Edit hex inline

Cargo.toml

@@ -4,24 +4,24 @@ description = "An emulator for the Virtual Boy."
 repository = "https://git.virtual-boy.com/PVB/lemur"
 publish = false
 license = "MIT"
-version = "0.15.0"
+version = "0.15.2"
 edition = "2024"
 
 [dependencies]
 anyhow = "1"
 atoi = "3"
-audioadapter-buffers = "4"
+audioadapter-buffers = "5"
 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 = { version = "0.36", features = ["persistence", "serde"] }
-egui_extras = { version = "0.34", features = ["image"] }
+egui_extras = { version = "0.36", features = ["image"] }
-egui-notify = "0.22"
+egui-notify = "0.23"
-egui-winit = "0.34"
+egui-winit = "0.36"
-egui-wgpu = { version = "0.34", features = ["winit"] }
+egui-wgpu = { version = "0.36", features = ["winit"] }
 fxprof-processed-profile = "0.8"
 fixed = { version = "1.28", features = ["num-traits"] }
 gilrs = { version = "0.11", features = ["serde-serialize"] }
@@ -31,22 +31,22 @@ image = { version = "0.25", default-features = false, features = ["png"] }
 itertools = "0.15"
 normpath = "1"
 notify = "8"
-num-derive = "0.4"
+num-derive = "0.5"
 num-traits = "0.2"
-object = "0.39"
+object = "0.40"
 oneshot = { version = "0.2", features = ["async", "std"] }
 pollster = "1"
 rand = "0.10"
 rfd = "0.17"
-rtrb = "0.3"
+rtrb = "0.4"
-rubato = "4"
+rubato = "5"
 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"] }
+wgpu = { version = "30", features = ["serde"] }
 wholesym = "0.8"
 winit = { version = "0.30", features = ["serde"] }
 

build.Dockerfile

@@ -10,30 +10,30 @@ 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 && \
+    apt-get install -y bash bzip2 clang-23 git lld-23 llvm-23 make patch xz-utils && \
-    ln -s $(which clang-22) /usr/bin/clang && \
+    ln -s $(which clang-23) /usr/bin/clang && \
-    ln -s $(which clang++-22) /usr/bin/clang++ && \
+    ln -s $(which clang++-23) /usr/bin/clang++ && \
-    ln -s $(which ld64.lld-22) /usr/bin/ld64.lld && \
+    ln -s $(which ld64.lld-23) /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
+FROM rust:1.99-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 && \
+    apt-get install -y clang-23 lld-23 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-23) /usr/bin/clang && \
-    ln -s $(which clang++-22) /usr/bin/clang++
+    ln -s $(which clang++-23) /usr/bin/clang++
 COPY --from=osxcross /osxcross /osxcross
 
 ENV PATH="/osxcross/bin:$PATH" \
     LD_LIBRARY_PATH="/osxcross/lib" \
-    CC="clang-22" CXX="clang++-22" AR="llvm-ar-22" \
+    CC="clang-23" CXX="clang++-23" AR="llvm-ar-23" \
     CC_x86_64-apple-darwin="o64-clang" \
     CXX_x86_64-apple-darwin="o64-clang++" \
     CC_aarch64-apple-darwin="oa64-clang" \
@@ -43,11 +43,11 @@ ENV PATH="/osxcross/bin:$PATH" \
     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_PC_WINDOWS_MSVC_LINKER="lld-link-23" \
     CARGO_TARGET_X86_64_APPLE_DARWIN_LINKER="o64-clang" \
-    CARGO_TARGET_X86_64_APPLE_DARWIN_AR="llvm-ar-22" \
+    CARGO_TARGET_X86_64_APPLE_DARWIN_AR="llvm-ar-23" \
     CARGO_TARGET_AARCH64_APPLE_DARWIN_LINKER="oa64-clang" \
-    CARGO_TARGET_AARCH64_APPLE_DARWIN_AR="llvm-ar-22" \
+    CARGO_TARGET_AARCH64_APPLE_DARWIN_AR="llvm-ar-23" \
-    RC_PATH="llvm-rc-22" \
+    RC_PATH="llvm-rc-23" \
     MACOSX_DEPLOYMENT_TARGET="14.5"
 ENTRYPOINT ["bash"]

