337420c, 4);
+
+        assert!(!set.contains(0x133741ff));
+        for address in 0x13374200..0x13374210 {
+            assert!(set.contains(address));
+        }
+        assert!(!set.contains(0x13374210));
+
+        set.remove(0x13374200, 4);
+        set.remove(0x13374204, 4);
+        set.remove(0x13374208, 4);
+        set.remove(0x1337420c, 4);
+
+        assert!(set.is_empty());
+        for address in 0x133741ff..=0x13374210 {
+            assert!(!set.contains(address));
+        }
+    }
+
+    #[test]
+    fn should_find_start_of_range() {
+        let mut set = AddressSet::new();
+        set.add(0x13374200, 4);
+        assert_eq!(set.start_of_range_containing(0x133741ff), None);
+        for address in 0x13374200..0x13374204 {
+            assert_eq!(set.start_of_range_containing(address), Some(0x13374200));
+        }
+        assert_eq!(set.start_of_range_containing(0x13374204), None);
+    }
+
+    #[test]
+    fn should_ignore_ranges_not_containing_address() {
+        let mut set = AddressSet::new();
+        set.add(0x10000000, 1024);
+        set.add(0x30000000, 1024);
+
+        assert!(!set.contains(0x20000000));
+        assert_eq!(set.start_of_range_containing(0x20000000), None);
+    }
+}

src/emulator/cart.rs

@@ -0,0 +1,185 @@
+use anyhow::Result;
+use notify::Watcher;
+use rand::RngExt;
+use std::{
+    fs::{self, File},
+    io::{Read, Seek as _, SeekFrom, Write as _},
+    path::{Path, PathBuf},
+    sync::{Arc, atomic::AtomicBool},
+};
+
+use crate::emulator::{SimId, game_info::GameInfo, shrooms_vb_util::rom_from_isx};
+
+pub struct Cart {
+    pub file_path: PathBuf,
+    pub rom: Vec<u8>,
+    sram_file: File,
+    pub sram: Vec<u8>,
+    pub info: Arc<GameInfo>,
+    watcher: Option<notify::RecommendedWatcher>,
+    changed: Arc<AtomicBool>,
+}
+
+impl Cart {
+    pub fn load(file_path: &Path, sim_id: SimId, watch: bool) -> Result<Self> {
+        let (rom, info) = Self::read_rom(file_path)?;
+
+        let mut sram_file = File::options()
+            .read(true)
+            .write(true)
+            .create(true)
+            .truncate(false)
+            .open(sram_path(file_path, sim_id))?;
+
+        let sram = if sram_file.metadata()?.len() == 0 {
+            // new SRAM file, randomize the contents
+            let mut sram = vec![0; 16 * 1024];
+            let mut rng = rand::rng();
+            for dst in sram.iter_mut().step_by(2) {
+                *dst = rng.random();
+            }
+            sram
+        } else {
+            let mut sram = Vec::with_capacity(16 * 1024);
+            sram_file.read_to_end(&mut sram)?;
+            sram
+        };
+
+        let changed = Arc::new(AtomicBool::new(false));
+        let watcher = if watch {
+            build_watcher(file_path, changed.clone())
+        } else {
+            None
+        };
+
+        Ok(Cart {
+            file_path: file_path.to_path_buf(),
+            rom,
+            sram_file,
+            sram,
+            info: Arc::new(info),
+            watcher,
+            changed,
+        })
+    }
+
+    pub fn reload(&mut self) -> Result<()> {
+        let (rom, info) = Self::read_rom(&self.file_path)?;
+        self.rom = rom;
+        self.info = Arc::new(info);
+        if self.is_watching() {
+            self.restart_watching();
+        }
+        Ok(())
+    }
+
+    pub fn save_sram(&mut self) -> Result<()> {
+        self.sram_file.seek(SeekFrom::Start(0))?;
+        self.sram_file.write_all(&self.sram)?;
+        Ok(())
+    }
+
+    pub fn changed(&self) -> bool {
+        self.changed.load(std::sync::atomic::Ordering::Relaxed)
+    }
+
+    pub fn is_watching(&self) -> bool {
+        self.watcher.is_some()
+    }
+
+    pub fn restart_watching(&mut self) {
+        self.changed = Arc::new(AtomicBool::new(false));
+        if let Some(mut watcher) = self.watcher.take() {
+            let _ = watcher.unwatch(&self.file_path);
+        };
+        self.watcher = build_watcher(&self.file_path, self.changed.clone());
+    }
+
+    pub fn stop_watching(&mut self) {
+        self.changed = Arc::new(AtomicBool::new(false));
+        self.watcher = None;
+    }
+
+    fn read_rom(file_path: &Path) -> Result<(Vec<u8>, GameInfo)> {
+        let rom = fs::read(file_path)?;
+        let (rom, info) = try_parse_isx(file_path, &rom)
+            .or_else(|| try_parse_elf(file_path, &rom))
+            .unwrap_or_else(|| (rom, GameInfo::empty(file_path)));
+        Ok((rom, info))
+    }
+}
+
+fn build_watcher(file_path: &Path, changed: Arc<AtomicBool>) -> Option<notify::RecommendedWatcher> {
+    let file_path = file_path.to_path_buf();
+    let mut watcher =
+        notify::recommended_watcher(move |event: Result<notify::Event, notify::Error>| {
+            let Ok(e) = event else {
+                return;
+            };
+            let modified = !matches!(
+                e.kind,
+                notify::EventKind::Access(_)
+                    | notify::EventKind::Modify(notify::event::ModifyKind::Metadata(_))
+            );
+            if modified {
+                changed.store(true, std::sync::atomic::Ordering::Relaxed);
+            }
+        })
+        .ok()?;
+    watcher
+        .watch(&file_path, notify::RecursiveMode::NonRecursive)
+        .ok()?;
+    Some(watcher)
+}
+
+fn try_parse_isx(file_path: &Path, data: &[u8]) -> Option<(Vec<u8>, GameInfo)> {
+    let rom = rom_from_isx(data)?;
+    let info = GameInfo::from_isx(file_path, data);
+    Some((rom, info))
+}
+
+fn try_parse_elf(file_path: &Path, data: &[u8]) -> Option<(Vec<u8>, GameInfo)> {
+    use object::read::elf::FileHeader;
+    let program = match object::FileKind::parse(data).ok()? {
+        object::FileKind::Elf32 => {
+            let header = object::elf::FileHeader32::parse(data).ok()?;
+            parse_elf_program(header, data)?
+        }
+        object::FileKind::Elf64 => {
+            let header = object::elf::FileHeader64::parse(data).ok()?;
+            parse_elf_program(header, data)?
+        }
+        _ => return None,
+    };
+    let info = GameInfo::from_elf(file_path, data).unwrap_or_else(|_| GameInfo::empty(file_path));
+    Some((program, info))
+}
+
+fn parse_elf_program<Elf: object::read::elf::FileHeader<Endian = object::Endianness>>(
+    header: &Elf,
+    data: &[u8],
+) -> Option<Vec<u8>> {
+    use object::read::elf::ProgramHeader;
+    let endian = header.endian().ok()?;
+    let mut bytes = vec![];
+    let mut pstart = None;
+    for phdr in header.program_headers(endian, data).ok()? {
+        let pma = phdr.p_paddr(endian).into();
+        if pma < 0x07000000 || phdr.p_filesz(endian).into() == 0 {
+            continue;
+        }
+        let start = pstart.unwrap_or(pma);
+        pstart = Some(start);
+        bytes.resize((pma - start) as usize, 0);
+        let data = phdr.data(endian, data).ok()?;
+        bytes.extend_from_slice(data);
+    }
+    Some(bytes)
+}
+
+fn sram_path(file_path: &Path, sim_id: SimId) -> PathBuf {
+    match sim_id {
+        SimId::Player1 => file_path.with_extension("p1.sram"),
+        SimId::Player2 => file_path.with_extension("p2.sram"),
+    }
+}

src/emulator/game_info.rs

@@ -0,0 +1,284 @@
+use std::{borrow::Cow, path::Path, sync::Arc};
+
+use anyhow::{Result, bail};
+use fxprof_processed_profile::{LibraryInfo, Symbol, SymbolTable, debugid::DebugId};
+use object::{Object, ObjectSection, ObjectSymbol};
+use wholesym::samply_symbols::{DebugIdExt, demangle_any};
+
+use crate::emulator::inline_stack_map::{InlineStackMap, InlineStackMapBuilder};
+
+#[derive(Debug)]
+pub struct GameInfo {
+    library_info: LibraryInfo,
+    inline_stack_map: InlineStackMap,
+}
+
+impl GameInfo {
+    pub fn from_elf(file_path: &Path, input: &[u8]) -> Result<Self> {
+        let file = object::File::parse(input)?;
+
+        let (name, path) = name_and_path(file_path);
+        let debug_id = file
+            .build_id()?
+            .map(|id| DebugId::from_identifier(id, true))
+            .unwrap_or_default();
+        let code_id = file.build_id()?.map(hex::encode);
+        let mut symbols = vec![];
+        for sym in file.symbols() {
+            symbols.push(Symbol {
+                address: sym.address() as u32,
+                size: Some(sym.size() as u32),
+                name: demangle_any(sym.name()?),
+            });
+        }
+
+        let inline_stack_map =
+            build_inline_stack_map(file).unwrap_or_else(|_| InlineStackMap::empty());
+
+        let library_info = LibraryInfo {
+            name: name.clone(),
+            debug_name: name,
+            path: path.clone(),
+            debug_path: path,
+            debug_id,
+            code_id,
+            arch: None,
+            symbol_table: Some(Arc::new(SymbolTable::new(symbols))),
+        };
+
+        Ok(Self {
+            library_info,
+            inline_stack_map,
+        })
+    }
+
+    pub fn from_isx(file_path: &Path, input: &[u8]) -> Self {
+        let (name, path) = name_and_path(file_path);
+        let symbols = extract_isx_symbols(input);
+        let library_info = LibraryInfo {
+            name: name.clone(),
+            debug_name: name,
+            path: path.clone(),
+            debug_path: path,
+            debug_id: DebugId::default(),
+            code_id: None,
+            arch: None,
+            symbol_table: symbols.map(|syms| Arc::new(SymbolTable::new(syms))),
+        };
+        let inline_stack_map = InlineStackMap::empty();
+        Self {
+            library_info,
+            inline_stack_map,
+        }
+    }
+
+    pub fn empty(file_path: &Path) -> Self {
+        let (name, path) = name_and_path(file_path);
+        let library_info = LibraryInfo {
+            name: name.clone(),
+            debug_name: name,
+            path: path.clone(),
+            debug_path: path,
+            debug_id: DebugId::default(),
+            code_id: None,
+            arch: None,
+            symbol_table: None,
+        };
+        let inline_stack_map = InlineStackMap::empty();
+        Self {
+            library_info,
+            inline_stack_map,
+        }
+    }
+
+    pub fn name(&self) -> &str {
+        &self.library_info.name
+    }
+
+    pub fn library_info(&self) -> &LibraryInfo {
+        &self.library_info
+    }
+
+    pub fn inline_stack_map(&self) -> &InlineStackMap {
+        &self.inline_stack_map
+    }
+}
+
+fn build_inline_stack_map(file: object::File) -> Result<InlineStackMap> {
+    let endian = if file.is_little_endian() {
+        gimli::RunTimeEndian::Little
+    } else {
+        gimli::RunTimeEndian::Big
+    };
+    fn load_section<'a>(file: &'a object::File, id: gimli::SectionId) -> Result<Cow<'a, [u8]>> {
+        let input = match file.section_by_name(id.name()) {
+            Some(section) => section.uncompressed_data()?,
+            None => Cow::Owned(vec![]),
+        };
+        Ok(input)
+    }
+    let dorf = gimli::DwarfSections::load(|id| load_section(&file, id))?;
+    let dorf = dorf.borrow(|sec| gimli::EndianSlice::new(sec, endian));
+    let mut units = dorf.units();
+    let mut frames = InlineStackMap::builder();
+    while let Some(header) = units.next()? {
+        let unit = dorf.unit(header)?;
+        let mut entree = unit.entries_tree(None)?;
+        let root = entree.root()?;
+        let mut ctx = ParseContext {
+            dorf: &dorf,
+            unit: &unit,
+            frames: &mut frames,
+        };
+        parse_inline(&mut ctx, root)?;
+    }
+    Ok(frames.build())
+}
+
+fn extract_isx_symbols(input: &[u8]) -> Option<Vec<Symbol>> {
+    let mut syms = vec![];
+    let (_, mut buf) = input.split_at_checked(32)?;
+    while !buf.is_empty() {
+        let typ;
+        (typ, buf) = buf.split_first()?;
+        match typ {
+            0x11 => {
+                // Code (Virtual Boy)
+                (_, buf) = buf.split_at_checked(4)?;
+                let len_bytes;
+                (len_bytes, buf) = buf.split_first_chunk()?;
+                let len = u32::from_le_bytes(*len_bytes);
+                (_, buf) = buf.split_at_checked(len as usize)?;
+            }
+            0x13 => {
+                // Range (Virtual Boy)
+                let count_bytes;
+                (count_bytes, buf) = buf.split_first_chunk()?;
+                let count = u16::from_le_bytes(*count_bytes);
+                (_, buf) = buf.split_at_checked(count as usize * 9)?;
+            }
+            0x14 => {
+                // Symbol (Virtual Boy)
+                let count_bytes;
+                (count_bytes, buf) = buf.split_first_chunk()?;
+                let count = u16::from_le_bytes(*count_bytes);
+                for _ in 0..count {
+                    let name_len;
+                    (name_len, buf) = buf.split_first()?;
+                    let name_bytes;
+                    (name_bytes, buf) = buf.split_at_checked(*name_len as usize)?;
+                    (_, buf) = buf.split_at_checked(2)?;
+                    let address_bytes;
+                    (address_bytes, buf) = buf.split_first_chunk()?;
+
+                    let name_str = String::from_utf8_lossy(name_bytes);
+                    let address = u32::from_le_bytes(*address_bytes);
+                    syms.push(Symbol {
+                        address: address & 0x07ffffff,
+                        size: Some(4),
+                        name: demangle_any(&name_str),
+                    });
+                }
+            }
+            0x20..=0x22 => {
+                // System (undocumented)
+                let length_bytes;
+                (length_bytes, buf) = buf.split_first_chunk()?;
+                let length = u32::from_le_bytes(*length_bytes);
+                (_, buf) = buf.split_at_checked(length as usize)?;
+            }
+            _ => {
+                return None;
+            }
+        }
+    }
+    Some(syms)
+}
+
+type Reader<'a> = gimli::EndianSlice<'a, gimli::RunTimeEndian>;
+
+struct ParseContext<'a> {
+    dorf: &'a gimli::Dwarf<Reader<'a>>,
+    unit: &'a gimli::Unit<Reader<'a>>,
+    frames: &'a mut InlineStackMapBuilder,
+}
+impl ParseContext<'_> {
+    fn name_attr(&self, attr: gimli::AttributeValue<Reader>) -> Result<Option<String>> {
+        match attr {
+            gimli::AttributeValue::DebugInfoRef(offset) => {
+                let mut units = self.dorf.units();
+                while let Some(header) = units.next()? {
+                    if let Some(offset) = offset.to_unit_offset(&header) {
+                        let unit = self.dorf.unit(header)?;
+                        return self.name_entry(&unit, offset);
+                    }
+                }
+                Ok(None)
+            }
+            gimli::AttributeValue::UnitRef(offset) => self.name_entry(self.unit, offset),
+            other => {
+                bail!("unrecognized attr {other:?}");
+            }
+        }
+    }
+
+    fn name_entry(
+        &self,
+        unit: &gimli::Unit<Reader>,
+        offset: gimli::UnitOffset,
+    ) -> Result<Option<String>> {
+        let abbreviations = self.dorf.abbreviations(&unit.header)?;
+        let mut entries = unit.header.entries_raw(&abbreviations, Some(offset))?;
+        let Some(abbrev) = entries.read_abbreviation()? else {
+            return Ok(None);
+        };
+        let mut name = None;
+        for spec in abbrev.attributes() {
+            let attr = entries.read_attribute(*spec)?;
+            if attr.name() == gimli::DW_AT_linkage_name
+                || (attr.name() == gimli::DW_AT_name && name.is_none())
+            {
+                name = Some(self.dorf.attr_string(unit, attr.value())?)
+            }
+        }
+        Ok(name.map(|n| demangle_any(&String::from_utf8_lossy(&n))))
+    }
+}
+
+fn parse_inline<'a>(
+    ctx: &mut ParseContext<'a>,
+    node: gimli::EntriesTreeNode<'a, '_, Reader<'a>>,
+) -> Result<()> {
+    if node.entry().tag() == gimli::DW_TAG_inlined_subroutine
+        && let Some(attr) = node.entry().attr_value(gimli::DW_AT_abstract_origin)
+        && let Some(name) = ctx.name_attr(attr)?
+    {
+        let name = Arc::new(name);
+        let mut ranges = ctx.dorf.die_ranges(ctx.unit, node.entry())?;
+        while let Some(range) = ranges.next()? {
+            let start = range.begin as u32 & 0x07ffffff;
+            let end = range.end as u32 & 0x07ffffff;
+            ctx.frames.add(start, end, name.clone());
+        }
+    }
+    let mut children = node.children();
+    while let Some(child) = children.next()? {
+        parse_inline(ctx, child)?;
+    }
+    Ok(())
+}
+
+fn name_and_path(file_path: &Path) -> (String, String) {
+    let normalized = normpath::PathExt::normalize(file_path);
+    let path = normalized
+        .as_ref()
+        .map(|n| n.as_path())
+        .unwrap_or(file_path);
+
+    let name = match path.file_stem() {
+        Some(s) => s.to_string_lossy().into_owned(),
+        None => "game".to_string(),
+    };
+    let path = path.to_string_lossy().into_owned();
+    (name, path)
+}

src/emulator/inline_stack_map.rs

@@ -0,0 +1,87 @@
+use std::{
+    collections::{BTreeMap, HashMap},
+    sync::Arc,
+};
+
+pub type InlineStack = Arc<Vec<Arc<String>>>;
+
+#[derive(Debug, Clone)]
+pub struct InlineStackMap {
+    entries: Vec<(u32, InlineStack)>,
+    empty: InlineStack,
+}
+
+impl InlineStackMap {
+    pub fn empty() -> Self {
+        Self {
+            entries: vec![],
+            empty: Arc::new(vec![]),
+        }
+    }
+    pub fn builder() -> InlineStackMapBuilder {
+        InlineStackMapBuilder {
+            events: BTreeMap::new(),
+        }
+    }
+    pub fn get(&self, address: u32) -> &InlineStack {
+        match self.entries.binary_search_by_key(&address, |(a, _)| *a) {
+            Ok(index) => self.entries.get(index),
+            Err(after) => after.checked_sub(1).and_then(|i| self.entries.get(i)),
+        }
+        .map(|(_, s)| s)
+        .unwrap_or(&self.empty)
+    }
+}
+
+#[derive(Default)]
+struct Event {
+    end: usize,
+    start: Vec<Arc<String>>,
+}
+
+pub struct InlineStackMapBuilder {
+    events: BTreeMap<u32, Event>,
+}
+
+impl InlineStackMapBuilder {
+    pub fn add(&mut self, start: u32, end: u32, name: Arc<String>) {
+        self.events.entry(start).or_default().start.push(name);
+        self.events.entry(end).or_default().end += 1;
+    }
+
+    pub fn build(self) -> InlineStackMap {
+        let empty = Arc::new(vec![]);
+        let mut entries = vec![];
+        let mut stack_indexes = vec![];
+        let mut stack = vec![];
+        let mut string_dedup = HashMap::new();
+        let mut stack_dedup = BTreeMap::new();
+        stack_dedup.insert(vec![], empty.clone());
+
+        for (address, event) in self.events {
+            for _ in 0..event.end {
+                stack.pop();
+                stack_indexes.pop();
+            }
+            for call in event.start {
+                if let Some(index) = string_dedup.get(&call) {
+                    stack.push(call);
+                    stack_indexes.push(*index);
+                } else {
+                    let index = string_dedup.len();
+                    string_dedup.insert(call.clone(), index);
+                    stack.push(call);
+                    stack_indexes.push(index);
+                }
+            }
+            if let Some(stack) = stack_dedup.get(&stack_indexes) {
+                entries.push((address, stack.clone()));
+            } else {
+                let stack = Arc::new(stack.clone());
+                stack_dedup.insert(stack_indexes.clone(), stack.clone());
+                entries.push((address, stack));
+            }
+        }
+        InlineStackMap { entries, empty }
+    }
+}

src/emulator/shrooms_vb_core.rs

@@ -0,0 +1,925 @@
+use std::{borrow::Cow, ffi::c_void, ptr, slice, sync::Arc};
+
+use anyhow::{Result, anyhow};
+use bitflags::bitflags;
+use num_derive::{FromPrimitive, ToPrimitive};
+use serde::{Deserialize, Serialize};
+
+use crate::emulator::inline_stack_map::{InlineStack, InlineStackMap};
+
+use super::address_set::AddressSet;
+
+#[repr(C)]
+struct VB {
+    _data: [u8; 0],
+}
+
+#[allow(non_camel_case_types)]
+type c_int = i32;
+#[allow(non_camel_case_types)]
+type c_uint = u32;
+
+#[repr(u32)]
+#[derive(FromPrimitive, ToPrimitive)]
+enum VBDataType {
+    S8 = 0,
+    U8 = 1,
+    S16 = 2,
+    U16 = 3,
+    S32 = 4,
+    F32 = 5,
+}
+
+#[repr(i32)]
+#[derive(FromPrimitive, ToPrimitive)]
+enum VBOption {
+    PseudoHalt = 0,
+}
+
+bitflags! {
+    #[repr(transparent)]
+    #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
+    pub struct VBKey: u16 {
+        const PWR = 0x0001;
+        const SGN = 0x0002;
+        const A   = 0x0004;
+        const B   = 0x0008;
+        const RT  = 0x0010;
+        const LT  = 0x0020;
+        const RU  = 0x0040;
+        const RR  = 0x0080;
+        const LR  = 0x0100;
+        const LL  = 0x0200;
+        const LD  = 0x0400;
+        const LU  = 0x0800;
+        const STA = 0x1000;
+        const SEL = 0x2000;
+        const RL  = 0x4000;
+        const RD  = 0x8000;
+    }
+}
+
+#[derive(Clone, Copy, Debug)]
+pub enum VBRegister {
+    Program(u32),
+    System(u32),
+    PC,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum VBWatchpointType {
+    Read,
+    Write,
+    Access,
+}
+
+type OnException = extern "C" fn(sim: *mut VB, cause: *mut u16) -> c_int;
+type OnExecute =
+    extern "C" fn(sim: *mut VB, address: u32, code: *const u16, length: c_int) -> c_int;
+type OnFetch = extern "C" fn(
+    sim: *mut VB,
+    fetch: c_int,
+    address: u32,
+    value: *mut i32,
+    cycles: *mut u32,
+) -> c_int;
+type OnFrame = extern "C" fn(sim: *mut VB) -> c_int;
+type OnRead = extern "C" fn(
+    sim: *mut VB,
+    address: u32,
+    type_: VBDataType,
+    value: *mut i32,
+    cycles: *mut u32,
+) -> c_int;
+type OnWrite = extern "C" fn(
+    sim: *mut VB,
+    address: u32,
+    type_: VBDataType,
+    value: *mut i32,
+    cycles: *mut u32,
+    cancel: *mut c_int,
+) -> c_int;
+
+#[link(name = "vb")]
+unsafe extern "C" {
+    #[link_name = "vbEmulate"]
+    fn vb_emulate(sim: *mut VB, cycles: *mut u32) -> c_int;
+    #[link_name = "vbEmulateEx"]
+    fn vb_emulate_ex(sims: *mut *mut VB, count: c_uint, cycles: *mut u32) -> c_int;
+    #[link_name = "vbGetCartRAM"]
+    fn vb_get_cart_ram(sim: *mut VB, size: *mut u32) -> *mut c_void;
+    #[link_name = "vbGetCartROM"]
+    fn vb_get_cart_rom(sim: *mut VB, size: *mut u32) -> *mut c_void;
+    #[link_name = "vbGetPixels"]
+    fn vb_get_pixels(
+        sim: *mut VB,
+        left: *mut c_void,
+        left_stride_x: c_int,
+        left_stride_y: c_int,
+        right: *mut c_void,
+        right_stride_x: c_int,
+        right_stride_y: c_int,
+    );
+    #[link_name = "vbGetProgramCounter"]
+    fn vb_get_program_counter(sim: *mut VB) -> u32;
+    #[link_name = "vbGetProgramRegister"]
+    fn vb_get_program_register(sim: *mut VB, index: c_uint) -> i32;
+    #[link_name = "vbGetSamples"]
+    fn vb_get_samples(
+        sim: *mut VB,
+        typ_: *mut VBDataType,
+        capacity: *mut c_uint,
+        position: *mut c_uint,
+    ) -> *mut c_void;
+    #[link_name = "vbGetSystemRegister"]
+    fn vb_get_system_register(sim: *mut VB, index: c_uint) -> i32;
+    #[link_name = "vbGetUserData"]
+    fn vb_get_user_data(sim: *mut VB) -> *mut c_void;
+    #[link_name = "vbInit"]
+    fn vb_init(sim: *mut VB) -> *mut VB;
+    #[link_name = "vbRead"]
+    fn vb_read(sim: *mut VB, address: u32, typ_: VBDataType) -> i32;
+    #[link_name = "vbReset"]
+    fn vb_reset(sim: *mut VB);
+    #[link_name = "vbSetCartRAM"]
+    fn vb_set_cart_ram(sim: *mut VB, sram: *mut c_void, size: u32) -> c_int;
+    #[link_name = "vbSetCartROM"]
+    fn vb_set_cart_rom(sim: *mut VB, rom: *mut c_void, size: u32) -> c_int;
+    #[link_name = "vbSetExceptionCallback"]
+    fn vb_set_exception_callback(
+        sim: *mut VB,
+        callback: Option<OnException>,
+    ) -> Option<OnException>;
+    #[link_name = "vbSetExecuteCallback"]
+    fn vb_set_execute_callback(sim: *mut VB, callback: Option<OnExecute>) -> Option<OnExecute>;
+    #[link_name = "vbSetFetchCallback"]
+    fn vb_set_fetch_callback(sim: *mut VB, callback: Option<OnFetch>) -> Option<OnFetch>;
+    #[link_name = "vbSetFrameCallback"]
+    fn vb_set_frame_callback(sim: *mut VB, callback: Option<OnFrame>) -> Option<OnFrame>;
+    #[link_name = "vbSetKeys"]
+    fn vb_set_keys(sim: *mut VB, keys: u16) -> u16;
+    #[link_name = "vbSetOption"]
+    fn vb_set_option(sim: *mut VB, key: VBOption, value: c_int);
+    #[link_name = "vbSetPeer"]
+    fn vb_set_peer(sim: *mut VB, peer: *mut VB);
+    #[link_name = "vbSetProgramCounter"]
+    fn vb_set_program_counter(sim: *mut VB, value: u32) -> u32;
+    #[link_name = "vbSetProgramRegister"]
+    fn vb_set_program_register(sim: *mut VB, index: c_uint, value: i32) -> i32;
+    #[link_name = "vbSetReadCallback"]
+    fn vb_set_read_callback(sim: *mut VB, callback: Option<OnRead>) -> Option<OnRead>;
+    #[link_name = "vbSetSamples"]
+    fn vb_set_samples(
+        sim: *mut VB,
+        samples: *mut c_void,
+        typ_: VBDataType,
+        capacity: c_uint,
+    ) -> c_int;
+    #[link_name = "vbSetSystemRegister"]
+    fn vb_set_system_register(sim: *mut VB, index: c_uint, value: u32) -> u32;
+    #[link_name = "vbSetUserData"]
+    fn vb_set_user_data(sim: *mut VB, tag: *mut c_void);
+    #[link_name = "vbSetWriteCallback"]
+    fn vb_set_write_callback(sim: *mut VB, callback: Option<OnWrite>) -> Option<OnWrite>;
+    #[link_name = "vbSizeOf"]
+    fn vb_size_of() -> usize;
+    #[link_name = "vbWrite"]
+    fn vb_write(sim: *mut VB, address: u32, _type: VBDataType, value: i32) -> i32;
+}
+
+#[unsafe(no_mangle)]
+extern "C" fn on_frame(sim: *mut VB) -> c_int {
+    // SAFETY: the *mut VB owns its userdata.
+    // There is no way for the userdata to be null or otherwise invalid.
+    let data: &mut VBState = unsafe { &mut *vb_get_user_data(sim).cast() };
+    data.frame_seen = true;
+    if data.monitor.enabled {
+        data.monitor.event = Some(SimEvent::Marker(Cow::Borrowed("Frame Drawn")));
+    }
+    1
+}
+
+#[unsafe(no_mangle)]
+extern "C" fn on_execute(sim: *mut VB, address: u32, code: *const u16, length: c_int) -> c_int {
+    // SAFETY: the *mut VB owns its userdata.
+    // There is no way for the userdata to be null or otherwise invalid.
+    let data: &mut VBState = unsafe { &mut *vb_get_user_data(sim).cast() };
+
+    if data.monitor.enabled {
+        // SAFETY: length is the length of code, in elements
+        let code = unsafe { slice::from_raw_parts(code, length as usize) };
+        data.monitor.detect_event(sim, address, code);
+        // Something interesting will happen after this instruction is run.
+        // We'll react in the on_fetch callback it does.
+    }
+
+    let mut stopped = data.stop_reason.is_some() || data.monitor.event.is_some();
+    if data.step_from.is_some_and(|s| s != address) {
+        data.step_from = None;
+        data.stop_reason = Some(StopReason::Stepped);
+        stopped = true;
+    }
+    if data.breakpoints.binary_search(&address).is_ok() {
+        data.stop_reason = Some(StopReason::Breakpoint);
+        stopped = true;
+    }
+
+    if stopped { 1 } else { 0 }
+}
+
+#[unsafe(no_mangle)]
+extern "C" fn on_fetch(
+    sim: *mut VB,
+    _fetch: c_int,
+    address: u32,
+    _value: *mut i32,
+    _cycles: *mut u32,
+) -> c_int {
+    // SAFETY: the *mut VB owns its userdata.
+    // There is no way for the userdata to be null or otherwise invalid.
+    let data: &mut VBState = unsafe { &mut *vb_get_user_data(sim).cast() };
+    data.monitor.event = data.monitor.queued_event.take();
+    data.monitor.new_inline_stack = data.monitor.detect_new_inline_stack(address);
+    unsafe { vb_set_exception_callback(sim, Some(on_exception)) };
+    if data.monitor.event.is_some() || data.monitor.new_inline_stack.is_some() {
+        1
+    } else {
+        0
+    }
+}
+
+#[unsafe(no_mangle)]
+extern "C" fn on_exception(sim: *mut VB, cause: *mut u16) -> c_int {
+    // SAFETY: the *mut VB owns its userdata.
+    // There is no way for the userdata to be null or otherwise invalid.
+    let data: &mut VBState = unsafe { &mut *vb_get_user_data(sim).cast() };
+    let cause = unsafe { *cause };
+    let pc = if cause == 0xff70 {
+        0xffffff60
+    } else {
+        (cause & 0xfff0) as u32 | 0xffff0000
+    };
+    data.monitor.event = data.monitor.queued_event.take();
+    data.monitor.new_inline_stack = data.monitor.detect_new_inline_stack(pc);
+    data.monitor.queued_event = Some(SimEvent::Interrupt(cause, pc & 0x07ffffff));
+    unsafe { vb_set_exception_callback(sim, None) };
+    if data.monitor.event.is_some() || data.monitor.new_inline_stack.is_some() {
+        1
+    } else {
+        0
+    }
+}
+
+#[unsafe(no_mangle)]
+extern "C" fn on_read(
+    sim: *mut VB,
+    address: u32,
+    _type: VBDataType,
+    _value: *mut i32,
+    _cycles: *mut u32,
+) -> c_int {
+    // SAFETY: the *mut VB owns its userdata.
+    // There is no way for the userdata to be null or otherwise invalid.
+    let data: &mut VBState = unsafe { &mut *vb_get_user_data(sim).cast() };
+
+    if let Some(start) = data.read_watchpoints.start_of_range_containing(address) {
+        let watch = if data.write_watchpoints.contains(address) {
+            VBWatchpointType::Access
+        } else {
+            VBWatchpointType::Read
+        };
+        data.stop_reason = Some(StopReason::Watchpoint(watch, start));
+    }
+
+    // Don't stop here, the debugger expects us to break after the memory access.
+    // We'll stop in on_execute instead.
+    0
+}
+
+#[unsafe(no_mangle)]
+extern "C" fn on_write(
+    sim: *mut VB,
+    address: u32,
+    typ_: VBDataType,
+    value: *mut i32,
+    _cycles: *mut u32,
+    _cancel: *mut c_int,
+) -> c_int {
+    // SAFETY: the *mut VB owns its userdata.
+    // There is no way for the userdata to be null or otherwise invalid.
+    let data: &mut VBState = unsafe { &mut *vb_get_user_data(sim).cast() };
+
+    // If we're monitoring stdout, track this write
+    if let Some(stdout) = data.stdout.as_mut() {
+        let normalized_hw_address = address & 0x0700003f;
+        if normalized_hw_address == 0x02000030 {
+            stdout.push(unsafe { *value } as u8);
+        }
+    }
+
+    // If we have profiling enabled, track custom markers
+    if data.monitor.enabled {
+        let normalized_hw_address = address & 0x0700003f;
+        if normalized_hw_address == 0x02000038 && matches!(typ_, VBDataType::S32) {
+            assert!(data.monitor.queued_event.is_none());
+            // The game has written the address of a null-terminated string
+            // (whose length is at most 64 bytes). Read that string.
+            let str_address = unsafe { *value } as u32;
+            let mut bytes = [0u8; 64];
+            let mut len = 0;
+            for (dst, src_address) in bytes.iter_mut().zip(str_address..str_address + 64) {
+                let char = unsafe { vb_read(sim, src_address, VBDataType::U8) } as u8;
+                if char == 0 {
+                    break;
+                }
+                *dst = char;
+                len += 1;
+            }
+            let name = String::from_utf8_lossy(&bytes[..len]).into_owned();
+            data.monitor.queued_event = Some(SimEvent::Marker(Cow::Owned(name)));
+        }
+    }
+
+    if let Some(start) = data.write_watchpoints.start_of_range_containing(address) {
+        let watch = if data.read_watchpoints.contains(address) {
+            VBWatchpointType::Access
+        } else {
+            VBWatchpointType::Write
+        };
+        data.stop_reason = Some(StopReason::Watchpoint(watch, start));
+    }
+
+    // Don't stop here, the debugger expects us to break after the memory access.
+    // We'll stop in on_execute instead.
+    0
+}
+
+#[allow(dead_code)]
+#[derive(Debug)]
+pub enum SimEvent {
+    Call(u32),
+    Return,
+    Halt,
+    Interrupt(u16, u32),
+    Reti,
+    Marker(Cow<'static, str>),
+}
+
+struct EventMonitor {
+    enabled: bool,
+    event: Option<SimEvent>,
+    queued_event: Option<SimEvent>,
+    just_halted: bool,
+    inline_stack_map: InlineStackMap,
+    new_inline_stack: Option<InlineStack>,
+    last_inline_stack: InlineStack,
+}
+
+impl EventMonitor {
+    fn new() -> Self {
+        let inline_stack_map = InlineStackMap::empty();
+        let last_inline_stack = inline_stack_map.get(0).clone();
+        Self {
+            enabled: false,
+            event: None,
+            queued_event: None,
+            just_halted: false,
+            inline_stack_map,
+            new_inline_stack: None,
+            last_inline_stack,
+        }
+    }
+
+    fn detect_new_inline_stack(&mut self, address: u32) -> Option<InlineStack> {
+        let stack = self.inline_stack_map.get(address);
+        if Arc::ptr_eq(stack, &self.last_inline_stack) {
+            return None;
+        }
+        self.last_inline_stack = stack.clone();
+        Some(stack.clone())
+    }
+
+    fn detect_event(&mut self, sim: *mut VB, address: u32, code: &[u16]) -> bool {
+        self.queued_event = self.do_detect_event(sim, address, code);
+        self.queued_event.is_some()
+    }
+
+    fn do_detect_event(&mut self, sim: *mut VB, address: u32, code: &[u16]) -> Option<SimEvent> {
+        const HALT_OPCODE: u16 = 0b011010;
+        const JAL_OPCODE: u16 = 0b101011;
+        const JMP_OPCODE: u16 = 0b000110;
+        const RETI_OPCODE: u16 = 0b011001;
+
+        const fn format_i_reg_1(code: &[u16]) -> u8 {
+            (code[0] & 0x1f) as u8
+        }
+
+        const fn format_iv_disp(code: &[u16]) -> i32 {
+            let value = ((code[0] & 0x3ff) as i32) << 16 | (code[1] as i32);
+            value << 6 >> 6
+        }
+
+        let opcode = code[0] >> 10;
+
+        if opcode == HALT_OPCODE {
+            if !self.just_halted {
+                self.just_halted = true;
+                self.event = Some(SimEvent::Halt);
+            } else {
+                self.just_halted = false;
+            }
+            // Don't _return_ an event, we want to emit this right away.
+            // If the CPU is halting, no other callbacks will run for a long time.
+            return None;
+        }
+
+        if opcode == JAL_OPCODE {
+            let disp = format_iv_disp(code);
+            if disp != 4 {
+                // JAL .+4 is how programs get r31 to a known value for indirect calls
+                // (which we detect later.)
+                // Any other JAL is a function call.
+                return Some(SimEvent::Call(
+                    address.wrapping_add_signed(disp) & 0x07ffffff,
+                ));
+            }
+        }
+
+        if opcode == JMP_OPCODE {
+            let jmp_reg = format_i_reg_1(code);
+            if jmp_reg == 31 {
+                // JMP[r31] is a return
+                return Some(SimEvent::Return);
+            }
+            let r31 = unsafe { vb_get_program_register(sim, 31) };
+            if r31 as u32 == address.wrapping_add(2) {
+                // JMP anywhere else, if r31 points to after the JMP, is an indirect call
+                let target = unsafe { vb_get_program_register(sim, jmp_reg as u32) };
+                return Some(SimEvent::Call(target as u32 & 0x07ffffff));
+            }
+        }
+
+        if opcode == RETI_OPCODE {
+            return Some(SimEvent::Reti);
+        }
+
+        None
+    }
+}
+
+const AUDIO_CAPACITY_SAMPLES: usize = 834 * 4;
+const AUDIO_CAPACITY_FLOATS: usize = AUDIO_CAPACITY_SAMPLES * 2;
+pub const EXPECTED_FRAME_SIZE: usize = 834 * 2;
+
+struct VBState {
+    frame_seen: bool,
+    stop_reason: Option<StopReason>,
+    monitor: EventMonitor,
+    step_from: Option<u32>,
+    breakpoints: Vec<u32>,
+    read_watchpoints: AddressSet,
+    write_watchpoints: AddressSet,
+    stdout: Option<Vec<u8>>,
+}
+
+impl VBState {
+    fn needs_execute_callback(&self) -> bool {
+        self.step_from.is_some()
+            || self.monitor.enabled
+            || !self.breakpoints.is_empty()
+            || !self.read_watchpoints.is_empty()
+            || !self.write_watchpoints.is_empty()
+    }
+
+    fn needs_write_callback(&self) -> bool {
+        self.stdout.is_some() || self.monitor.enabled || !self.write_watchpoints.is_empty()
+    }
+}
+
+pub enum StopReason {
+    Breakpoint,
+    Watchpoint(VBWatchpointType, u32),
+    Stepped,
+}
+
+#[repr(transparent)]
+pub struct Sim {
+    sim: *mut VB,
+}
+
+impl Sim {
+    pub fn new() -> Self {
+        // init the VB instance itself
+        let size = unsafe { vb_size_of() };
+        // allocate a vec of u64 so that this memory is 8-byte aligned
+        let memory = vec![0u64; size.div_ceil(4)];
+        let sim: *mut VB = Box::into_raw(memory.into_boxed_slice()).cast();
+        unsafe { vb_init(sim) };
+        // pseudohalt is disabled due to breaking red alarm
+        unsafe { vb_set_option(sim, VBOption::PseudoHalt, 0) };
+        unsafe { vb_set_keys(sim, VBKey::SGN.bits()) };
+        unsafe { vb_reset(sim) };
+
+        // set up userdata
+        let state = VBState {
+            frame_seen: false,
+            stop_reason: None,
+            monitor: EventMonitor::new(),
+            step_from: None,
+            breakpoints: vec![],
+            read_watchpoints: AddressSet::new(),
+            write_watchpoints: AddressSet::new(),
+            stdout: None,
+        };
+        unsafe { vb_set_user_data(sim, Box::into_raw(Box::new(state)).cast()) };
+        unsafe { vb_set_frame_callback(sim, Some(on_frame)) };
+
+        // set up audio buffer
+        let audio_buffer = vec![0.0f32; AUDIO_CAPACITY_FLOATS];
+        let samples: *mut c_void = Box::into_raw(audio_buffer.into_boxed_slice()).cast();
+        unsafe { vb_set_samples(sim, samples, VBDataType::F32, AUDIO_CAPACITY_SAMPLES as u32) };
+
+        Sim { sim }
+    }
+
+    pub fn reset(&mut self) {
+        unsafe { vb_reset(self.sim) };
+    }
+
+    pub fn monitor_events(&mut self, enabled: bool, inline_stack_map: InlineStackMap) {
+        let state = self.get_state();
+        state.monitor.enabled = enabled;
+        state.monitor.event = None;
+        state.monitor.queued_event = None;
+        state.monitor.new_inline_stack = None;
+        state.monitor.last_inline_stack = inline_stack_map.get(0).clone();
+        state.monitor.inline_stack_map = inline_stack_map;
+        if enabled {
+            unsafe { vb_set_execute_callback(self.sim, Some(on_execute)) };
+            unsafe { vb_set_exception_callback(self.sim, Some(on_exception)) };
+            unsafe { vb_set_fetch_callback(self.sim, Some(on_fetch)) };
+            unsafe { vb_set_write_callback(self.sim, Some(on_write)) };
+        } else {
+            let needs_execute = state.needs_execute_callback();
+            let needs_write = state.needs_write_callback();
+            if !needs_execute {
+                unsafe { vb_set_execute_callback(self.sim, None) };
+            }
+            unsafe { vb_set_exception_callback(self.sim, None) };
+            unsafe { vb_set_fetch_callback(self.sim, None) };
+            if !needs_write {
+                unsafe { vb_set_write_callback(self.sim, None) };
+            }
+        }
+    }
+
+    pub fn load_cart(&mut self, mut rom: Vec<u8>, mut sram: Vec<u8>) -> Result<()> {
+        self.unload_cart();
+
+        rom.shrink_to_fit();
+        sram.shrink_to_fit();
+
+        let size = rom.len() as u32;
+        let rom = Box::into_raw(rom.into_boxed_slice()).cast();
+        let status = unsafe { vb_set_cart_rom(self.sim, rom, size) };
+        if status != 0 {
+            let _: Vec<u8> =
+                unsafe { Vec::from_raw_parts(rom.cast(), size as usize, size as usize) };
+            return Err(anyhow!("Invalid ROM size of {} bytes", size));
+        }
+
+        let size = sram.len() as u32;
+        let sram = Box::into_raw(sram.into_boxed_slice()).cast();
+        let status = unsafe { vb_set_cart_ram(self.sim, sram, size) };
+        if status != 0 {
+            let _: Vec<u8> =
+                unsafe { Vec::from_raw_parts(sram.cast(), size as usize, size as usize) };
+            return Err(anyhow!("Invalid SRAM size of {} bytes", size));
+        }
+
+        Ok(())
+    }
+
+    fn unload_cart(&mut self) {
+        let mut size = 0;
+        let rom = unsafe { vb_get_cart_rom(self.sim, &mut size) };
+        unsafe { vb_set_cart_rom(self.sim, ptr::null_mut(), 0) };
+        if !rom.is_null() {
+            let _: Vec<u8> =
+                unsafe { Vec::from_raw_parts(rom.cast(), size as usize, size as usize) };
+        }
+
+        let sram = unsafe { vb_get_cart_ram(self.sim, &mut size) };
+        unsafe { vb_set_cart_ram(self.sim, ptr::null_mut(), 0) };
+        if !sram.is_null() {
+            let _: Vec<u8> =
+                unsafe { Vec::from_raw_parts(sram.cast(), size as usize, size as usize) };
+        }
+    }
+
+    pub fn read_sram(&mut self, buffer: &mut [u8]) {
+        let mut size = 0;
+        let sram = unsafe { vb_get_cart_ram(self.sim, &mut size) };
+        if sram.is_null() {
+            return;
+        }
+        let bytes = unsafe { slice::from_raw_parts(sram.cast(), size as usize) };
+        buffer.copy_from_slice(bytes);
+    }
+
+    pub fn link(&mut self, peer: &mut Sim) {
+        unsafe { vb_set_peer(self.sim, peer.sim) };
+    }
+
+    pub fn unlink(&mut self) {
+        unsafe { vb_set_peer(self.sim, ptr::null_mut()) };
+    }
+
+    pub fn emulate(&mut self, cycles: &mut u32) {
+        unsafe { vb_emulate(self.sim, cycles) };
+    }
+
+    pub fn emulate_many(sims: &mut [Sim], cycles: &mut u32) {
+        let count = sims.len() as c_uint;
+        let sims = sims.as_mut_ptr().cast();
+        unsafe { vb_emulate_ex(sims, count, cycles) };
+    }
+
+    pub fn read_pixels(&mut self, buffers: &mut [u8]) -> bool {
+        let data = self.get_state();
+        if !data.frame_seen {
+            return false;
+        }
+        data.frame_seen = false;
+
+        // the buffer must be big enough for our data
+        assert!(buffers.len() >= 384 * 224 * 2);
+        unsafe {
+            vb_get_pixels(
+                self.sim,
+                buffers.as_mut_ptr().cast(),
+                2,
+                384 * 2,
+                buffers.as_mut_ptr().offset(1).cast(),
+                2,
+                384 * 2,
+            );
+        };
+        true
+    }
+
+    pub fn read_samples(&mut self, samples: &mut Vec<f32>, weight: f32) {
+        let mut position = 0;
+        let ptr =
+            unsafe { vb_get_samples(self.sim, ptr::null_mut(), ptr::null_mut(), &mut position) };
+        // SAFETY: position is an offset in a buffer of (f32, f32). so, position * 2 is an offset in a buffer of f32.
+        let read_samples: &[f32] =
+            unsafe { slice::from_raw_parts(ptr.cast(), position as usize * 2) };
+        samples.resize(read_samples.len(), 0.0);
+        for (index, sample) in read_samples.iter().enumerate() {
+            samples[index] += sample * weight;
+        }
+
+        unsafe {
+            vb_set_samples(
+                self.sim,
+                ptr,
+                VBDataType::F32,
+                AUDIO_CAPACITY_SAMPLES as u32,
+            )
+        };
+    }
+
+    pub fn set_keys(&mut self, keys: VBKey) {
+        unsafe { vb_set_keys(self.sim, keys.bits()) };
+    }
+
+    pub fn read_register(&mut self, register: VBRegister) -> u32 {
+        match register {
+            VBRegister::Program(index) => unsafe {
+                vb_get_program_register(self.sim, index) as u32
+            },
+            VBRegister::System(index) => unsafe { vb_get_system_register(self.sim, index) as u32 },
+            VBRegister::PC => unsafe { vb_get_program_counter(self.sim) },
+        }
+    }
+
+    pub fn write_register(&mut self, register: VBRegister, value: u32) {
+        match register {
+            VBRegister::Program(index) => unsafe {
+                vb_set_program_register(self.sim, index, value as i32);
+            },
+            VBRegister::System(index) => unsafe {
+                vb_set_system_register(self.sim, index, value);
+            },
+            VBRegister::PC => unsafe {
+                vb_set_program_counter(self.sim, value);
+            },
+        }
+    }
+
+    pub fn read_memory(&mut self, start: u32, length: usize, into: &mut Vec<u8>) {
+        let mut address = start;
+        for _ in 0..length {
+            let byte = unsafe { vb_read(self.sim, address, VBDataType::U8) };
+            into.push(byte as u8);
+            address = address.wrapping_add(1);
+        }
+    }
+
+    pub fn write_memory(&mut self, start: u32, buffer: &[u8]) {
+        let mut address = start;
+        for byte in buffer {
+            unsafe { vb_write(self.sim, address, VBDataType::U8, *byte as i32) };
+            address = address.wrapping_add(1);
+        }
+    }
+
+    pub fn add_breakpoint(&mut self, address: u32) {
+        let data = self.get_state();
+        if let Err(index) = data.breakpoints.binary_search(&address) {
+            data.breakpoints.insert(index, address);
+        }
+
+        unsafe {
+            vb_set_execute_callback(self.sim, Some(on_execute));
+        }
+    }
+
+    pub fn remove_breakpoint(&mut self, address: u32) {
+        let data = self.get_state();
+        if let Ok(index) = data.breakpoints.binary_search(&address) {
+            data.breakpoints.remove(index);
+            if !data.needs_execute_callback() {
+                unsafe { vb_set_execute_callback(self.sim, None) };
+            }
+        }
+    }
+
+    pub fn add_watchpoint(&mut self, address: u32, length: usize, watch: VBWatchpointType) {
+        match watch {
+            VBWatchpointType::Read => self.add_read_watchpoint(address, length),
+            VBWatchpointType::Write => self.add_write_watchpoint(address, length),
+            VBWatchpointType::Access => {
+                self.add_read_watchpoint(address, length);
+                self.add_write_watchpoint(address, length);
+            }
+        }
+    }
+
+    fn add_read_watchpoint(&mut self, address: u32, length: usize) {
+        let state = self.get_state();
+        state.read_watchpoints.add(address, length);
+        if !state.read_watchpoints.is_empty() {
+            unsafe { vb_set_read_callback(self.sim, Some(on_read)) };
+            unsafe { vb_set_execute_callback(self.sim, Some(on_execute)) };
+        }
+    }
+
+    fn add_write_watchpoint(&mut self, address: u32, length: usize) {
+        let state = self.get_state();
+        state.write_watchpoints.add(address, length);
+        if !state.write_watchpoints.is_empty() {
+            unsafe { vb_set_write_callback(self.sim, Some(on_write)) };
+            unsafe { vb_set_execute_callback(self.sim, Some(on_execute)) };
+        }
+    }
+
+    pub fn remove_watchpoint(&mut self, address: u32, length: usize, watch: VBWatchpointType) {
+        match watch {
+            VBWatchpointType::Read => self.remove_read_watchpoint(address, length),
+            VBWatchpointType::Write => self.remove_write_watchpoint(address, length),
+            VBWatchpointType::Access => {
+                self.remove_read_watchpoint(address, length);
+                self.remove_write_watchpoint(address, length);
+            }
+        }
+    }
+
+    fn remove_read_watchpoint(&mut self, address: u32, length: usize) {
+        let state = self.get_state();
+        state.read_watchpoints.remove(address, length);
+        let needs_execute = state.needs_execute_callback();
+        if state.read_watchpoints.is_empty() {
+            unsafe { vb_set_read_callback(self.sim, None) };
+            if !needs_execute {
+                unsafe { vb_set_execute_callback(self.sim, None) };
+            }
+        }
+    }
+
+    fn remove_write_watchpoint(&mut self, address: u32, length: usize) {
+        let state = self.get_state();
+        state.write_watchpoints.remove(address, length);
+        let needs_write = state.needs_write_callback();
+        let needs_execute = state.needs_execute_callback();
+        if state.write_watchpoints.is_empty() {
+            if !needs_write {
+                unsafe { vb_set_write_callback(self.sim, None) };
+            }
+            if !needs_execute {
+                unsafe { vb_set_execute_callback(self.sim, None) };
+            }
+        }
+    }
+
+    pub fn step(&mut self) {
+        let current_pc = unsafe { vb_get_program_counter(self.sim) };
+        let data = self.get_state();
+        data.step_from = Some(current_pc);
+        unsafe {
+            vb_set_execute_callback(self.sim, Some(on_execute));
+        }
+    }
+
+    pub fn clear_debug_state(&mut self) {
+        let data = self.get_state();
+        data.step_from = None;
+        data.breakpoints.clear();
+        data.read_watchpoints.clear();
+        data.write_watchpoints.clear();
+        let needs_write = data.needs_write_callback();
+        let needs_execute = data.needs_execute_callback();
+        unsafe { vb_set_read_callback(self.sim, None) };
+        if !needs_write {
+            unsafe { vb_set_write_callback(self.sim, None) };
+        }
+        if !needs_execute {
+            unsafe { vb_set_execute_callback(self.sim, None) };
+        }
+    }
+
+    pub fn watch_stdout(&mut self, watch: bool) {
+        let data = self.get_state();
+        if watch {
+            if data.stdout.is_none() {
+                data.stdout = Some(vec![]);
+                unsafe { vb_set_write_callback(self.sim, Some(on_write)) };
+            }
+        } else {
+            data.stdout.take();
+            if !data.needs_write_callback() {
+                unsafe { vb_set_write_callback(self.sim, None) };
+            }
+        }
+    }
+
+    pub fn take_stdout(&mut self) -> Option<String> {
+        let data = self.get_state();
+        let stdout = data.stdout.take()?;
+        let string = match String::from_utf8(stdout) {
+            Ok(str) => str,
+            Err(err) => String::from_utf8_lossy(err.as_bytes()).into_owned(),
+        };
+        data.stdout = Some(vec![]);
+        Some(string)
+    }
+
+    pub fn take_stop_reason(&mut self) -> Option<StopReason> {
+        let data = self.get_state();
+        let reason = data.stop_reason.take();
+        if !data.needs_execute_callback() {
+            unsafe { vb_set_execute_callback(self.sim, None) };
+        }
+        reason
+    }
+
+    pub fn take_profiler_updates(&mut self) -> (Option<SimEvent>, Option<InlineStack>) {
+        let data = self.get_state();
+        let event = data.monitor.event.take();
+        let inline_stack = data.monitor.new_inline_stack.take();
+        (event, inline_stack)
+    }
+
+    fn get_state(&mut self) -> &mut VBState {
+        // SAFETY: the *mut VB owns its userdata.
+        // There is no way for the userdata to be null or otherwise invalid.
+        unsafe { &mut *vb_get_user_data(self.sim).cast() }
+    }
+}
+
+impl Drop for Sim {
+    fn drop(&mut self) {
+        let ptr =
+            unsafe { vb_get_samples(self.sim, ptr::null_mut(), ptr::null_mut(), ptr::null_mut()) };
+        // SAFETY: the audio buffer originally came from a Vec<u32>
+        let floats: Vec<f32> = unsafe {
+            Vec::from_raw_parts(ptr.cast(), AUDIO_CAPACITY_FLOATS, AUDIO_CAPACITY_FLOATS)
+        };
+        drop(floats);
+
+        // SAFETY: the *mut VB owns its userdata.
+        // There is no way for the userdata to be null or otherwise invalid.
+        let ptr: *mut VBState = unsafe { vb_get_user_data(self.sim).cast() };
+        // SAFETY: we made this pointer ourselves, we can for sure free it
+        unsafe { drop(Box::from_raw(ptr)) };
+
+        // If we're linked to another sim, unlink from them.
+        unsafe { vb_set_peer(self.sim, ptr::null_mut()) };
+
+        let len = unsafe { vb_size_of() }.div_ceil(4);
+        // SAFETY: the sim's memory originally came from a Vec<u64>
+        let bytes: Vec<u64> = unsafe { Vec::from_raw_parts(self.sim.cast(), len, len) };
+        drop(bytes);
+    }
+}

src/emulator/shrooms_vb_util.rs

@@ -0,0 +1,31 @@
+use std::ffi::c_void;
+
+#[unsafe(no_mangle)]
+unsafe fn vbu_realloc_shim(ptr: *mut c_void, new_size: usize) -> *mut c_void {
+    if !ptr.is_null() {
+        // not supporting proper realloc because it needs bookkeeping and it's unnecessary
+        return std::ptr::null_mut();
+    }
+    let allocation = vec![0u8; new_size].into_boxed_slice();
+    Box::into_raw(allocation).cast()
+}
+
+#[link(name = "vb")]
+unsafe extern "C" {
+    #[link_name = "vbuFromISX"]
+    fn vbu_from_isx(bytes: *const c_void, length: usize, rom_length: *mut usize) -> *mut c_void;
+}
+
+pub fn rom_from_isx(bytes: &[u8]) -> Option<Vec<u8>> {
+    if !bytes.starts_with(b"ISX") {
+        return None;
+    }
+    let mut rom_length = 0;
+    let raw_rom = unsafe { vbu_from_isx(bytes.as_ptr().cast(), bytes.len(), &mut rom_length) };
+    if raw_rom.is_null() {
+        return None;
+    }
+    // SAFETY: the rom was allocated by vbu_realloc_shim, which created it from a Vec<u8>.
+    let rom = unsafe { Vec::from_raw_parts(raw_rom.cast(), rom_length, rom_length) };
+    Some(rom)
+}

src/filepicker.rs

@@ -0,0 +1,103 @@
+#[cfg(target_os = "linux")]
+use std::fmt::Write as _;
+use std::{
+    path::PathBuf,
+    sync::{Arc, Weak},
+};
+
+use winit::window::Window;
+
+pub struct FilePicker {
+    window: Option<Weak<Window>>,
+}
+
+impl FilePicker {
+    pub fn new() -> Self {
+        Self { window: None }
+    }
+
+    pub fn set_window(&mut self, window: &Arc<Window>) {
+        self.window = Some(Arc::downgrade(window));
+    }
+
+    pub fn pick_file_dialog(&self) -> FileDialogBuilder {
+        self.new_dialog(FileDialogAction::PickFile, false)
+    }
+
+    pub fn save_file_dialog(&self) -> FileDialogBuilder {
+        self.new_dialog(FileDialogAction::SaveFile, cfg!(not(target_os = "windows")))
+    }
+
+    fn new_dialog(&self, action: FileDialogAction, attach_window: bool) -> FileDialogBuilder {
+        #[cfg(not(target_os = "macos"))]
+        let mut dialog = rfd::AsyncFileDialog::new();
+        #[cfg(target_os = "macos")]
+        let mut dialog = rfd::FileDialog::new();
+
+        if attach_window && let Some(window) = self.window.as_ref().and_then(|w| w.upgrade()) {
+            dialog = dialog.set_parent(&window);
+        }
+        FileDialogBuilder { dialog, action }
+    }
+}
+
+pub struct FileDialogBuilder {
+    #[cfg(not(target_os = "macos"))]
+    dialog: rfd::AsyncFileDialog,
+    #[cfg(target_os = "macos")]
+    dialog: rfd::FileDialog,
+    action: FileDialogAction,
+}
+
+impl FileDialogBuilder {
+    pub fn add_filter(self, name: impl Into<String>, extensions: &[impl ToString]) -> Self {
+        #[cfg(target_os = "linux")]
+        let exts = extensions
+            .iter()
+            .map(|ext| {
+                let mut normalized = String::new();
+                for char in ext.to_string().chars() {
+                    if char.is_ascii_lowercase() {
+                        let _ = write!(&mut normalized, "[{char}{}]", char.to_ascii_uppercase());
+                    } else {
+                        normalized.push(char);
+                    }
+                }
+                normalized
+            })
+            .collect::<Vec<_>>();
+        #[cfg(target_os = "linux")]
+        let extensions = &exts;
+        Self {
+            dialog: self.dialog.add_filter(name, extensions),
+            ..self
+        }
+    }
+
+    pub fn set_file_name(self, file_name: impl Into<String>) -> Self {
+        Self {
+            dialog: self.dialog.set_file_name(file_name),
+            ..self
+        }
+    }
+
+    pub fn open(self) -> Option<PathBuf> {
+        #[cfg(not(target_os = "macos"))]
+        fn resolve(action: impl Future<Output = Option<rfd::FileHandle>>) -> Option<PathBuf> {
+            pollster::block_on(action).map(Into::into)
+        }
+        #[cfg(target_os = "macos")]
+        fn resolve(action: Option<PathBuf>) -> Option<PathBuf> {
+            action
+        }
+        match self.action {
+            FileDialogAction::PickFile => resolve(self.dialog.pick_file()),
+            FileDialogAction::SaveFile => resolve(self.dialog.save_file()),
+        }
+    }
+}
+
+enum FileDialogAction {
+    PickFile,
+    SaveFile,
+}

src/game.wgsl

@@ -0,0 +1,79 @@
+// Vertex shader
+
+struct VertexOutput {
+    @builtin(position) clip_position: vec4<f32>,
+    @location(0) tex_coords: vec2<f32>,
+};
+
+@vertex
+fn vs_main(
+    @builtin(vertex_index) in_vertex_index: u32,
+) -> VertexOutput {
+    var out: VertexOutput;
+    var x: f32;
+    var y: f32;
+    switch in_vertex_index {
+        case 0u, 3u: {
+            x = -1.0;
+            y = 1.0;
+        }
+        case 1u: {
+            x = -1.0;
+            y = -1.0;
+        }
+        case 2u, 4u: {
+            x = 1.0;
+            y = -1.0;
+        }
+        default: {
+            x = 1.0;
+            y = 1.0;
+        }
+    }
+    out.clip_position = vec4<f32>(x, y, 0.0, 1.0);
+    out.tex_coords = vec2<f32>((x + 1.0) / 2.0, (1.0 - y) / 2.0);
+    return out;
+}
+
+// Fragment shader
+@group(0) @binding(0)
+var u_texture: texture_2d<f32>;
+@group(0) @binding(1)
+var u_sampler: sampler;
+
+struct Colors {
+    left: vec4<f32>,
+    right: vec4<f32>,
+};
+@group(0) @binding(2)
+var<uniform> colors: Colors;
+
+@fragment
+fn fs_lefteye(in: VertexOutput) -> @location(0) vec4<f32> {
+    let brt = textureSample(u_texture, u_sampler, in.tex_coords);
+    return colors.left * brt[0];
+}
+
+@fragment
+fn fs_righteye(in: VertexOutput) -> @location(0) vec4<f32> {
+    let brt = textureSample(u_texture, u_sampler, in.tex_coords);
+    return colors.left * brt[1];
+}
+
+@fragment
+fn fs_anaglyph(in: VertexOutput) -> @location(0) vec4<f32> {
+    let brt = textureSample(u_texture, u_sampler, in.tex_coords);
+    return colors.left * brt[0] + colors.right * brt[1];
+}
+
+@fragment
+fn fs_sidebyside(in: VertexOutput) -> @location(0) vec4<f32> {
+    var point = in.tex_coords;
+    point.x = (point.x * 2.0) % 1.0;
+    let brt = textureSample(u_texture, u_sampler, point);
+    if in.tex_coords.x < 0.5 {
+        return colors.left * brt[0];
+    } else {
+        return colors.left * brt[1];
+    };
+}

src/gdbserver.rs

@@ -0,0 +1,560 @@
+use anyhow::{Result, bail};
+use registers::REGISTERS;
+use request::{Request, RequestKind, RequestSource};
+use response::Response;
+use std::{
+    sync::{Arc, Mutex},
+    thread,
+};
+use tokio::{
+    io::{AsyncWriteExt as _, BufReader},
+    net::{TcpListener, TcpStream},
+    pin, select,
+    sync::{mpsc, oneshot},
+};
+use tracing::{Level, debug, enabled, error, info};
+
+use crate::emulator::{
+    DebugEvent, DebugStopReason, EmulatorClient, EmulatorCommand, SimId, VBWatchpointType,
+};
+
+mod registers;
+mod request;
+mod response;
+
+pub struct GdbServer {
+    sim_id: SimId,
+    client: EmulatorClient,
+    status: Arc<Mutex<GdbServerStatus>>,
+    killer: Option<oneshot::Sender<()>>,
+}
+
+impl GdbServer {
+    pub fn new(sim_id: SimId, client: EmulatorClient) -> Self {
+        Self {
+            sim_id,
+            client,
+            status: Arc::new(Mutex::new(GdbServerStatus::Stopped)),
+            killer: None,
+        }
+    }
+
+    pub fn status(&self) -> GdbServerStatus {
+        self.status.lock().unwrap().clone()
+    }
+
+    pub fn start(&mut self, port: u16) {
+        *self.status.lock().unwrap() = GdbServerStatus::Connecting;
+        let sim_id = self.sim_id;
+        let client = self.client.clone();
+        let status = self.status.clone();
+        let (tx, rx) = oneshot::channel();
+        self.killer = Some(tx);
+        thread::spawn(move || {
+            tokio::runtime::Builder::new_current_thread()
+                .enable_all()
+                .build()
+                .unwrap()
+                .block_on(async move {
+                    select! {
+                        _ = run_server(sim_id, client.clone(), port, &status) => {}
+                        _ = rx => {
+                            client.send_command(EmulatorCommand::StopDebugging(sim_id));
+                            *status.lock().unwrap() = GdbServerStatus::Stopped;
+                        }
+                    }
+                })
+        });
+    }
+
+    pub fn stop(&mut self) {
+        if let Some(killer) = self.killer.take() {
+            let _ = killer.send(());
+        }
+    }
+}
+
+impl Drop for GdbServer {
+    fn drop(&mut self) {
+        self.stop();
+    }
+}
+
+async fn run_server(
+    sim_id: SimId,
+    client: EmulatorClient,
+    port: u16,
+    status: &Mutex<GdbServerStatus>,
+) {
+    let (debug_sink, mut debug_source) = mpsc::unbounded_channel();
+    client.send_command(EmulatorCommand::StartDebugging(sim_id, debug_sink));
+
+    info!("Connecting to debugger on port {port}...");
+    let connect_future = try_connect(port, status);
+    pin!(connect_future);
+
+    let stream = loop {
+        select! {
+            stream = &mut connect_future => {
+                if let Some(stream) = stream {
+                    break stream;
+                } else {
+                    return;
+                }
+            }
+            event = debug_source.recv() => {
+                if event.is_none() {
+                    // The sim has stopped (or was never started)
+                    *status.lock().unwrap() = GdbServerStatus::Stopped;
+                    return;
+                }
+            }
+        }
+    };
+    info!("Connected!");
+    let mut connection = GdbConnection::new(sim_id, client);
+    match connection.run(stream, debug_source).await {
+        Ok(()) => {
+            info!("Finished debugging.");
+            *status.lock().unwrap() = GdbServerStatus::Stopped;
+        }
+        Err(error) => {
+            error!(%error, "Error from debugger.");
+            *status.lock().unwrap() = GdbServerStatus::Error(error.to_string());
+        }
+    }
+}
+
+async fn try_connect(port: u16, status: &Mutex<GdbServerStatus>) -> Option<TcpStream> {
+    *status.lock().unwrap() = GdbServerStatus::Connecting;
+    let listener = match TcpListener::bind(("127.0.0.1", port)).await {
+        Ok(l) => l,
+        Err(err) => {
+            error!(%err, "Could not open port.");
+            *status.lock().unwrap() = GdbServerStatus::Error(err.to_string());
+            return None;
+        }
+    };
+    match listener.accept().await {
+        Ok((stream, _)) => {
+            *status.lock().unwrap() = GdbServerStatus::Running;
+            Some(stream)
+        }
+        Err(err) => {
+            error!(%err, "Could not connect to debugger.");
+            *status.lock().unwrap() = GdbServerStatus::Error(err.to_string());
+            None
+        }
+    }
+}
+
+#[derive(Clone)]
+pub enum GdbServerStatus {
+    Stopped,
+    Connecting,
+    Running,
+    Error(String),
+}
+
+impl GdbServerStatus {
+    pub fn running(&self) -> bool {
+        matches!(self, Self::Connecting | Self::Running)
+    }
+}
+
+struct GdbConnection {
+    sim_id: SimId,
+    client: EmulatorClient,
+    ack_messages: bool,
+    stop_reason: Option<DebugStopReason>,
+    response_buf: Option<Vec<u8>>,
+    memory_buf: Option<Vec<u8>>,
+}
+
+impl GdbConnection {
+    fn new(sim_id: SimId, client: EmulatorClient) -> Self {
+        Self {
+            sim_id,
+            client,
+            ack_messages: true,
+            stop_reason: None,
+            response_buf: None,
+            memory_buf: None,
+        }
+    }
+    async fn run(
+        &mut self,
+        stream: TcpStream,
+        mut debug_source: mpsc::UnboundedReceiver<DebugEvent>,
+    ) -> Result<()> {
+        let (rx, mut tx) = stream.into_split();
+        let mut request_source = RequestSource::new(BufReader::new(rx));
+        loop {
+            let response = select! {
+                maybe_event = debug_source.recv() => {
+                    let Some(event) = maybe_event else {
+                        // debugger has stopped running
+                        break;
+                    };
+                    self.handle_event(event)
+                }
+                maybe_request = request_source.recv() => {
+                    let req = maybe_request?;
+                    self.handle_request(req)?
+                }
+            };
+            if let Some(res) = response {
+                let buffer = res.finish();
+                if enabled!(Level::DEBUG) {
+                    match std::str::from_utf8(&buffer) {
+                        Ok(text) => debug!("response: {text}"),
+                        Err(_) => debug!("response: {buffer:02x?}"),
+                    }
+                }
+                tx.write_all(&buffer).await?;
+                self.response_buf = Some(buffer);
+                tx.flush().await?;
+            }
+        }
+        Ok(())
+    }
+
+    fn handle_event(&mut self, event: DebugEvent) -> Option<Response> {
+        let res = match event {
+            DebugEvent::Stopped(reason) => {
+                if self.stop_reason.is_some_and(|r| r == reason) {
+                    return None;
+                }
+                self.stop_reason = Some(reason);
+                self.response()
+                    .write_str(&debug_stop_reason_string(self.stop_reason))
+            }
+        };
+        Some(res)
+    }
+
+    fn handle_request(&mut self, mut req: Request<'_>) -> Result<Option<Response>> {
+        debug!("received {:02x?}", req);
+
+        if req.kind == RequestKind::Signal {
+            self.client
+                .send_command(EmulatorCommand::DebugInterrupt(self.sim_id));
+            return Ok(None); // we'll send a message when the emulator reports it has stopped
+        }
+
+        let res = if req.match_str("QStartNoAckMode") {
+            let res = self.response().write_str("OK");
+            self.ack_messages = false;
+            res
+        } else if req.match_str("qSupported:") {
+            self.response()
+                .write_str("multiprocess+;swbreak+;vContSupported+;PacketSize=10000;SupportedWatchpointTypes=x86_64,aarch64-bas,aarch64-mask")
+        } else if req
+            .match_some_str([
+                "QThreadSuffixSupported",
+                "QListThreadsInStopReply",
+                "QEnableErrorStrings",
+            ])
+            .is_some()
+        {
+            self.response().write_str("OK")
+        } else if req.match_str("qHostInfo") {
+            self.response().write_str(&format!(
+                "triple:{};endian:little;ptrsize:4;",
+                hex::encode("v810-unknown-vb")
+            ))
+        } else if req.match_str("qProcessInfo") {
+            self.response().write_str(&format!(
+                "pid:1;triple:{};endian:little;ptrsize:4;",
+                hex::encode("v810-unknown-vb")
+            ))
+        } else if req.match_str("qRegisterInfo") {
+            let mut get_reg_info = || {
+                let register = req.match_hex::<usize>()?;
+                REGISTERS.get(register)
+            };
+            if let Some(reg_info) = get_reg_info() {
+                self.response().write_str(&reg_info.to_description())
+            } else {
+                self.response()
+            }
+        } else if req.match_str("vCont?") {
+            self.response().write_str("vCont;c;s;")
+        } else if req.match_str("qC") {
+            // The v810 has no threads, so report that the "current thread" is 1.
+            self.response().write_str("QCp1.t1")
+        } else if req.match_str("qfThreadInfo") {
+            self.response().write_str("mp1.t1")
+        } else if req.match_str("qsThreadInfo") {
+            self.response().write_str("l")
+        } else if req.match_str("k") {
+            bail!("debug process was killed");
+        } else if req.match_str("?") {
+            self.response()
+                .write_str(&debug_stop_reason_string(self.stop_reason))
+        } else if req.match_some_str(["c", "vCont;c:"]).is_some() {
+            self.client
+                .send_command(EmulatorCommand::DebugContinue(self.sim_id));
+            self.stop_reason = None;
+            // Don't send a response until we hit a breakpoint or get interrupted
+            return Ok(None);
+        } else if req.match_some_str(["s", "vCont;s:"]).is_some() {
+            self.client
+                .send_command(EmulatorCommand::DebugStep(self.sim_id));
+            self.stop_reason = None;
+            // Don't send a response until we hit a breakpoint or get interrupted
+            return Ok(None);
+        } else if req.match_str("p") {
+            let mut read_register = || {
+                let register_index = req.match_hex::<usize>()?;
+                let register = REGISTERS.get(register_index)?.to_vb_register();
+                let (tx, rx) = ::oneshot::channel();
+                self.client
+                    .send_command(EmulatorCommand::ReadRegister(self.sim_id, register, tx));
+                rx.recv().ok()
+            };
+            if let Some(value) = read_register() {
+                self.response().write_hex(value)
+            } else {
+                self.response()
+            }
+        } else if req.match_str("P") {
+            let mut write_register = || {
+                let register_index = req.match_hex::<usize>()?;
+                let register = REGISTERS.get(register_index)?.to_vb_register();
+                if !req.match_str("=") {
+                    return None;
+                }
+                let value = {
+                    let mut buffer = [0; 4];
+                    if !req.match_hex_bytes(&mut buffer) {
+                        return None;
+                    }
+                    u32::from_le_bytes(buffer)
+                };
+                self.client.send_command(EmulatorCommand::WriteRegister(
+                    self.sim_id,
+                    register,
+                    value,
+                ));
+                Some(())
+            };
+            if let Some(()) = write_register() {
+                self.response().write_str("OK")
+            } else {
+                self.response()
+            }
+        } else if let Some(op) = req.match_some_str(["m", "x"]) {
+            let mut read_memory = || {
+                let (start, length) = parse_memory_range(&mut req)?;
+                let mut buf = self.memory_buf.take().unwrap_or_default();
+                buf.clear();
+                if length == 0 {
+                    return Some(buf);
+                }
+                let (tx, rx) = ::oneshot::channel();
+                self.client.send_command(EmulatorCommand::ReadMemory(
+                    self.sim_id,
+                    start,
+                    length,
+                    buf,
+                    tx,
+                ));
+                rx.recv().ok()
+            };
+            if let Some(memory) = read_memory() {
+                let mut res = self.response();
+                if memory.is_empty() {
+                    res = res.write_str("OK");
+                } else if op == "m" {
+                    // send the hex-encoded byte stream
+                    for byte in &memory {
+                        res = res.write_hex(*byte);
+                    }
+                } else {
+                    // send the raw byte stream
+                    for byte in &memory {
+                        res = res.write_byte(*byte);
+                    }
+                }
+                self.memory_buf = Some(memory);
+                res
+            } else {
+                self.response()
+            }
+        } else if let Some(op) = req.match_some_str(["M", "X"]) {
+            let mut write_memory = || {
+                let (start, length) = parse_memory_range(&mut req)?;
+                if length == 0 {
+                    return Some(());
+                }
+                if !req.match_str(":") {
+                    return None;
+                }
+                let mut buf = self.memory_buf.take().unwrap_or_default();
+                buf.resize(length, 0);
+                let successful_read = if op == "M" {
+                    req.match_hex_bytes(&mut buf)
+                } else {
+                    req.match_bytes(&mut buf)
+                };
+                if !successful_read {
+                    self.memory_buf = Some(buf);
+                    return None;
+                }
+                let (tx, rx) = ::oneshot::channel();
+                self.client
+                    .send_command(EmulatorCommand::WriteMemory(self.sim_id, start, buf, tx));
+                let buf = rx.recv().ok()?;
+                self.memory_buf = Some(buf);
+                Some(())
+            };
+            if write_memory().is_some() {
+                self.response().write_str("OK")
+            } else {
+                self.response()
+            }
+        } else if req.match_str("Z") {
+            let mut parse_request = || {
+                let type_ = req.match_hex::<u8>()?;
+                if !req.match_str(",") {
+                    return None;
+                }
+                let address = req.match_hex()?;
+                if type_ == 0 || type_ == 1 {
+                    return Some(EmulatorCommand::AddBreakpoint(self.sim_id, address));
+                }
+                if !req.match_str(",") {
+                    return None;
+                }
+                let length = req.match_hex()?;
+                let watch = match type_ {
+                    2 => VBWatchpointType::Write,
+                    3 => VBWatchpointType::Read,
+                    4 => VBWatchpointType::Access,
+                    _ => return None,
+                };
+                Some(EmulatorCommand::AddWatchpoint(
+                    self.sim_id,
+                    address,
+                    length,
+                    watch,
+                ))
+            };
+            if let Some(command) = parse_request() {
+                self.client.send_command(command);
+                self.response().write_str("OK")
+            } else {
+                self.response()
+            }
+        } else if req.match_str("z") {
+            let mut parse_request = || {
+                let type_ = req.match_hex::<u8>()?;
+                if !req.match_str(",") {
+                    return None;
+                }
+                let address = req.match_hex()?;
+                if type_ == 0 || type_ == 1 {
+                    return Some(EmulatorCommand::RemoveBreakpoint(self.sim_id, address));
+                }
+                if !req.match_str(",") {
+                    return None;
+                }
+                let length = req.match_hex()?;
+                let watch = match type_ {
+                    2 => VBWatchpointType::Write,
+                    3 => VBWatchpointType::Read,
+                    4 => VBWatchpointType::Access,
+                    _ => return None,
+                };
+                Some(EmulatorCommand::RemoveWatchpoint(
+                    self.sim_id,
+                    address,
+                    length,
+                    watch,
+                ))
+            };
+            if let Some(command) = parse_request() {
+                self.client.send_command(command);
+                self.response().write_str("OK")
+            } else {
+                self.response()
+            }
+        } else {
+            // unrecognized command
+            self.response()
+        };
+        Ok(Some(res))
+    }
+
+    fn response(&mut self) -> Response {
+        Response::new(
+            self.response_buf.take().unwrap_or_default(),
+            self.ack_messages,
+        )
+    }
+}
+
+impl Drop for GdbConnection {
+    fn drop(&mut self) {
+        self.client
+            .send_command(EmulatorCommand::StopDebugging(self.sim_id));
+    }
+}
+
+// parse a memory range into a start and a length.
+fn parse_memory_range(req: &mut Request<'_>) -> Option<(u32, usize)> {
+    let start = req.match_hex::<u64>()?;
+    if !req.match_str(",") {
+        return None;
+    };
+    let length = req.match_hex::<usize>()?;
+    let Ok(start) = u32::try_from(start) else {
+        // The v810 has a 32-bit address space.
+        // Addresses wrap within that space, but we don't need to implement that for 64-bit addresses.
+        // Just refuse to return any info for addresses above 0xffffffff.
+        return Some((0, 0));
+    };
+    let length = length.min((u32::MAX - start) as usize + 1);
+    Some((start, length))
+}
+
+fn debug_stop_reason_string(reason: Option<DebugStopReason>) -> String {
+    let mut result = String::new();
+    result += if reason.is_some_and(|r| r != DebugStopReason::Paused) {
+        "T05;"
+    } else {
+        "T00;"
+    };
+    if let Some(DebugStopReason::Breakpoint) = reason {
+        result += "swbreak;";
+    }
+    if let Some(DebugStopReason::Watchpoint(watch, address)) = reason {
+        result += match watch {
+            VBWatchpointType::Write => "watch:",
+            VBWatchpointType::Read => "rwatch:",
+            VBWatchpointType::Access => "awatch:",
+        };
+        result += &format!("{address:08x};");
+    }
+
+    result += "thread:p1.t1;threads:p1.t1;";
+
+    if let Some(reason) = reason {
+        result += "reason:";
+        result += match reason {
+            DebugStopReason::Trace => "trace;",
+            DebugStopReason::Breakpoint => "breakpoint;",
+            DebugStopReason::Watchpoint(_, _) => "watchpoint;",
+            DebugStopReason::Paused => "trap;",
+        };
+    }
+
+    if let Some(DebugStopReason::Watchpoint(_, address)) = reason {
+        result += "description:";
+        result += &hex::encode(address.to_string());
+        result += ";";
+    }
+
+    result
+}

src/gdbserver/registers.rs

@@ -0,0 +1,130 @@
+use crate::emulator::VBRegister;
+
+pub struct RegisterInfo {
+    dwarf: u32,
+    name: &'static str,
+    set: &'static str,
+    alt_name: Option<&'static str>,
+    generic: Option<&'static str>,
+}
+
+impl RegisterInfo {
+    pub fn to_description(&self) -> String {
+        let mut string = format!("name:{}", self.name);
+        if let Some(alt) = self.alt_name {
+            string.push_str(&format!(";alt-name:{alt}"));
+        }
+        string.push_str(&format!(
+            ";bitsize:32;offset:{};encoding:uint;format:hex;set:{};dwarf:{}",
+            self.dwarf * 4,
+            self.set,
+            self.dwarf
+        ));
+        if let Some(generic) = self.generic {
+            string.push_str(&format!(";generic:{generic}"));
+        }
+        string
+    }
+
+    pub fn to_vb_register(&self) -> VBRegister {
+        match self.dwarf {
+            0..32 => VBRegister::Program(self.dwarf),
+            32..40 => VBRegister::System(self.dwarf - 32),
+            40..42 => VBRegister::System(self.dwarf - 16),
+            42..45 => VBRegister::System(self.dwarf - 13),
+            45 => VBRegister::PC,
+            other => panic!("unexpected DWARF register {other}"),
+        }
+    }
+}
+
+macro_rules! register {
+    ($set:expr, $dwarf:expr, $name:expr) => {
+        RegisterInfo {
+            dwarf: $dwarf,
+            name: $name,
+            set: $set,
+            alt_name: None,
+            generic: None,
+        }
+    };
+    ($set:expr, $dwarf:expr, $name:expr, alt: $alt:expr) => {
+        RegisterInfo {
+            dwarf: $dwarf,
+            name: $name,
+            set: $set,
+            alt_name: Some($alt),
+            generic: None,
+        }
+    };
+    ($set:expr, $dwarf:expr, $name:expr, generic: $generic:expr) => {
+        RegisterInfo {
+            dwarf: $dwarf,
+            name: $name,
+            set: $set,
+            alt_name: None,
+            generic: Some($generic),
+        }
+    };
+    ($set:expr, $dwarf:expr, $name:expr, alt: $alt:expr, generic: $generic:expr) => {
+        RegisterInfo {
+            dwarf: $dwarf,
+            name: $name,
+            set: $set,
+            alt_name: Some($alt),
+            generic: Some($generic),
+        }
+    };
+}
+
+const GENERAL: &str = "General Purpose Registers";
+const SPECIAL: &str = "Special Registers";
+
+pub const REGISTERS: [RegisterInfo; 46] = [
+    register!(GENERAL, 0, "r0"),
+    register!(GENERAL, 1, "r1"),
+    register!(GENERAL, 2, "fp", alt: "r2", generic: "fp"),
+    register!(GENERAL, 3, "sp", alt: "r3", generic: "sp"),
+    register!(GENERAL, 4, "gp", alt: "r4"),
+    register!(GENERAL, 5, "tp", alt: "r5"),
+    register!(GENERAL, 6, "r6", generic: "arg1"),
+    register!(GENERAL, 7, "r7", generic: "arg2"),
+    register!(GENERAL, 8, "r8", generic: "arg3"),
+    register!(GENERAL, 9, "r9", generic: "arg4"),
+    register!(GENERAL, 10, "r10"),
+    register!(GENERAL, 11, "r11"),
+    register!(GENERAL, 12, "r12"),
+    register!(GENERAL, 13, "r13"),
+    register!(GENERAL, 14, "r14"),
+    register!(GENERAL, 15, "r15"),
+    register!(GENERAL, 16, "r16"),
+    register!(GENERAL, 17, "r17"),
+    register!(GENERAL, 18, "r18"),
+    register!(GENERAL, 19, "r19"),
+    register!(GENERAL, 20, "r20"),
+    register!(GENERAL, 21, "r21"),
+    register!(GENERAL, 22, "r22"),
+    register!(GENERAL, 23, "r23"),
+    register!(GENERAL, 24, "r24"),
+    register!(GENERAL, 25, "r25"),
+    register!(GENERAL, 26, "r26"),
+    register!(GENERAL, 27, "r27"),
+    register!(GENERAL, 28, "r28"),
+    register!(GENERAL, 29, "r29"),
+    register!(GENERAL, 30, "r30"),
+    register!(GENERAL, 31, "lp", alt: "r31", generic: "ra"),
+    register!(SPECIAL, 32, "eipc", alt: "sr0"),
+    register!(SPECIAL, 33, "eipsw", alt: "sr1"),
+    register!(SPECIAL, 34, "fepc", alt: "sr2"),
+    register!(SPECIAL, 35, "fepsw", alt: "sr3"),
+    register!(SPECIAL, 36, "ecr", alt: "sr4"),
+    register!(SPECIAL, 37, "psw", alt: "sr5", generic: "flags"),
+    register!(SPECIAL, 38, "pir", alt: "sr6"),
+    register!(SPECIAL, 39, "tkcw", alt: "sr7"),
+    register!(SPECIAL, 40, "chcw", alt: "sr24"),
+    register!(SPECIAL, 41, "adtre", alt: "sr25"),
+    register!(SPECIAL, 42, "sr29"),
+    register!(SPECIAL, 43, "sr30"),
+    register!(SPECIAL, 44, "sr31"),
+    register!(SPECIAL, 45, "pc", generic: "pc"),
+];