build.rs

@@ -31,7 +31,7 @@ fn main() -> Result<(), Box<dyn Error>> {
         .define("VB_DIRECT_FRAME", "on_frame")
         .define("VB_DIRECT_READ", "on_read")
         .define("VB_DIRECT_WRITE", "on_write")
-        .define("VBU_REALLOC", "vbu_realloc_shim")
+        .define("VBU_MEMMGR", "VBU_MEMMGR")
         .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"))

llvm.sources

@@ -1,4 +1,4 @@
 Types: deb deb-src
 URIs: http://apt.llvm.org/trixie/
-Suites: llvm-toolchain-trixie-22
+Suites: llvm-toolchain-trixie-23
 Components: main

src/app.rs

@@ -23,13 +23,13 @@ use winit::{
 };
 
 use crate::{
-    config::{AppConfig, CliArgs},
+    config::{AppConfig, CliArgs, Config},
     controller::ControllerManager,
     emulator::{EmulatorClient, EmulatorCommand, SimId},
+    filesystem::Persistence,
     images::ImageTextureLoader,
     input::{MappingProvider, ShortcutProvider},
     memory::MemoryClient,
-    persistence::Persistence,
     window::{AppWindow, ChildWindow, GameScreen, GameWindow, InitArgs},
 };
 
@@ -56,7 +56,7 @@ 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,
+                surface: egui_wgpu::SurfaceConfig::HIGH_THROUGHPUT,
                 wgpu_setup: egui_wgpu::WgpuSetup::Existing(self.wgpu.init(window)),
                 ..egui_wgpu::WgpuConfiguration::default()
             };
@@ -94,7 +94,7 @@ impl Application {
         handle: OwnedDisplayHandle,
         persistence: Persistence,
         args: CliArgs,
-        config: AppConfig,
+        config: Config<AppConfig>,
     ) -> Self {
         let wgpu = WgpuState::new(handle, config);
         let icon = load_icon().ok().map(Arc::new);
@@ -179,6 +179,9 @@ impl Application {
         if args.registers {
             initial_windows.push(ChildWindow::Registers);
         }
+        if args.memory {
+            initial_windows.push(ChildWindow::Memory);
+        }
         if args.terminal {
             initial_windows.push(ChildWindow::Terminal);
         }
@@ -257,7 +260,7 @@ impl Application {
                 continue;
             }
             input.viewports = self.shared.viewport_info.clone();
-            let output = self.ctx.run_ui(input, |ui| {
+            let mut 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()) {
@@ -304,8 +307,9 @@ impl Application {
                 output.pixels_per_point,
                 [0.0, 0.0, 0.0, 0.0],
                 &clipped_primitives,
-                &output.textures_delta,
+                &mut output.textures_delta,
                 vec![],
+                &viewport.window,
             );
         }
         let mut active_viewports = ViewportIdSet::default();
@@ -503,11 +507,11 @@ impl ApplicationHandler<UserEvent> for Application {
 struct WgpuState {
     instance: wgpu::Instance,
     device_descriptor: Arc<dyn Fn(&wgpu::Adapter) -> wgpu::DeviceDescriptor<'static> + Send + Sync>,
-    config: AppConfig,
+    config: Config<AppConfig>,
 }
 
 impl WgpuState {
-    fn new(handle: OwnedDisplayHandle, config: AppConfig) -> Self {
+    fn new(handle: OwnedDisplayHandle, config: Config<AppConfig>) -> Self {
         #[allow(unused_variables)]
         let egui_wgpu::WgpuSetupCreateNew {
             instance_descriptor: wgpu::InstanceDescriptor { backends, .. },
@@ -530,6 +534,7 @@ impl WgpuState {
     }
 
     fn init(&mut self, window: &Window) -> egui_wgpu::WgpuSetupExisting {
+        self.config.refresh();
         let power_preference =
             wgpu::PowerPreference::from_env().unwrap_or(self.config.power_preference);
         debug!("power preference: {power_preference:?}");
@@ -550,6 +555,7 @@ impl WgpuState {
                 power_preference,
                 compatible_surface: Some(&surface),
                 force_fallback_adapter,
+                apply_limit_buckets: false,
             }))
             .expect("could not create adapter");
         debug!("selected adapter: {:?}", adapter.get_info());

src/config.rs

@@ -1,9 +1,10 @@
-use anyhow::Result;
+use bytemuck::NoUninit;
 use clap::{Parser, ValueEnum};
 use egui::{Color32, Pos2, Vec2};
 use serde::{Deserialize, Serialize};
 
-use crate::{emulator::SimId, persistence::Persistence, window::DisplayMode};
+pub use crate::filesystem::Config;
+use crate::{emulator::SimId, filesystem::Persistence, window::DisplayMode};
 use std::path::PathBuf;
 
 #[derive(Parser)]
@@ -35,6 +36,9 @@ pub struct CliArgs {
     /// Open registers window
     #[arg(short, long)]
     pub registers: bool,
+    /// Open memory window
+    #[arg(short, long)]
+    pub memory: bool,
     /// Open terminal
     #[arg(short, long)]
     pub terminal: bool,
@@ -53,6 +57,9 @@ pub struct CliArgs {
     /// Set a preference for whether to use a low-power or high-performance GPU adapter
     #[arg(long)]
     pub wgpu_power_preference: Option<PowerPreferenceWrapper>,
+    /// Choose whether save files are kept in the rom or the data directory
+    #[arg(long)]
+    pub save_data_location: Option<SaveDataLocation>,
 }
 
 #[derive(ValueEnum, Clone, Copy)]
@@ -90,40 +97,53 @@ const fn default_power_preference() -> wgpu::PowerPreference {
     wgpu::PowerPreference::LowPower
 }
 
+#[derive(Serialize, Deserialize, Clone, Copy, PartialEq, Eq, ValueEnum, Debug, NoUninit)]
+#[repr(usize)]
+pub enum SaveDataLocation {
+    /// The same directory as the ROM
+    RomDirectory,
+    /// This application's data directory
+    DataDirectory,
+}
+
+const fn default_save_data_location() -> SaveDataLocation {
+    SaveDataLocation::RomDirectory
+}
+
 #[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,
+    #[serde(default = "default_save_data_location")]
+    pub save_data_location: SaveDataLocation,
 }
-
+impl Default for AppConfig {
-impl AppConfig {
+    fn default() -> Self {
-    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,
+            save_data_location: default_save_data_location(),
         }
     }
+}
+
+impl AppConfig {
+    pub fn load(persistence: &Persistence) -> Config<Self> {
+        persistence.config(APP_CONFIG_FILENAME)
+    }
 
-    pub fn save(&self, persistence: &Persistence) -> Result<()> {
+    pub fn apply_updates(&mut self, args: &CliArgs) {
-        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
+        if let Some(save_data_location) = args.save_data_location {
+            self.save_data_location = save_data_location;
+        }
     }
 }
 
@@ -147,12 +167,8 @@ pub struct SimConfig {
     #[serde(default)]
     pub position: Option<Pos2>,
 }
-
+impl Default for SimConfig {
-impl SimConfig {
+    fn default() -> Self {
-    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],
@@ -163,9 +179,11 @@ impl SimConfig {
             position: None,
         }
     }
+}
 