src/gdbserver/request.rs

@@ -0,0 +1,202 @@
+use anyhow::{Result, bail};
+use atoi::FromRadix16;
+use tokio::io::{AsyncRead, AsyncReadExt as _};
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum RequestKind {
+    Signal,
+    Command,
+}
+impl RequestKind {
+    fn name(self) -> &'static str {
+        match self {
+            Self::Signal => "Signal",
+            Self::Command => "Command",
+        }
+    }
+}
+
+pub struct Request<'a> {
+    pub kind: RequestKind,
+    buffer: &'a [u8],
+}
+
+impl std::fmt::Debug for Request<'_> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let mut ds = f.debug_tuple(self.kind.name());
+        match self.kind {
+            RequestKind::Signal => ds.field(&self.buffer),
+            RequestKind::Command => match std::str::from_utf8(self.buffer) {
+                Ok(str) => ds.field(&str),
+                Err(_) => ds.field(&self.buffer),
+            },
+        };
+        ds.finish()
+    }
+}
+
+impl Request<'_> {
+    pub fn match_str(&mut self, prefix: &str) -> bool {
+        if let Some(new_buffer) = self.buffer.strip_prefix(prefix.as_bytes()) {
+            self.buffer = new_buffer;
+            return true;
+        }
+        false
+    }
+
+    pub fn match_some_str<'a, I: IntoIterator<Item = &'a str>>(
+        &mut self,
+        prefixes: I,
+    ) -> Option<&'a str> {
+        prefixes.into_iter().find(|&prefix| self.match_str(prefix))
+    }
+
+    pub fn match_hex<I: FromRadix16>(&mut self) -> Option<I> {
+        match I::from_radix_16(self.buffer) {
+            (_, 0) => None,
+            (val, used) => {
+                self.buffer = self.buffer.split_at(used).1;
+                Some(val)
+            }
+        }
+    }
+
+    pub fn match_hex_bytes(&mut self, buffer: &mut [u8]) -> bool {
+        if self.buffer.len() < buffer.len() * 2 {
+            return false;
+        }
+        for (i, item) in buffer.iter_mut().enumerate() {
+            match u8::from_radix_16(&self.buffer[(i * 2)..(i * 2) + 2]) {
+                (byte, 2) => *item = byte,
+                _ => return false,
+            };
+        }
+        self.buffer = self.buffer.split_at(buffer.len()).1;
+        true
+    }
+
+    pub fn match_bytes(&mut self, buffer: &mut [u8]) -> bool {
+        if self.buffer.len() < buffer.len() {
+            return false;
+        }
+        buffer.copy_from_slice(&self.buffer[0..buffer.len()]);
+        self.buffer = self.buffer.split_at(buffer.len()).1;
+        true
+    }
+}
+
+pub struct RequestSource<R> {
+    reader: R,
+    buffer: Vec<u8>,
+    state: RequestReadState,
+}
+
+impl<R: AsyncRead + Unpin> RequestSource<R> {
+    pub fn new(reader: R) -> Self {
+        Self {
+            reader,
+            buffer: vec![],
+            state: RequestReadState::Header,
+        }
+    }
+
+    pub async fn recv(&mut self) -> Result<Request<'_>> {
+        let mut char = self.reader.read_u8().await?;
+        if matches!(self.state, RequestReadState::Start) {
+            self.buffer.clear();
+            self.state = RequestReadState::Header;
+        }
+        if matches!(self.state, RequestReadState::Header) {
+            // Just ignore positive acks
+            while char == b'+' {
+                char = self.reader.read_u8().await?;
+            }
+            if char == b'-' {
+                bail!("no support for negative acks");
+            }
+            if char == 0x03 {
+                // This is how the client "cancels an in-flight request"
+                self.buffer.push(char);
+                self.state = RequestReadState::Start;
+                return Ok(Request {
+                    kind: RequestKind::Signal,
+                    buffer: &self.buffer,
+                });
+            }
+            if char != b'$' {
+                // Messages are supposed to start with a dollar sign
+                bail!("malformed message");
+            }
+            self.state = RequestReadState::Body {
+                checksum: 0,
+                escaping: false,
+            };
+            char = self.reader.read_u8().await?;
+        }
+        while let RequestReadState::Body { checksum, escaping } = &mut self.state {
+            if char == b'#' && !*escaping {
+                self.state = RequestReadState::Checksum {
+                    expected: *checksum,
+                    actual: 0,
+                    digits: 0,
+                };
+                char = self.reader.read_u8().await?;
+                break;
+            }
+            *checksum = checksum.wrapping_add(char);
+
+            if *escaping {
+                // escaped character
+                self.buffer.push(char ^ 0x20);
+                *escaping = false;
+            } else if char == b'}' {
+                // next character will be escaped
+                *escaping = true;
+            } else {
+                self.buffer.push(char);
+            }
+            char = self.reader.read_u8().await?;
+        }
+        while let RequestReadState::Checksum {
+            expected,
+            actual,
+            digits,
+        } = &mut self.state
+        {
+            let digit = match char {
+                b'0'..=b'9' => char - b'0',
+                b'a'..=b'f' => char - b'a' + 10,
+                b'A'..=b'F' => char - b'A' + 10,
+                _ => bail!("invalid checksum"),
+            };
+            *actual = (*actual << 4) + digit;
+            *digits += 1;
+            if *digits == 2 {
+                if *expected != *actual {
+                    bail!("mismatched checksum");
+                }
+                self.state = RequestReadState::Start;
+                return Ok(Request {
+                    kind: RequestKind::Command,
+                    buffer: &self.buffer,
+                });
+            }
+            char = self.reader.read_u8().await?;
+        }
+        unreachable!();
+    }
+}
+
+enum RequestReadState {
+    Start,
+    Header,
+    Body {
+        checksum: u8,
+        escaping: bool,
+    },
+    Checksum {
+        expected: u8,
+        actual: u8,
+        digits: u8,
+    },
+}

src/gdbserver/response.rs

@@ -0,0 +1,63 @@
+use num_traits::ToBytes;
+
+pub struct Response {
+    buffer: Vec<u8>,
+    checksum: u8,
+}
+
+impl Response {
+    pub fn new(mut buffer: Vec<u8>, ack: bool) -> Self {
+        buffer.clear();
+        if ack {
+            buffer.push(b'+');
+        }
+        buffer.push(b'$');
+        Self {
+            buffer,
+            checksum: 0,
+        }
+    }
+
+    pub fn write_str(self, str: &str) -> Self {
+        let mut me = self;
+        for byte in str.as_bytes() {
+            me = me.write_byte(*byte);
+        }
+        me
+    }
+
+    pub fn write_byte(mut self, byte: u8) -> Self {
+        if byte == b'}' || byte == b'#' || byte == b'$' || byte == b'*' {
+            self.buffer.push(b'}');
+            self.checksum = self.checksum.wrapping_add(b'}');
+            let escaped = byte ^ 0x20;
+            self.buffer.push(escaped);
+            self.checksum = self.checksum.wrapping_add(escaped);
+        } else {
+            self.buffer.push(byte);
+            self.checksum = self.checksum.wrapping_add(byte);
+        }
+        self
+    }
+
+    pub fn write_hex<T: ToBytes>(mut self, value: T) -> Self {
+        for byte in value.to_le_bytes().as_ref() {
+            for digit in [(byte >> 4), (byte & 0xf)] {
+                let char = if digit > 9 {
+                    b'a' + digit - 10
+                } else {
+                    b'0' + digit
+                };
+                self.buffer.push(char);
+                self.checksum = self.checksum.wrapping_add(char);
+            }
+        }
+        self
+    }
+
+    pub fn finish(mut self) -> Vec<u8> {
+        let checksum = self.checksum;
+        self.buffer.push(b'#');
+        self.write_hex(checksum).buffer
+    }
+}

src/graphics.rs

@@ -0,0 +1,142 @@
+use std::{
+    sync::{
+        Arc, Mutex, MutexGuard,
+        atomic::{AtomicU64, Ordering},
+        mpsc,
+    },
+    thread,
+};
+
+use anyhow::{Result, bail};
+use itertools::Itertools as _;
+use wgpu::{
+    Device, Extent3d, Origin3d, Queue, TexelCopyBufferLayout, TexelCopyTextureInfo, Texture,
+    TextureDescriptor, TextureFormat, TextureUsages, TextureView, TextureViewDescriptor,
+};
+
+#[derive(Debug)]
+pub struct TextureSink {
+    buffers: Arc<BufferPool>,
+    sink: mpsc::Sender<u64>,
+}
+
+impl TextureSink {
+    pub fn new(device: &Device, queue: Queue) -> (Self, TextureView) {
+        let texture = Self::create_texture(device);
+        let view = texture.create_view(&TextureViewDescriptor::default());
+        let buffers = Arc::new(BufferPool::new());
+        let (sink, source) = mpsc::channel();
+        let bufs = buffers.clone();
+        thread::spawn(move || {
+            let mut local_buf = vec![0; 384 * 224 * 2];
+            while let Ok(id) = source.recv() {
+                {
+                    let Some(bytes) = bufs.read(id) else {
+                        continue;
+                    };
+                    local_buf.copy_from_slice(bytes.as_slice());
+                }
+                Self::write_texture(&queue, &texture, local_buf.as_slice());
+            }
+        });
+        let sink = Self { buffers, sink };
+        (sink, view)
+    }
+
+    pub fn queue_render(&mut self, bytes: &[u8]) -> Result<()> {
+        let id = {
+            let (mut buf, id) = self.buffers.write()?;
+            buf.copy_from_slice(bytes);
+            id
+        };
+        self.sink.send(id)?;
+        Ok(())
+    }
+
+    fn create_texture(device: &Device) -> Texture {
+        let desc = TextureDescriptor {
+            label: Some("eyes"),
+            size: Extent3d {
+                width: 384,
+                height: 224,
+                depth_or_array_layers: 1,
+            },
+            mip_level_count: 1,
+            sample_count: 1,
+            dimension: wgpu::TextureDimension::D2,
+            format: TextureFormat::Rg8Unorm,
+            usage: TextureUsages::COPY_DST | TextureUsages::TEXTURE_BINDING,
+            view_formats: &[TextureFormat::Rg8Unorm],
+        };
+        device.create_texture(&desc)
+    }
+
+    fn write_texture(queue: &Queue, texture: &Texture, bytes: &[u8]) {
+        let texture = TexelCopyTextureInfo {
+            texture,
+            mip_level: 0,
+            origin: Origin3d::ZERO,
+            aspect: wgpu::TextureAspect::All,
+        };
+        let size = Extent3d {
+            width: 384,
+            height: 224,
+            depth_or_array_layers: 1,
+        };
+        let data_layout = TexelCopyBufferLayout {
+            offset: 0,
+            bytes_per_row: Some(384 * 2),
+            rows_per_image: Some(224),
+        };
+        queue.write_texture(texture, bytes, data_layout, size);
+    }
+}
+
+#[derive(Debug)]
+struct BufferPool {
+    buffers: [Buffer; 3],
+}
+impl BufferPool {
+    fn new() -> Self {
+        Self {
+            buffers: std::array::from_fn(|i| Buffer::new(i as u64)),
+        }
+    }
+
+    fn read(&self, id: u64) -> Option<MutexGuard<'_, Vec<u8>>> {
+        let buf = self
+            .buffers
+            .iter()
+            .find(|buf| buf.id.load(Ordering::Acquire) == id)?;
+        buf.data.lock().ok()
+    }
+
+    fn write(&self) -> Result<(MutexGuard<'_, Vec<u8>>, u64)> {
+        let (min, max) = self
+            .buffers
+            .iter()
+            .minmax_by_key(|buf| buf.id.load(Ordering::Acquire))
+            .into_option()
+            .unwrap();
+        let Ok(lock) = min.data.lock() else {
+            bail!("lock was poisoned")
+        };
+        let id = max.id.load(Ordering::Acquire) + 1;
+        min.id.store(id, Ordering::Release);
+        Ok((lock, id))
+    }
+}
+
+#[derive(Debug)]
+struct Buffer {
+    data: Mutex<Vec<u8>>,
+    id: AtomicU64,
+}
+impl Buffer {
+    fn new(id: u64) -> Self {
+        Self {
+            data: Mutex::new(vec![0; 384 * 224 * 2]),
+            id: AtomicU64::new(id),
+        }
+    }
+}

src/images.rs

@@ -0,0 +1,337 @@
+use std::{
+    collections::{HashMap, hash_map::Entry},
+    ops::Deref,
+    sync::{Arc, Mutex, Weak},
+    thread,
+    time::Duration,
+};
+
+use egui::{
+    Color32, ColorImage, TextureHandle,
+    epaint::ImageDelta,
+    generate_loader_id,
+    load::{LoadError, SizedTexture, TextureLoader, TexturePoll},
+};
+use tokio::{sync::mpsc, time::timeout};
+
+use crate::emulator::SimId;
+
+pub struct ImageTextureLoader {
+    cache: Mutex<HashMap<String, ImageEntry>>,
+    sender: mpsc::UnboundedSender<Box<dyn ImageRendererImpl>>,
+}
+
+impl ImageTextureLoader {
+    pub fn new() -> Self {
+        let (sender, receiver) = mpsc::unbounded_channel();
+        thread::spawn(move || {
+            tokio::runtime::Builder::new_current_thread()
+                .enable_all()
+                .build()
+                .unwrap()
+                .block_on(async move {
+                    let mut worker = ImageTextureLoaderWorker {
+                        receiver,
+                        renderers: vec![],
+                    };
+                    worker.run().await
+                })
+        });
+        Self {
+            cache: Mutex::new(HashMap::new()),
+            sender,
+        }
+    }
+
+    pub fn add<const N: usize, R: ImageRenderer<N> + 'static>(
+        &self,
+        sim_id: SimId,
+        renderer: R,
+        params: R::Params,
+    ) -> ImageParams<R::Params> {
+        let states = renderer.sizes().map(ImageState::new);
+        let images = renderer
+            .sizes()
+            .map(|[width, height]| ImageBuffer::new(width, height));
+        {
+            let mut cache = self.cache.lock().unwrap();
+            for (name, state) in renderer.names().into_iter().zip(&states) {
+                let url = format!("vip://{sim_id}/{name}");
+                let entry = ImageEntry {
+                    size: state.size.map(|i| i as f32),
+                    data: Arc::downgrade(&state.sink),
+                    texture: None,
+                };
+                match cache.entry(url) {
+                    Entry::Vacant(e) => {
+                        e.insert(entry);
+                    }
+                    Entry::Occupied(mut e) => {
+                        // Only overwrite an old entry if that entry is dead.
+                        // Otherwise, we clear out the reference to a texture actually in use.
+                        if e.get().data.strong_count() == 0 {
+                            e.insert(entry);
+                        }
+                    }
+                }
+            }
+        }
+        let sink = Arc::new(Mutex::new(params.clone()));
+        let _ = self.sender.send(Box::new(ImageRendererWrapper {
+            renderer,
+            params: Arc::downgrade(&sink),
+            images,
+            states,
+        }));
+        ImageParams {
+            value: params,
+            sink,
+        }
+    }
+}
+
+impl TextureLoader for ImageTextureLoader {
+    fn id(&self) -> &str {
+        generate_loader_id!(ImageTextureLoader2)
+    }
+
+    fn load(
+        &self,
+        ctx: &egui::Context,
+        uri: &str,
+        texture_options: egui::TextureOptions,
+        _size_hint: egui::SizeHint,
+    ) -> Result<TexturePoll, LoadError> {
+        let mut cache = self.cache.lock().unwrap();
+        let Some(entry) = cache.get_mut(uri) else {
+            return Err(LoadError::NotSupported);
+        };
+        if texture_options != egui::TextureOptions::NEAREST {
+            return Err(LoadError::Loading(
+                "Only TextureOptions::NEAREST are supported".into(),
+            ));
+        }
+        let Some(data) = entry.data.upgrade() else {
+            cache.remove(uri);
+            return Err(LoadError::Loading("Backing loader no longer exists".into()));
+        };
+        match (data.lock().unwrap().take(), entry.texture.as_ref()) {
+            (Some(update), Some(handle)) => {
+                let delta = ImageDelta::full(update, texture_options);
+                ctx.tex_manager().write().set(handle.id(), delta);
+                let texture = SizedTexture::new(handle, entry.size);
+                Ok(TexturePoll::Ready { texture })
+            }
+            (Some(update), None) => {
+                let handle = ctx.load_texture(uri, update, texture_options);
+                let texture = SizedTexture::new(&handle, entry.size);
+                entry.texture.replace(handle);
+                Ok(TexturePoll::Ready { texture })
+            }
+            (None, Some(handle)) => {
+                let texture = SizedTexture::new(handle, entry.size);
+                Ok(TexturePoll::Ready { texture })
+            }
+            (None, None) => {
+                let size = entry.size.into();
+                Ok(TexturePoll::Pending { size: Some(size) })
+            }
+        }
+    }
+
+    fn forget(&self, uri: &str) {
+        let _ = uri;
+    }
+
+    fn forget_all(&self) {}
+
+    fn byte_size(&self) -> usize {
+        self.cache
+            .lock()
+            .unwrap()
+            .values()
+            .map(|entry| {
+                let [width, height] = entry.size;
+                width as usize * height as usize * 4
+            })
+            .sum()
+    }
+}
+
+struct ImageTextureLoaderWorker {
+    receiver: mpsc::UnboundedReceiver<Box<dyn ImageRendererImpl>>,
+    renderers: Vec<Box<dyn ImageRendererImpl>>,
+}
+
+impl ImageTextureLoaderWorker {
+    async fn run(&mut self) {
+        loop {
+            if self.renderers.is_empty() {
+                // if we have nothing to do, block until we have something to do
+                if self.receiver.recv_many(&mut self.renderers, 64).await == 0 {
+                    // shutdown
+                    return;
+                }
+                while let Ok(renderer) = self.receiver.try_recv() {
+                    self.renderers.push(renderer);
+                }
+            }
+            self.renderers
+                .retain_mut(|renderer| renderer.try_update().is_ok());
+            // wait up to 10 ms for more renderers
+            if timeout(
+                Duration::from_millis(10),
+                self.receiver.recv_many(&mut self.renderers, 64),
+            )
+            .await
+            .is_ok()
+            {
+                while let Ok(renderer) = self.receiver.try_recv() {
+                    self.renderers.push(renderer);
+                }
+            }
+        }
+    }
+}
+
+pub struct ImageBuffer {
+    pub size: [usize; 2],
+    pub pixels: Vec<Color32>,
+}
+
+impl ImageBuffer {
+    pub fn new(width: usize, height: usize) -> Self {
+        Self {
+            size: [width, height],
+            pixels: vec![Color32::BLACK; width * height],
+        }
+    }
+
+    pub fn clear(&mut self) {
+        for pixel in self.pixels.iter_mut() {
+            *pixel = Color32::BLACK;
+        }
+    }
+
+    pub fn write(&mut self, coords: (usize, usize), pixel: Color32) {
+        self.pixels[coords.1 * self.size[0] + coords.0] = pixel;
+    }
+
+    pub fn add(&mut self, coords: (usize, usize), pixel: Color32) {
+        let index = coords.1 * self.size[0] + coords.0;
+        let old = self.pixels[index];
+        self.pixels[index] = Color32::from_rgb(
+            old.r() + pixel.r(),
+            old.g() + pixel.g(),
+            old.b() + pixel.b(),
+        );
+    }
+
+    pub fn changed(&self, image: &ColorImage) -> bool {
+        image.pixels.iter().zip(&self.pixels).any(|(a, b)| a != b)
+    }
+
+    pub fn read(&self, image: &mut ColorImage) {
+        image.pixels.copy_from_slice(&self.pixels);
+    }
+}
+
+struct ImageEntry {
+    size: [f32; 2],
+    data: Weak<Mutex<Option<Arc<ColorImage>>>>,
+    texture: Option<TextureHandle>,
+}
+
+pub struct ImageParams<T> {
+    value: T,
+    sink: Arc<Mutex<T>>,
+}
+
+impl<T> Deref for ImageParams<T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        &self.value
+    }
+}
+
+impl<T: Clone + Eq> ImageParams<T> {
+    pub fn write(&mut self, value: T) {
+        if self.value != value {
+            self.value = value.clone();
+            *self.sink.lock().unwrap() = value;
+        }
+    }
+}
+
+pub trait ImageRenderer<const N: usize>: Send {
+    type Params: Clone + Send;
+    fn names(&self) -> [&str; N];
+    fn sizes(&self) -> [[usize; 2]; N];
+    fn render(&mut self, params: &Self::Params, images: &mut [ImageBuffer; N]);
+}
+
+#[derive(Clone)]
+struct ImageState {
+    size: [usize; 2],
+    buffers: [Arc<ColorImage>; 2],
+    last_buffer: usize,
+    sink: Arc<Mutex<Option<Arc<ColorImage>>>>,
+}
+
+impl ImageState {
+    fn new(size: [usize; 2]) -> Self {
+        let buffers = [
+            Arc::new(ColorImage::filled(size, Color32::BLACK)),
+            Arc::new(ColorImage::filled(size, Color32::BLACK)),
+        ];
+        let sink = buffers[0].clone();
+        Self {
+            size,
+            buffers,
+            last_buffer: 0,
+            sink: Arc::new(Mutex::new(Some(sink))),
+        }
+    }
+    fn try_send_update(&mut self, image: &ImageBuffer) {
+        let last = &self.buffers[self.last_buffer];
+        if !image.changed(last) {
+            return;
+        }
+
+        let next_buffer = (self.last_buffer + 1) % self.buffers.len();
+        let next = &mut self.buffers[next_buffer];
+        image.read(Arc::make_mut(next));
+        self.last_buffer = next_buffer;
+        self.sink.lock().unwrap().replace(next.clone());
+    }
+}
+
+struct ImageRendererWrapper<const N: usize, R: ImageRenderer<N>> {
+    renderer: R,
+    params: Weak<Mutex<R::Params>>,
+    images: [ImageBuffer; N],
+    states: [ImageState; N],
+}
+
+trait ImageRendererImpl: Send {
+    fn try_update(&mut self) -> Result<(), ()>;
+}
+
+impl<const N: usize, R: ImageRenderer<N> + Send> ImageRendererImpl for ImageRendererWrapper<N, R> {
+    fn try_update(&mut self) -> Result<(), ()> {
+        let params = match self.params.upgrade() {
+            Some(params) => params.lock().unwrap().clone(),
+            None => {
+                // the UI isn't using this anymore
+                return Err(());
+            }
+        };
+        self.renderer.render(&params, &mut self.images);
+
+        for (state, image) in self.states.iter_mut().zip(&self.images) {
+            state.try_send_update(image);
+        }
+        Ok(())
+    }
+}

src/input.rs

@@ -0,0 +1,789 @@
+use std::{
+    cmp::Ordering,
+    collections::{HashMap, hash_map::Entry},
+    fmt::Display,
+    str::FromStr,
+    sync::{Arc, Mutex, RwLock},
+};
+
+use anyhow::anyhow;
+use egui::{Event, Key, KeyboardShortcut, Modifiers};
+use gilrs::{Axis, Button, Gamepad, GamepadId, ev::Code};
+use serde::{Deserialize, Serialize};
+use winit::keyboard::{KeyCode, PhysicalKey};
+
+use crate::{
+    emulator::{SimId, VBKey},
+    persistence::Persistence,
+};
+
+#[derive(Clone, PartialEq, Eq, Hash)]
+struct DeviceId(u16, u16);
+
+impl FromStr for DeviceId {
+    type Err = anyhow::Error;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let mut ids = s.split("-");
+        let vendor_id: u16 = ids.next().ok_or(anyhow!("missing vendor id"))?.parse()?;
+        let product_id: u16 = ids.next().ok_or(anyhow!("missing product id"))?.parse()?;
+        Ok(Self(vendor_id, product_id))
+    }
+}
+
+impl Display for DeviceId {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_fmt(format_args!("{}-{}", self.0, self.1))
+    }
+}
+
+#[derive(Clone)]
+pub struct GamepadInfo {
+    pub id: GamepadId,
+    pub name: String,
+    device_id: DeviceId,
+    pub bound_to: Option<SimId>,
+}
+
+pub trait Mappings {
+    fn mapping_names(&self) -> HashMap<VBKey, Vec<String>>;
+    fn clear_mappings(&mut self, key: VBKey);
+    fn clear_all_mappings(&mut self);
+    fn use_default_mappings(&mut self);
+}
+
+#[derive(Clone, Copy, Serialize, Deserialize)]
+pub struct AxisMapping {
+    pub neg: VBKey,
+    pub pos: VBKey,
+    pub pair: Option<Code>,
+}
+impl Default for AxisMapping {
+    fn default() -> Self {
+        Self {
+            neg: VBKey::empty(),
+            pos: VBKey::empty(),
+            pair: None,
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct GamepadMapping {
+    buttons: HashMap<Code, VBKey>,
+    axes: HashMap<Code, AxisMapping>,
+    default_buttons: HashMap<Code, VBKey>,
+    default_axes: HashMap<Code, AxisMapping>,
+}
+
+impl GamepadMapping {
+    fn for_gamepad(gamepad: &Gamepad) -> Self {
+        let mut default_buttons = HashMap::new();
+        let mut default_button = |btn: Button, key: VBKey| {
+            if let Some(code) = gamepad.button_code(btn) {
+                default_buttons.insert(code, key);
+            }
+        };
+        default_button(Button::South, VBKey::A);
+        default_button(Button::West, VBKey::B);
+        default_button(Button::RightTrigger, VBKey::RT);
+        default_button(Button::LeftTrigger, VBKey::LT);
+        default_button(Button::Start, VBKey::STA);
+        default_button(Button::Select, VBKey::SEL);
+
+        let mut default_axes = HashMap::new();
+        let mut default_axis = |axis: Axis, neg: VBKey, pos: VBKey| {
+            if let Some(code) = gamepad.axis_code(axis) {
+                let pair = axis.second_axis().and_then(|a| gamepad.axis_code(a));
+                default_axes.insert(code, AxisMapping { neg, pos, pair });
+            }
+        };
+        default_axis(Axis::LeftStickX, VBKey::LL, VBKey::LR);
+        default_axis(Axis::LeftStickY, VBKey::LD, VBKey::LU);
+        default_axis(Axis::RightStickX, VBKey::RL, VBKey::RR);
+        default_axis(Axis::RightStickY, VBKey::RD, VBKey::RU);
+        default_axis(Axis::DPadX, VBKey::LL, VBKey::LR);
+        default_axis(Axis::DPadY, VBKey::LD, VBKey::LU);
+
+        Self {
+            buttons: default_buttons.clone(),
+            axes: default_axes.clone(),
+            default_buttons,
+            default_axes,
+        }
+    }
+
+    pub fn add_button_mapping(&mut self, key: VBKey, code: Code) {
+        let entry = self.buttons.entry(code).or_insert(VBKey::empty());
+        *entry = entry.union(key);
+    }
+
+    pub fn add_axis_neg_mapping(&mut self, key: VBKey, code: Code) {
+        let entry = self.axes.entry(code).or_default();
+        entry.neg = entry.neg.union(key);
+    }
+
+    pub fn add_axis_pos_mapping(&mut self, key: VBKey, code: Code) {
+        let entry = self.axes.entry(code).or_default();
+        entry.pos = entry.pos.union(key);
+    }
+
+    fn save_mappings(&self) -> PersistedGamepadMapping {
+        fn flatten<V: Copy>(values: &HashMap<Code, V>) -> Vec<(Code, V)> {
+            values.iter().map(|(k, v)| (*k, *v)).collect()
+        }
+        PersistedGamepadMapping {
+            buttons: flatten(&self.buttons),
+            axes: flatten(&self.axes),
+            default_buttons: flatten(&self.default_buttons),
+            default_axes: flatten(&self.default_axes),
+        }
+    }
+
+    fn from_mappings(mappings: &PersistedGamepadMapping) -> Self {
+        fn unflatten<V: Copy>(values: &[(Code, V)]) -> HashMap<Code, V> {
+            values.iter().map(|(k, v)| (*k, *v)).collect()
+        }
+        Self {
+            buttons: unflatten(&mappings.buttons),
+            axes: unflatten(&mappings.axes),
+            default_buttons: unflatten(&mappings.default_buttons),
+            default_axes: unflatten(&mappings.default_axes),
+        }
+    }
+}
+
+impl Mappings for GamepadMapping {
+    fn mapping_names(&self) -> HashMap<VBKey, Vec<String>> {
+        let mut results: HashMap<VBKey, Vec<String>> = HashMap::new();
+        for (axis, mapping) in &self.axes {
+            for key in mapping.neg.iter() {
+                results.entry(key).or_default().push(format!("-{axis}"));
+            }
+            for key in mapping.pos.iter() {
+                results.entry(key).or_default().push(format!("+{axis}"));
+            }
+        }
+        for (button, keys) in &self.buttons {
+            for key in keys.iter() {
+                results.entry(key).or_default().push(format!("{button}"));
+            }
+        }
+        results
+    }
+
+    fn clear_mappings(&mut self, key: VBKey) {
+        self.axes.retain(|_, mapping| {
+            mapping.neg = mapping.neg.difference(key);
+            mapping.pos = mapping.pos.difference(key);
+            !(mapping.neg.is_empty() && mapping.pos.is_empty())
+        });
+        self.buttons.retain(|_, keys| {
+            *keys = keys.difference(key);
+            !keys.is_empty()
+        });
+    }
+
+    fn clear_all_mappings(&mut self) {
+        self.axes.clear();
+        self.buttons.clear();
+    }
+
+    fn use_default_mappings(&mut self) {
+        self.axes = self.default_axes.clone();
+        self.buttons = self.default_buttons.clone();
+    }
+}
+
+#[derive(Default)]
+pub struct InputMapping {
+    keys: HashMap<PhysicalKey, VBKey>,
+    gamepads: HashMap<GamepadId, Arc<RwLock<GamepadMapping>>>,
+}
+
+impl InputMapping {
+    pub fn map_keyboard(&self, key: &PhysicalKey) -> Option<VBKey> {
+        self.keys.get(key).copied()
+    }
+
+    pub fn map_button(&self, id: &GamepadId, code: &Code) -> Option<VBKey> {
+        let mappings = self.gamepads.get(id)?.read().unwrap();
+        mappings.buttons.get(code).copied()
+    }
+
+    pub fn map_axis(&self, id: &GamepadId, code: &Code) -> Option<AxisMapping> {
+        let mappings = self.gamepads.get(id)?.read().unwrap();
+        mappings.axes.get(code).copied()
+    }
+
+    pub fn add_keyboard_mapping(&mut self, key: VBKey, keyboard_key: PhysicalKey) {
+        let entry = self.keys.entry(keyboard_key).or_insert(VBKey::empty());
+        *entry = entry.union(key);
+    }
+
+    fn save_mappings(&self) -> PersistedKeyboardMapping {
+        PersistedKeyboardMapping {
+            keys: self.keys.iter().map(|(k, v)| (*k, *v)).collect(),
+        }
+    }
+
+    fn restore_mappings(&mut self, persisted: &PersistedKeyboardMapping) {
+        self.keys = persisted.keys.iter().map(|(k, v)| (*k, *v)).collect();
+    }
+}
+
+impl Mappings for InputMapping {
+    fn mapping_names(&self) -> HashMap<VBKey, Vec<String>> {
+        let mut results: HashMap<VBKey, Vec<String>> = HashMap::new();
+        for (keyboard_key, keys) in &self.keys {
+            let name = match keyboard_key {
+                PhysicalKey::Code(code) => format!("{code:?}"),
+                k => format!("{k:?}"),
+            };
+            for key in keys.iter() {
+                results.entry(key).or_default().push(name.clone());
+            }
+        }
+        results
+    }
+
+    fn clear_mappings(&mut self, key: VBKey) {
+        self.keys.retain(|_, keys| {
+            *keys = keys.difference(key);
+            !keys.is_empty()
+        });
+    }
+
+    fn clear_all_mappings(&mut self) {
+        self.keys.clear();
+    }
+
+    fn use_default_mappings(&mut self) {
+        self.keys.clear();
+        let mut default_key = |code, key| {
+            self.keys.insert(PhysicalKey::Code(code), key);
+        };
+        default_key(KeyCode::KeyA, VBKey::SEL);
+        default_key(KeyCode::KeyS, VBKey::STA);
+        default_key(KeyCode::KeyD, VBKey::B);
+        default_key(KeyCode::KeyF, VBKey::A);
+        default_key(KeyCode::KeyE, VBKey::LT);
+        default_key(KeyCode::KeyR, VBKey::RT);
+        default_key(KeyCode::KeyI, VBKey::RU);
+        default_key(KeyCode::KeyJ, VBKey::RL);
+        default_key(KeyCode::KeyK, VBKey::RD);
+        default_key(KeyCode::KeyL, VBKey::RR);
+        default_key(KeyCode::ArrowUp, VBKey::LU);
+        default_key(KeyCode::ArrowLeft, VBKey::LL);
+        default_key(KeyCode::ArrowDown, VBKey::LD);
+        default_key(KeyCode::ArrowRight, VBKey::LR);
+    }
+}
+
+#[derive(Clone)]
+pub struct MappingProvider {
+    persistence: Persistence,
+    first_gamepad_is_p2: bool,
+    device_mappings: Arc<RwLock<HashMap<DeviceId, Arc<RwLock<GamepadMapping>>>>>,
+    sim_mappings: HashMap<SimId, Arc<RwLock<InputMapping>>>,
+    gamepad_info: Arc<RwLock<HashMap<GamepadId, GamepadInfo>>>,
+}
+
+impl MappingProvider {
+    pub fn new(persistence: Persistence, first_gamepad_is_p2: bool) -> Self {
+        let mut sim_mappings = HashMap::new();
+        let mut device_mappings = HashMap::new();
+
+        let mut p1_mappings = InputMapping::default();
+        let mut p2_mappings = InputMapping::default();
+
+        if let Ok(persisted) = persistence.load_config::<PersistedInputMappings>("mappings") {
+            p1_mappings.restore_mappings(&persisted.p1_keyboard);
+            p2_mappings.restore_mappings(&persisted.p2_keyboard);
+
+            for (device_id, mappings) in persisted.gamepads {
+                let Ok(device_id) = device_id.parse::<DeviceId>() else {
+                    continue;
+                };
+                let gamepad = GamepadMapping::from_mappings(&mappings);
+                device_mappings.insert(device_id, Arc::new(RwLock::new(gamepad)));
+            }
+        } else {
+            p1_mappings.use_default_mappings();
+        }
+
+        sim_mappings.insert(SimId::Player1, Arc::new(RwLock::new(p1_mappings)));
+        sim_mappings.insert(SimId::Player2, Arc::new(RwLock::new(p2_mappings)));
+        Self {
+            persistence,
+            device_mappings: Arc::new(RwLock::new(device_mappings)),
+            gamepad_info: Arc::new(RwLock::new(HashMap::new())),
+            sim_mappings,
+            first_gamepad_is_p2,
+        }
+    }
+
+    pub fn for_sim(&self, sim_id: SimId) -> &Arc<RwLock<InputMapping>> {
+        self.sim_mappings.get(&sim_id).unwrap()
+    }
+
+    pub fn for_gamepad(&self, gamepad_id: GamepadId) -> Option<Arc<RwLock<GamepadMapping>>> {
+        let lock = self.gamepad_info.read().unwrap();
+        let device_id = lock.get(&gamepad_id)?.device_id.clone();
+        drop(lock);
+        let lock = self.device_mappings.read().unwrap();
+        lock.get(&device_id).cloned()
+    }
+
+    pub fn handle_gamepad_connect(&self, gamepad: &Gamepad) {
+        let device_id = DeviceId(
+            gamepad.vendor_id().unwrap_or_default(),
+            gamepad.product_id().unwrap_or_default(),
+        );
+        let mut lock = self.device_mappings.write().unwrap();
+        let mappings = match lock.entry(device_id.clone()) {
+            Entry::Vacant(entry) => {
+                let mappings = GamepadMapping::for_gamepad(gamepad);
+                entry.insert(Arc::new(RwLock::new(mappings)))
+            }
+            Entry::Occupied(entry) => entry.into_mut(),
+        }
+        .clone();
+        drop(lock);
+        let mut lock = self.gamepad_info.write().unwrap();
+        let players = if self.first_gamepad_is_p2 {
+            vec![SimId::Player2, SimId::Player1]
+        } else {
+            vec![SimId::Player1, SimId::Player2]
+        };
+        let bound_to = players
+            .into_iter()
+            .find(|sim_id| lock.values().all(|info| info.bound_to != Some(*sim_id)));
+        if let Entry::Vacant(entry) = lock.entry(gamepad.id()) {
+            let info = GamepadInfo {
+                id: *entry.key(),
+                name: gamepad.name().to_string(),
+                device_id,
+                bound_to,
+            };
+            entry.insert(info);
+        }
+        drop(lock);
+        if let Some(sim_id) = bound_to {
+            self.for_sim(sim_id)
+                .write()
+                .unwrap()
+                .gamepads
+                .insert(gamepad.id(), mappings);
+        }
+    }
+
+    pub fn handle_gamepad_disconnect(&self, gamepad_id: GamepadId) {
+        let mut lock = self.gamepad_info.write().unwrap();
+        let Some(info) = lock.remove(&gamepad_id) else {
+            return;
+        };
+        if let Some(sim_id) = info.bound_to {
+            self.for_sim(sim_id)
+                .write()
+                .unwrap()
+                .gamepads
+                .remove(&gamepad_id);
+        }
+    }
+
+    pub fn assign_gamepad(&self, gamepad_id: GamepadId, sim_id: SimId) {
+        self.unassign_gamepad(gamepad_id);
+        let mut lock = self.gamepad_info.write().unwrap();
+        let Some(info) = lock.get_mut(&gamepad_id) else {
+            return;
+        };
+        info.bound_to = Some(sim_id);
+        let device_id = info.device_id.clone();
+        drop(lock);
+        let Some(device_mappings) = self
+            .device_mappings
+            .write()
+            .unwrap()
+            .get(&device_id)
+            .cloned()
+        else {
+            return;
+        };
+        self.for_sim(sim_id)
+            .write()
+            .unwrap()
+            .gamepads
+            .insert(gamepad_id, device_mappings);
+    }
+
+    pub fn unassign_gamepad(&self, gamepad_id: GamepadId) {
+        let mut lock = self.gamepad_info.write().unwrap();
+        let Some(info) = lock.get_mut(&gamepad_id) else {
+            return;
+        };
+        if let Some(sim_id) = info.bound_to {
+            let mut sim_mapping = self.for_sim(sim_id).write().unwrap();
+            sim_mapping.gamepads.remove(&gamepad_id);
+        }
+        info.bound_to = None;
+    }
+
+    pub fn gamepad_info(&self) -> Vec<GamepadInfo> {
+        self.gamepad_info
+            .read()
+            .unwrap()
+            .values()
+            .cloned()
+            .collect()
+    }
+
+    pub fn save(&self) {
+        let p1_keyboard = self.for_sim(SimId::Player1).read().unwrap().save_mappings();
+        let p2_keyboard = self.for_sim(SimId::Player2).read().unwrap().save_mappings();
+        let mut gamepads = HashMap::new();
+        for (device_id, gamepad) in self.device_mappings.read().unwrap().iter() {
+            let mapping = gamepad.read().unwrap().save_mappings();
+            gamepads.insert(device_id.to_string(), mapping);
+        }
+        let persisted = PersistedInputMappings {
+            p1_keyboard,
+            p2_keyboard,
+            gamepads,
+        };
+        let _ = self.persistence.save_config("mappings", &persisted);
+    }
+}
+
+#[derive(Serialize, Deserialize)]
+struct PersistedInputMappings {
+    p1_keyboard: PersistedKeyboardMapping,
+    p2_keyboard: PersistedKeyboardMapping,
+    gamepads: HashMap<String, PersistedGamepadMapping>,
+}
+
+#[derive(Serialize, Deserialize)]
+struct PersistedKeyboardMapping {
+    keys: Vec<(PhysicalKey, VBKey)>,
+}
+
+#[derive(Serialize, Deserialize)]
+struct PersistedGamepadMapping {
+    buttons: Vec<(Code, VBKey)>,
+    axes: Vec<(Code, AxisMapping)>,
+    default_buttons: Vec<(Code, VBKey)>,
+    default_axes: Vec<(Code, AxisMapping)>,
+}
+
+#[derive(Clone, Copy, Serialize, Deserialize, PartialEq, Eq, Hash)]
+pub enum Command {
+    OpenRom,
+    ReloadRom,
+    Quit,
+    FrameAdvance,
+    FastForward(u32),
+    Reset,
+    PauseResume,
+    Screenshot,
+    // if you update this, update Command::all and add a default
+}
+
+impl Command {
+    pub fn all() -> [Self; 8] {
+        [
+            Self::OpenRom,
+            Self::ReloadRom,
+            Self::Quit,
+            Self::PauseResume,
+            Self::Reset,
+            Self::FrameAdvance,
+            Self::FastForward(0),
+            Self::Screenshot,
+        ]
+    }
+
+    pub fn name(self) -> &'static str {
+        match self {
+            Self::OpenRom => "Open ROM",
+            Self::ReloadRom => "Reload ROM",
+            Self::Quit => "Exit",
+            Self::PauseResume => "Pause/Resume",
+            Self::Reset => "Reset",
+            Self::FrameAdvance => "Frame Advance",
+            Self::FastForward(_) => "Fast Forward",
+            Self::Screenshot => "Screenshot",
+        }
+    }
+}
+
+impl Display for Command {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(self.name())
+    }
+}
+
+struct Shortcuts {
+    all: Vec<(Command, KeyboardShortcut)>,
+    by_command: HashMap<Command, KeyboardShortcut>,
+}
+
+impl Default for Shortcuts {
+    fn default() -> Self {
+        let mut shortcuts = Shortcuts {
+            all: vec![],
+            by_command: HashMap::new(),
+        };
+        shortcuts.set(
+            Command::OpenRom,
+            KeyboardShortcut::new(Modifiers::COMMAND, Key::O),
+        );
+        shortcuts.set(
+            Command::ReloadRom,
+            KeyboardShortcut::new(Modifiers::COMMAND | Modifiers::SHIFT, Key::F5),
+        );
+        shortcuts.set(
+            Command::Quit,
+            KeyboardShortcut::new(Modifiers::COMMAND, Key::Q),
+        );
+        shortcuts.set(
+            Command::PauseResume,
+            KeyboardShortcut::new(Modifiers::NONE, Key::F5),
+        );
+        shortcuts.set(
+            Command::Reset,
+            KeyboardShortcut::new(Modifiers::SHIFT, Key::F5),
+        );
+        shortcuts.set(
+            Command::FrameAdvance,
+            KeyboardShortcut::new(Modifiers::NONE, Key::F6),
+        );
+        shortcuts.set(
+            Command::FastForward(0),
+            KeyboardShortcut::new(Modifiers::NONE, Key::Space),
+        );
+        shortcuts.set(
+            Command::Screenshot,
+            KeyboardShortcut::new(Modifiers::NONE, Key::F12),
+        );
+        shortcuts
+    }
+}
+
+impl Shortcuts {
+    fn set(&mut self, command: Command, shortcut: KeyboardShortcut) {
+        if self.by_command.insert(command, shortcut).is_some() {
+            for (cmd, sht) in &mut self.all {
+                if *cmd == command {
+                    *sht = shortcut;
+                    break;
+                }
+            }
+        } else {
+            self.all.push((command, shortcut));
+        }
+        self.all.sort_by(|l, r| order_shortcut(l.1, r.1));
+    }
+
+    fn unset(&mut self, command: Command) {
+        if self.by_command.remove(&command).is_some() {
+            self.all.retain(|(c, _)| *c != command);
+        }
+    }
+
+    fn save(&self, saved: &mut PersistedSettings) {
+        for command in Command::all() {
+            let shortcut = self.by_command.get(&command).copied();
+            saved.shortcuts.push((command, shortcut));
+        }
+    }
+}
+
+fn order_shortcut(left: KeyboardShortcut, right: KeyboardShortcut) -> Ordering {
+    left.logical_key.cmp(&right.logical_key).then_with(|| {
+        specificity(left.modifiers)
+            .cmp(&specificity(right.modifiers))
+            .reverse()
+    })
+}
+
+fn specificity(modifiers: egui::Modifiers) -> usize {
+    let mut mods = 0;
+    if modifiers.alt {
+        mods += 1;
+    }
+    if modifiers.command || modifiers.ctrl {
+        mods += 1;
+    }
+    if modifiers.shift {
+        mods += 1;
+    }
+    mods
+}
+
+#[derive(Serialize, Deserialize, Default)]
+struct PersistedSettings {
+    shortcuts: Vec<(Command, Option<KeyboardShortcut>)>,
+    #[serde(default)]
+    ff_settings: FastForwardSettings,
+}
+
+#[derive(Default, Clone)]
+struct ShortcutState {
+    ff_toggled: bool,
+}
+
+#[derive(Default)]
+struct Settings {
+    shortcuts: Shortcuts,
+    ff_settings: FastForwardSettings,
+    state: ShortcutState,
+}
+
+impl Settings {
+    fn save(&self) -> PersistedSettings {
+        let mut saved = PersistedSettings {
+            shortcuts: vec![],
+            ff_settings: self.ff_settings.clone(),
+        };
+        self.shortcuts.save(&mut saved);
+        saved
+    }
+}
+
+#[derive(Clone)]
+pub struct ShortcutProvider {
+    persistence: Persistence,
+    settings: Arc<Mutex<Settings>>,
+}
+
+impl ShortcutProvider {
+    pub fn new(persistence: Persistence) -> Self {
+        let mut settings = Settings::default();
+        if let Ok(saved) = persistence.load_config::<PersistedSettings>("shortcuts") {
+            for (command, shortcut) in saved.shortcuts {
+                if let Some(shortcut) = shortcut {
+                    settings.shortcuts.set(command, shortcut);
+                } else {
+                    settings.shortcuts.unset(command);
+                }
+            }
+            settings.ff_settings = saved.ff_settings;
+        };
+        Self {
+            persistence,
+            settings: Arc::new(Mutex::new(settings)),
+        }
+    }
+
+    pub fn shortcut_for(&self, command: Command) -> Option<KeyboardShortcut> {
+        let lock = self.settings.lock().unwrap();
+        lock.shortcuts.by_command.get(&command).copied()
+    }
+
+    pub fn ff_settings(&self) -> FastForwardSettings {
+        let lock = self.settings.lock().unwrap();
+        lock.ff_settings.clone()
+    }
+
+    pub fn consume_all(&self, input: &mut egui::InputState) -> Vec<Command> {
+        let mut lock = self.settings.lock().unwrap();
+        let mut state = lock.state.clone();
+        let mut consumed = vec![];
+        for (command, shortcut) in &lock.shortcuts.all {
+            input.events.retain(|event| {
+                let Event::Key {
+                    key,
+                    pressed,
+                    repeat,
+                    modifiers,
+                    ..
+                } = event
+                else {
+                    return true;
+                };
+                if *key != shortcut.logical_key || !modifiers.contains(shortcut.modifiers) {
+                    return true;
+                }
+                if matches!(command, Command::FastForward(_)) {
+                    if *repeat {
+                        return true;
+                    }
+                    let sped_up = if lock.ff_settings.toggle {
+                        if !*pressed {
+                            return true;
+                        }
+                        state.ff_toggled = !state.ff_toggled;
+                        state.ff_toggled
+                    } else {
+                        *pressed
+                    };
+                    let speed = if sped_up { lock.ff_settings.speed } else { 1 };
+                    consumed.push(Command::FastForward(speed));
+                    false
+                } else {
+                    if !*pressed {
+                        return true;
+                    }
+                    consumed.push(*command);
+                    false
+                }
+            });
+        }
+        lock.state = state;
+        consumed
+    }
+
+    pub fn set(&self, command: Command, shortcut: KeyboardShortcut) {
+        let updated = {
+            let mut lock = self.settings.lock().unwrap();
+            lock.shortcuts.set(command, shortcut);
+            lock.save()
+        };
+        let _ = self.persistence.save_config("shortcuts", &updated);
+    }
+
+    pub fn unset(&self, command: Command) {
+        let updated = {
+            let mut lock = self.settings.lock().unwrap();
+            lock.shortcuts.unset(command);
+            lock.save()
+        };
+        let _ = self.persistence.save_config("shortcuts", &updated);
+    }
+
+    pub fn update_ff_settings(&self, ff_settings: FastForwardSettings) {
+        let updated = {
+            let mut lock = self.settings.lock().unwrap();
+            lock.ff_settings = ff_settings;
+            if !lock.ff_settings.toggle {
+                lock.state.ff_toggled = false;
+            }
+            lock.save()
+        };
+        let _ = self.persistence.save_config("shortcuts", &updated);
+    }
+
+    pub fn reset(&self) {
+        let updated = {
+            let mut lock = self.settings.lock().unwrap();
+            *lock = Settings::default();
+            lock.save()
+        };
+        let _ = self.persistence.save_config("shortcuts", &updated);
+    }
+}
+
+#[derive(Serialize, Deserialize, Clone)]
+pub struct FastForwardSettings {
+    pub toggle: bool,
+    pub speed: u32,
+}
+
+impl Default for FastForwardSettings {
+    fn default() -> Self {
+        Self {
+            toggle: false,
+            speed: 10,
+        }
+    }
+}