-    pub fn save(&self, persistence: &Persistence, sim_id: SimId) -> Result<()> {
+impl SimConfig {
-        persistence.save_config(sim_config_filename(sim_id), self)
+    pub fn load(persistence: &Persistence, sim_id: SimId) -> Config<Self> {
+        persistence.config(sim_config_filename(sim_id))
     }
 }
 

src/emulator.rs

@@ -18,6 +18,7 @@ use tracing::{error, warn};
 
 use crate::{
     audio::Audio,
+    config::SaveDataLocation,
     graphics::TextureSink,
     memory::{MemoryRange, MemoryRegion},
 };
@@ -74,12 +75,13 @@ pub struct EmulatorBuilder {
     state: Arc<Atomic<EmulatorState>>,
     audio_on: Arc<[AtomicBool; 2]>,
     linked: Arc<AtomicBool>,
+    save_data_location: Arc<Atomic<SaveDataLocation>>,
     start_paused: bool,
     watch_rom: Arc<[AtomicBool; 2]>,
 }
 
 impl EmulatorBuilder {
-    pub fn new() -> (Self, EmulatorClient) {
+    pub fn new(save_data_location: SaveDataLocation) -> (Self, EmulatorClient) {
         let (queue, commands) = mpsc::channel();
         let builder = Self {
             rom: None,
@@ -91,6 +93,7 @@ impl EmulatorBuilder {
             state: Arc::new(Atomic::new(EmulatorState::Paused)),
             audio_on: Arc::new([AtomicBool::new(true), AtomicBool::new(true)]),
             linked: Arc::new(AtomicBool::new(false)),
+            save_data_location: Arc::new(Atomic::new(save_data_location)),
             start_paused: false,
             watch_rom: Arc::new([AtomicBool::new(false), AtomicBool::new(false)]),
         };
@@ -98,8 +101,9 @@ impl EmulatorBuilder {
             queue,
             sim_state: builder.sim_state.clone(),
             state: builder.state.clone(),
-            watch_rom: builder.watch_rom.clone(),
             linked: builder.linked.clone(),
+            save_data_location: builder.save_data_location.clone(),
+            watch_rom: builder.watch_rom.clone(),
         };
         (builder, client)
     }
@@ -131,18 +135,42 @@ impl EmulatorBuilder {
     }
 
     pub fn build(self) -> Result<Emulator> {
-        let mut emulator = Emulator::new(
+        let Self {
-            self.commands,
+            rom,
-            self.sim_state,
+            commands,
-            self.state,
+            sim_state,
-            self.audio_on,
+            state,
-            self.watch_rom,
+            audio_on,
-            self.linked,
+            watch_rom,
-        );
+            linked,
-        if let Some(path) = self.rom {
+            save_data_location,
+            start_paused,
+        } = self;
+        let mut emulator = Emulator {
+            sims: vec![],
+            carts: [None, None],
+            audio: Audio::init(),
+            commands,
+            sim_state,
+            state,
+            audio_on,
+            watch_rom,
+            linked,
+            save_data_location,
+            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![],
+        };
+        if let Some(path) = rom {
             emulator.load_cart(SimId::Player1, &path)?;
         }
-        if self.start_paused {
+        if start_paused {
             emulator.pause_sims()?;
         }
         Ok(emulator)
@@ -159,6 +187,7 @@ pub struct Emulator {
     audio_on: Arc<[AtomicBool; 2]>,
     watch_rom: Arc<[AtomicBool; 2]>,
     linked: Arc<AtomicBool>,
+    save_data_location: Arc<Atomic<SaveDataLocation>>,
     profilers: [Option<ProfileSender>; 2],
     renderers: HashMap<SimId, TextureSink>,
     messages: HashMap<SimId, mpsc::Sender<Toast>>,
@@ -171,36 +200,6 @@ pub struct Emulator {
 }
 
 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(());
@@ -211,7 +210,12 @@ impl Emulator {
 
     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)?;
+        let cart = Cart::load(
+            path,
+            sim_id,
+            self.save_data_location.load(Ordering::Acquire),
+            watch,
+        )?;
         self.try_reset_sim(sim_id, Some(cart))?;
         Ok(())
     }
@@ -224,7 +228,12 @@ impl Emulator {
         };
         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)?),
+            Some(rom_path) => Some(Cart::load(
+                &rom_path,
+                SimId::Player2,
+                self.save_data_location.load(Ordering::Acquire),
+                watch,
+            )?),
             None => None,
         };
         self.try_reset_sim(SimId::Player2, cart)?;
@@ -687,6 +696,20 @@ impl Emulator {
                     cart.stop_watching();
                 }
             }
+            EmulatorCommand::SetSaveDataLocation(save_data_location) => {
+                self.save_data_location
+                    .store(save_data_location, Ordering::Release);
+                for sim_id in SimId::values() {
+                    if let Some(cart) = self.carts[sim_id.to_index()].as_mut()
+                        && let Err(error) = cart.change_save_data_location(save_data_location)
+                    {
+                        self.report_error(
+                            sim_id,
+                            format!("Error changing save data location: {error}"),
+                        );
+                    }
+                }
+            }
             EmulatorCommand::StartSecondSim(path) => {
                 if let Err(error) = self.start_second_sim(path) {
                     self.report_error(
@@ -854,6 +877,7 @@ pub enum EmulatorCommand {
     LoadGame(SimId, PathBuf),
     ReloadRom(SimId),
     WatchRom(SimId, bool),
+    SetSaveDataLocation(SaveDataLocation),
     StartSecondSim(Option<PathBuf>),
     StopSecondSim,
     Pause,
@@ -943,6 +967,7 @@ pub struct EmulatorClient {
     sim_state: Arc<[Atomic<SimState>; 2]>,
     state: Arc<Atomic<EmulatorState>>,
     linked: Arc<AtomicBool>,
+    save_data_location: Arc<Atomic<SaveDataLocation>>,
     watch_rom: Arc<[AtomicBool; 2]>,
 }
 
@@ -959,6 +984,9 @@ impl EmulatorClient {
     pub fn are_sims_linked(&self) -> bool {
         self.linked.load(Ordering::Acquire)
     }
+    pub fn save_data_location(&self) -> SaveDataLocation {
+        self.save_data_location.load(Ordering::Acquire)
+    }
     pub fn is_rom_watched(&self, sim_id: SimId) -> bool {
         self.watch_rom[sim_id.to_index()].load(Ordering::Acquire)
     }

src/emulator/cart.rs

@@ -8,10 +8,15 @@ use std::{
     sync::{Arc, atomic::AtomicBool},
 };
 
-use crate::emulator::{SimId, game_info::GameInfo, shrooms_vb_util::rom_from_isx};
+use crate::{
+    config::SaveDataLocation,
+    emulator::{SimId, game_info::GameInfo, shrooms_vb_util::rom_from_isx},
+    filesystem,
+};
 
 pub struct Cart {
     pub file_path: PathBuf,
+    sim_id: SimId,
     pub rom: Vec<u8>,
     sram_file: File,
     pub sram: Vec<u8>,
@@ -21,7 +26,12 @@ pub struct Cart {
 }
 
 impl Cart {
-    pub fn load(file_path: &Path, sim_id: SimId, watch: bool) -> Result<Self> {
+    pub fn load(
+        file_path: &Path,
+        sim_id: SimId,
+        save_data_location: SaveDataLocation,
+        watch: bool,
+    ) -> Result<Self> {
         let (rom, info) = Self::read_rom(file_path)?;
 
         let mut sram_file = File::options()
@@ -29,7 +39,7 @@ impl Cart {
             .write(true)
             .create(true)
             .truncate(false)
-            .open(sram_path(file_path, sim_id))?;
+            .open(sram_path(file_path, sim_id, save_data_location))?;
 
         let sram = if sram_file.metadata()?.len() == 0 {
             // new SRAM file, randomize the contents
@@ -54,6 +64,7 @@ impl Cart {
 
         Ok(Cart {
             file_path: file_path.to_path_buf(),
+            sim_id,
             rom,
             sram_file,
             sram,
@@ -73,6 +84,19 @@ impl Cart {
         Ok(())
     }
 