src/main.rs

@@ -0,0 +1,154 @@
+// hide console in release mode
+#![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
+
+use std::{process, time::SystemTime};
+
+use anyhow::{Result, bail};
+use app::Application;
+use clap::Parser;
+use emulator::EmulatorBuilder;
+use thread_priority::{ThreadBuilder, ThreadPriority};
+use tracing::error;
+use tracing_subscriber::{EnvFilter, Layer, layer::SubscriberExt, util::SubscriberInitExt};
+use winit::event_loop::{ControlFlow, EventLoop};
+
+use crate::{
+    config::{AppConfig, CliArgs, SimConfig},
+    emulator::SimId,
+    persistence::Persistence,
+};
+
+mod app;
+mod audio;
+mod config;
+mod controller;
+mod emulator;
+mod filepicker;
+mod gdbserver;
+mod graphics;
+mod images;
+mod input;
+mod memory;
+mod persistence;
+mod profiler;
+mod window;
+
+fn init_logger() {
+    let directives = std::env::var("RUST_LOG").unwrap_or("error,lemur=info".into());
+    let filter = EnvFilter::builder().parse_lossy(directives);
+    let layer = tracing_subscriber::fmt::layer().with_filter(filter);
+    tracing_subscriber::registry().with(layer).init();
+}
+
+fn set_panic_handler() {
+    std::panic::set_hook(Box::new(|info| {
+        let mut message = String::new();
+        if let Some(msg) = info.payload().downcast_ref::<&str>() {
+            message += &format!("{msg}\n");
+        } else if let Some(msg) = info.payload().downcast_ref::<String>() {
+            message += &format!("{msg}\n");
+        }
+        if let Some(location) = info.location() {
+            message += &format!(
+                "    in file '{}' at line {}\n",
+                location.file(),
+                location.line()
+            );
+        }
+        let backtrace = std::backtrace::Backtrace::force_capture();
+        message += &format!("stack trace:\n{backtrace:#}\n");
+
+        eprint!("{message}");
+
+        let Some(project_dirs) = directories::ProjectDirs::from("com", "virtual-boy", "Lemur")
+        else {
+            return;
+        };
+        let data_dir = project_dirs.data_dir();
+        if std::fs::create_dir_all(data_dir).is_err() {
+            return;
+        }
+        let timestamp = SystemTime::now()
+            .duration_since(SystemTime::UNIX_EPOCH)
+            .unwrap()
+            .as_millis();
+        let logfile_name = format!("crash-{timestamp}.txt");
+        let _ = std::fs::write(data_dir.join(logfile_name), message);
+    }));
+}
+
+#[cfg(windows)]
+fn set_process_priority_to_high() -> Result<()> {
+    use windows::Win32::{Foundation, System::Threading};
+    let process = unsafe { Threading::GetCurrentProcess() };
+    unsafe { Threading::SetPriorityClass(process, Threading::HIGH_PRIORITY_CLASS)? };
+    unsafe { Foundation::CloseHandle(process)? };
+    Ok(())
+}
+
+fn main() -> Result<()> {
+    init_logger();
+
+    set_panic_handler();
+
+    #[cfg(windows)]
+    set_process_priority_to_high()?;
+
+    let args = CliArgs::parse();
+
+    let persistence = Persistence::new();
+
+    let (mut builder, client) = EmulatorBuilder::new();
+    if let Some(path) = &args.rom {
+        builder = builder.with_rom(path);
+    }
+    if args.debug_port.is_some() {
+        if args.rom.is_none() {
+            bail!("to start debugging, please select a game.");
+        }
+        builder = builder.start_paused(true);
+    }
+    if args.profile {
+        builder = builder.start_paused(true)
+    }
+    let mut config = AppConfig::load(&persistence);
+    if config.update(&args) {
+        let _ = config.save(&persistence);
+    }
+    let p1 = SimConfig::load(&persistence, SimId::Player1);
+    let p2 = SimConfig::load(&persistence, SimId::Player2);
+
+    let watch = args.watch;
+
+    builder = builder
+        .with_audio_on(p1.audio_enabled, p2.audio_enabled)
+        .with_watch_rom(watch, watch);
+
+    ThreadBuilder::default()
+        .name("Emulator".to_owned())
+        .priority(ThreadPriority::Max)
+        .spawn_careless(move || {
+            let mut emulator = match builder.build() {
+                Ok(e) => e,
+                Err(error) => {
+                    error!(%error, "Error initializing emulator");
+                    process::exit(1);
+                }
+            };
+            emulator.run();
+        })?;
+
+    let event_loop = EventLoop::with_user_event().build().unwrap();
+    event_loop.set_control_flow(ControlFlow::Poll);
+    let proxy = event_loop.create_proxy();
+    let handle = event_loop.owned_display_handle();
+    event_loop.run_app(&mut Application::new(
+        client,
+        proxy,
+        handle,
+        persistence,
+        args,
+        config,
+    ))?;
+    Ok(())
+}

src/memory.rs

@@ -0,0 +1,276 @@
+use std::{
+    collections::HashMap,
+    fmt::Debug,
+    iter::FusedIterator,
+    sync::{Arc, Mutex, RwLock, RwLockReadGuard, TryLockError, Weak, atomic::AtomicU64},
+};
+
+use bytemuck::BoxBytes;
+use itertools::Itertools;
+use tracing::warn;
+
+use crate::emulator::{EmulatorClient, EmulatorCommand, SimId};
+
+pub struct MemoryClient {
+    client: EmulatorClient,
+    regions: Mutex<HashMap<MemoryRange, Weak<MemoryRegion>>>,
+}
+
+impl MemoryClient {
+    pub fn new(client: EmulatorClient) -> Self {
+        Self {
+            client,
+            regions: Mutex::new(HashMap::new()),
+        }
+    }
+
+    pub fn watch(&self, sim: SimId, start: u32, length: usize) -> MemoryView {
+        let range = MemoryRange { sim, start, length };
+        let mut regions = self.regions.lock().unwrap_or_else(|e| e.into_inner());
+        let region = regions
+            .get(&range)
+            .and_then(|r| r.upgrade())
+            .unwrap_or_else(|| {
+                let region = Arc::new(MemoryRegion::new(start, length));
+                regions.insert(range, Arc::downgrade(&region));
+                self.client
+                    .send_command(EmulatorCommand::WatchMemory(range, Arc::downgrade(&region)));
+                region
+            });
+        MemoryView { region }
+    }
+
+    pub fn write<T: MemoryValue>(&self, sim: SimId, address: u32, data: &T) {
+        let mut buffer = vec![];
+        data.to_bytes(&mut buffer);
+        let (tx, _) = oneshot::channel();
+        self.client
+            .send_command(EmulatorCommand::WriteMemory(sim, address, buffer, tx));
+    }
+}
+
+fn aligned_memory(start: u32, length: usize) -> BoxBytes {
+    if start.is_multiple_of(4) && length.is_multiple_of(4) {
+        let memory = vec![0u32; length / 4].into_boxed_slice();
+        return bytemuck::box_bytes_of(memory);
+    }
+    if start.is_multiple_of(2) && length.is_multiple_of(2) {
+        let memory = vec![0u16; length / 2].into_boxed_slice();
+        return bytemuck::box_bytes_of(memory);
+    }
+    let memory = vec![0u8; length].into_boxed_slice();
+    bytemuck::box_bytes_of(memory)
+}
+
+pub struct MemoryView {
+    region: Arc<MemoryRegion>,
+}
+
+impl MemoryView {
+    pub fn borrow(&self) -> MemoryRef<'_> {
+        self.region.borrow()
+    }
+}
+
+pub struct MemoryRef<'a> {
+    inner: RwLockReadGuard<'a, BoxBytes>,
+}
+
+pub trait MemoryValue {
+    fn from_bytes(bytes: &[u8]) -> Self;
+    fn to_bytes(&self, buffer: &mut Vec<u8>);
+}
+
+macro_rules! primitive_memory_value_impl {
+    ($T:ty, $L: expr) => {
+        impl MemoryValue for $T {
+            #[inline]
+            fn from_bytes(bytes: &[u8]) -> Self {
+                let bytes: [u8; std::mem::size_of::<$T>()] = std::array::from_fn(|i| bytes[i]);
+                <$T>::from_le_bytes(bytes)
+            }
+            #[inline]
+            fn to_bytes(&self, buffer: &mut Vec<u8>) {
+                buffer.extend_from_slice(&self.to_le_bytes())
+            }
+        }
+    };
+}
+
+primitive_memory_value_impl!(u8, 1);
+primitive_memory_value_impl!(i8, 1);
+primitive_memory_value_impl!(u16, 2);
+primitive_memory_value_impl!(i16, 2);
+primitive_memory_value_impl!(u32, 4);
+primitive_memory_value_impl!(i32, 4);
+
+impl<const N: usize, T: MemoryValue> MemoryValue for [T; N] {
+    #[inline]
+    fn from_bytes(bytes: &[u8]) -> Self {
+        std::array::from_fn(|i| {
+            T::from_bytes(&bytes[i * std::mem::size_of::<T>()..(i + 1) * std::mem::size_of::<T>()])
+        })
+    }
+    #[inline]
+    fn to_bytes(&self, buffer: &mut Vec<u8>) {
+        for item in self {
+            item.to_bytes(buffer);
+        }
+    }
+}
+
+pub struct MemoryIter<'a, T> {
+    bytes: &'a [u8],
+    _phantom: std::marker::PhantomData<T>,
+}
+
+impl<'a, T> MemoryIter<'a, T> {
+    fn new(bytes: &'a [u8]) -> Self {
+        Self {
+            bytes,
+            _phantom: std::marker::PhantomData,
+        }
+    }
+}
+
+impl<T: MemoryValue> Iterator for MemoryIter<'_, T> {
+    type Item = T;
+
+    #[inline]
+    fn next(&mut self) -> Option<Self::Item> {
+        let (bytes, rest) = self.bytes.split_at_checked(std::mem::size_of::<T>())?;
+        self.bytes = rest;
+        Some(T::from_bytes(bytes))
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let size = self.bytes.len() / std::mem::size_of::<T>();
+        (size, Some(size))
+    }
+}
+
+impl<T: MemoryValue> DoubleEndedIterator for MemoryIter<'_, T> {
+    fn next_back(&mut self) -> Option<Self::Item> {
+        let mid = self.bytes.len().checked_sub(std::mem::size_of::<T>())?;
+        // SAFETY: the checked_sub above is effectively a bounds check
+        let (rest, bytes) = unsafe { self.bytes.split_at_unchecked(mid) };
+        self.bytes = rest;
+        Some(T::from_bytes(bytes))
+    }
+}
+
+impl<T: MemoryValue> FusedIterator for MemoryIter<'_, T> {}
+
+impl MemoryRef<'_> {
+    pub fn read<T: MemoryValue>(&self, index: usize) -> T {
+        let from = index * size_of::<T>();
+        let to = from + size_of::<T>();
+        T::from_bytes(&self.inner[from..to])
+    }
+
+    pub fn range<T: MemoryValue>(&self, start: usize, count: usize) -> MemoryIter<'_, T> {
+        let from = start * size_of::<T>();
+        let to = from + (count * size_of::<T>());
+        MemoryIter::new(&self.inner[from..to])
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub struct MemoryRange {
+    pub sim: SimId,
+    pub start: u32,
+    pub length: usize,
+}
+
+const BUFFERS: usize = 4;
+pub struct MemoryRegion {
+    gens: [AtomicU64; BUFFERS],
+    bufs: [RwLock<BoxBytes>; BUFFERS],
+}
+impl Debug for MemoryRegion {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("MemoryRegion")
+            .field("gens", &self.gens)
+            .finish_non_exhaustive()
+    }
+}
+// SAFETY: BoxBytes is meant to be Send+Sync, will be in a future version
+unsafe impl Send for MemoryRegion {}
+// SAFETY: BoxBytes is meant to be Send+Sync, will be in a future version
+unsafe impl Sync for MemoryRegion {}
+
+impl MemoryRegion {
+    fn new(start: u32, length: usize) -> Self {
+        Self {
+            gens: std::array::from_fn(|i| AtomicU64::new(i as u64)),
+            bufs: std::array::from_fn(|_| RwLock::new(aligned_memory(start, length))),
+        }
+    }
+
+    pub fn borrow(&self) -> MemoryRef<'_> {
+        /*
+         * When reading memory, a thread will grab the newest buffer (with the highest gen)
+         * It will only fail to grab the lock if the writer already has it,
+         * but the writer prioritizes older buffers (with lower gens).
+         * So this method will only block if the writer produces three full buffers
+         * in the time it takes the reader to do four atomic reads and grab a lock.
+         * In the unlikely event this happens... just try again.
+         */
+        loop {
+            let newest_index = self
+                .gens
+                .iter()
+                .map(|i| i.load(std::sync::atomic::Ordering::Acquire))
+                .enumerate()
+                .max_by_key(|(_, g)| *g)
+                .map(|(i, _)| i)
+                .unwrap();
+            let inner = match self.bufs[newest_index].try_read() {
+                Ok(inner) => inner,
+                Err(TryLockError::Poisoned(e)) => e.into_inner(),
+                Err(TryLockError::WouldBlock) => {
+                    continue;
+                }
+            };
+            break MemoryRef { inner };
+        }
+    }
+
+    pub fn update(&self, data: &[u8]) {
+        let gens = self
+            .gens
+            .each_ref()
+            .map(|i| i.load(std::sync::atomic::Ordering::Acquire));
+        let next_gen = gens.iter().max().unwrap() + 1;
+        let indices = gens
+            .into_iter()
+            .enumerate()
+            .sorted_by_key(|(_, val)| *val)
+            .map(|(i, _)| i);
+        for index in indices {
+            let mut lock = match self.bufs[index].try_write() {
+                Ok(inner) => inner,
+                Err(TryLockError::Poisoned(e)) => e.into_inner(),
+                Err(TryLockError::WouldBlock) => {
+                    continue;
+                }
+            };
+            lock.copy_from_slice(data);
+            self.gens[index].store(next_gen, std::sync::atomic::Ordering::Release);
+            return;
+        }
+        /*
+         * We have four buffers, and (at time of writing) only three threads interacting with memory:
+         * - The UI thread, reading small regions of memory
+         * - The "image renderer" thread, reading large regions of memory
+         * - The emulation thread, writing memory every so often
+         * So it should be impossible for all four buffers to have a read lock at the same time,
+         *  and (because readers always read the newest buffer) at least one of the oldest three
+         *  buffers will be free the entire time we're in this method.
+         * TL;DR this should never happen.
+         * But if it does, do nothing. This isn't medical software, better to show stale data than crash.
+         */
+        warn!("all buffers were locked by a reader at the same time")
+    }
+}

src/persistence.rs

@@ -0,0 +1,46 @@
+use std::{fs, path::PathBuf};
+
+use anyhow::{Result, bail};
+use directories::ProjectDirs;
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone)]
+pub struct Persistence {
+    dirs: Option<Dirs>,
+}
+
+impl Persistence {
+    pub fn new() -> Self {
+        Self { dirs: init_dirs() }
+    }
+
+    pub fn save_config<T: Serialize>(&self, file: &str, data: &T) -> Result<()> {
+        if let Some(dirs) = self.dirs.as_ref() {
+            let bytes = serde_json::to_vec_pretty(data)?;
+            let filename = dirs.config_dir.join(file).with_extension("json");
+            fs::write(&filename, bytes)?;
+        }
+        Ok(())
+    }
+
+    pub fn load_config<T: for<'a> Deserialize<'a>>(&self, file: &str) -> Result<T> {
+        let Some(dirs) = self.dirs.as_ref() else {
+            bail!("config directory not found");
+        };
+        let filename = dirs.config_dir.join(file).with_extension("json");
+        let bytes = fs::read(filename)?;
+        Ok(serde_json::from_slice(&bytes)?)
+    }
+}
+
+#[derive(Clone)]
+struct Dirs {
+    config_dir: PathBuf,
+}
+
+fn init_dirs() -> Option<Dirs> {
+    let dirs = ProjectDirs::from("com", "virtual-boy", "Lemur")?;
+    let config_dir = dirs.config_dir().to_path_buf();
+    fs::create_dir_all(&config_dir).ok()?;
+    Some(Dirs { config_dir })
+}

src/profiler.rs

@@ -0,0 +1,264 @@
+use std::{
+    sync::{Arc, Mutex},
+    thread,
+};
+
+use anyhow::Result;
+use tokio::{select, sync::mpsc};
+
+use crate::emulator::{
+    EmulatorClient, EmulatorCommand, GameInfo, InlineStack, ProfileEvent, SimEvent, SimId,
+};
+use recording::Recording;
+use state::ProgramState;
+
+mod recording;
+mod state;
+
+pub struct Profiler {
+    sim_id: SimId,
+    client: EmulatorClient,
+    status: Arc<Mutex<ProfilerStatus>>,
+    action: Option<mpsc::UnboundedSender<RecordingAction>>,
+    killer: Option<oneshot::Sender<()>>,
+}
+
+impl Profiler {
+    pub fn new(sim_id: SimId, client: EmulatorClient) -> Self {
+        Self {
+            sim_id,
+            client,
+            status: Arc::new(Mutex::new(ProfilerStatus::Disabled)),
+            action: None,
+            killer: None,
+        }
+    }
+
+    pub fn status(&self) -> ProfilerStatus {
+        self.status.lock().unwrap().clone()
+    }
+
+    pub fn enable(&mut self) {
+        let sim_id = self.sim_id;
+        let client = self.client.clone();
+        let status = self.status.clone();
+        let (action_tx, action_rx) = mpsc::unbounded_channel();
+        self.action = Some(action_tx);
+        let (killer_tx, killer_rx) = oneshot::channel();
+        self.killer = Some(killer_tx);
+        thread::spawn(move || {
+            tokio::runtime::Builder::new_current_thread()
+                .enable_all()
+                .build()
+                .unwrap()
+                .block_on(async move {
+                    select! {
+                        _ = run_profile(sim_id, client, status.clone(), action_rx) => {}
+                        _ = killer_rx => {
+                            *status.lock().unwrap() = ProfilerStatus::Disabled;
+                        }
+                    }
+                })
+        });
+    }
+
+    pub fn disable(&mut self) {
+        if let Some(killer) = self.killer.take() {
+            let _ = killer.send(());
+        }
+    }
+
+    pub fn start_recording(&mut self) {
+        if let Some(action) = &self.action {
+            let _ = action.send(RecordingAction::Start);
+        }
+    }
+
+    pub fn finish_recording(&mut self) -> oneshot::Receiver<Vec<u8>> {
+        let (tx, rx) = oneshot::channel();
+        if let Some(action) = &self.action {
+            let _ = action.send(RecordingAction::Finish(tx));
+        }
+        rx
+    }
+
+    pub fn cancel_recording(&mut self) {
+        if let Some(action) = &self.action {
+            let _ = action.send(RecordingAction::Cancel);
+        }
+    }
+}
+
+impl Drop for Profiler {
+    fn drop(&mut self) {
+        self.disable();
+    }
+}
+
+async fn run_profile(
+    sim_id: SimId,
+    client: EmulatorClient,
+    status: Arc<Mutex<ProfilerStatus>>,
+    mut action_source: mpsc::UnboundedReceiver<RecordingAction>,
+) {
+    let (profile_sync, mut profile_source) = mpsc::unbounded_channel();
+    client.send_command(EmulatorCommand::StartProfiling(sim_id, profile_sync));
+
+    *status.lock().unwrap() = ProfilerStatus::Enabled;
+
+    let mut session = ProfilerSession::new();
+    loop {
+        select! {
+            maybe_event = profile_source.recv() => {
+                let Some(event) = maybe_event else {
+                    break; // emulator thread disconnected
+                };
+                if let Err(error) = handle_event(event, &mut session).await {
+                    *status.lock().unwrap() = ProfilerStatus::Error(error.to_string());
+                    return;
+                }
+            }
+            maybe_action = action_source.recv() => {
+                let Some(action) = maybe_action else {
+                    break; // ui thread disconnected
+                };
+                handle_action(action, &mut session, &status);
+            }
+        }
+    }
+
+    *status.lock().unwrap() = ProfilerStatus::Disabled;
+}
+
+async fn handle_event(event: ProfileEvent, session: &mut ProfilerSession) -> Result<()> {
+    match event {
+        ProfileEvent::Start { info } => session.start_profiling(info).await,
+        ProfileEvent::Update {
+            cycles,
+            event,
+            inline_stack,
+        } => {
+            session.track_elapsed_cycles(cycles);
+            if let Some(event) = event {
+                session.track_event(event)?;
+            }
+            if let Some(stack) = inline_stack {
+                session.track_inline_stack(stack);
+            }
+        }
+    }
+    Ok(())
+}
+
+fn handle_action(
+    action: RecordingAction,
+    session: &mut ProfilerSession,
+    status: &Mutex<ProfilerStatus>,
+) {
+    match action {
+        RecordingAction::Start => {
+            session.start_recording();
+            *status.lock().unwrap() = ProfilerStatus::Recording;
+        }
+        RecordingAction::Finish(rx) => {
+            if let Some(bytes) = session.finish_recording() {
+                let _ = rx.send(bytes);
+            }
+            *status.lock().unwrap() = ProfilerStatus::Enabled;
+        }
+        RecordingAction::Cancel => {
+            session.cancel_recording();
+            *status.lock().unwrap() = ProfilerStatus::Enabled;
+        }
+    }
+}
+
+#[derive(Clone)]
+pub enum ProfilerStatus {
+    Disabled,
+    Enabled,
+    Recording,
+    Error(String),
+}
+
+impl ProfilerStatus {
+    pub fn enabled(&self) -> bool {
+        matches!(self, Self::Enabled | Self::Recording)
+    }
+}
+
+enum RecordingAction {
+    Start,
+    Finish(oneshot::Sender<Vec<u8>>),
+    Cancel,
+}
+
+struct ProfilerSession {
+    program: Option<ProgramState>,
+    recording: Option<Recording>,
+}
+
+impl ProfilerSession {
+    fn new() -> Self {
+        Self {
+            program: None,
+            recording: None,
+        }
+    }
+
+    async fn start_profiling(&mut self, info: Arc<GameInfo>) {
+        let program = ProgramState::new(info).await;
+        let recording = if self.recording.is_some() {
+            Some(Recording::new(&program))
+        } else {
+            None
+        };
+        self.program = Some(program);
+        self.recording = recording;
+    }
+
+    fn track_elapsed_cycles(&mut self, cycles: u32) {
+        if let (Some(state), Some(recording)) = (&self.program, &mut self.recording) {
+            recording.track_elapsed_cycles(state, cycles);
+        }
+    }
+
+    fn track_event(&mut self, event: SimEvent) -> Result<()> {
+        let Some(program) = &mut self.program else {
+            return Ok(());
+        };
+        match event {
+            SimEvent::Call(address) => program.track_call(address),
+            SimEvent::Return => program.track_return(),
+            SimEvent::Halt => program.track_halt(),
+            SimEvent::Interrupt(code, address) => program.track_interrupt(code, address),
+            SimEvent::Reti => program.track_reti(),
+            SimEvent::Marker(name) => {
+                if let Some(recording) = &mut self.recording {
+                    recording.track_marker(name);
+                };
+                Ok(())
+            }
+        }
+    }
+
+    fn track_inline_stack(&mut self, inline_stack: InlineStack) {
+        if let Some(program) = &mut self.program {
+            program.track_inline_stack(inline_stack);
+        }
+    }
+
+    fn start_recording(&mut self) {
+        if let Some(program) = &self.program {
+            self.recording = Some(Recording::new(program));
+        }
+    }
+
+    fn finish_recording(&mut self) -> Option<Vec<u8>> {
+        self.recording.take().map(|r| r.finish())
+    }
+
+    fn cancel_recording(&mut self) {
+        self.recording.take();
+    }
+}

src/profiler/recording.rs

@@ -0,0 +1,152 @@
+use std::{borrow::Cow, collections::HashMap};
+
+use fxprof_processed_profile::{
+    CategoryHandle, CpuDelta, Frame, FrameFlags, FrameInfo, MarkerTiming, ProcessHandle, Profile,
+    ReferenceTimestamp, SamplingInterval, StackHandle, StaticSchemaMarker, StringHandle,
+    ThreadHandle, Timestamp,
+};
+
+use crate::profiler::state::{ProgramState, RESET_CODE, StackFrame};
+
+pub struct Recording {
+    profile: Profile,
+    process: ProcessHandle,
+    threads: HashMap<u16, ThreadHandle>,
+    now: u64,
+}
+
+impl Recording {
+    pub fn new(state: &ProgramState) -> Self {
+        let reference_timestamp = ReferenceTimestamp::from_millis_since_unix_epoch(0.0);
+        let interval = SamplingInterval::from_hz(20_000_000.0);
+        let mut profile = Profile::new(state.name(), reference_timestamp, interval);
+
+        let process =
+            profile.add_process(state.name(), 1, Timestamp::from_nanos_since_reference(0));
+
+        let lib = profile.add_lib(state.library_info().clone());
+        profile.add_lib_mapping(process, lib, 0x00000000, 0xffffffff, 0);
+
+        let mut me = Self {
+            profile,
+            process,
+            threads: HashMap::new(),
+            now: 0,
+        };
+        me.track_elapsed_cycles(state, 0);
+        me
+    }
+
+    pub fn track_elapsed_cycles(&mut self, state: &ProgramState, cycles: u32) {
+        self.now += cycles as u64;
+        let timestamp = Timestamp::from_nanos_since_reference(self.now * 50);
+        let weight = 1;
+
+        let active_code = if let Some((code, frames)) = state.current_stack() {
+            let thread = *self.threads.entry(code).or_insert_with(|| {
+                let process = self.process;
+                let tid = code as u32;
+                let start_time = Timestamp::from_nanos_since_reference(self.now * 50);
+                let is_main = code == RESET_CODE;
+                let thread = self.profile.add_thread(process, tid, start_time, is_main);
+                self.profile
+                    .set_thread_name(thread, &thread_name_for_code(code));
+                thread
+            });
+
+            let stack = self.handle_for_stack(thread, frames);
+            let cpu_delta = CpuDelta::from_nanos((self.now - cycles as u64) * 50);
+            self.profile
+                .add_sample(thread, timestamp, stack, cpu_delta, weight);
+            Some(code)
+        } else {
+            None
+        };
+        for (code, thread) in &self.threads {
+            if active_code == Some(*code) {
+                continue;
+            }
+            self.profile
+                .add_sample_same_stack_zero_cpu(*thread, timestamp, weight);
+        }
+    }
+
+    pub fn track_marker(&mut self, name: Cow<'static, str>) {
+        let Some(thread) = self.threads.get(&RESET_CODE) else {
+            return;
+        };
+        let timing = MarkerTiming::Instant(Timestamp::from_nanos_since_reference(self.now * 50));
+        let marker = SimpleMarker(name);
+        self.profile.add_marker(*thread, timing, marker);
+    }
+
+    pub fn finish(self) -> Vec<u8> {
+        serde_json::to_vec(&self.profile).expect("could not serialize profile")
+    }
+
+    fn handle_for_stack(
+        &mut self,
+        thread: ThreadHandle,
+        frames: &[StackFrame],
+    ) -> Option<StackHandle> {
+        let frames = frames
+            .iter()
+            .map(|f| {
+                let frame = match f {
+                    StackFrame::Address(address) => Frame::InstructionPointer(*address as u64),
+                    StackFrame::Label(label) => Frame::Label(self.profile.intern_string(label)),
+                };
+                FrameInfo {
+                    frame,
+                    category_pair: CategoryHandle::OTHER.into(),
+                    flags: FrameFlags::empty(),
+                }
+            })
+            .collect::<Vec<_>>();
+        self.profile.intern_stack_frames(thread, frames.into_iter())
+    }
+}
+
+struct SimpleMarker(Cow<'static, str>);
+
+impl StaticSchemaMarker for SimpleMarker {
+    const UNIQUE_MARKER_TYPE_NAME: &'static str = "Simple";
+    const FIELDS: &'static [fxprof_processed_profile::StaticSchemaMarkerField] = &[];
+
+    fn name(&self, profile: &mut Profile) -> StringHandle {
+        profile.intern_string(&self.0)
+    }
+
+    fn category(&self, _profile: &mut Profile) -> CategoryHandle {
+        CategoryHandle::OTHER
+    }
+
+    fn string_field_value(&self, _field_index: u32) -> StringHandle {
+        unreachable!()
+    }
+
+    fn number_field_value(&self, _field_index: u32) -> f64 {
+        unreachable!()
+    }
+}
+
+fn thread_name_for_code(code: u16) -> std::borrow::Cow<'static, str> {
+    match code {
+        RESET_CODE => "Main".into(),
+        0xffd0 => "Duplexed exception".into(),
+        0xfe40 => "VIP interrupt".into(),
+        0xfe30 => "Communication interrupt".into(),
+        0xfe20 => "Game pak interrupt".into(),
+        0xfe10 => "Timer interrupt".into(),
+        0xfe00 => "Game pad interrupt".into(),
+        0xffc0 => "Address trap".into(),
+        0xffa0..0xffc0 => format!("Trap (vector {})", code - 0xffa0).into(),
+        0xff90 => "Illegal opcode exception".into(),
+        0xff80 => "Zero division exception".into(),
+        0xff60 => "Floating-point reserved operand exception".into(),
+        0xff70 => "Floating-point invalid operation exception".into(),
+        0xff68 => "Floating-point zero division exception".into(),
+        0xff64 => "Floating-point overflow exception".into(),
+        other => format!("Unrecognized handler (0x{other:04x})").into(),
+    }
+}

src/profiler/state.rs

@@ -0,0 +1,129 @@
+use std::{collections::HashMap, sync::Arc};
+
+use anyhow::{Result, bail};
+use fxprof_processed_profile::LibraryInfo;
+
+use crate::emulator::{GameInfo, InlineStack};
+
+pub struct ProgramState {
+    info: Arc<GameInfo>,
+    call_stacks: HashMap<u16, Vec<StackFrame>>,
+    context_stack: Vec<u16>,
+}
+
+pub enum StackFrame {
+    Address(u32),
+    Label(Arc<String>),
+}
+
+pub const RESET_CODE: u16 = 0xfff0;
+impl ProgramState {
+    pub async fn new(info: Arc<GameInfo>) -> Self {
+        let mut call_stacks = HashMap::new();
+        call_stacks.insert(RESET_CODE, vec![StackFrame::Address(0xfffffff0)]);
+        Self {
+            info,
+            call_stacks,
+            context_stack: vec![RESET_CODE],
+        }
+    }
+
+    pub fn name(&self) -> &str {
+        self.info.name()
+    }
+
+    pub fn library_info(&self) -> &LibraryInfo {
+        self.info.library_info()
+    }
+
+    pub fn current_stack(&self) -> Option<(u16, &[StackFrame])> {
+        let code = self.context_stack.last()?;
+        let call_stack = self.call_stacks.get(code)?;
+        Some((*code, call_stack))
+    }
+
+    pub fn track_call(&mut self, address: u32) -> Result<()> {
+        let Some(code) = self.context_stack.last() else {
+            bail!("How did we call anything when we're halted?");
+        };
+        let Some(stack) = self.call_stacks.get_mut(code) else {
+            bail!("missing stack {code:04x}");
+        };
+        stack.push(StackFrame::Address(address));
+        Ok(())
+    }
+
+    pub fn track_return(&mut self) -> Result<()> {
+        let Some(code) = self.context_stack.last() else {
+            bail!("how did we return when we're halted?");
+        };
+        let Some(stack) = self.call_stacks.get_mut(code) else {
+            bail!("missing stack {code:04x}");
+        };
+        // just popping the inline frames first
+        while stack
+            .pop_if(|f| matches!(f, StackFrame::Label(_)))
+            .is_some()
+        {}
+        if stack.pop().is_none() {
+            bail!("returned from {code:04x} but stack was empty");
+        }
+        if stack.is_empty() {
+            bail!("returned to oblivion");
+        }
+        Ok(())
+    }
+
+    pub fn track_halt(&mut self) -> Result<()> {
+        let Some(RESET_CODE) = self.context_stack.pop() else {
+            bail!("halted when not in an interrupt");
+        };
+        Ok(())
+    }
+
+    pub fn track_interrupt(&mut self, code: u16, address: u32) -> Result<()> {
+        // if the CPU was halted before, wake it up now
+        if self.context_stack.is_empty() {
+            self.context_stack.push(RESET_CODE);
+        }
+
+        self.context_stack.push(code);
+        if self
+            .call_stacks
+            .insert(code, vec![StackFrame::Address(address)])
+            .is_some()
+        {
+            bail!("{code:04x} fired twice");
+        }
+        Ok(())
+    }
+
+    pub fn track_reti(&mut self) -> Result<()> {
+        let Some(code) = self.context_stack.pop() else {
+            bail!("RETI when halted");
+        };
+        if code == RESET_CODE {
+            bail!("RETI when not in interrupt");
+        }
+        if self.call_stacks.remove(&code).is_none() {
+            bail!("{code:04x} popped but never called");
+        }
+        Ok(())
+    }
+
+    pub fn track_inline_stack(&mut self, inline_stack: InlineStack) {
+        let Some(code) = self.context_stack.last() else {
+            return;
+        };
+        let Some(call_stack) = self.call_stacks.get_mut(code) else {
+            return;
+        };
+        while call_stack
+            .pop_if(|f| matches!(f, StackFrame::Label(_)))
+            .is_some()
+        {}
+        for label in inline_stack.iter() {
+            call_stack.push(StackFrame::Label(label.clone()));
+        }
+    }
+}

src/window.rs

@@ -0,0 +1,59 @@
+use std::{path::PathBuf, sync::Arc};
+
+pub use about::AboutWindow;
+use egui::{Ui, ViewportBuilder};
+pub use game::{ChildWindow, GameWindow};
+pub use game_screen::{DisplayMode, GameScreen};
+pub use gdb::GdbServerWindow;
+pub use hotkeys::HotkeysWindow;
+pub use input::InputWindow;
+pub use profile::ProfileWindow;
+pub use terminal::TerminalWindow;
+pub use vip::{
+    BgMapWindow, CharacterDataWindow, FrameBufferWindow, ObjectWindow, RegisterWindow, WorldWindow,
+};
+use winit::{event::KeyEvent, window::Window};
+
+use crate::emulator::SimId;
+
+mod about;
+mod game;
+mod game_screen;
+mod gdb;
+mod hotkeys;
+mod input;
+mod profile;
+mod terminal;
+mod utils;
+mod vip;
+
+pub trait AppWindow {
+    fn sim_id(&self) -> Option<SimId> {
+        None
+    }
+    fn image_url(&self, name: &str) -> String {
+        format!("vip://{}/{name}", self.sim_id().unwrap_or(SimId::Player1))
+    }
+    fn initial_viewport(&self) -> ViewportBuilder;
+    fn show(&mut self, ui: &mut Ui);
+    fn on_init(&mut self, args: InitArgs) {
+        let _ = args;
+    }
+    fn handle_key_event(&mut self, event: &KeyEvent) -> bool {
+        let _ = event;
+        false
+    }
+    fn handle_gamepad_event(&mut self, event: &gilrs::Event) -> bool {
+        let _ = event;
+        false
+    }
+    fn handle_dropped_file(&mut self, path: PathBuf) -> bool {
+        let _ = path;
+        false
+    }
+}
+
+pub struct InitArgs<'a> {
+    pub window: &'a Arc<Window>,
+    pub render_state: &'a egui_wgpu::RenderState,
+}

src/window/about.rs

@@ -0,0 +1,27 @@
+use egui::{CentralPanel, Image, Ui, ViewportBuilder};
+
+use super::AppWindow;
+
+pub struct AboutWindow;
+
+impl AppWindow for AboutWindow {
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title("About Lemur")
+            .with_inner_size((300.0, 200.0))
+    }
+
+    fn show(&mut self, ui: &mut Ui) {
+        CentralPanel::default().show_inside(ui, |ui| {
+            ui.vertical_centered(|ui| {
+                ui.label("Lemur Virtual Boy Emulator");
+                ui.label(format!("Version {}", env!("CARGO_PKG_VERSION")));
+                ui.hyperlink("https://git.virtual-boy.com/PVB/lemur");
+                let logo = Image::new(egui::include_image!("../../assets/lemur-256x256.png"))
+                    .max_width(256.0)
+                    .maintain_aspect_ratio(true);
+                ui.add(logo);
+            });
+        });
+    }
+}

src/window/game.rs

@@ -0,0 +1,887 @@
+use std::{
+    ops::{Deref, DerefMut},
+    path::PathBuf,
+    sync::{Arc, Mutex, atomic::AtomicBool, mpsc},
+    time::Duration,
+};
+
+use crate::{
+    app::UserEvent,
+    config::{COLOR_PRESETS, SimConfig},
+    emulator::{EmulatorClient, EmulatorCommand, EmulatorState, SimId, SimState},
+    filepicker::FilePicker,
+    images::ImageTextureLoader,
+    input::{Command, MappingProvider, ShortcutProvider},
+    memory::MemoryClient,
+    persistence::Persistence,
+    window::{
+        AboutWindow, BgMapWindow, CharacterDataWindow, FrameBufferWindow, GdbServerWindow,
+        HotkeysWindow, InitArgs, InputWindow, ObjectWindow, ProfileWindow, RegisterWindow,
+        TerminalWindow, WorldWindow, utils::UiData,
+    },
+};
+use anyhow::Context as _;
+use egui::{
+    Align2, Button, CentralPanel, Color32, Context, Frame, MenuBar, Panel, Pos2, Ui, Vec2,
+    ViewportBuilder, ViewportCommand, ViewportId, ViewportIdMap, Window,
+};
+use egui_notify::{Anchor, Toast, Toasts};
+use serde::{Deserialize, Serialize};
+use winit::{event::KeyEvent, event_loop::EventLoopProxy};
+
+use super::{
+    AppWindow,
+    game_screen::{DisplayMode, GameScreen},
+    utils::UiExt as _,
+};
+
+pub struct GameWindow {
+    viewport_id: ViewportId,
+    client: EmulatorClient,
+    proxy: EventLoopProxy<UserEvent>,
+    persistence: Persistence,
+    shortcuts: ShortcutProvider,
+    sim_id: SimId,
+    config: SimConfig,
+    toasts: Toasts,
+    screen: Option<GameScreen>,
+    messages: mpsc::Receiver<Toast>,
+    message_sink: mpsc::Sender<Toast>,
+    color_picker: Option<ColorPickerState>,
+    file_picker: FilePicker,
+    memory: Arc<MemoryClient>,
+    images: Arc<ImageTextureLoader>,
+    mappings: MappingProvider,
+    children: ViewportIdMap<ChildWindowWrapper>,
+    child_states: UiData<ViewportIdMap<ChildState>>,
+    queued_children: Vec<ChildWindow>,
+    show_player_name: bool,
+}
+
+impl GameWindow {
+    #[expect(clippy::too_many_arguments)]
+    pub fn new(
+        viewport_id: ViewportId,
+        client: EmulatorClient,
+        proxy: EventLoopProxy<UserEvent>,
+        persistence: Persistence,
+        shortcuts: ShortcutProvider,
+        memory: &Arc<MemoryClient>,
+        images: &Arc<ImageTextureLoader>,
+        mappings: MappingProvider,
+        sim_id: SimId,
+    ) -> Self {
+        let config = SimConfig::load(&persistence, sim_id);
+        let _ = proxy.send_event(UserEvent::LowBattery(sim_id, config.low_battery));
+        client.send_command(EmulatorCommand::WatchRom(sim_id, config.watch_rom));
+        let toasts = Toasts::new()
+            .with_anchor(Anchor::BottomLeft)
+            .with_margin((10.0, 10.0).into())
+            .reverse(true);
+        let (message_sink, messages) = mpsc::channel();
+        Self {
+            viewport_id,
+            client,
+            proxy,
+            persistence,
+            shortcuts,
+            sim_id,
+            config,
+            toasts,
+            screen: None,
+            messages,
+            message_sink,
+            color_picker: None,
+            file_picker: FilePicker::new(),
+            memory: memory.clone(),
+            images: images.clone(),
+            mappings: mappings.clone(),
+            children: ViewportIdMap::default(),
+            child_states: UiData::new(),
+            queued_children: vec![],
+            show_player_name: false,
+        }
+    }
+
+    pub fn open(&mut self, window: ChildWindow) {
+        // queue opening this child until our next render call,
+        // so that we get a chance to look up its size
+        self.queued_children.push(window);
+    }
+
+    pub fn close(&mut self, window: ChildWindow) {
+        let id = window.viewport_id(self.sim_id);
+        self.children.remove(&id);
+    }
+
+    fn do_open(&mut self, window: ChildWindow) {
+        let viewport_id = window.viewport_id(self.sim_id);
+        if self.children.contains_key(&viewport_id) {
+            return;
+        }
+        let child = match window {
+            ChildWindow::About => AppWrapper::of_dyn(AboutWindow),
+            ChildWindow::CharacterData => AppWrapper::of_dyn(CharacterDataWindow::new(
+                self.sim_id,
+                &self.memory,
+                &self.images,
+            )),
+            ChildWindow::BgMap => {
+                AppWrapper::of_dyn(BgMapWindow::new(self.sim_id, &self.memory, &self.images))
+            }
+            ChildWindow::Objects => {
+                AppWrapper::of_dyn(ObjectWindow::new(self.sim_id, &self.memory, &self.images))
+            }
+            ChildWindow::Worlds => {
+                AppWrapper::of_dyn(WorldWindow::new(self.sim_id, &self.memory, &self.images))
+            }
+            ChildWindow::FrameBuffers => AppWrapper::of_dyn(FrameBufferWindow::new(
+                self.sim_id,
+                &self.memory,
+                &self.images,
+            )),
+            ChildWindow::Registers => {
+                AppWrapper::of_dyn(RegisterWindow::new(self.sim_id, &self.memory))
+            }
+            ChildWindow::Terminal => {
+                AppWrapper::of_dyn(TerminalWindow::new(self.sim_id, &self.client))
+            }
+            ChildWindow::Profiler { launch } => {
+                let mut profile = ProfileWindow::new(self.sim_id, self.client.clone());
+                if launch {
+                    profile.launch();
+                }
+                AppWrapper::of_dyn(profile)
+            }
+            ChildWindow::Debugger { port } => {
+                let mut debugger =
+                    GdbServerWindow::new(self.sim_id, self.client.clone(), self.proxy.clone());
+                if let Some(port) = port {
+                    debugger.launch(port);
+                }
+                AppWrapper::of_dyn(debugger)
+            }
+            ChildWindow::Input => AppWrapper::of_dyn(InputWindow::new(self.mappings.clone())),
+            ChildWindow::Hotkeys => AppWrapper::of_dyn(HotkeysWindow::new(self.shortcuts.clone())),
+            ChildWindow::Player2 => {
+                if self.sim_id == SimId::Player2 {
+                    return;
+                }
+                AppWrapper::of_game(GameWindow::new(
+                    viewport_id,
+                    self.client.clone(),
+                    self.proxy.clone(),
+                    self.persistence.clone(),
+                    self.shortcuts.clone(),
+                    &self.memory,
+                    &self.images,
+                    self.mappings.clone(),
+                    SimId::Player2,
+                ))
+            }
+        };
+
+        let mut viewport = child.initial_viewport();
+        let title = viewport.title.clone().unwrap();
+        let sim_id = child.sim_id();
+        if let Some(sim_id) = sim_id
+            && self.show_player_name
+        {
+            viewport.title = Some(format!("{title} ({sim_id})"));
+        }
+        if let Some(state) = self.child_states.get(&viewport_id) {
+            viewport.position = Some(state.position);
+            viewport.inner_size = Some(state.size);
+        }
+        self.children.insert(
+            viewport_id,
+            ChildWindowWrapper {
+                app: Arc::new(Mutex::new(child)),
+                title,
+                sim_id,
+                updates: Some(viewport),
+                close_requested: Arc::new(AtomicBool::new(false)),
+            },
+        );
+    }
+
+    pub fn handle_init(&mut self, viewport_id: ViewportId, args: InitArgs) {
+        self.handle_event(viewport_id, |window| window.on_init(args))
+    }
+
+    pub fn handle_key_event(&mut self, viewport_id: ViewportId, event: &KeyEvent) -> bool {
+        self.handle_event(viewport_id, |window| window.handle_key_event(event))
+    }
+
+    pub fn handle_gamepad_event(&mut self, viewport_id: ViewportId, event: &gilrs::Event) -> bool {
+        self.handle_event(viewport_id, |window| window.handle_gamepad_event(event))
+    }
+
+    pub fn handle_dropped_file(&mut self, viewport_id: ViewportId, path: PathBuf) -> bool {
+        self.handle_event(viewport_id, |window| window.handle_dropped_file(path))
+    }
+
+    fn handle_event<F, R>(&mut self, viewport_id: ViewportId, cb: F) -> R
+    where
+        F: FnOnce(&mut dyn AppWindow) -> R,
+        R: Default,
+    {
+        let p2_viewport_id = ChildWindow::Player2.viewport_id(SimId::Player1);
+
+        if self.viewport_id == viewport_id {
+            cb(self)
+        } else if let Some(child) = self.children.get_mut(&viewport_id) {
+            cb(child.app.lock().unwrap().deref_mut().deref_mut())
+        } else if let Some(mut p2) = self
+            .children
+            .get_mut(&p2_viewport_id)
+            .map(|w| w.app.lock().unwrap())
+        {
+            if let AppWrapper::Game(g) = p2.deref_mut() {
+                g.handle_event(viewport_id, cb)
+            } else {
+                R::default()
+            }
+        } else {
+            R::default()
+        }
+    }
+
+    fn show_menu(&mut self, ui: &mut Ui) {
+        let state = self.client.emulator_state();
+        let is_ready = self.client.sim_state(self.sim_id) == SimState::Ready;
+        let can_pause = is_ready && state == EmulatorState::Running;
+        let can_resume = is_ready && state == EmulatorState::Paused;
+        let can_frame_advance = is_ready && state != EmulatorState::Debugging;
+
+        for command in ui.input_mut(|input| self.shortcuts.consume_all(input)) {
+            match command {
+                Command::OpenRom => {
+                    let rom = self
+                        .file_picker
+                        .pick_file_dialog()
+                        .add_filter("Virtual Boy ROMs", &["vb", "vbrom", "elf", "isx"])
+                        .open();
+                    if let Some(path) = rom {
+                        self.client
+                            .send_command(EmulatorCommand::LoadGame(self.sim_id, path));
+                    }
+                }
+                Command::ReloadRom => {
+                    self.client
+                        .send_command(EmulatorCommand::ReloadRom(self.sim_id));
+                }
+                Command::Quit => {
+                    let _ = self.proxy.send_event(UserEvent::Quit(self.sim_id));
+                }
+                Command::PauseResume => {
+                    if state == EmulatorState::Paused && can_resume {
+                        self.client.send_command(EmulatorCommand::Resume);
+                    }
+                    if state == EmulatorState::Running && can_pause {
+                        self.client.send_command(EmulatorCommand::Pause);
+                    }
+                }
+                Command::Reset => {
+                    if is_ready {
+                        self.client
+                            .send_command(EmulatorCommand::Reset(self.sim_id));
+                    }
+                }
+                Command::FrameAdvance => {
+                    if can_frame_advance {
+                        self.client.send_command(EmulatorCommand::FrameAdvance);
+                    }
+                }
+                Command::FastForward(speed) => {
+                    self.client
+                        .send_command(EmulatorCommand::SetSpeed(speed as f64));
+                }
+                Command::Screenshot => {
+                    let autopause = state == EmulatorState::Running && can_pause;
+                    if autopause {
+                        self.client.send_command(EmulatorCommand::Pause);
+                    }
+                    pollster::block_on(self.take_screenshot());
+                    if autopause {
+                        self.client.send_command(EmulatorCommand::Resume);
+                    }
+                }
+            }
+        }
+
+        ui.menu_button("ROM", |ui| {
+            if ui
+                .add(self.button_for(ui.ctx(), "Open ROM", Command::OpenRom))
+                .clicked()
+            {
+                let rom = self
+                    .file_picker
+                    .pick_file_dialog()
+                    .add_filter("Virtual Boy ROMs", &["vb", "vbrom", "elf", "isx"])
+                    .open();
+                if let Some(path) = rom {
+                    self.client
+                        .send_command(EmulatorCommand::LoadGame(self.sim_id, path));
+                }
+            }
+            if ui
+                .add(self.button_for(ui.ctx(), "Reload ROM", Command::ReloadRom))
+                .clicked()
+            {
+                self.client
+                    .send_command(EmulatorCommand::ReloadRom(self.sim_id));
+            }
+            let watch_rom = self.client.is_rom_watched(self.sim_id);
+            if ui.selectable_button(watch_rom, "Watch ROM").clicked() {
+                self.update_config(|c| c.watch_rom = !watch_rom);
+                self.client
+                    .send_command(EmulatorCommand::WatchRom(self.sim_id, !watch_rom));
+            }
+            if ui
+                .add(self.button_for(ui.ctx(), "Quit", Command::Quit))
+                .clicked()
+            {
+                let _ = self.proxy.send_event(UserEvent::Quit(self.sim_id));
+            }
+        });
+        ui.menu_button("Emulation", |ui| {
+            if state == EmulatorState::Running {
+                if ui
+                    .add_enabled(
+                        can_pause,
+                        self.button_for(ui.ctx(), "Pause", Command::PauseResume),
+                    )
+                    .clicked()
+                {
+                    self.client.send_command(EmulatorCommand::Pause);
+                }
+            } else if ui
+                .add_enabled(
+                    can_resume,
+                    self.button_for(ui.ctx(), "Resume", Command::PauseResume),
+                )
+                .clicked()
+            {
+                self.client.send_command(EmulatorCommand::Resume);
+            }
+            if ui
+                .add_enabled(is_ready, self.button_for(ui.ctx(), "Reset", Command::Reset))
+                .clicked()
+            {
+                self.client
+                    .send_command(EmulatorCommand::Reset(self.sim_id));
+            }
+            ui.separator();
+            if ui
+                .add_enabled(
+                    can_frame_advance,
+                    self.button_for(ui.ctx(), "Frame Advance", Command::FrameAdvance),
+                )
+                .clicked()
+            {
+                self.client.send_command(EmulatorCommand::FrameAdvance);
+            }
+            ui.separator();
+            if ui
+                .add_enabled(
+                    is_ready,
+                    self.button_for(ui.ctx(), "Screenshot", Command::Screenshot),
+                )
+                .clicked()
+            {
+                pollster::block_on(self.take_screenshot());
+            }
+            ui.separator();
+            let low_battery = self.config.low_battery;
+            if ui.selectable_button(low_battery, "Low Battery").clicked() {
+                self.update_config(|c| c.low_battery = !low_battery);
+                let _ = self
+                    .proxy
+                    .send_event(UserEvent::LowBattery(self.sim_id, !low_battery));
+            }
+        });
+        ui.menu_button("Options", |ui| self.show_options_menu(ui));
+        ui.menu_button("Multiplayer", |ui| {
+            let has_player_2 = self.client.has_player_2();
+            if self.sim_id == SimId::Player1
+                && !has_player_2
+                && ui.button("Open Player 2").clicked()
+            {
+                self.client
+                    .send_command(EmulatorCommand::StartSecondSim(None));
+                self.open(ChildWindow::Player2);
+            }
+            if has_player_2 {
+                let linked = self.client.are_sims_linked();
+                if linked && ui.button("Unlink").clicked() {
+                    self.client.send_command(EmulatorCommand::Unlink);
+                }
+                if !linked && ui.button("Link").clicked() {
+                    self.client.send_command(EmulatorCommand::Link);
+                }
+            }
+        });
+        ui.menu_button("Tools", |ui| {
+            if ui.button("Terminal").clicked() {
+                self.open(ChildWindow::Terminal);
+            }
+            if ui.button("Profiler").clicked() {
+                self.open(ChildWindow::Profiler { launch: false });
+            }
+            if ui.button("GDB Server").clicked() {
+                self.open(ChildWindow::Debugger { port: None });
+            }
+            ui.separator();
+            if ui.button("Character Data").clicked() {
+                self.open(ChildWindow::CharacterData);
+            }
+            if ui.button("Background Maps").clicked() {
+                self.open(ChildWindow::BgMap);
+            }
+            if ui.button("Objects").clicked() {
+                self.open(ChildWindow::Objects);
+            }
+            if ui.button("Worlds").clicked() {
+                self.open(ChildWindow::Worlds);
+            }
+            if ui.button("Frame Buffers").clicked() {
+                self.open(ChildWindow::FrameBuffers);
+            }
+            if ui.button("Registers").clicked() {
+                self.open(ChildWindow::Registers);
+            }
+        });
+        ui.menu_button("Help", |ui| {
+            if ui.button("About").clicked() {
+                self.open(ChildWindow::About);
+            }
+        });
+    }
+
+    async fn take_screenshot(&mut self) {
+        match self.try_take_screenshot().await {
+            Ok(Some(path)) => {
+                let mut toast = Toast::info(format!("Saved to {path}"));
+                toast.duration(Some(Duration::from_secs(5)));
+                self.toasts.add(toast);
+            }
+            Ok(None) => {}
+            Err(error) => {
+                let mut toast = Toast::error(format!("{error:#}"));
+                toast.duration(Some(Duration::from_secs(5)));
+                self.toasts.add(toast);
+            }
+        }
+    }
+
+    async fn try_take_screenshot(&self) -> anyhow::Result<Option<String>> {
+        let (tx, rx) = oneshot::channel();
+        self.client
+            .send_command(EmulatorCommand::Screenshot(self.sim_id, tx));
+        let bytes = rx.await.context("Could not take screenshot")?;
+        let file = self
+            .file_picker
+            .save_file_dialog()
+            .add_filter("PNG images", &["png"])
+            .set_file_name("screenshot.png")
+            .open();
+        let Some(path) = file else {
+            return Ok(None);
+        };
+        if bytes.len() != 384 * 224 * 2 {
+            anyhow::bail!("Unexpected screenshot size");
+        }
+        let mut screencap = image::GrayImage::new(384 * 2, 224);
+        for (index, pixel) in bytes.into_iter().enumerate() {
+            let x = (index / 2) % 384 + ((index % 2) * 384);
+            let y = (index / 2) / 384;
+            screencap.put_pixel(x as u32, y as u32, image::Luma([pixel]));
+        }
+        screencap.save(&path).context("Could not save screenshot")?;
+        Ok(Some(path.display().to_string()))
+    }
+
+    fn show_options_menu(&mut self, ui: &mut Ui) {
+        ui.menu_button("Video", |ui| {
+            ui.menu_button("Screen Size", |ui| {
+                let current_dims = self.config.dimensions;
+
+                for scale in 1..=4 {
+                    let label = format!("x{scale}");
+                    let scale = scale as f32;
+                    let dims = {
+                        let Vec2 { x, y } = self.config.display_mode.proportions();
+                        Vec2::new(x * scale, y * scale + 22.0)
+                    };
+                    if ui
+                        .selectable_button((current_dims - dims).length() < 1.0, label)
+                        .clicked()
+                    {
+                        ui.send_viewport_cmd(ViewportCommand::InnerSize(dims));
+                    }
+                }
+            });
+
+            ui.menu_button("Display Mode", |ui| {
+                let old_proportions = self.config.display_mode.proportions();
+                let mut changed = false;
+                let mut display_mode = self.config.display_mode;
+                changed |= ui
+                    .selectable_option(&mut display_mode, DisplayMode::Anaglyph, "Anaglyph")
+                    .clicked();
+                changed |= ui
+                    .selectable_option(&mut display_mode, DisplayMode::LeftEye, "Left Eye")
+                    .clicked();
+                changed |= ui
+                    .selectable_option(&mut display_mode, DisplayMode::RightEye, "Right Eye")
+                    .clicked();
+                changed |= ui
+                    .selectable_option(&mut display_mode, DisplayMode::SideBySide, "Side by Side")
+                    .clicked();
+
+                if !changed {
+                    return;
+                }
+
+                let current_dims = self.config.dimensions;
+                let new_proportions = display_mode.proportions();
+                let scale = new_proportions / old_proportions;
+                if scale != Vec2::new(1.0, 1.0) {
+                    ui.send_viewport_cmd(ViewportCommand::InnerSize(current_dims * scale));
+                }
+
+                self.update_config(|c| {
+                    c.display_mode = display_mode;
+                    c.dimensions = current_dims * scale;
+                });
+            });
+            ui.menu_button("Colors", |ui| {
+                for preset in COLOR_PRESETS {
+                    if ui.color_pair_button(preset[0], preset[1]).clicked() {
+                        self.update_config(|c| c.colors = preset);
+                    }
+                }
+                ui.with_layout(ui.layout().with_cross_align(egui::Align::Center), |ui| {
+                    if ui.button("Custom").clicked() {
+                        let color_str = |color: Color32| {
+                            format!("{:02x}{:02x}{:02x}", color.r(), color.g(), color.b())
+                        };
+                        let is_running = self.client.emulator_state() == EmulatorState::Running;
+                        if is_running {
+                            self.client.send_command(EmulatorCommand::Pause);
+                        }
+                        let color_codes = [
+                            color_str(self.config.colors[0]),
+                            color_str(self.config.colors[1]),
+                        ];
+                        self.color_picker = Some(ColorPickerState {
+                            color_codes,
+                            just_opened: true,
+                            unpause_on_close: is_running,
+                        });
+                    }
+                });
+            });
+        });
+        ui.menu_button("Audio", |ui| {
+            if ui
+                .selectable_button(self.config.audio_enabled, "Enabled")
+                .clicked()
+            {
+                self.update_config(|c| c.audio_enabled = !c.audio_enabled);
+                self.client.send_command(EmulatorCommand::SetAudioEnabled(
+                    self.sim_id,
+                    self.config.audio_enabled,
+                ));
+            }
+        });
+        ui.menu_button("Input", |ui| {
+            if ui.button("Bind Inputs").clicked() {
+                self.open(ChildWindow::Input);
+            }
+        });
+        if ui.button("Hotkeys").clicked() {
+            self.open(ChildWindow::Hotkeys);
+        }
+    }
+
+    fn show_color_picker(&mut self, ui: &mut Ui) {
+        let mut colors = self.config.colors;
+        let Some(state) = self.color_picker.as_mut() else {
+            return;
+        };
+        let (open, updated) = ui
+            .horizontal(|ui| {
+                let left_color = ui.color_picker(&mut colors[0], &mut state.color_codes[0]);
+                if state.just_opened {
+                    left_color.request_focus();
+                    state.just_opened = false;
+                }
+                let right_color = ui.color_picker(&mut colors[1], &mut state.color_codes[1]);
+                let open = left_color.has_focus() || right_color.has_focus();
+                let updated = left_color.changed() || right_color.changed();
+                (open, updated)
+            })
+            .inner;
+        if !open {
+            if state.unpause_on_close {
+                self.client.send_command(EmulatorCommand::Resume);
+            }
+            self.color_picker = None;
+        }
+        if updated {
+            self.update_config(|c| c.colors = colors);
+        }
+    }
+
+    fn update_config(&mut self, update: impl FnOnce(&mut SimConfig)) {
+        let mut new_config = self.config.clone();
+        update(&mut new_config);
+        if self.config != new_config {
+            let _ = new_config.save(&self.persistence, self.sim_id);
+        }
+        self.config = new_config;
+    }
+
+    fn button_for(&self, ctx: &Context, text: &str, command: Command) -> Button<'_> {
+        let button = Button::new(text);
+        match self.shortcuts.shortcut_for(command) {
+            Some(shortcut) => button.shortcut_text(ctx.format_shortcut(&shortcut)),
+            None => button,
+        }
+    }
+}
+
+impl AppWindow for GameWindow {
+    fn sim_id(&self) -> Option<SimId> {
+        Some(self.sim_id)
+    }
+
+    fn initial_viewport(&self) -> ViewportBuilder {
+        let builder = ViewportBuilder::default()
+            .with_title("Lemur")
+            .with_inner_size(self.config.dimensions);
+        if let Some(position) = self.config.position {
+            builder.with_position(position)
+        } else {
+            builder
+        }
+    }
+
+    fn show(&mut self, ui: &mut Ui) {
+        let has_player_2 = self.client.has_player_2();
+        if !self.show_player_name && has_player_2 {
+            ui.send_viewport_cmd(ViewportCommand::Title(format!("Lemur ({})", self.sim_id)));
+            for (viewport_id, child) in &self.children {
+                if let Some(sim_id) = child.sim_id {
+                    ui.send_viewport_cmd_to(
+                        *viewport_id,
+                        ViewportCommand::Title(format!("{} ({sim_id})", child.title)),
+                    );
+                }
+            }
+            self.show_player_name = true;
+        } else if self.show_player_name && !has_player_2 {
+            ui.send_viewport_cmd(ViewportCommand::Title("Lemur".to_string()));
+            for (viewport_id, child) in &self.children {
+                if child.sim_id.is_some() {
+                    ui.send_viewport_cmd_to(
+                        *viewport_id,
+                        ViewportCommand::Title(child.title.clone()),
+                    );
+                }
+            }
+            self.show_player_name = false;
+        }
+        self.child_states.load(ui);
+        let dimensions = {
+            let bounds = ui.content_rect();
+            bounds.max - bounds.min
+        };
+        let position = ui.input(|i| i.viewport().outer_rect.map(|r| r.min));
+        self.update_config(|c| {
+            c.dimensions = dimensions;
+            c.position = position;
+        });
+
+        while let Ok(toast) = self.messages.try_recv() {
+            self.toasts.add(toast);
+        }
+        Panel::top("menubar")
+            .exact_size(22.0)
+            .show_inside(ui, |ui| {
+                MenuBar::new().ui(ui, |ui| {
+                    self.show_menu(ui);
+                });
+            });
+        if self.color_picker.is_some() {
+            Window::new("Color Picker")
+                .title_bar(false)
+                .resizable(false)
+                .anchor(Align2::CENTER_CENTER, Vec2::ZERO)
+                .show(ui, |ui| {
+                    self.show_color_picker(ui);
+                });
+        }
+        let frame = Frame::central_panel(ui.style()).fill(Color32::BLACK);
+        CentralPanel::default().frame(frame).show_inside(ui, |ui| {
+            if let Some(screen) = self.screen.as_mut() {
+                screen.update(self.config.display_mode, self.config.colors);
+                ui.add(screen);
+            }
+        });
+        self.toasts.show(ui);
+        for window in std::mem::take(&mut self.queued_children) {
+            self.do_open(window);
+        }
+        self.children.retain(|id, child| {
+            if child
+                .close_requested
+                .load(std::sync::atomic::Ordering::Relaxed)
+            {
+                return false;
+            }
+            let app = child.app.clone();
+            let viewport_builder = child.updates.take().unwrap_or_default();
+            let close_requested = child.close_requested.clone();
+            if let (Some(outer), Some(inner)) = ui.input_for(*id, |inp| {
+                let viewport = inp.viewport();
+                (viewport.outer_rect, viewport.inner_rect)
+            }) {
+                self.child_states.insert(
+                    *id,
+                    ChildState {
+                        position: outer.min,
+                        size: inner.size(),
+                    },
+                );
+            }
+            ui.show_viewport_deferred(*id, viewport_builder, move |ui, _| {
+                app.lock().unwrap().show(ui);
+                if ui.input(|s| s.viewport().close_requested()) {
+                    close_requested.store(true, std::sync::atomic::Ordering::Relaxed);
+                }
+            });
+            true
+        });
+        self.child_states.save(ui);
+        ui.request_repaint_after(Duration::from_millis(10));
+    }
+
+    fn on_init(&mut self, args: InitArgs) {
+        if self.screen.is_none() {
+            let (screen, sink) = GameScreen::init(args.render_state);
+            self.client.send_command(EmulatorCommand::ConnectToSim(
+                self.sim_id,
+                sink,
+                self.message_sink.clone(),
+            ));
+            self.screen = Some(screen);
+        }
+        self.file_picker.set_window(args.window);
+    }
+
+    fn handle_dropped_file(&mut self, path: PathBuf) -> bool {
+        self.client
+            .send_command(EmulatorCommand::LoadGame(self.sim_id, path));
+        true
+    }
+}
+
+impl Drop for GameWindow {
+    fn drop(&mut self) {
+        if self.sim_id == SimId::Player2 {
+            self.client.send_command(EmulatorCommand::StopSecondSim);
+        }
+        let _ = self.proxy.send_event(UserEvent::Quit(self.sim_id));
+    }
+}
+
+struct ColorPickerState {
+    color_codes: [String; 2],
+    just_opened: bool,
+    unpause_on_close: bool,
+}
+
+struct ChildWindowWrapper {
+    app: Arc<Mutex<AppWrapper>>,
+    title: String,
+    sim_id: Option<SimId>,
+    updates: Option<ViewportBuilder>,
+    close_requested: Arc<AtomicBool>,
+}
+enum AppWrapper {
+    Game(Box<GameWindow>),
+    Dyn(Box<dyn AppWindow + Send + 'static>),
+}
+impl AppWrapper {
+    fn of_game(game: GameWindow) -> Self {
+        Self::Game(Box::new(game))
+    }
+    fn of_dyn<T: AppWindow + Send + 'static>(inner: T) -> Self {
+        Self::Dyn(Box::new(inner))
+    }
+}
+impl Deref for AppWrapper {
+    type Target = dyn AppWindow + Send + 'static;
+    fn deref(&self) -> &Self::Target {
+        match self {
+            Self::Dyn(inner) => inner.as_ref(),
+            Self::Game(inner) => inner.as_ref(),
+        }
+    }
+}
+impl DerefMut for AppWrapper {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        match self {
+            Self::Dyn(inner) => inner.as_mut(),
+            Self::Game(inner) => inner.as_mut(),
+        }
+    }
+}
+
+#[derive(Debug)]
+pub enum ChildWindow {
+    About,
+    CharacterData,
+    BgMap,
+    Objects,
+    Worlds,
+    FrameBuffers,
+    Registers,
+    Terminal,
+    Profiler { launch: bool },
+    Debugger { port: Option<u16> },
+    Input,
+    Hotkeys,
+    Player2,
+}
+impl ChildWindow {
+    fn viewport_id(&self, sim_id: SimId) -> ViewportId {
+        ViewportId::from_hash_of(format!("{sim_id:?}{}", self.name()))
+    }
+    fn name(&self) -> &'static str {
+        match self {
+            Self::About => "About",
+            Self::CharacterData => "CharacterData",
+            Self::BgMap => "BgMap",
+            Self::Objects => "Objects",
+            Self::Worlds => "Worlds",
+            Self::FrameBuffers => "FrameBuffers",
+            Self::Registers => "Registers",
+            Self::Terminal => "Terminal",
+            Self::Profiler { .. } => "Profiler",
+            Self::Debugger { .. } => "Debugger",
+            Self::Input => "Input",
+            Self::Hotkeys => "Hotkeys",
+            Self::Player2 => "Player2",
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+struct ChildState {
+    position: Pos2,
+    size: Vec2,
+}

src/window/game_screen.rs

@@ -0,0 +1,277 @@
+use std::{collections::HashMap, sync::Arc};
+
+use egui::{Color32, Rgba, Vec2, Widget};
+use serde::{Deserialize, Serialize};
+use wgpu::{BindGroup, BindGroupLayout, Buffer, RenderPipeline, util::DeviceExt as _};
+
+use crate::graphics::TextureSink;
+
+pub struct GameScreen {
+    bind_group: Arc<BindGroup>,
+    color_buffer: Arc<Buffer>,
+    display_mode: DisplayMode,
+    colors: Colors,
+}
+
+impl GameScreen {
+    pub fn init_pipeline(render_state: &egui_wgpu::RenderState) {
+        let device = &render_state.device;
+
+        let bind_group_layout = device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
+            label: Some("texture bind group layout"),
+            entries: &[
+                wgpu::BindGroupLayoutEntry {
+                    binding: 0,
+                    visibility: wgpu::ShaderStages::FRAGMENT,
+                    ty: wgpu::BindingType::Texture {
+                        sample_type: wgpu::TextureSampleType::Float { filterable: true },
+                        view_dimension: wgpu::TextureViewDimension::D2,
+                        multisampled: false,
+                    },
+                    count: None,
+                },
+                wgpu::BindGroupLayoutEntry {
+                    binding: 1,
+                    visibility: wgpu::ShaderStages::FRAGMENT,
+                    ty: wgpu::BindingType::Sampler(wgpu::SamplerBindingType::Filtering),
+                    count: None,
+                },
+                wgpu::BindGroupLayoutEntry {
+                    binding: 2,
+                    visibility: wgpu::ShaderStages::FRAGMENT,
+                    ty: wgpu::BindingType::Buffer {
+                        ty: wgpu::BufferBindingType::Uniform,
+                        has_dynamic_offset: false,
+                        min_binding_size: None,
+                    },
+                    count: None,
+                },
+            ],
+        });
+
+        let shader = device.create_shader_module(wgpu::include_wgsl!("../game.wgsl"));
+        let render_pipeline_layout =
+            device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
+                label: Some("render pipeline layout"),
+                bind_group_layouts: &[Some(&bind_group_layout)],
+                immediate_size: 0,
+            });
+
+        let create_render_pipeline = |entry_point: &str| {
+            device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
+                label: Some("render pipeline"),
+                layout: Some(&render_pipeline_layout),
+                vertex: wgpu::VertexState {
+                    module: &shader,
+                    entry_point: Some("vs_main"),
+                    buffers: &[],
+                    compilation_options: wgpu::PipelineCompilationOptions::default(),
+                },
+                fragment: Some(wgpu::FragmentState {
+                    module: &shader,
+                    entry_point: Some(entry_point),
+                    targets: &[Some(wgpu::ColorTargetState {
+                        format: render_state.target_format,
+                        blend: Some(wgpu::BlendState::REPLACE),
+                        write_mask: wgpu::ColorWrites::ALL,
+                    })],
+                    compilation_options: wgpu::PipelineCompilationOptions::default(),
+                }),
+                primitive: wgpu::PrimitiveState {
+                    topology: wgpu::PrimitiveTopology::TriangleList,
+                    strip_index_format: None,
+                    front_face: wgpu::FrontFace::Ccw,
+                    cull_mode: Some(wgpu::Face::Back),
+                    polygon_mode: wgpu::PolygonMode::Fill,
+                    unclipped_depth: false,
+                    conservative: false,
+                },
+                depth_stencil: None,
+                multisample: wgpu::MultisampleState {
+                    count: 1,
+                    mask: !0,
+                    alpha_to_coverage_enabled: false,
+                },
+                multiview_mask: None,
+                cache: None,
+            })
+        };
+
+        let mut render_pipelines = HashMap::new();
+        render_pipelines.insert(DisplayMode::Anaglyph, create_render_pipeline("fs_anaglyph"));
+        render_pipelines.insert(DisplayMode::LeftEye, create_render_pipeline("fs_lefteye"));
+        render_pipelines.insert(DisplayMode::RightEye, create_render_pipeline("fs_righteye"));
+        render_pipelines.insert(
+            DisplayMode::SideBySide,
+            create_render_pipeline("fs_sidebyside"),
+        );
+
+        render_state
+            .renderer
+            .write()
+            .callback_resources
+            .insert(SharedGameScreenResources {
+                render_pipelines,
+                bind_group_layout,
+            });
+    }
+
+    pub fn init(render_state: &egui_wgpu::RenderState) -> (Self, TextureSink) {
+        let device = &render_state.device;
+        let queue = &render_state.queue;
+
+        let (sink, texture_view) = TextureSink::new(device, queue.clone());
+        let sampler = device.create_sampler(&wgpu::SamplerDescriptor::default());
+        let colors = Colors::new(
+            Color32::from_rgb(0xff, 0x00, 0x00),
+            Color32::from_rgb(0x00, 0xc6, 0xf0),
+        );
+
+        let color_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
+            label: Some("colors"),
+            contents: bytemuck::bytes_of(&colors),
+            usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
+        });
+
+        let renderer = render_state.renderer.read();
+        let resources: &SharedGameScreenResources = renderer.callback_resources.get().unwrap();
+
+        let bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
+            label: Some("bind group"),
+            layout: &resources.bind_group_layout,
+            entries: &[
+                wgpu::BindGroupEntry {
+                    binding: 0,
+                    resource: wgpu::BindingResource::TextureView(&texture_view),
+                },
+                wgpu::BindGroupEntry {
+                    binding: 1,
+                    resource: wgpu::BindingResource::Sampler(&sampler),
+                },
+                wgpu::BindGroupEntry {
+                    binding: 2,
+                    resource: color_buffer.as_entire_binding(),
+                },
+            ],
+        });
+
+        (
+            Self {
+                bind_group: Arc::new(bind_group),
+                color_buffer: Arc::new(color_buffer),
+                display_mode: DisplayMode::Anaglyph,
+                colors,
+            },
+            sink,
+        )
+    }
+
+    pub fn update(&mut self, display_mode: DisplayMode, colors: [Color32; 2]) {
+        self.display_mode = display_mode;
+        self.colors = Colors::new(colors[0], colors[1]);
+    }
+}
+
+impl Widget for &mut GameScreen {
+    fn ui(self, ui: &mut egui::Ui) -> egui::Response {
+        let response = ui.allocate_rect(ui.clip_rect(), egui::Sense::hover());
+        let callback = egui_wgpu::Callback::new_paint_callback(
+            response.rect,
+            GameScreenCallback {
+                bind_group: self.bind_group.clone(),
+                color_buffer: self.color_buffer.clone(),
+                display_mode: self.display_mode,
+                colors: self.colors,
+            },
+        );
+        ui.painter().add(callback);
+        response
+    }
+}
+
+struct GameScreenCallback {
+    bind_group: Arc<BindGroup>,
+    color_buffer: Arc<Buffer>,
+    display_mode: DisplayMode,
+    colors: Colors,
+}
+
+impl egui_wgpu::CallbackTrait for GameScreenCallback {
+    fn prepare(
+        &self,
+        _device: &wgpu::Device,
+        queue: &wgpu::Queue,
+        _screen_descriptor: &egui_wgpu::ScreenDescriptor,
+        _egui_encoder: &mut wgpu::CommandEncoder,
+        _callback_resources: &mut egui_wgpu::CallbackResources,
+    ) -> Vec<wgpu::CommandBuffer> {
+        queue.write_buffer(&self.color_buffer, 0, bytemuck::bytes_of(&self.colors));
+        vec![]
+    }
+    fn paint(
+        &self,
+        info: egui::PaintCallbackInfo,
+        render_pass: &mut wgpu::RenderPass<'static>,
+        callback_resources: &egui_wgpu::CallbackResources,
+    ) {
+        let resources: &SharedGameScreenResources = callback_resources.get().unwrap();
+        let viewport = info.viewport_in_pixels();
+        let left = viewport.left_px as f32;
+        let top = viewport.top_px as f32;
+        let width = viewport.width_px as f32;
+        let height = viewport.height_px as f32;
+        let aspect_ratio = {
+            let proportions = self.display_mode.proportions();
+            proportions.x / proportions.y
+        };
+        let w = width.min(height * aspect_ratio);
+        let h = height.min(width / aspect_ratio);
+        let x = left + (width - w) / 2.0;
+        let y = top + (height - h) / 2.0;
+        let pipeline = resources
+            .render_pipelines
+            .get(&self.display_mode)
+            .unwrap_or_else(|| panic!("Unrecognized display mode {:?}", self.display_mode));
+        render_pass.set_pipeline(pipeline);
+        render_pass.set_bind_group(0, Some(self.bind_group.as_ref()), &[]);
+        render_pass.set_viewport(x, y, w, h, 0.0, 1.0);
+        render_pass.draw(0..6, 0..1);
+    }
+}
+
+struct SharedGameScreenResources {
+    render_pipelines: HashMap<DisplayMode, RenderPipeline>,
+    bind_group_layout: BindGroupLayout,
+}
+
+#[derive(Clone, Copy, bytemuck::Pod, bytemuck::Zeroable)]
+#[repr(C)]
+struct Colors {
+    left: Rgba,
+    right: Rgba,
+}
+impl Colors {
+    fn new(left: Color32, right: Color32) -> Self {
+        Self {
+            left: left.into(),
+            right: right.into(),
+        }
+    }
+}
+
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, Serialize, Deserialize)]
+pub enum DisplayMode {
+    Anaglyph,
+    LeftEye,
+    RightEye,
+    SideBySide,
+}
+
+impl DisplayMode {
+    pub fn proportions(self) -> Vec2 {
+        match self {
+            Self::SideBySide => Vec2::new(768.0, 224.0),
+            _ => Vec2::new(384.0, 224.0),
+        }
+    }
+}

src/window/gdb.rs

@@ -0,0 +1,107 @@
+use egui::{Button, CentralPanel, TextEdit, ViewportBuilder};
+use winit::event_loop::EventLoopProxy;
+
+use crate::{
+    app::UserEvent,
+    emulator::{EmulatorClient, SimId, SimState},
+    gdbserver::{GdbServer, GdbServerStatus},
+};
+
+use super::AppWindow;
+
+pub struct GdbServerWindow {
+    sim_id: SimId,
+    client: EmulatorClient,
+    port_str: String,
+    connected: bool,
+    quit_on_disconnect: bool,
+    server: GdbServer,
+    proxy: EventLoopProxy<UserEvent>,
+}
+
+impl GdbServerWindow {
+    pub fn new(sim_id: SimId, client: EmulatorClient, proxy: EventLoopProxy<UserEvent>) -> Self {
+        Self {
+            sim_id,
+            client: client.clone(),
+            port_str: (8080 + sim_id.to_index()).to_string(),
+            connected: false,
+            quit_on_disconnect: false,
+            server: GdbServer::new(sim_id, client),
+            proxy,
+        }
+    }
+
+    pub fn launch(&mut self, port: u16) {
+        self.server.stop();
+        self.port_str = port.to_string();
+        self.quit_on_disconnect = true;
+        self.server.start(port);
+        self.connected = true;
+    }
+}
+
+impl AppWindow for GdbServerWindow {
+    fn sim_id(&self) -> Option<SimId> {
+        Some(self.sim_id)
+    }
+
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title("GDB Server")
+            .with_inner_size((300.0, 200.0))
+    }
+
+    fn show(&mut self, ui: &mut egui::Ui) {
+        let port_num: Option<u16> = self.port_str.parse().ok();
+        let status = self.server.status();
+        CentralPanel::default().show_inside(ui, |ui| {
+            ui.horizontal(|ui| {
+                if port_num.is_none() {
+                    let style = ui.style_mut();
+                    let error = style.visuals.error_fg_color;
+                    style.visuals.widgets.active.bg_stroke.color = error;
+                    style.visuals.widgets.hovered.bg_stroke.color = error;
+                }
+                ui.label("Port");
+                let port_editor = TextEdit::singleline(&mut self.port_str).desired_width(100.0);
+                ui.add_enabled(!status.running(), port_editor);
+                ui.checkbox(&mut self.quit_on_disconnect, "Quit on disconnect");
+            });
+
+            if !status.running() {
+                if self.connected && self.quit_on_disconnect {
+                    self.proxy.send_event(UserEvent::Quit(self.sim_id)).unwrap();
+                } else {
+                    self.connected = false;
+                }
+                let start_button = Button::new("Start");
+                let can_start =
+                    port_num.is_some() && self.client.sim_state(self.sim_id) == SimState::Ready;
+                if ui.add_enabled(can_start, start_button).clicked() {
+                    let port = port_num.unwrap();
+                    self.server.start(port);
+                    self.connected = true;
+                }
+            } else {
+                let stop_button = Button::new("Stop");
+                if ui.add(stop_button).clicked() {
+                    self.server.stop();
+                }
+            }
+
+            match &status {
+                GdbServerStatus::Stopped => {}
+                GdbServerStatus::Connecting => {
+                    ui.label("Connecting...");
+                }
+                GdbServerStatus::Running => {
+                    ui.label("Running");
+                }
+                GdbServerStatus::Error(message) => {
+                    ui.label(message);
+                }
+            }
+        });
+    }
+}

src/window/hotkeys.rs

@@ -0,0 +1,145 @@
+use egui::{
+    Button, CentralPanel, Event, KeyboardShortcut, Label, Layout, Slider, Ui, ViewportBuilder,
+};
+use egui_extras::{Column, TableBuilder};
+
+use crate::input::{Command, ShortcutProvider};
+
+use super::{AppWindow, utils::UiExt};
+
+pub struct HotkeysWindow {
+    shortcuts: ShortcutProvider,
+    now_binding: Option<Command>,
+}
+
+impl HotkeysWindow {
+    pub fn new(shortcuts: ShortcutProvider) -> Self {
+        Self {
+            shortcuts,
+            now_binding: None,
+        }
+    }
+
+    fn show_shortcuts(&mut self, ui: &mut Ui) {
+        let row_height = ui.spacing().interact_size.y;
+        ui.section("Shortcuts", |ui| {
+            let width = ui.available_width() - 16.0;
+            TableBuilder::new(ui)
+                .column(Column::exact(width * 0.3))
+                .column(Column::exact(width * 0.5))
+                .column(Column::exact(width * 0.2))
+                .cell_layout(Layout::left_to_right(egui::Align::Center))
+                .body(|mut body| {
+                    for command in Command::all() {
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.add_sized(ui.available_size(), Label::new(command.name()));
+                            });
+                            row.col(|ui| {
+                                let button = if self.now_binding == Some(command) {
+                                    Button::new("Binding...")
+                                } else if let Some(shortcut) = self.shortcuts.shortcut_for(command)
+                                {
+                                    Button::new(ui.ctx().format_shortcut(&shortcut))
+                                } else {
+                                    Button::new("")
+                                };
+                                if ui.add_sized(ui.available_size(), button).clicked() {
+                                    self.now_binding = Some(command);
+                                }
+                            });
+                            row.col(|ui| {
+                                if ui
+                                    .add_sized(ui.available_size(), Button::new("Clear"))
+                                    .clicked()
+                                {
+                                    self.shortcuts.unset(command);
+                                    self.now_binding = None;
+                                }
+                            });
+                        });
+                    }
+                });
+        });
+        if let Some(command) = self.now_binding
+            && let Some(shortcut) = ui.input_mut(|i| {
+                i.events.iter().find_map(|event| match event {
+                    Event::Key {
+                        key,
+                        pressed: true,
+                        modifiers,
+                        ..
+                    } => Some(KeyboardShortcut::new(*modifiers, *key)),
+                    _ => None,
+                })
+            })
+        {
+            self.shortcuts.set(command, shortcut);
+            self.now_binding = None;
+        }
+    }
+
+    fn show_ff_settings(&mut self, ui: &mut Ui) {
+        let row_height = ui.spacing().interact_size.y;
+        ui.section("Fast Forward", |ui| {
+            let width = ui.available_width() - 8.0;
+            let mut ff_settings = self.shortcuts.ff_settings();
+            let mut updated = false;
+            TableBuilder::new(ui)
+                .column(Column::exact(width * 0.5))
+                .column(Column::exact(width * 0.5))
+                .body(|mut body| {
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("Treat button as toggle");
+                        });
+                        row.col(|ui| {
+                            if ui.checkbox(&mut ff_settings.toggle, "").changed() {
+                                updated = true;
+                            }
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("Speed multiplier");
+                        });
+                        row.col(|ui| {
+                            if ui
+                                .add_sized(
+                                    ui.available_size(),
+                                    Slider::new(&mut ff_settings.speed, 1..=15),
+                                )
+                                .changed()
+                            {
+                                updated = true;
+                            }
+                        });
+                    });
+                });
+            if updated {
+                self.shortcuts.update_ff_settings(ff_settings);
+            }
+        });
+    }
+}
+
+impl AppWindow for HotkeysWindow {
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title("Keyboard Shortcuts")
+            .with_inner_size((400.0, 400.0))
+    }
+
+    fn show(&mut self, ui: &mut Ui) {
+        CentralPanel::default().show_inside(ui, |ui| {
+            ui.horizontal(|ui| {
+                if ui.button("Use defaults").clicked() {
+                    self.shortcuts.reset();
+                }
+            });
+            ui.separator();
+            self.show_shortcuts(ui);
+            self.show_ff_settings(ui);
+        });
+    }
+}

src/window/input.rs

@@ -0,0 +1,262 @@
+use egui::{Button, CentralPanel, Label, Layout, Panel, Ui, ViewportBuilder};
+use egui_extras::{Column, TableBuilder};
+use gilrs::{EventType, GamepadId};
+use std::sync::RwLock;
+
+use crate::{
+    emulator::{SimId, VBKey},
+    input::{MappingProvider, Mappings},
+};
+
+use super::AppWindow;
+
+pub struct InputWindow {
+    mappings: MappingProvider,
+    now_binding: Option<VBKey>,
+    active_tab: InputTab,
+}
+
+const KEY_NAMES: [(VBKey, &str); 14] = [
+    (VBKey::LU, "Up"),
+    (VBKey::LD, "Down"),
+    (VBKey::LL, "Left"),
+    (VBKey::LR, "Right"),
+    (VBKey::SEL, "Select"),
+    (VBKey::STA, "Start"),
+    (VBKey::B, "B"),
+    (VBKey::A, "A"),
+    (VBKey::LT, "L-Trigger"),
+    (VBKey::RT, "R-Trigger"),
+    (VBKey::RU, "R-Up"),
+    (VBKey::RD, "R-Down"),
+    (VBKey::RL, "R-Left"),
+    (VBKey::RR, "R-Right"),
+];
+
+impl InputWindow {
+    pub fn new(mappings: MappingProvider) -> Self {
+        Self {
+            mappings,
+            now_binding: None,
+            active_tab: InputTab::Player1,
+        }
+    }
+
+    fn show_bindings<T: Mappings>(
+        &mut self,
+        ui: &mut Ui,
+        mappings: &RwLock<T>,
+        bind_message: &str,
+    ) {
+        ui.horizontal(|ui| {
+            if ui.button("Use defaults").clicked() {
+                mappings.write().unwrap().use_default_mappings();
+                self.mappings.save();
+                self.now_binding = None;
+            }
+            if ui.button("Clear all").clicked() {
+                mappings.write().unwrap().clear_all_mappings();
+                self.mappings.save();
+                self.now_binding = None;
+            }
+        });
+        ui.separator();
+        let mut names = {
+            let mapping = mappings.read().unwrap();
+            mapping.mapping_names()
+        };
+        TableBuilder::new(ui)
+            .column(Column::remainder())
+            .column(Column::remainder())
+            .cell_layout(Layout::left_to_right(egui::Align::Center))
+            .body(|mut body| {
+                for keys in KEY_NAMES.chunks_exact(2) {
+                    body.row(20.0, |mut row| {
+                        for (key, name) in keys {
+                            let binding = names.remove(key).map(|mut s| {
+                                s.sort();
+                                s.join(", ")
+                            });
+                            row.col(|ui| {
+                                let size = ui.available_size_before_wrap();
+                                let width = size.x;
+                                let height = size.y;
+                                ui.add_sized((width * 0.2, height), Label::new(*name));
+                                let label_text = if self.now_binding == Some(*key) {
+                                    bind_message
+                                } else {
+                                    binding.as_deref().unwrap_or("")
+                                };
+                                if ui
+                                    .add_sized((width * 0.6, height), Button::new(label_text))
+                                    .clicked()
+                                {
+                                    self.now_binding = Some(*key);
+                                }
+                                if ui
+                                    .add_sized(ui.available_size(), Button::new("Clear"))
+                                    .clicked()
+                                {
+                                    let mut mapping = mappings.write().unwrap();
+                                    mapping.clear_mappings(*key);
+                                    drop(mapping);
+                                    self.mappings.save();
+                                    self.now_binding = None;
+                                }
+                            });
+                        }
+                    });
+                }
+            });
+    }
+
+    fn show_key_bindings(&mut self, ui: &mut Ui, sim_id: SimId) {
+        let mappings = self.mappings.for_sim(sim_id).clone();
+        self.show_bindings(ui, &mappings, "Press any key");
+    }
+
+    fn show_gamepads(&mut self, ui: &mut Ui) {
+        let mut gamepads = self.mappings.gamepad_info();
+        gamepads.sort_by_key(|g| usize::from(g.id));
+
+        if gamepads.is_empty() {
+            ui.label("No gamepads connected.");
+            return;
+        }
+
+        for (index, gamepad) in gamepads.into_iter().enumerate() {
+            ui.horizontal(|ui| {
+                ui.label(format!("Gamepad {index}: {}", gamepad.name));
+                let mut bound_to = gamepad.bound_to;
+                let mut rebind = false;
+                rebind |= ui
+                    .selectable_value(&mut bound_to, Some(SimId::Player1), "Player 1")
+                    .changed();
+                rebind |= ui
+                    .selectable_value(&mut bound_to, Some(SimId::Player2), "Player 2")
+                    .changed();
+                rebind |= ui.selectable_value(&mut bound_to, None, "Nobody").changed();
+                if rebind {
+                    match bound_to {
+                        Some(sim_id) => self.mappings.assign_gamepad(gamepad.id, sim_id),
+                        None => self.mappings.unassign_gamepad(gamepad.id),
+                    }
+                }
+                ui.separator();
+                if ui.button("Rebind").clicked() {
+                    self.active_tab = InputTab::RebindGamepad(gamepad.id);
+                }
+            });
+        }
+    }
+
+    fn show_gamepad_bindings(&mut self, ui: &mut Ui, gamepad_id: GamepadId) {
+        let Some(mappings) = self.mappings.for_gamepad(gamepad_id) else {
+            self.active_tab = InputTab::Gamepads;
+            return;
+        };
+        self.show_bindings(ui, &mappings, "Press any input");
+    }
+}
+
+impl AppWindow for InputWindow {
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title("Bind Inputs")
+            .with_inner_size((600.0, 400.0))
+    }
+
+    fn show(&mut self, ui: &mut Ui) {
+        Panel::top("options").show_inside(ui, |ui| {
+            ui.horizontal(|ui| {
+                let old_active_tab = self.active_tab;
+                ui.selectable_value(&mut self.active_tab, InputTab::Player1, "Player 1");
+                ui.selectable_value(&mut self.active_tab, InputTab::Player2, "Player 2");
+                ui.selectable_value(&mut self.active_tab, InputTab::Gamepads, "Gamepads");
+                if matches!(self.active_tab, InputTab::RebindGamepad(_)) {
+                    let tab = self.active_tab;
+                    ui.selectable_value(&mut self.active_tab, tab, "Rebind Gamepad");
+                }
+                if old_active_tab != self.active_tab {
+                    self.now_binding = None;
+                }
+            });
+        });
+        CentralPanel::default().show_inside(ui, |ui| {
+            match self.active_tab {
+                InputTab::Player1 => self.show_key_bindings(ui, SimId::Player1),
+                InputTab::Player2 => self.show_key_bindings(ui, SimId::Player2),
+                InputTab::Gamepads => self.show_gamepads(ui),
+                InputTab::RebindGamepad(id) => self.show_gamepad_bindings(ui, id),
+            };
+        });
+    }
+
+    fn handle_key_event(&mut self, event: &winit::event::KeyEvent) -> bool {
+        if !event.state.is_pressed() {
+            return false;
+        }
+        let sim_id = match self.active_tab {
+            InputTab::Player1 => SimId::Player1,
+            InputTab::Player2 => SimId::Player2,
+            _ => {
+                return false;
+            }
+        };
+        let Some(vb) = self.now_binding.take() else {
+            return false;
+        };
+        let mut mappings = self.mappings.for_sim(sim_id).write().unwrap();
+        mappings.add_keyboard_mapping(vb, event.physical_key);
+        drop(mappings);
+        self.mappings.save();
+        true
+    }
+
+    fn handle_gamepad_event(&mut self, event: &gilrs::Event) -> bool {
+        let InputTab::RebindGamepad(gamepad_id) = self.active_tab else {
+            return false;
+        };
+        if gamepad_id != event.id {
+            return false;
+        }
+        let Some(mappings) = self.mappings.for_gamepad(gamepad_id) else {
+            return false;
+        };
+        let Some(vb) = self.now_binding else {
+            return false;
+        };
+        match event.event {
+            EventType::ButtonPressed(_, code) => {
+                let mut mapping = mappings.write().unwrap();
+                mapping.add_button_mapping(vb, code);
+                self.now_binding.take();
+                true
+            }
+            EventType::AxisChanged(_, value, code) => {
+                if value < -0.75 {
+                    let mut mapping = mappings.write().unwrap();
+                    mapping.add_axis_neg_mapping(vb, code);
+                    self.now_binding.take();
+                    true
+                } else if value > 0.75 {
+                    let mut mapping = mappings.write().unwrap();
+                    mapping.add_axis_pos_mapping(vb, code);
+                    self.now_binding.take();
+                    true
+                } else {
+                    false
+                }
+            }
+            _ => false,
+        }
+    }
+}
+
+#[derive(Clone, Copy, PartialEq, Eq)]
+enum InputTab {
+    Player1,
+    Player2,
+    Gamepads,
+    RebindGamepad(GamepadId),
+}

src/window/profile.rs

@@ -0,0 +1,168 @@
+use std::{fs, time::Duration};
+
+use anyhow::Result;
+use egui::{Button, CentralPanel, Checkbox, Label, ViewportBuilder};
+use egui_notify::{Anchor, Toast, Toasts};
+
+use crate::{
+    emulator::{EmulatorClient, EmulatorCommand, EmulatorState, SimId},
+    filepicker::FilePicker,
+    profiler::{Profiler, ProfilerStatus},
+    window::{AppWindow, InitArgs},
+};
+
+pub struct ProfileWindow {
+    sim_id: SimId,
+    client: EmulatorClient,
+    profiler: Profiler,
+    toasts: Toasts,
+    file_picker: FilePicker,
+}
+
+impl ProfileWindow {
+    pub fn new(sim_id: SimId, client: EmulatorClient) -> Self {
+        Self {
+            sim_id,
+            client: client.clone(),
+            profiler: Profiler::new(sim_id, client),
+            toasts: Toasts::new()
+                .with_anchor(Anchor::BottomLeft)
+                .with_margin((10.0, 10.0).into())
+                .reverse(true),
+            file_picker: FilePicker::new(),
+        }
+    }
+
+    pub fn launch(&mut self) {
+        self.profiler.enable();
+    }
+
+    fn finish_recording(&mut self) {
+        let pause = matches!(self.client.emulator_state(), EmulatorState::Running);
+        if pause {
+            self.client.send_command(EmulatorCommand::Pause);
+        }
+        match self.try_finish_recording() {
+            Ok(Some(path)) => {
+                let mut toast = Toast::info(format!("Saved to {path}"));
+                toast.duration(Some(Duration::from_secs(5)));
+                self.toasts.add(toast);
+            }
+            Ok(None) => {}
+            Err(error) => {
+                let mut toast = Toast::error(format!("{error:#}"));
+                toast.duration(Some(Duration::from_secs(5)));
+                self.toasts.add(toast);
+            }
+        }
+        if pause {
+            self.client.send_command(EmulatorCommand::Resume);
+        }
+    }
+
+    fn try_finish_recording(&mut self) -> Result<Option<String>> {
+        let bytes_receiver = self.profiler.finish_recording();
+        let file = self
+            .file_picker
+            .save_file_dialog()
+            .add_filter("Profiler files", &["json"])
+            .set_file_name("profile.json")
+            .open();
+        if let Some(path) = file {
+            let bytes = pollster::block_on(bytes_receiver)?;
+            let _ = fs::remove_file(&path);
+            fs::write(&path, bytes)?;
+            Ok(Some(path.display().to_string()))
+        } else {
+            self.profiler.cancel_recording();
+            Ok(None)
+        }
+    }
+}
+
+impl AppWindow for ProfileWindow {
+    fn sim_id(&self) -> Option<SimId> {
+        Some(self.sim_id)
+    }
+
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title("Profiler")
+            .with_inner_size((300.0, 200.0))
+    }
+
+    fn show(&mut self, ui: &mut egui::Ui) {
+        let status = self.profiler.status();
+        let recording = matches!(status, ProfilerStatus::Recording);
+        CentralPanel::default().show_inside(ui, |ui| {
+            ui.horizontal_wrapped(|ui| {
+                ui.spacing_mut().item_spacing.x = 0.0;
+                ui.add(
+                    Label::new(
+                        "Use this tool to record performance profiles of your game, for use in ",
+                    )
+                    .wrap_mode(egui::TextWrapMode::Wrap),
+                );
+                ui.hyperlink("https://profiler.firefox.com");
+                ui.label(".");
+            });
+            ui.horizontal_wrapped(|ui| {
+                ui.spacing_mut().item_spacing.x = 0.0;
+                ui.add(
+                    Label::new("For more instructions, see ").wrap_mode(egui::TextWrapMode::Wrap),
+                );
+                ui.hyperlink_to(
+                    "the Lemur wiki",
+                    "https://git.virtual-boy.com/PVB/lemur/wiki/Profiling-with-Lemur",
+                );
+                ui.label(".");
+            });
+            ui.separator();
+
+            let mut enabled = status.enabled();
+            let enabled_checkbox = Checkbox::new(&mut enabled, "Enable profiling");
+            if ui.add_enabled(!recording, enabled_checkbox).changed() {
+                if enabled {
+                    self.profiler.enable();
+                } else {
+                    self.profiler.disable();
+                }
+            }
+            if !enabled {
+                ui.label("Enabling profiling will restart your current game.");
+            } else {
+                ui.horizontal(|ui| {
+                    if !recording {
+                        let record_button = Button::new("Record");
+                        let can_record = matches!(status, ProfilerStatus::Enabled);
+                        if ui.add_enabled(can_record, record_button).clicked() {
+                            self.profiler.start_recording();
+                        }
+                    } else {
+                        if ui.button("Finish recording").clicked() {
+                            self.finish_recording();
+                        }
+                        if ui.button("Cancel recording").clicked() {
+                            self.profiler.cancel_recording();
+                        }
+                    }
+                });
+            }
+
+            match &status {
+                ProfilerStatus::Recording => {
+                    ui.label("Recording...");
+                }
+                ProfilerStatus::Error(message) => {
+                    ui.label(message);
+                }
+                _ => {}
+            }
+        });
+        self.toasts.show(ui);
+    }
+
+    fn on_init(&mut self, args: InitArgs) {
+        self.file_picker.set_window(args.window);
+    }
+}

src/window/terminal.rs

@@ -0,0 +1,72 @@
+use std::{collections::VecDeque, sync::mpsc};
+
+use egui::{Align, CentralPanel, FontFamily, Label, RichText, ScrollArea, Ui, ViewportBuilder};
+
+use crate::emulator::{EmulatorClient, EmulatorCommand, SimId};
+
+use super::AppWindow;
+
+const SCROLLBACK: usize = 1000;
+
+pub struct TerminalWindow {
+    sim_id: SimId,
+    receiver: mpsc::Receiver<String>,
+    lines: VecDeque<String>,
+}
+
+impl TerminalWindow {
+    pub fn new(sim_id: SimId, client: &EmulatorClient) -> Self {
+        let (sender, receiver) = mpsc::channel();
+        client.send_command(EmulatorCommand::WatchStdout(sim_id, sender));
+        let mut lines = VecDeque::new();
+        lines.push_back(String::new());
+        Self {
+            sim_id,
+            receiver,
+            lines,
+        }
+    }
+}
+
+impl AppWindow for TerminalWindow {
+    fn sim_id(&self) -> Option<SimId> {
+        Some(self.sim_id)
+    }
+
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title("Terminal")
+            .with_inner_size((640.0, 480.0))
+    }
+
+    fn show(&mut self, ui: &mut Ui) {
+        if let Ok(text) = self.receiver.try_recv() {
+            let mut rest = text.as_str();
+            while let Some(index) = rest.find('\n') {
+                let (line, lines) = rest.split_at(index);
+                let current = self.lines.back_mut().unwrap();
+                current.push_str(line);
+                self.lines.push_back(String::new());
+                if self.lines.len() > SCROLLBACK {
+                    self.lines.pop_front();
+                }
+                rest = &lines[1..];
+            }
+            self.lines.back_mut().unwrap().push_str(rest);
+        }
+        CentralPanel::default().show_inside(ui, |ui| {
+            ScrollArea::vertical()
+                .stick_to_bottom(true)
+                .auto_shrink([false, false])
+                .animated(false)
+                .show(ui, |ui| {
+                    for line in &self.lines {
+                        let label = Label::new(RichText::new(line).family(FontFamily::Monospace))
+                            .halign(Align::LEFT)
+                            .wrap();
+                        ui.add(label);
+                    }
+                });
+        });
+    }
+}

src/window/utils.rs

@@ -0,0 +1,463 @@
+use std::{
+    fmt::{Display, UpperHex},
+    ops::{AddAssign, Bound, Deref, DerefMut, MulAssign, RangeBounds},
+    str::FromStr,
+};
+
+use atoi::FromRadix16;
+use egui::{
+    Align, Color32, CornerRadius, CursorIcon, Event, Frame, Key, Layout, Margin, Rect, Response,
+    RichText, Sense, Shape, Stroke, StrokeKind, TextEdit, Ui, UiBuilder, Vec2, Widget, WidgetText,
+    ecolor::HexColor, util::id_type_map::SerializableAny,
+};
+use num_traits::{CheckedAdd, CheckedSub, One, Zero};
+
+pub trait UiExt {
+    fn section(&mut self, title: impl Into<String>, add_contents: impl FnOnce(&mut Ui));
+    fn selectable_button(&mut self, selected: bool, text: impl Into<WidgetText>) -> Response;
+    fn selectable_option<T: Eq>(
+        &mut self,
+        current_value: &mut T,
+        selected_value: T,
+        text: impl Into<WidgetText>,
+    ) -> Response {
+        let response = self.selectable_button(*current_value == selected_value, text);
+        if response.clicked() {
+            *current_value = selected_value;
+        }
+        response
+    }
+
+    fn color_pair_button(&mut self, left: Color32, right: Color32) -> Response;
+
+    fn color_picker(&mut self, color: &mut Color32, hex: &mut String) -> Response;
+}
+
+impl UiExt for Ui {
+    fn section(&mut self, title: impl Into<String>, add_contents: impl FnOnce(&mut Ui)) {
+        let title: String = title.into();
+        let mut frame = Frame::group(self.style());
+        frame.outer_margin.top += 10;
+        frame.inner_margin.top += 2;
+        let res = self.push_id(&title, |ui| {
+            frame.show(ui, |ui| {
+                ui.set_max_width(ui.available_width());
+                add_contents(ui);
+            })
+        });
+        let text = RichText::new(title).background_color(self.style().visuals.panel_fill);
+        let old_rect = res.response.rect;
+        let mut text_rect = old_rect;
+        text_rect.min.x += 6.0;
+        self.scope_builder(UiBuilder::new().max_rect(text_rect), |ui| ui.label(text));
+        if old_rect.width() > 0.0 {
+            self.advance_cursor_after_rect(old_rect);
+        }
+    }
+
+    fn selectable_button(&mut self, selected: bool, text: impl Into<WidgetText>) -> Response {
+        self.style_mut().visuals.widgets.inactive.bg_fill = Color32::TRANSPARENT;
+        self.style_mut().visuals.widgets.hovered.bg_fill = Color32::TRANSPARENT;
+        self.style_mut().visuals.widgets.active.bg_fill = Color32::TRANSPARENT;
+        let mut selected = selected;
+        self.checkbox(&mut selected, text)
+    }
+
+    fn color_pair_button(&mut self, left: Color32, right: Color32) -> Response {
+        let button_size = Vec2::new(60.0, 20.0);
+        let (rect, response) = self.allocate_at_least(button_size, Sense::click());
+        let center_x = rect.center().x;
+        let left_rect = rect.with_max_x(center_x);
+        self.painter().rect_filled(left_rect, 0.0, left);
+        let right_rect = rect.with_min_x(center_x);
+        self.painter().rect_filled(right_rect, 0.0, right);
+
+        let style = self.style().interact(&response);
+        self.painter()
+            .rect_stroke(rect, 0.0, style.fg_stroke, StrokeKind::Inside);
+        response
+    }
+
+    fn color_picker(&mut self, color: &mut Color32, hex: &mut String) -> Response {
+        self.allocate_ui_with_layout(
+            Vec2::new(100.0, 130.0),
+            Layout::top_down_justified(egui::Align::Center),
+            |ui| {
+                let (rect, _) = ui.allocate_at_least(Vec2::new(100.0, 100.0), Sense::hover());
+                ui.painter().rect_filled(rect, 0.0, *color);
+                let resp = ui.text_edit_singleline(hex);
+                if resp.changed()
+                    && let Ok(new_color) = HexColor::from_str_without_hash(hex)
+                {
+                    *color = new_color.color();
+                }
+                resp
+            },
+        )
+        .inner
+    }
+}
+
+enum Direction {
+    Up,
+    Down,
+}
+
+pub trait Number:
+    Copy
+    + Zero
+    + One
+    + AddAssign
+    + MulAssign
+    + CheckedAdd
+    + CheckedSub
+    + Eq
+    + Ord
+    + Display
+    + FromStr
+    + UpperHex
+    + Send
+    + Sync
+    + 'static
+{
+}
+impl<
+    T: Copy
+        + Zero
+        + One
+        + AddAssign
+        + MulAssign
+        + CheckedAdd
+        + CheckedSub
+        + Eq
+        + Ord
+        + Display
+        + FromStr
+        + UpperHex
+        + Send
+        + Sync
+        + 'static,
+> Number for T
+{
+}
+
+pub struct NumberEdit<'a, T: Number> {
+    value: &'a mut T,
+    increment: T,
+    precision: usize,
+    min: Option<T>,
+    max: Option<T>,
+    desired_width: Option<f32>,
+    arrows: bool,
+    hex: bool,
+}
+
+impl<'a, T: Number> NumberEdit<'a, T> {
+    pub fn new(value: &'a mut T) -> Self {
+        Self {
+            value,
+            increment: T::one(),
+            precision: 3,
+            min: None,
+            max: None,
+            desired_width: None,
+            arrows: true,
+            hex: false,
+        }
+    }
+
+    pub fn precision(self, precision: usize) -> Self {
+        Self { precision, ..self }
+    }
+
+    pub fn range(self, range: impl RangeBounds<T>) -> Self {
+        let min = match range.start_bound() {
+            Bound::Unbounded => None,
+            Bound::Included(t) => Some(*t),
+            Bound::Excluded(t) => t.checked_add(&self.increment),
+        };
+        let max = match range.end_bound() {
+            Bound::Unbounded => None,
+            Bound::Included(t) => Some(*t),
+            Bound::Excluded(t) => t.checked_sub(&self.increment),
+        };
+        Self { min, max, ..self }
+    }
+
+    pub fn desired_width(self, desired_width: f32) -> Self {
+        Self {
+            desired_width: Some(desired_width),
+            ..self
+        }
+    }
+
+    pub fn arrows(self, arrows: bool) -> Self {
+        Self { arrows, ..self }
+    }
+
+    pub fn hex(self, hex: bool) -> Self {
+        Self { hex, ..self }
+    }
+}
+
+impl<T: Number> Widget for NumberEdit<'_, T> {
+    fn ui(self, ui: &mut Ui) -> Response {
+        let id = ui.id();
+        let to_string = |val: &T| {
+            if self.hex {
+                format!("{val:.0$X}", self.precision)
+            } else {
+                format!("{val:.0$}", self.precision)
+            }
+        };
+        let from_string = |val: &str| {
+            if self.hex {
+                let bytes = val.as_bytes();
+                let (result, consumed) = atoi::Integer::<T>::from_radix_16(bytes);
+                (consumed == bytes.len()).then_some(result.0)
+            } else {
+                val.parse::<T>().ok()
+            }
+        };
+
+        let (last_value, mut str, focus) = ui.memory(|m| {
+            let (lv, s) = m
+                .data
+                .get_temp(id)
+                .unwrap_or((*self.value, to_string(self.value)));
+            let focus = m.has_focus(id);
+            (lv, s, focus)
+        });
+        let mut stale = false;
+        if *self.value != last_value {
+            str = to_string(self.value);
+            stale = true;
+        }
+        let valid = from_string(&str).is_some_and(|v: T| v == *self.value);
+        let mut up_pressed = false;
+        let mut down_pressed = false;
+        if focus {
+            ui.input_mut(|i| {
+                i.events.retain(|e| match e {
+                    Event::Key {
+                        key: Key::ArrowUp,
+                        pressed: true,
+                        ..
+                    } => {
+                        up_pressed = true;
+                        false
+                    }
+                    Event::Key {
+                        key: Key::ArrowDown,
+                        pressed: true,
+                        ..
+                    } => {
+                        down_pressed = true;
+                        false
+                    }
+                    _ => true,
+                })
+            });
+        }
+        let mut desired_width = self
+            .desired_width
+            .unwrap_or_else(|| ui.spacing().text_edit_width);
+        if self.arrows {
+            desired_width -= 16.0;
+        }
+        let text = TextEdit::singleline(&mut str)
+            .horizontal_align(Align::Max)
+            .id(id)
+            .desired_width(desired_width)
+            .margin(Margin {
+                left: 4,
+                right: if self.arrows { 20 } else { 4 },
+                top: 2,
+                bottom: 2,
+            });
+        let mut res = if valid {
+            ui.add(text)
+        } else {
+            let message = match (self.min, self.max) {
+                (Some(min), Some(max)) => format!(
+                    "Please enter a number between {} and {}.",
+                    to_string(&min),
+                    to_string(&max)
+                ),
+                (Some(min), None) => {
+                    format!("Please enter a number greater than {}.", to_string(&min))
+                }
+                (None, Some(max)) => {
+                    format!("Please enter a number less than {}.", to_string(&max))
+                }
+                (None, None) => "Please enter a number.".to_string(),
+            };
+            ui.scope(|ui| {
+                let style = ui.style_mut();
+                style.visuals.selection.stroke.color = style.visuals.error_fg_color;
+                style.visuals.widgets.hovered.bg_stroke.color =
+                    style.visuals.error_fg_color.gamma_multiply(0.60);
+                ui.add(text)
+            })
+            .inner
+            .on_hover_text(message)
+        };
+
+        let mut delta = None;
+        if self.arrows {
+            let arrow_left = res.rect.max.x - 16.0;
+            let arrow_right = res.rect.max.x;
+            let arrow_top = res.rect.min.y;
+            let arrow_middle = (res.rect.min.y + res.rect.max.y) / 2.0;
+            let arrow_bottom = res.rect.max.y;
+
+            let top_arrow_rect = Rect {
+                min: (arrow_left, arrow_top).into(),
+                max: (arrow_right, arrow_middle).into(),
+            };
+            if draw_arrow(ui, top_arrow_rect, true).clicked_or_dragged() || up_pressed {
+                delta = Some(Direction::Up);
+            }
+            let bottom_arrow_rect = Rect {
+                min: (arrow_left, arrow_middle).into(),
+                max: (arrow_right, arrow_bottom).into(),
+            };
+            if draw_arrow(ui, bottom_arrow_rect, false).clicked_or_dragged() || down_pressed {
+                delta = Some(Direction::Down);
+            }
+        }
+
+        let in_range =
+            |val: &T| self.min.is_none_or(|m| &m <= val) && self.max.is_none_or(|m| &m >= val);
+        if let Some(dir) = delta {
+            let value = match dir {
+                Direction::Up => self.value.checked_add(&self.increment),
+                Direction::Down => self.value.checked_sub(&self.increment),
+            };
+            if let Some(new_value) = value.filter(in_range) {
+                if *self.value != new_value {
+                    res.mark_changed();
+                }
+                *self.value = new_value;
+            }
+            str = to_string(self.value);
+            stale = true;
+        } else if res.changed() {
+            if let Some(new_value) = from_string(&str).filter(in_range) {
+                if *self.value != new_value {
+                    res.mark_changed();
+                }
+                *self.value = new_value;
+            }
+            stale = true;
+        }
+        if stale {
+            ui.memory_mut(|m| m.data.insert_temp(id, (*self.value, str)));
+        }
+        res
+    }
+}
+
+fn draw_arrow(ui: &mut Ui, rect: Rect, up: bool) -> Response {
+    let arrow_res = ui
+        .allocate_rect(rect, Sense::all())
+        .on_hover_cursor(CursorIcon::Default);
+    let visuals = ui.style().visuals.widgets.style(&arrow_res);
+    let painter = ui.painter_at(arrow_res.rect);
+
+    let rounding = if up {
+        CornerRadius {
+            ne: 2,
+            ..CornerRadius::ZERO
+        }
+    } else {
+        CornerRadius {
+            se: 2,
+            ..CornerRadius::ZERO
+        }
+    };
+    painter.rect_filled(arrow_res.rect, rounding, visuals.bg_fill);
+
+    let left = rect.left() + 4.0;
+    let center = (rect.left() + rect.right()) / 2.0;
+    let right = rect.right() - 4.0;
+    let top = rect.top() + 3.0;
+    let bottom = rect.bottom() - 3.0;
+    let points = if up {
+        vec![
+            (left, bottom).into(),
+            (center, top).into(),
+            (right, bottom).into(),
+        ]
+    } else {
+        vec![
+            (right, top).into(),
+            (center, bottom).into(),
+            (left, top).into(),
+        ]
+    };
+    painter.add(Shape::convex_polygon(
+        points,
+        visuals.fg_stroke.color,
+        Stroke::NONE,
+    ));
+    arrow_res
+}
+
+trait ResponseExt {
+    fn clicked_or_dragged(&self) -> bool;
+}
+
+impl ResponseExt for Response {
+    fn clicked_or_dragged(&self) -> bool {
+        self.clicked() || self.dragged()
+    }
+}
+
+pub struct UiData<T> {
+    current: T,
+    prev: T,
+    loaded: bool,
+}
+
+impl<T> UiData<T>
+where
+    T: Default + PartialEq + SerializableAny,
+{
+    pub fn new() -> Self {
+        Self {
+            current: T::default(),
+            prev: T::default(),
+            loaded: false,
+        }
+    }
+
+    pub fn load(&mut self, ui: &Ui) {
+        if !self.loaded {
+            self.current = ui
+                .data_mut(|d| d.get_persisted(ui.id()))
+                .unwrap_or_default();
+            self.loaded = true;
+        }
+    }
+
+    pub fn save(&mut self, ui: &Ui) {
+        if self.current != self.prev {
+            ui.data_mut(|d| d.insert_persisted(ui.id(), self.current.clone()));
+            self.prev = self.current.clone();
+        }
+    }
+}
+
+impl<T> Deref for UiData<T> {
+    type Target = T;
+    fn deref(&self) -> &Self::Target {
+        &self.current
+    }
+}
+
+impl<T> DerefMut for UiData<T> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.current
+    }
+}

src/window/vip.rs

@@ -0,0 +1,14 @@
+mod bgmap;
+mod chardata;
+mod framebuffer;
+mod object;
+mod registers;
+mod utils;
+mod world;
+
+pub use bgmap::*;
+pub use chardata::*;
+pub use framebuffer::*;
+pub use object::*;
+pub use registers::*;
+pub use world::*;

src/window/vip/bgmap.rs

@@ -0,0 +1,331 @@
+use std::sync::Arc;
+
+use egui::{
+    Align, CentralPanel, Checkbox, Color32, ComboBox, Image, ScrollArea, Slider, TextEdit,
+    TextureOptions, Ui, ViewportBuilder,
+};
+use egui_extras::{Column, Size, StripBuilder, TableBuilder};
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    emulator::SimId,
+    images::{ImageBuffer, ImageParams, ImageRenderer, ImageTextureLoader},
+    memory::{MemoryClient, MemoryView},
+    window::{
+        AppWindow,
+        utils::{NumberEdit, UiData, UiExt},
+    },
+};
+
+use super::utils::{self, CellData, CharacterGrid};
+
+#[derive(Clone, PartialEq, Serialize, Deserialize)]
+struct State {
+    cell_index: usize,
+    generic_palette: bool,
+    scale: f32,
+    show_grid: bool,
+}
+impl Default for State {
+    fn default() -> Self {
+        Self {
+            cell_index: 0,
+            generic_palette: false,
+            scale: 1.0,
+            show_grid: false,
+        }
+    }
+}
+
+pub struct BgMapWindow {
+    sim_id: SimId,
+    memory: Arc<MemoryClient>,
+    bgmaps: MemoryView,
+    params: ImageParams<BgMapParams>,
+    state: UiData<State>,
+}
+
+impl BgMapWindow {
+    pub fn new(sim_id: SimId, memory: &Arc<MemoryClient>, images: &ImageTextureLoader) -> Self {
+        let state: UiData<State> = UiData::new();
+        let renderer = BgMapRenderer::new(sim_id, memory);
+        let params = images.add(
+            sim_id,
+            renderer,
+            BgMapParams {
+                cell_index: state.cell_index,
+                generic_palette: state.generic_palette,
+            },
+        );
+        Self {
+            sim_id,
+            memory: memory.clone(),
+            bgmaps: memory.watch(sim_id, 0x00020000, 0x20000),
+            params,
+            state,
+        }
+    }
+
+    fn show_form(&mut self, ui: &mut Ui) {
+        let row_height = ui.spacing().interact_size.y;
+        ui.vertical(|ui| {
+            TableBuilder::new(ui)
+                .column(Column::auto())
+                .column(Column::remainder())
+                .body(|mut body| {
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("Map");
+                        });
+                        row.col(|ui| {
+                            let mut bgmap_index = self.state.cell_index / 4096;
+                            ui.add(NumberEdit::new(&mut bgmap_index).range(0..16));
+                            if bgmap_index != self.state.cell_index / 4096 {
+                                self.state.cell_index =
+                                    (bgmap_index * 4096) + (self.state.cell_index % 4096);
+                            }
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("Cell");
+                        });
+                        row.col(|ui| {
+                            ui.add(NumberEdit::new(&mut self.state.cell_index).range(0..16 * 4096));
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("Address");
+                        });
+                        row.col(|ui| {
+                            let address = 0x00020000 + (self.state.cell_index * 2);
+                            let mut address_str = format!("{address:08x}");
+                            ui.add_enabled(
+                                false,
+                                TextEdit::singleline(&mut address_str).horizontal_align(Align::Max),
+                            );
+                        });
+                    });
+                });
+            let image = Image::new(self.image_url("bgmap-cell"))
+                .maintain_aspect_ratio(true)
+                .texture_options(TextureOptions::NEAREST);
+            ui.add(image);
+            ui.section("Cell", |ui| {
+                let mut data = self.bgmaps.borrow().read::<u16>(self.state.cell_index);
+                let mut cell = CellData::parse(data);
+                TableBuilder::new(ui)
+                    .column(Column::remainder())
+                    .column(Column::remainder())
+                    .body(|mut body| {
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.label("Character");
+                            });
+                            row.col(|ui| {
+                                ui.add(NumberEdit::new(&mut cell.char_index).range(0..2048));
+                            });
+                        });
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.label("Palette");
+                            });
+                            row.col(|ui| {
+                                ComboBox::from_id_salt("palette")
+                                    .selected_text(format!("BG {}", cell.palette_index))
+                                    .width(ui.available_width())
+                                    .show_ui(ui, |ui| {
+                                        for palette in 0..4 {
+                                            ui.selectable_value(
+                                                &mut cell.palette_index,
+                                                palette,
+                                                format!("BG {palette}"),
+                                            );
+                                        }
+                                    });
+                            });
+                        });
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.add(Checkbox::new(&mut cell.hflip, "H-flip"));
+                            });
+                            row.col(|ui| {
+                                ui.add(Checkbox::new(&mut cell.vflip, "V-flip"));
+                            });
+                        });
+                    });
+                if cell.update(&mut data) {
+                    let address = 0x00020000 + (self.state.cell_index * 2);
+                    self.memory.write(self.sim_id, address as u32, &data);
+                }
+            });
+            ui.section("Display", |ui| {
+                ui.horizontal(|ui| {
+                    ui.label("Scale");
+                    ui.spacing_mut().slider_width = ui.available_width();
+                    let slider = Slider::new(&mut self.state.scale, 1.0..=10.0)
+                        .step_by(1.0)
+                        .show_value(false);
+                    ui.add(slider);
+                });
+                ui.checkbox(&mut self.state.show_grid, "Show grid");
+                ui.checkbox(&mut self.state.generic_palette, "Generic palette");
+            });
+        });
+        self.params.write(BgMapParams {
+            cell_index: self.state.cell_index,
+            generic_palette: self.state.generic_palette,
+        });
+    }
+
+    fn show_bgmap(&mut self, ui: &mut Ui) {
+        let grid = CharacterGrid::new(self.image_url("bgmap"))
+            .with_scale(self.state.scale)
+            .with_grid(self.state.show_grid)
+            .with_selected(self.state.cell_index % 4096);
+        if let Some(selected) = grid.show(ui) {
+            self.state.cell_index = (self.state.cell_index / 4096 * 4096) + selected;
+        }
+    }
+}
+
+impl AppWindow for BgMapWindow {
+    fn sim_id(&self) -> Option<SimId> {
+        Some(self.sim_id)
+    }
+
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title("BG Map Data")
+            .with_inner_size((640.0, 480.0))
+    }
+
+    fn show(&mut self, ui: &mut Ui) {
+        self.state.load(ui);
+        CentralPanel::default().show_inside(ui, |ui| {
+            ui.horizontal_top(|ui| {
+                StripBuilder::new(ui)
+                    .size(Size::relative(0.3).at_most(200.0))
+                    .size(Size::remainder())
+                    .horizontal(|mut strip| {
+                        strip.cell(|ui| {
+                            ScrollArea::vertical().show(ui, |ui| self.show_form(ui));
+                        });
+                        strip.cell(|ui| {
+                            ScrollArea::both().show(ui, |ui| self.show_bgmap(ui));
+                        });
+                    })
+            });
+        });
+        self.state.save(ui);
+    }
+}
+
+#[derive(Default, Clone, PartialEq, Eq)]
+struct BgMapParams {
+    cell_index: usize,
+    generic_palette: bool,
+}
+
+struct BgMapRenderer {
+    chardata: MemoryView,
+    bgmaps: MemoryView,
+    brightness: MemoryView,
+    palettes: MemoryView,
+}
+
+impl BgMapRenderer {
+    pub fn new(sim_id: SimId, memory: &MemoryClient) -> Self {
+        Self {
+            chardata: memory.watch(sim_id, 0x00078000, 0x8000),
+            bgmaps: memory.watch(sim_id, 0x00020000, 0x20000),
+            brightness: memory.watch(sim_id, 0x0005f824, 8),
+            palettes: memory.watch(sim_id, 0x0005f860, 16),
+        }
+    }
+
+    fn render_bgmap(&self, image: &mut ImageBuffer, bgmap_index: usize, generic_palette: bool) {
+        let chardata = self.chardata.borrow();
+        let bgmaps = self.bgmaps.borrow();
+        let brightness = self.brightness.borrow();
+        let palettes = self.palettes.borrow();
+
+        let brts = brightness.read::<[u8; 8]>(0);
+        let colors = if generic_palette {
+            [utils::generic_palette(Color32::RED); 4]
+        } else {
+            [0, 2, 4, 6].map(|i| utils::palette_colors(palettes.read(i), &brts, Color32::RED))
+        };
+
+        for (i, cell) in bgmaps.range::<u16>(bgmap_index * 4096, 4096).enumerate() {
+            let CellData {
+                char_index,
+                vflip,
+                hflip,
+                palette_index,
+            } = CellData::parse(cell);
+            let char = chardata.read::<[u16; 8]>(char_index);
+            let palette = &colors[palette_index];
+
+            for row in 0..8 {
+                let y = row + (i / 64) * 8;
+                for (col, pixel) in utils::read_char_row(&char, hflip, vflip, row).enumerate() {
+                    let x = col + (i % 64) * 8;
+                    image.write((x, y), palette[pixel as usize]);
+                }
+            }
+        }
+    }
+
+    fn render_bgmap_cell(&self, image: &mut ImageBuffer, index: usize, generic_palette: bool) {
+        let chardata = self.chardata.borrow();
+        let bgmaps = self.bgmaps.borrow();
+        let brightness = self.brightness.borrow();
+        let palettes = self.palettes.borrow();
+
+        let brts = brightness.read::<[u8; 8]>(0);
+
+        let cell = bgmaps.read::<u16>(index);
+
+        let CellData {
+            char_index,
+            vflip,
+            hflip,
+            palette_index,
+        } = CellData::parse(cell);
+        let char = chardata.read::<[u16; 8]>(char_index);
+        let palette = if generic_palette {
+            utils::generic_palette(Color32::RED)
+        } else {
+            utils::palette_colors(palettes.read(palette_index * 2), &brts, Color32::RED)
+        };
+
+        for row in 0..8 {
+            for (col, pixel) in utils::read_char_row(&char, hflip, vflip, row).enumerate() {
+                image.write((col, row), palette[pixel as usize]);
+            }
+        }
+    }
+}
+
+impl ImageRenderer<2> for BgMapRenderer {
+    type Params = BgMapParams;
+
+    fn names(&self) -> [&str; 2] {
+        ["bgmap-cell", "bgmap"]
+    }
+
+    fn sizes(&self) -> [[usize; 2]; 2] {
+        [[8, 8], [8 * 64, 8 * 64]]
+    }
+
+    fn render(&mut self, params: &Self::Params, images: &mut [ImageBuffer; 2]) {
+        self.render_bgmap_cell(&mut images[0], params.cell_index, params.generic_palette);
+        self.render_bgmap(
+            &mut images[1],
+            params.cell_index / 4096,
+            params.generic_palette,
+        );
+    }
+}

src/window/vip/chardata.rs

@@ -0,0 +1,362 @@
+use std::fmt::Display;
+
+use egui::{
+    Align, CentralPanel, Color32, ComboBox, Image, ScrollArea, Slider, TextEdit, TextureOptions,
+    Ui, Vec2, ViewportBuilder,
+};
+use egui_extras::{Column, Size, StripBuilder, TableBuilder};
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    emulator::SimId,
+    images::{ImageBuffer, ImageParams, ImageRenderer, ImageTextureLoader},
+    memory::{MemoryClient, MemoryView},
+    window::{
+        AppWindow,
+        utils::{NumberEdit, UiData, UiExt as _},
+    },
+};
+
+use super::utils::{self, CharacterGrid};
+
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
+pub enum Palette {
+    #[default]
+    Generic,
+    Bg0,
+    Bg1,
+    Bg2,
+    Bg3,
+    Obj0,
+    Obj1,
+    Obj2,
+    Obj3,
+}
+
+impl Palette {
+    pub const fn values() -> [Palette; 9] {
+        [
+            Self::Generic,
+            Self::Bg0,
+            Self::Bg1,
+            Self::Bg2,
+            Self::Bg3,
+            Self::Obj0,
+            Self::Obj1,
+            Self::Obj2,
+            Self::Obj3,
+        ]
+    }
+
+    pub const fn offset(self) -> Option<usize> {
+        match self {
+            Self::Generic => None,
+            Self::Bg0 => Some(0),
+            Self::Bg1 => Some(2),
+            Self::Bg2 => Some(4),
+            Self::Bg3 => Some(6),
+            Self::Obj0 => Some(8),
+            Self::Obj1 => Some(10),
+            Self::Obj2 => Some(12),
+            Self::Obj3 => Some(14),
+        }
+    }
+}
+
+impl Display for Palette {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Generic => f.write_str("Generic"),
+            Self::Bg0 => f.write_str("BG 0"),
+            Self::Bg1 => f.write_str("BG 1"),
+            Self::Bg2 => f.write_str("BG 2"),
+            Self::Bg3 => f.write_str("BG 3"),
+            Self::Obj0 => f.write_str("OBJ 0"),
+            Self::Obj1 => f.write_str("OBJ 1"),
+            Self::Obj2 => f.write_str("OBJ 2"),
+            Self::Obj3 => f.write_str("OBJ 3"),
+        }
+    }
+}
+
+#[derive(Clone, PartialEq, Serialize, Deserialize)]
+struct State {
+    palette: Palette,
+    index: usize,
+    scale: f32,
+    show_grid: bool,
+}
+impl Default for State {
+    fn default() -> Self {
+        Self {
+            palette: Palette::default(),
+            index: 0,
+            scale: 4.0,
+            show_grid: true,
+        }
+    }
+}
+
+pub struct CharacterDataWindow {
+    sim_id: SimId,
+    brightness: MemoryView,
+    palettes: MemoryView,
+    params: ImageParams<CharDataParams>,
+    state: UiData<State>,
+}
+
+impl CharacterDataWindow {
+    pub fn new(sim_id: SimId, memory: &MemoryClient, images: &ImageTextureLoader) -> Self {
+        let state: UiData<State> = UiData::new();
+        let renderer = CharDataRenderer::new(sim_id, memory);
+        let params = images.add(
+            sim_id,
+            renderer,
+            CharDataParams {
+                palette: state.palette,
+                index: state.index,
+            },
+        );
+        Self {
+            sim_id,
+            brightness: memory.watch(sim_id, 0x0005f824, 8),
+            palettes: memory.watch(sim_id, 0x0005f860, 16),
+            params,
+            state,
+        }
+    }
+
+    fn show_form(&mut self, ui: &mut Ui) {
+        let row_height = ui.spacing().interact_size.y;
+        ui.vertical(|ui| {
+            TableBuilder::new(ui)
+                .column(Column::auto())
+                .column(Column::remainder())
+                .body(|mut body| {
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("Index");
+                        });
+                        row.col(|ui| {
+                            ui.add(NumberEdit::new(&mut self.state.index).range(0..2048));
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("Address");
+                        });
+                        row.col(|ui| {
+                            let address = match self.state.index {
+                                0x000..0x200 => 0x00060000 + self.state.index * 16,
+                                0x200..0x400 => 0x000e0000 + (self.state.index - 0x200) * 16,
+                                0x400..0x600 => 0x00160000 + (self.state.index - 0x400) * 16,
+                                0x600..0x800 => 0x001e0000 + (self.state.index - 0x600) * 16,
+                                _ => unreachable!("can't happen"),
+                            };
+                            let mut address_str = format!("{address:08x}");
+                            ui.add_enabled(
+                                false,
+                                TextEdit::singleline(&mut address_str).horizontal_align(Align::Max),
+                            );
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("Mirror");
+                        });
+                        row.col(|ui| {
+                            let mirror = 0x00078000 + (self.state.index * 16);
+                            let mut mirror_str = format!("{mirror:08x}");
+                            ui.add_enabled(
+                                false,
+                                TextEdit::singleline(&mut mirror_str).horizontal_align(Align::Max),
+                            );
+                        });
+                    });
+                });
+            let image = Image::new(self.image_url("chardata-char"))
+                .maintain_aspect_ratio(true)
+                .texture_options(TextureOptions::NEAREST);
+            ui.add(image);
+            ui.section("Colors", |ui| {
+                ui.horizontal(|ui| {
+                    ui.label("Palette");
+                    ComboBox::from_id_salt("palette")
+                        .selected_text(self.state.palette.to_string())
+                        .width(ui.available_width())
+                        .show_ui(ui, |ui| {
+                            for palette in Palette::values() {
+                                ui.selectable_value(
+                                    &mut self.state.palette,
+                                    palette,
+                                    palette.to_string(),
+                                );
+                            }
+                        });
+                });
+                TableBuilder::new(ui)
+                    .columns(Column::remainder(), 4)
+                    .body(|mut body| {
+                        let palette = self.load_palette_colors();
+                        body.row(30.0, |mut row| {
+                            for color in palette {
+                                row.col(|ui| {
+                                    let rect = ui.available_rect_before_wrap();
+                                    let scale = rect.height() / rect.width();
+                                    let rect = rect.scale_from_center2(Vec2::new(scale, 1.0));
+                                    ui.painter().rect_filled(rect, 0.0, color);
+                                });
+                            }
+                        });
+                    });
+            });
+            ui.section("Display", |ui| {
+                ui.horizontal(|ui| {
+                    ui.label("Scale");
+                    ui.spacing_mut().slider_width = ui.available_width();
+                    let slider = Slider::new(&mut self.state.scale, 1.0..=10.0)
+                        .step_by(1.0)
+                        .show_value(false);
+                    ui.add(slider);
+                });
+                ui.checkbox(&mut self.state.show_grid, "Show grid");
+            });
+        });
+
+        self.params.write(CharDataParams {
+            palette: self.state.palette,
+            index: self.state.index,
+        });
+    }
+
+    fn load_palette_colors(&self) -> [Color32; 4] {
+        let Some(offset) = self.state.palette.offset() else {
+            return utils::generic_palette(Color32::RED);
+        };
+        let palette = self.palettes.borrow().read(offset);
+        let brightnesses = self.brightness.borrow();
+        let brts = brightnesses.read(0);
+        utils::palette_colors(palette, &brts, Color32::RED)
+    }
+
+    fn show_chardata(&mut self, ui: &mut Ui) {
+        let grid = CharacterGrid::new(self.image_url("chardata"))
+            .with_scale(self.state.scale)
+            .with_grid(self.state.show_grid)
+            .with_selected(self.state.index);
+        if let Some(selected) = grid.show(ui) {
+            self.state.index = selected;
+        }
+    }
+}
+
+impl AppWindow for CharacterDataWindow {
+    fn sim_id(&self) -> Option<SimId> {
+        Some(self.sim_id)
+    }
+
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title("Character Data")
+            .with_inner_size((640.0, 480.0))
+    }
+
+    fn show(&mut self, ui: &mut Ui) {
+        self.state.load(ui);
+        CentralPanel::default().show_inside(ui, |ui| {
+            ui.horizontal_top(|ui| {
+                StripBuilder::new(ui)
+                    .size(Size::relative(0.3).at_most(200.0))
+                    .size(Size::remainder())
+                    .horizontal(|mut strip| {
+                        strip.cell(|ui| {
+                            ScrollArea::vertical().show(ui, |ui| self.show_form(ui));
+                        });
+                        strip.cell(|ui| {
+                            ScrollArea::both().show(ui, |ui| self.show_chardata(ui));
+                        });
+                    });
+            });
+        });
+        self.state.save(ui);
+    }
+}
+
+#[derive(Clone, PartialEq, Eq)]
+struct CharDataParams {
+    palette: Palette,
+    index: usize,
+}
+
+struct CharDataRenderer {
+    chardata: MemoryView,
+    brightness: MemoryView,
+    palettes: MemoryView,
+}
+
+impl ImageRenderer<2> for CharDataRenderer {
+    type Params = CharDataParams;
+
+    fn names(&self) -> [&str; 2] {
+        ["chardata-char", "chardata"]
+    }
+
+    fn sizes(&self) -> [[usize; 2]; 2] {
+        [[8, 8], [16 * 8, 128 * 8]]
+    }
+
+    fn render(&mut self, params: &Self::Params, image: &mut [ImageBuffer; 2]) {
+        self.render_character(&mut image[0], params.palette, params.index);
+        self.render_character_data(&mut image[1], params.palette);
+    }
+}
+
+impl CharDataRenderer {
+    pub fn new(sim_id: SimId, memory: &MemoryClient) -> Self {
+        Self {
+            chardata: memory.watch(sim_id, 0x00078000, 0x8000),
+            brightness: memory.watch(sim_id, 0x0005f824, 8),
+            palettes: memory.watch(sim_id, 0x0005f860, 16),
+        }
+    }
+
+    fn render_character(&self, image: &mut ImageBuffer, palette: Palette, index: usize) {
+        if index >= 2048 {
+            return;
+        }
+        let palette = self.load_palette(palette);
+        let chardata = self.chardata.borrow();
+        let character = chardata.range::<u16>(index * 8, 8);
+        for (row, pixels) in character.enumerate() {
+            for col in 0..8 {
+                let char = (pixels >> (col * 2)) & 0x03;
+                image.write((col, row), palette[char as usize]);
+            }
+        }
+    }
+
+    fn render_character_data(&self, image: &mut ImageBuffer, palette: Palette) {
+        let palette = self.load_palette(palette);
+        let chardata = self.chardata.borrow();
+        for (row, pixels) in chardata.range::<u16>(0, 8 * 2048).enumerate() {
+            let char_index = row / 8;
+            let row_index = row % 8;
+            let x = (char_index % 16) * 8;
+            let y = (char_index / 16) * 8 + row_index;
+            for col in 0..8 {
+                let char = (pixels >> (col * 2)) & 0x03;
+                image.write((x + col, y), palette[char as usize]);
+            }
+        }
+    }
+
+    fn load_palette(&self, palette: Palette) -> [Color32; 4] {
+        let Some(offset) = palette.offset() else {
+            return utils::GENERIC_PALETTE.map(|p| utils::shade(p, Color32::RED));
+        };
+        let palette = self.palettes.borrow().read(offset);
+        let brightnesses = self.brightness.borrow();
+        let brts = brightnesses.read(0);
+        utils::palette_colors(palette, &brts, Color32::RED)
+    }
+}

src/window/vip/framebuffer.rs

@@ -0,0 +1,277 @@
+use egui::{
+    Align, CentralPanel, Color32, Image, ScrollArea, Slider, TextEdit, TextureOptions, Ui,
+    ViewportBuilder,
+};
+use egui_extras::{Column, Size, StripBuilder, TableBuilder};
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    emulator::SimId,
+    images::{ImageBuffer, ImageParams, ImageRenderer, ImageTextureLoader},
+    memory::{MemoryClient, MemoryView},
+    window::{
+        AppWindow,
+        utils::{NumberEdit, UiData, UiExt as _},
+    },
+};
+
+use super::utils;
+
+#[derive(Clone, PartialEq, Serialize, Deserialize)]
+struct State {
+    index: usize,
+    left: bool,
+    right: bool,
+    generic_palette: bool,
+    scale: f32,
+}
+impl Default for State {
+    fn default() -> Self {
+        Self {
+            index: 0,
+            left: true,
+            right: true,
+            generic_palette: false,
+            scale: 2.0,
+        }
+    }
+}
+
+pub struct FrameBufferWindow {
+    sim_id: SimId,
+    params: ImageParams<FrameBufferParams>,
+    state: UiData<State>,
+}
+
+impl FrameBufferWindow {
+    pub fn new(sim_id: SimId, memory: &MemoryClient, images: &ImageTextureLoader) -> Self {
+        let state: UiData<State> = UiData::new();
+        let renderer = FrameBufferRenderer::new(sim_id, memory);
+        let params = images.add(
+            sim_id,
+            renderer,
+            FrameBufferParams {
+                index: state.index,
+                left: state.left,
+                right: state.right,
+                generic_palette: state.generic_palette,
+                left_color: Color32::from_rgb(0xff, 0x00, 0x00),
+                right_color: Color32::from_rgb(0x00, 0xc6, 0xf0),
+            },
+        );
+        Self {
+            sim_id,
+            params,
+            state,
+        }
+    }
+
+    fn show_form(&mut self, ui: &mut Ui) {
+        let row_height = ui.spacing().interact_size.y;
+        ui.vertical(|ui| {
+            TableBuilder::new(ui)
+                .column(Column::auto())
+                .column(Column::remainder())
+                .body(|mut body| {
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("Index");
+                        });
+                        row.col(|ui| {
+                            ui.add(NumberEdit::new(&mut self.state.index).range(0..2));
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("Left");
+                        });
+                        row.col(|ui| {
+                            let address = self.state.index * 0x00008000;
+                            let mut address_str = format!("{address:08x}");
+                            ui.add_enabled(
+                                false,
+                                TextEdit::singleline(&mut address_str).horizontal_align(Align::Max),
+                            );
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("Right");
+                        });
+                        row.col(|ui| {
+                            let address = self.state.index * 0x00008000 + 0x00010000;
+                            let mut address_str = format!("{address:08x}");
+                            ui.add_enabled(
+                                false,
+                                TextEdit::singleline(&mut address_str).horizontal_align(Align::Max),
+                            );
+                        });
+                    });
+                });
+            ui.section("Display", |ui| {
+                ui.horizontal(|ui| {
+                    ui.label("Scale");
+                    ui.spacing_mut().slider_width = ui.available_width();
+                    let slider = Slider::new(&mut self.state.scale, 1.0..=10.0)
+                        .step_by(1.0)
+                        .show_value(false);
+                    ui.add(slider);
+                });
+                TableBuilder::new(ui)
+                    .columns(Column::remainder(), 2)
+                    .body(|mut body| {
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.checkbox(&mut self.state.left, "Left");
+                            });
+                            row.col(|ui| {
+                                ui.checkbox(&mut self.state.right, "Right");
+                            });
+                        });
+                    });
+                ui.checkbox(&mut self.state.generic_palette, "Generic colors");
+            });
+        });
+
+        self.params.write(FrameBufferParams {
+            index: self.state.index,
+            left: self.state.left,
+            right: self.state.right,
+            generic_palette: self.state.generic_palette,
+            ..*self.params
+        });
+    }
+
+    fn show_buffers(&mut self, ui: &mut Ui) {
+        let image = Image::new(self.image_url("buffer"))
+            .fit_to_original_size(self.state.scale)
+            .texture_options(TextureOptions::NEAREST);
+        ui.add(image);
+    }
+}
+
+impl AppWindow for FrameBufferWindow {
+    fn sim_id(&self) -> Option<SimId> {
+        Some(self.sim_id)
+    }
+
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title("Frame Buffers")
+            .with_inner_size((640.0, 480.0))
+    }
+
+    fn show(&mut self, ui: &mut Ui) {
+        self.state.load(ui);
+        CentralPanel::default().show_inside(ui, |ui| {
+            ui.horizontal_top(|ui| {
+                StripBuilder::new(ui)
+                    .size(Size::relative(0.3).at_most(200.0))
+                    .size(Size::remainder())
+                    .horizontal(|mut strip| {
+                        strip.cell(|ui| {
+                            ScrollArea::vertical().show(ui, |ui| self.show_form(ui));
+                        });
+                        strip.cell(|ui| {
+                            ScrollArea::both().show(ui, |ui| self.show_buffers(ui));
+                        });
+                    });
+            });
+        });
+        self.state.save(ui);
+    }
+}
+
+#[derive(Clone, PartialEq, Eq)]
+struct FrameBufferParams {
+    index: usize,
+    left: bool,
+    right: bool,
+    generic_palette: bool,
+    left_color: Color32,
+    right_color: Color32,
+}
+
+struct FrameBufferRenderer {
+    buffers: [MemoryView; 4],
+    brightness: MemoryView,
+}
+
+impl FrameBufferRenderer {
+    fn new(sim_id: SimId, memory: &MemoryClient) -> Self {
+        Self {
+            buffers: [
+                memory.watch(sim_id, 0x00000000, 0x6000),
+                memory.watch(sim_id, 0x00008000, 0x6000),
+                memory.watch(sim_id, 0x00010000, 0x6000),
+                memory.watch(sim_id, 0x00018000, 0x6000),
+            ],
+            brightness: memory.watch(sim_id, 0x0005f824, 8),
+        }
+    }
+}
+
+impl ImageRenderer<1> for FrameBufferRenderer {
+    type Params = FrameBufferParams;
+
+    fn names(&self) -> [&str; 1] {
+        ["buffer"]
+    }
+
+    fn sizes(&self) -> [[usize; 2]; 1] {
+        [[384, 224]]
+    }
+
+    fn render(&mut self, params: &Self::Params, images: &mut [ImageBuffer; 1]) {
+        let image = &mut images[0];
+
+        let left_buffer = self.buffers[params.index].borrow();
+        let right_buffer = self.buffers[2 + params.index].borrow();
+
+        let colors = if params.generic_palette {
+            [
+                utils::generic_palette(params.left_color),
+                utils::generic_palette(params.right_color),
+            ]
+        } else {
+            let brts = self.brightness.borrow().read::<[u8; 8]>(0);
+            let shades = utils::parse_shades(&brts);
+            [
+                shades.map(|s| utils::shade(s, params.left_color)),
+                shades.map(|s| utils::shade(s, params.right_color)),
+            ]
+        };
+
+        let left_cols = left_buffer.range::<u8>(0, 0x6000);
+        let right_cols = right_buffer.range::<u8>(0, 0x6000);
+        for (index, (left, right)) in left_cols.zip(right_cols).enumerate() {
+            let top = (index % 64) * 4;
+            if top >= 224 {
+                continue;
+            }
+
+            let pixels = [0, 2, 4, 6].map(|i| {
+                let left = if params.left {
+                    colors[0][(left >> i) as usize & 0x3]
+                } else {
+                    Color32::BLACK
+                };
+                let right = if params.right {
+                    colors[1][(right >> i) as usize & 0x3]
+                } else {
+                    Color32::BLACK
+                };
+                Color32::from_rgb(
+                    left.r() + right.r(),
+                    left.g() + right.g(),
+                    left.b() + right.b(),
+                )
+            });
+            let x = index / 64;
+            for (i, pixel) in pixels.into_iter().enumerate() {
+                let y = top + i;
+                image.write((x, y), pixel);
+            }
+        }
+    }
+}

src/window/vip/object.rs

@@ -0,0 +1,353 @@
+use std::sync::Arc;
+
+use egui::{
+    Align, CentralPanel, Checkbox, Color32, ComboBox, Image, ScrollArea, Slider, TextEdit,
+    TextureOptions, Ui, ViewportBuilder,
+};
+use egui_extras::{Column, Size, StripBuilder, TableBuilder};
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    emulator::SimId,
+    images::{ImageBuffer, ImageParams, ImageRenderer, ImageTextureLoader},
+    memory::{MemoryClient, MemoryView},
+    window::{
+        AppWindow,
+        utils::{NumberEdit, UiData, UiExt as _},
+    },
+};
+
+use super::utils::{self, Object};
+
+#[derive(Clone, PartialEq, Serialize, Deserialize)]
+struct State {
+    index: usize,
+    generic_palette: bool,
+    scale: f32,
+}
+impl Default for State {
+    fn default() -> Self {
+        Self {
+            index: 0,
+            generic_palette: false,
+            scale: 1.0,
+        }
+    }
+}
+
+pub struct ObjectWindow {
+    sim_id: SimId,
+    memory: Arc<MemoryClient>,
+    objects: MemoryView,
+    params: ImageParams<ObjectParams>,
+    state: UiData<State>,
+}
+
+impl ObjectWindow {
+    pub fn new(sim_id: SimId, memory: &Arc<MemoryClient>, images: &ImageTextureLoader) -> Self {
+        let state: UiData<State> = UiData::new();
+        let renderer = ObjectRenderer::new(sim_id, memory);
+        let params = images.add(
+            sim_id,
+            renderer,
+            ObjectParams {
+                index: state.index,
+                generic_palette: state.generic_palette,
+                left_color: Color32::from_rgb(0xff, 0x00, 0x00),
+                right_color: Color32::from_rgb(0x00, 0xc6, 0xf0),
+            },
+        );
+        Self {
+            sim_id,
+            memory: memory.clone(),
+            objects: memory.watch(sim_id, 0x0003e000, 0x2000),
+            params,
+            state,
+        }
+    }
+
+    fn show_form(&mut self, ui: &mut Ui) {
+        let row_height = ui.spacing().interact_size.y;
+        ui.vertical(|ui| {
+            TableBuilder::new(ui)
+                .column(Column::auto())
+                .column(Column::remainder())
+                .body(|mut body| {
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("Index");
+                        });
+                        row.col(|ui| {
+                            ui.add(NumberEdit::new(&mut self.state.index).range(0..1024));
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("Address");
+                        });
+                        row.col(|ui| {
+                            let address = 0x3e000 + self.state.index * 8;
+                            let mut address_str = format!("{address:08x}");
+                            ui.add_enabled(
+                                false,
+                                TextEdit::singleline(&mut address_str).horizontal_align(Align::Max),
+                            );
+                        });
+                    });
+                });
+            let image = Image::new(self.image_url("object-zoom"))
+                .maintain_aspect_ratio(true)
+                .texture_options(TextureOptions::NEAREST);
+            ui.add(image);
+            ui.section("Properties", |ui| {
+                let mut object = self.objects.borrow().read::<[u16; 4]>(self.state.index);
+                let mut obj = Object::parse(object);
+                TableBuilder::new(ui)
+                    .column(Column::remainder())
+                    .column(Column::remainder())
+                    .body(|mut body| {
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.label("Character");
+                            });
+                            row.col(|ui| {
+                                ui.add(NumberEdit::new(&mut obj.data.char_index).range(0..2048));
+                            });
+                        });
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.label("Palette");
+                            });
+                            row.col(|ui| {
+                                ComboBox::from_id_salt("palette")
+                                    .selected_text(format!("OBJ {}", obj.data.palette_index))
+                                    .width(ui.available_width())
+                                    .show_ui(ui, |ui| {
+                                        for palette in 0..4 {
+                                            ui.selectable_value(
+                                                &mut obj.data.palette_index,
+                                                palette,
+                                                format!("OBJ {palette}"),
+                                            );
+                                        }
+                                    });
+                            });
+                        });
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.label("X");
+                            });
+                            row.col(|ui| {
+                                ui.add(NumberEdit::new(&mut obj.x).range(-512..512));
+                            });
+                        });
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.label("Y");
+                            });
+                            row.col(|ui| {
+                                ui.add(NumberEdit::new(&mut obj.y).range(-8..=224));
+                            });
+                        });
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.label("Parallax");
+                            });
+                            row.col(|ui| {
+                                ui.add(NumberEdit::new(&mut obj.parallax).range(-512..512));
+                            });
+                        });
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.add(Checkbox::new(&mut obj.data.hflip, "H-flip"));
+                            });
+                            row.col(|ui| {
+                                ui.add(Checkbox::new(&mut obj.data.vflip, "V-flip"));
+                            });
+                        });
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.add(Checkbox::new(&mut obj.lon, "Left"));
+                            });
+                            row.col(|ui| {
+                                ui.add(Checkbox::new(&mut obj.ron, "Right"));
+                            });
+                        });
+                    });
+                if obj.update(&mut object) {
+                    let address = 0x3e000 + self.state.index * 8;
+                    self.memory.write(self.sim_id, address as u32, &object);
+                }
+            });
+            ui.section("Display", |ui| {
+                ui.horizontal(|ui| {
+                    ui.label("Scale");
+                    ui.spacing_mut().slider_width = ui.available_width();
+                    let slider = Slider::new(&mut self.state.scale, 1.0..=10.0)
+                        .step_by(1.0)
+                        .show_value(false);
+                    ui.add(slider);
+                });
+                ui.checkbox(&mut self.state.generic_palette, "Generic palette");
+            });
+        });
+        self.params.write(ObjectParams {
+            index: self.state.index,
+            generic_palette: self.state.generic_palette,
+            ..*self.params
+        });
+    }
+
+    fn show_object(&mut self, ui: &mut Ui) {
+        let image = Image::new(self.image_url("object-full"))
+            .fit_to_original_size(self.state.scale)
+            .texture_options(TextureOptions::NEAREST);
+        ui.add(image);
+    }
+}
+
+impl AppWindow for ObjectWindow {
+    fn sim_id(&self) -> Option<SimId> {
+        Some(self.sim_id)
+    }
+
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title("Object Data")
+            .with_inner_size((640.0, 500.0))
+    }
+
+    fn show(&mut self, ui: &mut Ui) {
+        self.state.load(ui);
+        CentralPanel::default().show_inside(ui, |ui| {
+            ui.horizontal_top(|ui| {
+                StripBuilder::new(ui)
+                    .size(Size::relative(0.3).at_most(200.0))
+                    .size(Size::remainder())
+                    .horizontal(|mut strip| {
+                        strip.cell(|ui| {
+                            ScrollArea::vertical().show(ui, |ui| self.show_form(ui));
+                        });
+                        strip.cell(|ui| {
+                            ScrollArea::both().show(ui, |ui| self.show_object(ui));
+                        });
+                    });
+            });
+        });
+        self.state.save(ui);
+    }
+}
+
+#[derive(Clone, PartialEq, Eq)]
+struct ObjectParams {
+    index: usize,
+    generic_palette: bool,
+    left_color: Color32,
+    right_color: Color32,
+}
+
+enum Eye {
+    Left,
+    Right,
+}
+
+struct ObjectRenderer {
+    chardata: MemoryView,
+    objects: MemoryView,
+    brightness: MemoryView,
+    palettes: MemoryView,
+}
+
+impl ObjectRenderer {
+    pub fn new(sim_id: SimId, memory: &MemoryClient) -> Self {
+        Self {
+            chardata: memory.watch(sim_id, 0x00078000, 0x8000),
+            objects: memory.watch(sim_id, 0x0003e000, 0x2000),
+            brightness: memory.watch(sim_id, 0x0005f824, 8),
+            palettes: memory.watch(sim_id, 0x0005f860, 16),
+        }
+    }
+
+    fn render_object(
+        &self,
+        image: &mut ImageBuffer,
+        params: &ObjectParams,
+        use_pos: bool,
+        eye: Eye,
+    ) {
+        let chardata = self.chardata.borrow();
+        let objects = self.objects.borrow();
+        let brightness = self.brightness.borrow();
+        let palettes = self.palettes.borrow();
+
+        let object: [u16; 4] = objects.read(params.index);
+        let obj = Object::parse(object);
+
+        if match eye {
+            Eye::Left => !obj.lon,
+            Eye::Right => !obj.ron,
+        } {
+            return;
+        }
+
+        let brts = brightness.read::<[u8; 8]>(0);
+        let (x, y) = if use_pos {
+            let x = match eye {
+                Eye::Left => obj.x - obj.parallax,
+                Eye::Right => obj.x + obj.parallax,
+            };
+            (x, obj.y)
+        } else {
+            (0, 0)
+        };
+
+        let color = match eye {
+            Eye::Left => params.left_color,
+            Eye::Right => params.right_color,
+        };
+
+        let char = chardata.read::<[u16; 8]>(obj.data.char_index);
+        let palette = if params.generic_palette {
+            utils::generic_palette(color)
+        } else {
+            utils::palette_colors(palettes.read(8 + obj.data.palette_index * 2), &brts, color)
+        };
+
+        for row in 0..8 {
+            let real_y = y + row as i16;
+            if !(0..224).contains(&real_y) {
+                continue;
+            }
+            for (col, pixel) in
+                utils::read_char_row(&char, obj.data.hflip, obj.data.vflip, row).enumerate()
+            {
+                let real_x = x + col as i16;
+                if !(0..384).contains(&real_x) {
+                    continue;
+                }
+                image.add((real_x as usize, real_y as usize), palette[pixel as usize]);
+            }
+        }
+    }
+}
+
+impl ImageRenderer<2> for ObjectRenderer {
+    type Params = ObjectParams;
+
+    fn names(&self) -> [&str; 2] {
+        ["object-zoom", "object-full"]
+    }
+
+    fn sizes(&self) -> [[usize; 2]; 2] {
+        [[8, 8], [384, 224]]
+    }
+
+    fn render(&mut self, params: &Self::Params, images: &mut [ImageBuffer; 2]) {
+        images[0].clear();
+        self.render_object(&mut images[0], params, false, Eye::Left);
+        self.render_object(&mut images[0], params, false, Eye::Right);
+        images[1].clear();
+        self.render_object(&mut images[1], params, true, Eye::Left);
+        self.render_object(&mut images[1], params, true, Eye::Right);
+    }
+}

src/window/vip/registers.rs

@@ -0,0 +1,815 @@
+use std::sync::Arc;
+
+use egui::{
+    Align, Button, CentralPanel, Checkbox, Color32, Direction, Label, Layout, ScrollArea, TextEdit,
+    Ui, ViewportBuilder,
+};
+use egui_extras::{Column, Size, StripBuilder, TableBuilder};
+
+use crate::{
+    emulator::SimId,
+    memory::{MemoryClient, MemoryRef, MemoryValue, MemoryView},
+    window::{
+        AppWindow,
+        utils::{NumberEdit, UiExt},
+    },
+};
+
+use super::utils;
+
+pub struct RegisterWindow {
+    sim_id: SimId,
+    memory: Arc<MemoryClient>,
+    registers: MemoryView,
+}
+
+impl RegisterWindow {
+    pub fn new(sim_id: SimId, memory: &Arc<MemoryClient>) -> Self {
+        Self {
+            sim_id,
+            memory: memory.clone(),
+            registers: memory.watch(sim_id, 0x0005f800, 0x72),
+        }
+    }
+
+    fn show_interrupts(&mut self, ui: &mut Ui) {
+        let row_height = self.row_height(ui);
+        let [mut raw_intpnd, mut raw_intenb] = self.read_address(0x0005f800);
+        let mut intenb = InterruptReg::parse(raw_intenb);
+        let mut intpnd = InterruptReg::parse(raw_intpnd);
+        ui.section("Interrupt", |ui| {
+            let width = ui.available_width();
+            let xspace = ui.spacing().item_spacing.x;
+            ui.with_layout(Layout::top_down_justified(Align::Center), |ui| {
+                TableBuilder::new(ui)
+                    .id_salt("raw_values")
+                    .columns(Column::exact(width * 0.5 - xspace), 2)
+                    .cell_layout(Layout::left_to_right(Align::Max))
+                    .body(|mut body| {
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.label("INTENB");
+                            });
+                            row.col(|ui| {
+                                let mut text = format!("{raw_intenb:04x}");
+                                ui.add_sized(
+                                    ui.available_size(),
+                                    TextEdit::singleline(&mut text).horizontal_align(Align::Max),
+                                );
+                            });
+                        });
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.label("INTPND");
+                            });
+                            row.col(|ui| {
+                                let mut text = format!("{raw_intpnd:04x}");
+                                ui.add_enabled(
+                                    false,
+                                    TextEdit::singleline(&mut text).horizontal_align(Align::Max),
+                                );
+                            });
+                        });
+                    });
+                ui.add_space(8.0);
+                TableBuilder::new(ui)
+                    .id_salt("flags")
+                    .column(Column::exact(width * 0.5 - xspace))
+                    .columns(Column::exact(width * 0.25 - xspace), 2)
+                    .cell_layout(Layout::left_to_right(Align::Center).with_main_align(Align::RIGHT))
+                    .body(|mut body| {
+                        body.row(row_height, |mut row| {
+                            row.col(|_ui| {});
+                            row.col(|ui| {
+                                ui.add_sized(ui.available_size(), Label::new("ENB"));
+                            });
+                            row.col(|ui| {
+                                ui.add_sized(ui.available_size(), Label::new("PND"));
+                            });
+                        });
+                        let mut add_row = |label: &str, enb: &mut bool, pnd: &mut bool| {
+                            body.row(row_height, |mut row| {
+                                row.col(|ui| {
+                                    ui.label(label);
+                                });
+                                row.col(|ui| {
+                                    let space =
+                                        (ui.available_width() - ui.spacing().icon_width) / 2.0;
+                                    ui.add_space(space);
+                                    ui.checkbox(enb, "");
+                                });
+                                row.col(|ui| {
+                                    let space =
+                                        (ui.available_width() - ui.spacing().icon_width) / 2.0;
+                                    ui.add_space(space);
+                                    ui.checkbox(pnd, "");
+                                });
+                            });
+                        };
+                        add_row("TIMEERR", &mut intenb.timeerr, &mut intpnd.timeerr);
+                        add_row("XPEND", &mut intenb.xpend, &mut intpnd.xpend);
+                        add_row("SBHIT", &mut intenb.sbhit, &mut intpnd.sbhit);
+                        add_row("FRAMESTART", &mut intenb.framestart, &mut intpnd.framestart);
+                        add_row("GAMESTART", &mut intenb.gamestart, &mut intpnd.gamestart);
+                        add_row("RFBEND", &mut intenb.rfbend, &mut intpnd.rfbend);
+                        add_row("LFBEND", &mut intenb.lfbend, &mut intpnd.lfbend);
+                        add_row("SCANERR", &mut intenb.scanerr, &mut intpnd.scanerr);
+                    });
+            });
+            ui.allocate_space(ui.available_size());
+        });
+        if intpnd.update(&mut raw_intpnd) {
+            self.memory.write(self.sim_id, 0x0005f800, &raw_intpnd);
+        }
+        if intenb.update(&mut raw_intenb) {
+            self.memory.write(self.sim_id, 0x0005f802, &raw_intenb);
+        }
+    }
+
+    fn show_display_status(&mut self, ui: &mut Ui) {
+        let row_height = self.row_height(ui);
+        let mut raw_dpstts = self.read_address(0x0005f820);
+        let mut dpstts = DisplayReg::parse(raw_dpstts);
+        ui.section("Display", |ui| {
+            let width = ui.available_width();
+            TableBuilder::new(ui)
+                .column(Column::exact(width * 0.5))
+                .column(Column::exact(width * 0.5))
+                .cell_layout(Layout::left_to_right(Align::Max))
+                .body(|mut body| {
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("DPSTTS");
+                        });
+                        row.col(|ui| {
+                            let mut value_str = format!("{raw_dpstts:04x}");
+                            ui.add_enabled(
+                                false,
+                                TextEdit::singleline(&mut value_str).horizontal_align(Align::Max),
+                            );
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.add_enabled(true, Checkbox::new(&mut dpstts.lock, "LOCK"));
+                        });
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut dpstts.r1bsy, "R1BSY"));
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.add_enabled(true, Checkbox::new(&mut dpstts.synce, "SYNCE"));
+                        });
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut dpstts.l1bsy, "L1BSY"));
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.add_enabled(true, Checkbox::new(&mut dpstts.re, "RE"));
+                        });
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut dpstts.r0bsy, "R0BSY"));
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut dpstts.fclk, "FCLK"));
+                        });
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut dpstts.l0bsy, "L0BSY"));
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut dpstts.scanrdy, "SCANRDY"));
+                        });
+                        row.col(|ui| {
+                            ui.add_enabled(true, Checkbox::new(&mut dpstts.disp, "DISP"));
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|_ui| {});
+                        row.col(|ui| {
+                            if ui
+                                .add(Button::new("DPRST").min_size(ui.available_size()))
+                                .clicked()
+                            {
+                                dpstts.dprst = true;
+                            }
+                        });
+                    });
+                });
+            ui.allocate_space(ui.available_size());
+        });
+        if dpstts.update(&mut raw_dpstts) {
+            self.memory.write(self.sim_id, 0x0005f822, &raw_dpstts);
+        }
+    }
+
+    fn show_drawing_status(&mut self, ui: &mut Ui) {
+        let row_height = self.row_height(ui);
+        let [mut raw_xpstts, raw_xpctrl] = self.read_address(0x0005f840);
+        let mut xpstts = DrawingReg::parse(raw_xpstts);
+        ui.section("Drawing", |ui| {
+            let width = ui.available_width();
+            TableBuilder::new(ui)
+                .column(Column::exact(width * 0.5))
+                .column(Column::exact(width * 0.5))
+                .cell_layout(Layout::left_to_right(Align::Max))
+                .body(|mut body| {
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("XPCTRL");
+                        });
+                        row.col(|ui| {
+                            let mut value_str = format!("{raw_xpctrl:04x}");
+                            ui.add_enabled(
+                                false,
+                                TextEdit::singleline(&mut value_str).horizontal_align(Align::Max),
+                            );
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("XPSTTS");
+                        });
+                        row.col(|ui| {
+                            let mut value_str = format!("{raw_xpstts:04x}");
+                            ui.add_enabled(
+                                false,
+                                TextEdit::singleline(&mut value_str).horizontal_align(Align::Max),
+                            );
+                        });
+                    });
+                    /*
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("SBCMP");
+                        });
+                        row.col(|ui| {
+                            let old_value = xpctrl.sbcmp;
+                            ui.add_enabled(true, NumberEdit::new(&mut xpctrl.sbcmp).range(0..32));
+                            cmp_changed = xpctrl.sbcmp != old_value;
+                        });
+                    });
+                     */
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("SBCOUNT");
+                        });
+                        row.col(|ui| {
+                            ui.add_enabled(
+                                false,
+                                NumberEdit::new(&mut xpstts.sbcount)
+                                    .arrows(false)
+                                    .range(0..32),
+                            );
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut xpstts.sbout, "SBOUT"));
+                        });
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut xpstts.f1bsy, "F1BSY"));
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut xpstts.f0bsy, "F0BSY"));
+                        });
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut xpstts.overtime, "OVERTIME"));
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.add_enabled(true, Checkbox::new(&mut xpstts.xpen, "XPEN"));
+                        });
+                        row.col(|ui| {
+                            if ui
+                                .add(Button::new("XPRST").min_size(ui.available_size()))
+                                .clicked()
+                            {
+                                xpstts.xprst = true;
+                            }
+                        });
+                    });
+                });
+            ui.allocate_space(ui.available_size());
+        });
+        if xpstts.update(&mut raw_xpstts) {
+            xpstts.update(&mut raw_xpstts);
+            self.memory.write(self.sim_id, 0x0005f842, &raw_xpstts);
+        }
+    }
+
+    fn show_colors(&mut self, ui: &mut Ui) {
+        let row_height = self.row_height(ui);
+        let registers = self.registers.borrow();
+        ui.section("Colors", |ui| {
+            let width = ui.available_width();
+            let xspace = ui.spacing().item_spacing.x;
+            TableBuilder::new(ui)
+                .column(Column::exact(width * 0.2 - xspace))
+                .columns(Column::exact(width * 0.20 - xspace), 4)
+                .cell_layout(Layout::left_to_right(Align::Max))
+                .body(|mut body| {
+                    body.row(row_height, |mut row| {
+                        row.col(|_ui| {});
+                        row.col(|_ui| {});
+                        row.col(|ui| {
+                            ui.with_layout(
+                                Layout::centered_and_justified(Direction::LeftToRight),
+                                |ui| ui.label("1"),
+                            );
+                        });
+                        row.col(|ui| {
+                            ui.with_layout(
+                                Layout::centered_and_justified(Direction::LeftToRight),
+                                |ui| ui.label("2"),
+                            );
+                        });
+                        row.col(|ui| {
+                            ui.with_layout(
+                                Layout::centered_and_justified(Direction::LeftToRight),
+                                |ui| ui.label("3"),
+                            );
+                        });
+                    });
+                    let mut brts: [u16; 3] = [
+                        read_address(&registers, 0x0005f824),
+                        read_address(&registers, 0x0005f826),
+                        read_address(&registers, 0x0005f828),
+                    ];
+                    body.row(row_height, |mut row| {
+                        let mut stale = false;
+                        row.col(|ui| {
+                            ui.label("BRT");
+                        });
+                        row.col(|_ui| {});
+                        for brt in brts.iter_mut() {
+                            row.col(|ui| {
+                                if ui
+                                    .add(NumberEdit::new(brt).range(0..256).arrows(false).hex(true))
+                                    .changed()
+                                {
+                                    stale = true;
+                                }
+                            });
+                        }
+                        if stale {
+                            self.memory.write(self.sim_id, 0x0005f824, &brts);
+                        }
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|_ui| {});
+                        for shade in utils::parse_brts(&brts, Color32::RED) {
+                            row.col(|ui| {
+                                ui.painter().rect_filled(
+                                    ui.available_rect_before_wrap(),
+                                    0.0,
+                                    shade,
+                                );
+                            });
+                        }
+                    });
+                    let mut palettes = read_address::<[u16; 8]>(&registers, 0x0005f860);
+                    let mut add_row = |name: &str, address: u32, value: &mut u16| {
+                        let mut c1 = (*value >> 2) & 0x03;
+                        let mut c2 = (*value >> 4) & 0x03;
+                        let mut c3 = (*value >> 6) & 0x03;
+                        let mut stale = false;
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.label(name);
+                            });
+                            row.col(|ui| {
+                                if ui
+                                    .add(
+                                        NumberEdit::new(value)
+                                            .range(0..256)
+                                            .desired_width(width * 0.2)
+                                            .arrows(false)
+                                            .hex(true),
+                                    )
+                                    .changed()
+                                {
+                                    stale = true;
+                                };
+                            });
+                            row.col(|ui| {
+                                if ui
+                                    .add(
+                                        NumberEdit::new(&mut c1)
+                                            .range(0..4)
+                                            .desired_width(ui.available_width() - xspace),
+                                    )
+                                    .changed()
+                                {
+                                    *value = (*value & 0xfff3) | (c1 << 2);
+                                    stale = true;
+                                }
+                            });
+                            row.col(|ui| {
+                                if ui
+                                    .add(
+                                        NumberEdit::new(&mut c2)
+                                            .range(0..4)
+                                            .desired_width(ui.available_width() - xspace),
+                                    )
+                                    .changed()
+                                {
+                                    *value = (*value & 0xffcf) | (c2 << 4);
+                                    stale = true;
+                                }
+                            });
+                            row.col(|ui| {
+                                if ui
+                                    .add(
+                                        NumberEdit::new(&mut c3)
+                                            .range(0..4)
+                                            .desired_width(ui.available_width() - xspace),
+                                    )
+                                    .changed()
+                                {
+                                    *value = (*value & 0xff3f) | (c3 << 6);
+                                    stale = true;
+                                }
+                            });
+                        });
+                        if stale {
+                            self.memory.write(self.sim_id, address, value);
+                        }
+                    };
+
+                    add_row("GPLT0", 0x0005f860, &mut palettes[0]);
+                    add_row("GPLT1", 0x0005f862, &mut palettes[1]);
+                    add_row("GPLT2", 0x0005f864, &mut palettes[2]);
+                    add_row("GPLT3", 0x0005f866, &mut palettes[3]);
+                    add_row("JPLT0", 0x0005f868, &mut palettes[4]);
+                    add_row("JPLT1", 0x0005f86a, &mut palettes[5]);
+                    add_row("JPLT2", 0x0005f86c, &mut palettes[6]);
+                    add_row("JPLT3", 0x0005f86e, &mut palettes[7]);
+
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("BKCOL");
+                        });
+                        row.col(|ui| {
+                            let mut bkcol: u16 = read_address(&registers, 0x0005f870);
+                            if ui
+                                .add(
+                                    NumberEdit::new(&mut bkcol)
+                                        .range(0..4)
+                                        .desired_width(ui.available_width() - xspace),
+                                )
+                                .changed()
+                            {
+                                self.memory.write(self.sim_id, 0x0005f870, &bkcol);
+                            }
+                        });
+                        row.col(|_ui| {});
+                        row.col(|ui| {
+                            ui.label("REST");
+                        });
+                        row.col(|ui| {
+                            let mut rest: u16 = read_address(&registers, 0x0005f82a);
+                            if ui
+                                .add(
+                                    NumberEdit::new(&mut rest)
+                                        .range(0..256)
+                                        .arrows(false)
+                                        .hex(true),
+                                )
+                                .changed()
+                            {
+                                self.memory.write(self.sim_id, 0x0005f82a, &rest);
+                            }
+                        });
+                    });
+                });
+
+            ui.allocate_space(ui.available_size_before_wrap());
+        });
+    }
+
+    fn show_objects(&mut self, ui: &mut Ui) {
+        let row_height = self.row_height(ui);
+        ui.section("Objects", |ui| {
+            let width = ui.available_width();
+            let xspace = ui.spacing().item_spacing.x;
+            TableBuilder::new(ui)
+                .column(Column::exact(width * 0.3 - xspace))
+                .column(Column::exact(width * 0.3 - xspace))
+                .column(Column::exact(width * 0.4 - xspace))
+                .cell_layout(Layout::left_to_right(Align::Center).with_main_align(Align::RIGHT))
+                .body(|mut body| {
+                    body.row(row_height, |mut row| {
+                        row.col(|_ui| {});
+                        row.col(|ui| {
+                            ui.add_sized(ui.available_size(), Label::new("Start"));
+                        });
+                        row.col(|ui| {
+                            ui.add_sized(ui.available_size(), Label::new("End"));
+                        });
+                    });
+                    let mut spts = self.read_address::<[u16; 4]>(0x0005f848);
+                    let prevs = std::iter::once(0u16).chain(spts.map(|i| (i + 1) & 0x03ff));
+                    let mut changed = false;
+                    for (index, (spt, prev)) in spts.iter_mut().zip(prevs).enumerate() {
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.label(format!("SPT{index}"));
+                            });
+                            row.col(|ui| {
+                                ui.with_layout(Layout::right_to_left(Align::Center), |ui| {
+                                    ui.label(prev.to_string());
+                                });
+                            });
+                            row.col(|ui| {
+                                if ui.add(NumberEdit::new(spt).range(0..1024)).changed() {
+                                    changed = true;
+                                }
+                            });
+                        });
+                    }
+                    if changed {
+                        self.memory.write(self.sim_id, 0x0005f848, &spts);
+                    }
+                });
+            ui.allocate_space(ui.available_size_before_wrap());
+        });
+    }
+
+    fn show_misc(&mut self, ui: &mut Ui) {
+        let row_height = self.row_height(ui);
+        let registers = self.registers.borrow();
+        ui.section("Misc.", |ui| {
+            let width = ui.available_width();
+            let xspace = ui.spacing().item_spacing.x;
+            TableBuilder::new(ui)
+                .column(Column::exact(width * 0.5 - xspace))
+                .column(Column::exact(width * 0.5 - xspace))
+                .cell_layout(Layout::left_to_right(Align::Center).with_main_align(Align::RIGHT))
+                .body(|mut body| {
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("FRMCYC");
+                        });
+                        row.col(|ui| {
+                            let mut frmcyc = read_address::<u16>(&registers, 0x0005f82e);
+                            ui.with_layout(Layout::right_to_left(Align::Center), |ui| {
+                                if ui.add(NumberEdit::new(&mut frmcyc).range(0..32)).changed() {
+                                    self.memory.write(self.sim_id, 0x0005f82e, &frmcyc);
+                                }
+                            });
+                        });
+                    });
+                    let mut cta = read_address::<u16>(&registers, 0x0005f830);
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("CTA");
+                        });
+                        row.col(|ui| {
+                            ui.with_layout(Layout::right_to_left(Align::Center), |ui| {
+                                ui.add_enabled(
+                                    false,
+                                    NumberEdit::new(&mut cta).arrows(false).hex(true),
+                                );
+                            });
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("CTA_L");
+                        });
+                        row.col(|ui| {
+                            let mut cta_l = cta & 0xff;
+                            ui.with_layout(Layout::right_to_left(Align::Center), |ui| {
+                                ui.add_enabled(
+                                    false,
+                                    NumberEdit::new(&mut cta_l).arrows(false).hex(true),
+                                );
+                            });
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("CTA_R");
+                        });
+                        row.col(|ui| {
+                            let mut cta_r = (cta >> 8) & 0xff;
+                            ui.with_layout(Layout::right_to_left(Align::Center), |ui| {
+                                ui.add_enabled(
+                                    false,
+                                    NumberEdit::new(&mut cta_r).arrows(false).hex(true),
+                                );
+                            });
+                        });
+                    });
+                });
+            ui.allocate_space(ui.available_size_before_wrap());
+        });
+    }
+
+    fn row_height(&self, ui: &mut Ui) -> f32 {
+        ui.spacing().interact_size.y + ui.style().visuals.selection.stroke.width
+    }
+
+    fn read_address<T: MemoryValue>(&self, address: usize) -> T {
+        read_address(&self.registers.borrow(), address)
+    }
+}
+
+fn read_address<T: MemoryValue>(registers: &MemoryRef, address: usize) -> T {
+    let index = (address - 0x0005f800) / size_of::<T>();
+    registers.read(index)
+}
+
+impl AppWindow for RegisterWindow {
+    fn sim_id(&self) -> Option<SimId> {
+        Some(self.sim_id)
+    }
+
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title("Registers")
+            .with_inner_size((800.0, 480.0))
+    }
+
+    fn show(&mut self, ui: &mut Ui) {
+        CentralPanel::default().show_inside(ui, |ui| {
+            ScrollArea::vertical().show(ui, |ui| {
+                ui.horizontal_top(|ui| {
+                    let width = ui.available_width();
+                    let xspace = ui.spacing().item_spacing.x;
+                    StripBuilder::new(ui)
+                        .size(Size::exact(width * 0.25 - xspace))
+                        .size(Size::exact(width * 0.225 - xspace))
+                        .size(Size::exact(width * 0.325 - xspace))
+                        .size(Size::exact(width * 0.2 - xspace))
+                        .horizontal(|mut strip| {
+                            strip.cell(|ui| {
+                                self.show_interrupts(ui);
+                            });
+                            strip.strip(|nested| {
+                                nested.sizes(Size::remainder(), 2).vertical(|mut strip| {
+                                    strip.cell(|ui| {
+                                        self.show_display_status(ui);
+                                    });
+                                    strip.cell(|ui| {
+                                        self.show_drawing_status(ui);
+                                    });
+                                });
+                            });
+                            strip.cell(|ui| {
+                                self.show_colors(ui);
+                            });
+                            strip.strip(|nested| {
+                                nested.sizes(Size::remainder(), 2).vertical(|mut strip| {
+                                    strip.cell(|ui| {
+                                        self.show_objects(ui);
+                                    });
+                                    strip.cell(|ui| {
+                                        self.show_misc(ui);
+                                    });
+                                });
+                            });
+                        });
+                });
+            });
+        });
+    }
+}
+
+struct InterruptReg {
+    timeerr: bool,
+    xpend: bool,
+    sbhit: bool,
+    framestart: bool,
+    gamestart: bool,
+    rfbend: bool,
+    lfbend: bool,
+    scanerr: bool,
+}
+
+impl InterruptReg {
+    fn parse(value: u16) -> Self {
+        Self {
+            timeerr: value & 0x8000 != 0,
+            xpend: value & 0x4000 != 0,
+            sbhit: value & 0x2000 != 0,
+            framestart: value & 0x0010 != 0,
+            gamestart: value & 0x0008 != 0,
+            rfbend: value & 0x0004 != 0,
+            lfbend: value & 0x0002 != 0,
+            scanerr: value & 0x0001 != 0,
+        }
+    }
+
+    fn update(&self, value: &mut u16) -> bool {
+        let new_value = (*value & 0x1fe0)
+            | if self.timeerr { 0x8000 } else { 0x0000 }
+            | if self.xpend { 0x4000 } else { 0x0000 }
+            | if self.sbhit { 0x2000 } else { 0x0000 }
+            | if self.framestart { 0x0010 } else { 0x0000 }
+            | if self.gamestart { 0x0008 } else { 0x0000 }
+            | if self.rfbend { 0x0004 } else { 0x0000 }
+            | if self.lfbend { 0x0002 } else { 0x0000 }
+            | if self.scanerr { 0x0001 } else { 0x0000 };
+        let changed = *value != new_value;
+        *value = new_value;
+        changed
+    }
+}
+
+struct DisplayReg {
+    lock: bool,
+    synce: bool,
+    re: bool,
+    fclk: bool,
+    scanrdy: bool,
+    r1bsy: bool,
+    l1bsy: bool,
+    r0bsy: bool,
+    l0bsy: bool,
+    disp: bool,
+    dprst: bool,
+}
+
+impl DisplayReg {
+    fn parse(value: u16) -> Self {
+        Self {
+            lock: value & 0x0400 != 0,
+            synce: value & 0x0200 != 0,
+            re: value & 0x0100 != 0,
+            fclk: value & 0x0080 != 0,
+            scanrdy: value & 0x0040 != 0,
+            r1bsy: value & 0x0020 != 0,
+            l1bsy: value & 0x0010 != 0,
+            r0bsy: value & 0x0008 != 0,
+            l0bsy: value & 0x0004 != 0,
+            disp: value & 0x0002 != 0,
+            dprst: value & 0x0001 != 0,
+        }
+    }
+
+    fn update(&self, value: &mut u16) -> bool {
+        let new_value = (*value & 0xf800)
+            | if self.lock { 0x0400 } else { 0x0000 }
+            | if self.synce { 0x0200 } else { 0x0000 }
+            | if self.re { 0x0100 } else { 0x0000 }
+            | if self.fclk { 0x0080 } else { 0x0000 }
+            | if self.scanrdy { 0x0040 } else { 0x0000 }
+            | if self.r1bsy { 0x0020 } else { 0x0000 }
+            | if self.l1bsy { 0x0010 } else { 0x0000 }
+            | if self.r0bsy { 0x0008 } else { 0x0000 }
+            | if self.l0bsy { 0x0004 } else { 0x0000 }
+            | if self.disp { 0x0002 } else { 0x0000 }
+            | if self.dprst { 0x0001 } else { 0x0000 };
+        let changed = *value != new_value;
+        *value = new_value;
+        changed
+    }
+}
+
+struct DrawingReg {
+    sbout: bool,
+    sbcount: u8,
+    overtime: bool,
+    f1bsy: bool,
+    f0bsy: bool,
+    xpen: bool,
+    xprst: bool,
+}
+
+impl DrawingReg {
+    fn parse(value: u16) -> Self {
+        Self {
+            sbout: value & 0x8000 != 0,
+            sbcount: (value >> 8) as u8 & 0x1f,
+            overtime: value & 0x0010 != 0,
+            f1bsy: value & 0x0008 != 0,
+            f0bsy: value & 0x0004 != 0,
+            xpen: value & 0x0002 != 0,
+            xprst: value & 0x0001 != 0,
+        }
+    }
+
+    fn update(&self, value: &mut u16) -> bool {
+        let new_value = (*value & 0x60e0)
+            | if self.sbout { 0x8000 } else { 0x0000 }
+            | (((self.sbcount & 0x1f) as u16) << 8)
+            | if self.overtime { 0x0010 } else { 0x0000 }
+            | if self.f1bsy { 0x0008 } else { 0x0000 }
+            | if self.f0bsy { 0x0004 } else { 0x0000 }
+            | if self.xpen { 0x0002 } else { 0x0000 }
+            | if self.xprst { 0x0001 } else { 0x0000 };
+        let changed = *value != new_value;
+        *value = new_value;
+        changed
+    }
+}

src/window/vip/utils.rs

@@ -0,0 +1,251 @@
+use egui::{Color32, Image, ImageSource, Response, Sense, TextureOptions, Ui, Widget};
+
+pub const GENERIC_PALETTE: [u8; 4] = [0, 32, 64, 128];
+
+pub fn shade(brt: u8, color: Color32) -> Color32 {
+    let corrected = if brt > 132 {
+        255.0
+    } else {
+        (brt as f32 * 255.0 / 133.0).round()
+    };
+    color.gamma_multiply(corrected / 255.0)
+}
+
+pub fn generic_palette(color: Color32) -> [Color32; 4] {
+    GENERIC_PALETTE.map(|brt| shade(brt, color))
+}
+
+pub const fn parse_palette(palette: u8) -> [u8; 4] {
+    [
+        0,
+        (palette >> 2) & 0x03,
+        (palette >> 4) & 0x03,
+        (palette >> 6) & 0x03,
+    ]
+}
+
+pub const fn parse_shades(brts: &[u8; 8]) -> [u8; 4] {
+    [
+        0,
+        brts[0],
+        brts[2],
+        brts[0].saturating_add(brts[2]).saturating_add(brts[4]),
+    ]
+}
+
+pub fn parse_brts(brts: &[u16; 3], color: Color32) -> [Color32; 4] {
+    [
+        Color32::BLACK,
+        shade(brts[0] as u8, color),
+        shade(brts[1] as u8, color),
+        shade((brts[0] + brts[1] + brts[2]) as u8, color),
+    ]
+}
+
+pub fn palette_colors(palette: u8, brts: &[u8; 8], color: Color32) -> [Color32; 4] {
+    let colors = parse_shades(brts).map(|s| shade(s, color));
+    parse_palette(palette).map(|p| colors[p as usize])
+}
+
+pub struct Object {
+    pub x: i16,
+    pub lon: bool,
+    pub ron: bool,
+    pub parallax: i16,
+    pub y: i16,
+    pub data: CellData,
+}
+
+impl Object {
+    pub fn parse(object: [u16; 4]) -> Self {
+        let x = ((object[0] & 0x03ff) << 6 >> 6) as i16;
+        let parallax = ((object[1] & 0x03ff) << 6 >> 6) as i16;
+        let lon = object[1] & 0x8000 != 0;
+        let ron = object[1] & 0x4000 != 0;
+        let y = (object[2] & 0x00ff) as i16;
+        // Y is stored as the bottom 8 bits of an i16,
+        // so only sign extend if it's out of range.
+        let y = if y > 224 { y << 8 >> 8 } else { y };
+        let data = CellData::parse(object[3]);
+        Self {
+            x,
+            lon,
+            ron,
+            parallax,
+            y,
+            data,
+        }
+    }
+
+    pub fn update(&self, source: &mut [u16; 4]) -> bool {
+        let mut changed = false;
+
+        let new_x = (self.x as u16 & 0x03ff) | (source[0] & 0xfc00);
+        changed |= source[0] != new_x;
+        source[0] = new_x;
+
+        let new_p = if self.lon { 0x8000 } else { 0x0000 }
+            | if self.ron { 0x4000 } else { 0x0000 }
+            | (self.parallax as u16 & 0x3ff)
+            | (source[1] & 0x3c00);
+        changed |= source[1] != new_p;
+        source[1] = new_p;
+
+        let new_y = (self.y as u16 & 0x00ff) | (source[2] & 0xff00);
+        changed |= source[2] != new_y;
+        source[2] = new_y;
+
+        if self.data.update(&mut source[3]) {
+            changed = true;
+        }
+        changed
+    }
+}
+
+pub struct CellData {
+    pub palette_index: usize,
+    pub hflip: bool,
+    pub vflip: bool,
+    pub char_index: usize,
+}
+
+impl CellData {
+    pub fn parse(cell: u16) -> Self {
+        let char_index = (cell & 0x7ff) as usize;
+        let vflip = cell & 0x1000 != 0;
+        let hflip = cell & 0x2000 != 0;
+        let palette_index = (cell >> 14) as usize;
+        Self {
+            char_index,
+            vflip,
+            hflip,
+            palette_index,
+        }
+    }
+
+    pub fn update(&self, source: &mut u16) -> bool {
+        let new_value = ((self.palette_index as u16) << 14)
+            | if self.hflip { 0x2000 } else { 0x0000 }
+            | if self.vflip { 0x1000 } else { 0x0000 }
+            | (self.char_index as u16 & 0x07ff)
+            | (*source & 0x0800);
+        let changed = *source != new_value;
+        *source = new_value;
+        changed
+    }
+}
+
+pub fn read_char_row(
+    char: &[u16; 8],
+    hflip: bool,
+    vflip: bool,
+    row: usize,
+) -> impl Iterator<Item = u8> {
+    let pixels = if vflip { char[7 - row] } else { char[row] };
+    (0..16).step_by(2).map(move |i| {
+        let pixel = if hflip { 14 - i } else { i };
+        ((pixels >> pixel) & 0x3) as u8
+    })
+}
+
+pub fn read_char_pixel(char: &[u16; 8], hflip: bool, vflip: bool, row: usize, col: usize) -> u8 {
+    let pixels = if vflip { char[7 - row] } else { char[row] };
+    let pixel = if hflip { 7 - col } else { col } << 1;
+    ((pixels >> pixel) & 0x3) as u8
+}
+
+pub struct CharacterGrid<'a> {
+    source: ImageSource<'a>,
+    scale: f32,
+    show_grid: bool,
+    selected: Option<usize>,
+}
+
+impl<'a> CharacterGrid<'a> {
+    pub fn new(source: impl Into<ImageSource<'a>>) -> Self {
+        Self {
+            source: source.into(),
+            scale: 1.0,
+            show_grid: false,
+            selected: None,
+        }
+    }
+
+    pub fn with_scale(self, scale: f32) -> Self {
+        Self { scale, ..self }
+    }
+
+    pub fn with_grid(self, show_grid: bool) -> Self {
+        Self { show_grid, ..self }
+    }
+
+    pub fn with_selected(self, selected: usize) -> Self {
+        Self {
+            selected: Some(selected),
+            ..self
+        }
+    }
+
+    pub fn show(self, ui: &mut Ui) -> Option<usize> {
+        let start_pos = ui.cursor().min;
+        let cell_size = 8.0 * self.scale;
+
+        let res = self.ui(ui);
+
+        let grid_width_cells = ((res.rect.max.x - res.rect.min.x) / cell_size).round() as usize;
+
+        if res.clicked() {
+            let click_pos = res.interact_pointer_pos()?;
+            let grid_pos = (click_pos - start_pos) / cell_size;
+            Some((grid_pos.y as usize * grid_width_cells) + grid_pos.x as usize)
+        } else {
+            None
+        }
+    }
+}
+
+impl Widget for CharacterGrid<'_> {
+    fn ui(self, ui: &mut Ui) -> Response {
+        let image = Image::new(self.source)
+            .fit_to_original_size(self.scale)
+            .texture_options(TextureOptions::NEAREST)
+            .sense(Sense::click());
+        let res = ui.add(image);
+
+        let cell_size = 8.0 * self.scale;
+        let grid_width_cells = ((res.rect.max.x - res.rect.min.x) / cell_size).round() as usize;
+        let grid_height_cells = ((res.rect.max.y - res.rect.min.y) / cell_size).round() as usize;
+
+        let painter = ui.painter_at(res.rect);
+        if self.show_grid {
+            let stroke = ui.style().visuals.widgets.noninteractive.fg_stroke;
+            for x in (1..grid_width_cells).map(|i| (i as f32) * cell_size) {
+                let p1 = (res.rect.min.x + x, res.rect.min.y).into();
+                let p2 = (res.rect.min.x + x, res.rect.max.y).into();
+                painter.line_segment([p1, p2], stroke);
+            }
+            for y in (1..grid_height_cells).map(|i| (i as f32) * cell_size) {
+                let p1 = (res.rect.min.x, res.rect.min.y + y).into();
+                let p2 = (res.rect.max.x, res.rect.min.y + y).into();
+                painter.line_segment([p1, p2], stroke);
+            }
+        }
+        if let Some(selected) = self.selected {
+            let x1 = (selected % grid_width_cells) as f32 * cell_size;
+            let x2 = x1 + cell_size;
+            let y1 = (selected / grid_width_cells) as f32 * cell_size;
+            let y2 = y1 + cell_size;
+            painter.line(
+                vec![
+                    (res.rect.min + (x1, y1).into()),
+                    (res.rect.min + (x2, y1).into()),
+                    (res.rect.min + (x2, y2).into()),
+                    (res.rect.min + (x1, y2).into()),
+                    (res.rect.min + (x1, y1).into()),
+                ],
+                ui.style().visuals.widgets.active.fg_stroke,
+            );
+        }
+        res
+    }
+}

ui.c

@@ -1,218 +0,0 @@
-#include "audio.h"
-#include "controller.h"
-#include "emulation.h"
-#include "external/tinyfiledialogs.h"
-#include <stdio.h>
-#include <stdlib.h>
-#include "ui.h"
-#include "window.h"
-
-struct UIContext {
-    EmulationContext emu;
-    WindowContext win;
-    AudioContext aud;
-    ControllerState ctrl;
-};
-
-UIContext *uiInit() {
-    UIContext *ui = malloc(sizeof(UIContext));
-    if (emuInit(&ui->emu)) {
-        goto destroy_ui;
-    }
-    if (windowInit(&ui->win, "Shrooms VB")) {
-        goto destroy_emu;
-    }
-    if (audioInit(&ui->aud)) {
-        goto destroy_window;
-    }
-    ctrlInit(&ui->ctrl);
-    return ui;
-
-destroy_window:
-    windowDestroy(&ui->win);
-destroy_emu:
-    emuDestroy(&ui->emu);
-destroy_ui:
-    free(ui);
-    return NULL;
-}
-
-void uiDestroy(UIContext *ui) {
-    audioDestroy(&ui->aud);
-    windowDestroy(&ui->win);
-    emuDestroy(&ui->emu);
-    free(ui);
-}
-
-int uiLoadGame(UIContext *ui, const char *path) {
-    FILE *file = fopen(path, "rb");
-    uint8_t *rom = NULL;
-    long fileSize;
-    uint32_t romSize;
-    int result;
-
-    if (!file) {
-        perror("could not open file");
-        return -1;
-    }
-
-    if (fseek(file, 0, SEEK_END)) {
-        perror("could not seek file end");
-        goto close_file;
-    }
-    fileSize = ftell(file);
-    if (fileSize == -1) {
-        perror("could not read file size");
-        goto close_file;
-    }
-    if (fseek(file, 0, SEEK_SET)) {
-        perror("could not seek file start");
-        goto close_file;
-    }
-    romSize = (uint32_t) fileSize;
-
-    rom = malloc(romSize);
-    if (!rom) {
-        perror("could not allocate ROM");
-        goto close_file;
-    }
-    fread(rom, 1, romSize, file);
-    if (ferror(file)) {
-        perror("could not read file");
-        goto free_rom;
-    }
-    result = fclose(file);
-    file = NULL;
-    if (result) {
-        perror("could not close file");
-        goto free_rom;
-    }
-
-    emuLoadGame(&ui->emu, rom, romSize);
-    return 0;
-
-free_rom:
-    free(rom);
-close_file:
-    if (file) fclose(file);
-    return -1;
-}
-
-static const char *MENU_ITEMS[4] = {
-    "File",
-    "Emulation",
-    "Video",
-    NULL
-};
-
-static const char *ROM_EXTENSIONS[2] = {
-    "*.vb",
-    NULL
-};
-
-typedef enum status_t {
-    status_paused,
-    status_running
-} status_t;
-
-int uiRun(UIContext *ui, bool running) {
-    static uint8_t leftEye[384*224] = {0};
-    static uint8_t rightEye[384*224] = {0};
-    status_t status = running ? status_running : status_paused;
-    windowUpdate(&ui->win, leftEye, rightEye);
-
-    while (1) {
-        struct nk_context *ctx;
-        SDL_Event event;
-        void *samples;
-        uint32_t bytes;
-        ctx = ui->win.nk;
-
-        if (status == status_running) {
-            emuTick(&ui->emu);
-        }
-
-        if (emuReadPixels(&ui->emu, leftEye, rightEye)) {
-            windowUpdate(&ui->win, leftEye, rightEye);
-        }
-        emuReadSamples(&ui->emu, &samples, &bytes);
-        if (bytes) {
-            audioUpdate(&ui->aud, samples, bytes);
-        }
-
-        windowDisplayBegin(&ui->win);
-        /* GUI */
-        if (windowGuiBegin(&ui->win, "Shrooms VB")) {
-            windowMenubarBegin(&ui->win, MENU_ITEMS);
-
-            if (windowMenuBegin(&ui->win, "File", 100)) {
-                if (windowMenuItemLabel(&ui->win, "Open ROM")) {
-                    char *file = tinyfd_openFileDialog("Pick a ROM", NULL, 1, ROM_EXTENSIONS, "Virtual Boy ROM files", false);
-                    if (file) {
-                        uiLoadGame(ui, file);
-                        status = status_running;
-                    }
-                }
-                if (windowMenuItemLabel(&ui->win, "Quit")) {
-                    SDL_Event QuitEvent;
-                    QuitEvent.type = SDL_QUIT;
-                    QuitEvent.quit.timestamp = SDL_GetTicks();
-                    SDL_PushEvent(&QuitEvent);
-                }
-                windowMenuEnd(&ui->win);
-            }
-
-            if (windowMenuBegin(&ui->win, "Emulation", 100)) {
-                const char *label = status == status_paused ? "Resume" : "Pause";
-                if (windowMenuItemLabel(&ui->win, label)) {
-                    if (status == status_paused)
-                        status = status_running;
-                    else
-                        status = status_paused;
-                }
-                if (windowMenuItemLabel(&ui->win, "Reset")) {
-                    emuReset(&ui->emu);
-                    status = emuIsGameLoaded(&ui->emu) ? status_running : status_paused;
-                }
-                windowMenuEnd(&ui->win);
-            }
-
-            if (windowMenuBegin(&ui->win, "Video", 100)) {
-                float multiplier = windowGetScreenSizeMultiplier(&ui->win);
-                if (windowMenuItemLabelChecked(&ui->win, "x1", multiplier == 1.0f)) {
-                    windowSetScreenSizeMultiplier(&ui->win, 1.0f);
-                }
-                if (windowMenuItemLabelChecked(&ui->win, "x2", multiplier == 2.0f)) {
-                    windowSetScreenSizeMultiplier(&ui->win, 2.0f);
-                }
-                if (windowMenuItemLabelChecked(&ui->win, "x3", multiplier == 3.0f)) {
-                    windowSetScreenSizeMultiplier(&ui->win, 3.0f);
-                }
-                if (windowMenuItemLabelChecked(&ui->win, "x4", multiplier == 4.0f)) {
-                    windowSetScreenSizeMultiplier(&ui->win, 4.0f);
-                }
-                windowMenuEnd(&ui->win);
-            }
-
-            windowMenubarEnd(&ui->win);
-        }
-        windowGuiEnd(&ui->win);
-        windowDisplayEnd(&ui->win);
-
-        nk_input_begin(ctx);
-        while (SDL_PollEvent(&event)) {
-            nk_sdl_handle_event(&event);
-            if (event.type == SDL_QUIT) {
-                return 0;
-            }
-            if (event.type == SDL_KEYDOWN) {
-                ctrlKeyDown(&ui->ctrl, event.key.keysym.sym);
-            }
-            if (event.type == SDL_KEYUP) {
-                ctrlKeyUp(&ui->ctrl, event.key.keysym.sym);
-            }
-        }
-        nk_input_end(ctx);
-        emuSetKeys(&ui->emu, ctrlKeys(&ui->ctrl));
-    }
-}

ui.h

@@ -1,13 +0,0 @@
-#ifndef SHROOMS_VB_NATIVE_UI_
-#define SHROOMS_VB_NATIVE_UI_
-
-#include <stdbool.h>
-
-typedef struct UIContext UIContext;
-
-UIContext *uiInit();
-void uiDestroy(UIContext *ui);
-int uiLoadGame(UIContext *ui, const char *path);
-int uiRun(UIContext *ui, bool running);
-
-#endif

window.c

@@ -1,291 +0,0 @@
-#include "assets.h"
-#include "nuklear.h"
-#include <string.h>
-#include "window.h"
-
-#define MENU_HEIGHT 20
-#define SCREEN_WIDTH 384
-#define SCREEN_HEIGHT 224
-
-static void setColorTable(struct nk_color *table) {
-    table[NK_COLOR_TEXT] = nk_rgb(40, 40, 40);
-    table[NK_COLOR_WINDOW] = nk_rgb(255, 255, 255);
-    table[NK_COLOR_HEADER] = nk_rgb(40, 40, 40);
-    table[NK_COLOR_BORDER] = nk_rgb(175, 175, 175);
-    table[NK_COLOR_BUTTON] = nk_rgb(255, 255, 255);
-    table[NK_COLOR_BUTTON_HOVER] = nk_rgb(215, 215, 215);
-    table[NK_COLOR_BUTTON_ACTIVE] = nk_rgb(175, 175, 175);
-    table[NK_COLOR_TOGGLE] = nk_rgb(100, 100, 100);
-    table[NK_COLOR_TOGGLE_HOVER] = nk_rgb(120, 120, 120);
-    table[NK_COLOR_TOGGLE_CURSOR] = nk_rgb(45, 45, 45);
-    table[NK_COLOR_SELECT] = nk_rgb(45, 45, 45);
-    table[NK_COLOR_SELECT_ACTIVE] = nk_rgb(35, 35, 35);
-    table[NK_COLOR_SLIDER] = nk_rgb(38, 38, 38);
-    table[NK_COLOR_SLIDER_CURSOR] = nk_rgb(100, 100, 100);
-    table[NK_COLOR_SLIDER_CURSOR_HOVER] = nk_rgb(120, 120, 120);
-    table[NK_COLOR_SLIDER_CURSOR_ACTIVE] = nk_rgb(150, 150, 150);
-    table[NK_COLOR_PROPERTY] = nk_rgb(38, 38, 38);
-    table[NK_COLOR_EDIT] = nk_rgb(38, 38, 38);
-    table[NK_COLOR_EDIT_CURSOR] = nk_rgb(175, 175, 175);
-    table[NK_COLOR_COMBO] = nk_rgb(45, 45, 45);
-    table[NK_COLOR_CHART] = nk_rgb(120, 120, 120);
-    table[NK_COLOR_CHART_COLOR] = nk_rgb(45, 45, 45);
-    table[NK_COLOR_CHART_COLOR_HIGHLIGHT] = nk_rgb(255, 0, 0);
-    table[NK_COLOR_SCROLLBAR] = nk_rgb(40, 40, 40);
-    table[NK_COLOR_SCROLLBAR_CURSOR] = nk_rgb(100, 100, 100);
-    table[NK_COLOR_SCROLLBAR_CURSOR_HOVER] = nk_rgb(120, 120, 120);
-    table[NK_COLOR_SCROLLBAR_CURSOR_ACTIVE] = nk_rgb(150, 150, 150);
-    table[NK_COLOR_TAB_HEADER] = nk_rgb(40, 40, 40);
-    table[NK_COLOR_KNOB] = nk_rgb(38, 38, 38);
-    table[NK_COLOR_KNOB_CURSOR] = nk_rgb(100, 100, 100);
-    table[NK_COLOR_KNOB_CURSOR_HOVER] = nk_rgb(120, 120, 120);
-    table[NK_COLOR_KNOB_CURSOR_ACTIVE] = nk_rgb(150, 150, 150);
-}
-
-static void applyStyles(struct nk_context *ctx, float scaleX, float scaleY) {
-    struct nk_color table[NK_COLOR_COUNT];
-    setColorTable(table);
-    nk_style_from_table(ctx, table);
-    ctx->style.window.padding = nk_vec2(0, 0);
-    ctx->style.window.spacing = nk_vec2(0, 0);
-    ctx->style.window.menu_padding = nk_vec2(0, 0);
-    ctx->style.window.menu_border = 0;
-
-    ctx->style.menu_button.hover = nk_style_item_color(table[NK_COLOR_BUTTON_HOVER]);
-    ctx->style.menu_button.active = nk_style_item_color(table[NK_COLOR_BUTTON_ACTIVE]);
-    ctx->style.menu_button.padding = nk_vec2(2 * scaleX, 2 * scaleY);
-    ctx->style.contextual_button.padding = nk_vec2(20 * scaleX, 4 * scaleY);
-}
-
-/* scale the window for High-DPI displays */
-static void scaleWindow(WindowContext *win) {
-    int renderW, renderH;
-    int oldWindowX, oldWindowY;
-    int newWindowX, newWindowY;
-    int oldWindowW, oldWindowH;
-    int newWindowW, newWindowH;
-    float scaleX, scaleY;
-    float hdpi, vdpi;
-    SDL_GetRendererOutputSize(win->renderer, &renderW, &renderH);
-    SDL_GetWindowPosition(win->window, &oldWindowX, &oldWindowY);
-    SDL_GetWindowSize(win->window, &oldWindowW, &oldWindowH);
-    SDL_GetDisplayDPI(SDL_GetWindowDisplayIndex(win->window), NULL, &hdpi, &vdpi);
-    scaleX = (float)(renderW) / (float)(oldWindowW);
-    scaleY = (float)(renderH) / (float)(oldWindowH);
-    win->screenScaleX = (hdpi / 96) * scaleX;
-    win->screenScaleY = (vdpi / 96) * scaleY;
-
-    newWindowW = SCREEN_WIDTH * win->screenSizeMultiplier * (hdpi / 96) / scaleX;
-    newWindowH = (SCREEN_HEIGHT * win->screenSizeMultiplier + MENU_HEIGHT) * (vdpi / 96) / scaleY;
-    newWindowX = oldWindowX - (newWindowW - oldWindowW) / 2;
-    newWindowY = oldWindowY - (newWindowH - oldWindowH) / 2;
-    if (newWindowX < 0) newWindowX = 0;
-    if (newWindowY < 0) newWindowY = 0;
-    SDL_SetWindowSize(win->window, newWindowW, newWindowH);
-    SDL_SetWindowPosition(win->window, newWindowX, newWindowY);
-}
-
-int windowInit(WindowContext *win, const char *title) {
-    win->screenSizeMultiplier = 1.0f;
-
-    win->window = SDL_CreateWindow(title,
-        SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
-        SCREEN_WIDTH, SCREEN_HEIGHT + MENU_HEIGHT, SDL_WINDOW_SHOWN | SDL_WINDOW_ALLOW_HIGHDPI);
-    if (!win->window) {
-        fprintf(stderr, "Error creating window: %s\n", SDL_GetError());
-        return -1;
-    }
-
-    win->renderer = SDL_CreateRenderer(win->window, -1, 0);
-    if (!win->renderer) {
-        fprintf(stderr, "Error creating renderer: %s\n", SDL_GetError());
-        goto cleanup_window;
-    }
-
-    win->leftEye = SDL_CreateTexture(win->renderer, SDL_PIXELFORMAT_RGB24, SDL_TEXTUREACCESS_STREAMING, 384, 224);
-    if (!win->leftEye) {
-        fprintf(stderr, "Error creating left eye texture: %s\n", SDL_GetError());
-        goto cleanup_renderer;
-    }
-    SDL_SetTextureColorMod(win->leftEye, 0xff, 0, 0);
-
-    win->rightEye = SDL_CreateTexture(win->renderer, SDL_PIXELFORMAT_RGB24, SDL_TEXTUREACCESS_STREAMING, 384, 224);
-    if (!win->rightEye) {
-        fprintf(stderr, "Error creating right eye texture: %s\n", SDL_GetError());
-        goto cleanup_left_eye;
-    }
-    SDL_SetTextureColorMod(win->rightEye, 0, 0xc6, 0xf0);
-    SDL_SetTextureBlendMode(win->rightEye, SDL_BLENDMODE_ADD);
-
-    scaleWindow(win);
-
-    win->nk = nk_sdl_init(win->window, win->renderer);
-    applyStyles(win->nk, win->screenScaleX, win->screenScaleY);
-    /* tell nuklear the mouse moved somewhere so it doesn't think we're hovering in the top left */
-    nk_input_motion(win->nk, 1024, 1024);
-
-    {
-        struct nk_font_atlas *atlas;
-        struct nk_font_config config = nk_font_config(0);
-        config.pixel_snap = 1;
-        config.oversample_h = 8;
-        config.oversample_v = 8;
-        
-        nk_sdl_font_stash_begin(&atlas);
-        win->font = nk_font_atlas_add_from_memory(atlas, (void*) SELAWIK, SELAWIK_LEN, 13 * win->screenScaleY, &config);
-        nk_sdl_font_stash_end();
-
-        nk_style_set_font(win->nk, &win->font->handle);
-    }
-
-    return 0;
-
-cleanup_left_eye:
-    SDL_DestroyTexture(win->leftEye);
-cleanup_renderer:
-    SDL_DestroyRenderer(win->renderer);
-cleanup_window:
-    SDL_DestroyWindow(win->window);
-    return -1;
-}
-
-void windowDestroy(WindowContext *win) {
-    SDL_DestroyTexture(win->rightEye);
-    SDL_DestroyTexture(win->leftEye);
-    SDL_DestroyRenderer(win->renderer);
-    SDL_DestroyWindow(win->window);
-}
-
-float windowGetScreenSizeMultiplier(WindowContext *win) {
-    return win->screenSizeMultiplier;
-}
-
-void windowSetScreenSizeMultiplier(WindowContext *win, float multiplier) {
-    win->screenSizeMultiplier = multiplier;
-    scaleWindow(win);
-    applyStyles(win->nk, win->screenScaleX, win->screenScaleY);
-}
-
-static void copyScreenTexture(uint8_t *dst, const uint8_t *src, int pitch) {
-    int x, y, i;
-    uint8_t color;
-    int delta = pitch / 384;
-    for (y = 0; y < 224; ++y) {
-        for (x = 0; x < 384; x += 1) {
-            color = src[(y * 384) + x];
-            for (i = 0; i < delta; ++i) {
-                dst[(y * pitch) + (x * delta) + i] = color;
-            }
-        }
-    }
-}
-
-static void updateEye(SDL_Texture *eye, const uint8_t *bytes) {
-    void *target;
-    int pitch;
-    if (SDL_LockTexture(eye, NULL, &target, &pitch)) {
-        fprintf(stderr, "Error locking buffer for eye: %s\n", SDL_GetError());
-        return;
-    }
-    copyScreenTexture(target, bytes, pitch);
-    SDL_UnlockTexture(eye);
-}
-
-void windowUpdate(WindowContext *win, const uint8_t *left, const uint8_t *right) {
-    updateEye(win->leftEye, left);
-    updateEye(win->rightEye, right);
-}
-
-int windowScaleX(WindowContext *win, int x) {
-    return x * win->screenScaleX;
-}
-
-int windowScaleY(WindowContext *win, int y) {
-    return y * win->screenScaleY;
-}
-
-int windowGetMenuHeight(WindowContext *win) {
-    return (MENU_HEIGHT + 2) * win->screenScaleY;
-}
-
-int windowGetScreenHeight(WindowContext *win) {
-    return SCREEN_HEIGHT * win->screenSizeMultiplier * win->screenScaleY;
-}
-
-void windowDisplayBegin(WindowContext *win) {
-    SDL_Rect dst;
-    dst.x = 0;
-    dst.y = MENU_HEIGHT * win->screenScaleY;
-    dst.w = SCREEN_WIDTH * win->screenSizeMultiplier * win->screenScaleX;
-    dst.h = SCREEN_HEIGHT * win->screenSizeMultiplier * win->screenScaleY;
-
-    SDL_RenderClear(win->renderer);
-    SDL_RenderCopy(win->renderer, win->leftEye, NULL, &dst);
-    SDL_RenderCopy(win->renderer, win->rightEye, NULL, &dst);
-}
-
-void windowDisplayEnd(WindowContext *win) {
-    nk_sdl_render(NK_ANTI_ALIASING_ON);
-    SDL_RenderPresent(win->renderer);
-}
-
-bool windowGuiBegin(WindowContext *win, const char *title) {
-    return nk_begin(win->nk, title,
-        nk_rect(0, 0, SCREEN_WIDTH * win->screenSizeMultiplier * win->screenScaleX, MENU_HEIGHT * win->screenScaleY),
-        NK_WINDOW_NO_SCROLLBAR | NK_WINDOW_BACKGROUND);
-}
-
-void windowGuiEnd(WindowContext *win) {
-    nk_end(win->nk);
-}
-
-void windowMenubarBegin(WindowContext *win, const char **items) {
-    const char **item;
-    nk_menubar_begin(win->nk);
-    nk_layout_row_template_begin(win->nk, MENU_HEIGHT * win->screenScaleY);
-    for (item = items; *item != NULL; item++) {
-        struct nk_user_font *handle;
-        int len;
-        float width;
-        handle = &win->font->handle;
-        len = nk_strlen(*item);
-        width = handle->width(handle->userdata, handle->height, *item, len) + (16 * win->screenScaleX);
-        nk_layout_row_template_push_static(win->nk, width);
-    }
-    nk_layout_row_template_end(win->nk);
-}
-
-void windowMenubarEnd(WindowContext *win) {
-    nk_menubar_end(win->nk);
-}
-
-bool windowMenuBegin(WindowContext *win, const char *label, int width) {
-    if (!nk_menu_begin_label(win->nk, label, NK_TEXT_ALIGN_CENTERED, nk_vec2(windowScaleX(win, width), windowGetScreenHeight(win)))) {
-        return false;
-    }
-    nk_layout_row_dynamic(win->nk, windowGetMenuHeight(win), 1);
-    return true;
-}
-
-void windowMenuEnd(WindowContext *win) {
-    nk_menu_end(win->nk);
-}
-
-bool windowMenuItemLabel(WindowContext *win, const char *label) {
-    return nk_menu_item_label(win->nk, label, NK_TEXT_ALIGN_LEFT);
-}
-
-bool windowMenuItemLabelChecked(WindowContext *win, const char *label, bool checked) {
-    char buffer[80];
-    bool result;
-    if (!checked) {
-        return windowMenuItemLabel(win, label);
-    }
-    strcpy(buffer, "  *  ");
-    strncpy(buffer + 5, label, 74);
-    buffer[79] = '\0';
-    nk_style_push_vec2(win->nk, &win->nk->style.contextual_button.padding, nk_vec2(4 * win->screenScaleX, 4 * win->screenScaleY));
-    result = nk_menu_item_label(win->nk, buffer, NK_TEXT_ALIGN_LEFT);
-    nk_style_pop_vec2(win->nk);
-    return result;
-}

window.h

@@ -1,41 +0,0 @@
-#ifndef SHROOMS_VB_NATIVE_WINDOW_
-#define SHROOMS_VB_NATIVE_WINDOW_
-
-#include <SDL2/SDL.h>
-#include "nuklear.h"
-
-typedef struct WindowContext {
-    SDL_Window *window;
-    float screenSizeMultiplier;
-    float screenScaleX, screenScaleY;
-    SDL_Renderer *renderer;
-    SDL_Texture *leftEye;
-    SDL_Texture *rightEye;
-    struct nk_context *nk;
-    struct nk_font *font;
-} WindowContext;
-
-int windowInit(WindowContext *win, const char *title);
-void windowDestroy(WindowContext *win);
-
-float windowGetScreenSizeMultiplier(WindowContext *win);
-void windowSetScreenSizeMultiplier(WindowContext *win, float multiplier);
-void windowUpdate(WindowContext *win, const uint8_t *left, const uint8_t *right);
-
-int windowScaleX(WindowContext *win, int x);
-int windowScaleY(WindowContext *win, int y);
-int windowGetMenuHeight(WindowContext *win);
-int windowGetScreenHeight(WindowContext *win);
-
-void windowDisplayBegin(WindowContext *win);
-void windowDisplayEnd(WindowContext *win);
-bool windowGuiBegin(WindowContext *win, const char *title);
-void windowGuiEnd(WindowContext *win);
-void windowMenubarBegin(WindowContext *win, const char **items);
-void windowMenubarEnd(WindowContext *win);
-bool windowMenuBegin(WindowContext *win, const char *label, int width);
-void windowMenuEnd(WindowContext *win);
-bool windowMenuItemLabel(WindowContext *win, const char *label);
-bool windowMenuItemLabelChecked(WindowContext *win, const char *label, bool checked);
-
-#endif