+    pub fn change_save_data_location(
+        &mut self,
+        save_data_location: SaveDataLocation,
+    ) -> Result<()> {
+        self.sram_file = File::options()
+            .read(true)
+            .write(true)
+            .create(true)
+            .truncate(false)
+            .open(sram_path(&self.file_path, self.sim_id, save_data_location))?;
+        self.save_sram()
+    }
+
     pub fn save_sram(&mut self) -> Result<()> {
         self.sram_file.seek(SeekFrom::Start(0))?;
         self.sram_file.write_all(&self.sram)?;
@@ -177,9 +201,17 @@ fn parse_elf_program<Elf: object::read::elf::FileHeader<Endian = object::Endiann
     Some(bytes)
 }
 
-fn sram_path(file_path: &Path, sim_id: SimId) -> PathBuf {
+fn sram_path(file_path: &Path, sim_id: SimId, save_data_location: SaveDataLocation) -> PathBuf {
-    match sim_id {
+    let extension = match sim_id {
-        SimId::Player1 => file_path.with_extension("p1.sram"),
+        SimId::Player1 => "p1.sram",
-        SimId::Player2 => file_path.with_extension("p2.sram"),
+        SimId::Player2 => "p2.sram",
+    };
+    if let SaveDataLocation::DataDirectory = save_data_location
+        && let Some(data_dir) = filesystem::init_data_dir()
+        && let Some(rom_name) = file_path.file_name()
+    {
+        data_dir.join(rom_name).with_extension(extension)
+    } else {
+        file_path.with_extension(extension)
     }
 }

src/emulator/shrooms_vb_util.rs

@@ -1,13 +1,104 @@
-use std::ffi::c_void;
+use std::{
+    ffi::c_void,
+    sync::{LazyLock, Mutex},
+};
+
+#[derive(Default)]
+struct Reallocator {
+    allocations: Vec<Allocation>,
+}
+
+unsafe impl Send for Reallocator {}
+
+struct Allocation {
+    ptr: *mut u8,
+    size: usize,
+}
+impl Allocation {
+    fn new(size: usize) -> Self {
+        let layout = Self::layout(size);
+        // SAFETY: our layout is not zero, not too big, and properly aligned
+        let ptr = unsafe { std::alloc::alloc_zeroed(layout) };
+        if ptr.is_null() {
+            std::alloc::handle_alloc_error(layout);
+        }
+        Self { ptr, size }
+    }
+
+    fn layout(size: usize) -> std::alloc::Layout {
+        assert!(size != 0);
+        std::alloc::Layout::from_size_align(size, 8).expect("far too large an allocation")
+    }
+
+    fn as_slice(&self) -> &[u8] {
+        // SAFETY: we allocated this ourselves, it's safe
+        unsafe { std::slice::from_raw_parts(self.ptr, self.size) }
+    }
+
+    fn as_mut_slice(&mut self) -> &mut [u8] {
+        // SAFETY: we allocated this ourselves, it's safe
+        unsafe { std::slice::from_raw_parts_mut(self.ptr, self.size) }
+    }
+}
+
+impl Drop for Allocation {
+    fn drop(&mut self) {
+        // SAFETY: we allocated this ourselves with this layout, and it hasn't been freed
+        unsafe { std::alloc::dealloc(self.ptr, Self::layout(self.size)) };
+    }
+}
+
+impl Reallocator {
+    fn realloc(&mut self, ptr: *mut c_void, new_size: usize) -> *mut c_void {
+        if let Some(old_data) = self.load_allocation(ptr) {
+            if new_size == 0 {
+                // free
+                std::ptr::null_mut()
+            } else {
+                // actually reallocate and copy the data over
+                let mut new_data = Allocation::new(new_size);
+                let bytes_to_copy = old_data.size.min(new_size);
+                new_data.as_mut_slice()[..bytes_to_copy]
+                    .copy_from_slice(&old_data.as_slice()[..bytes_to_copy]);
+                self.store_allocation(new_data)
+            }
+        } else if new_size > 0 {
+            // fresh allocation
+            let allocation = Allocation::new(new_size);
+            self.store_allocation(allocation)
+        } else {
+            std::ptr::null_mut()
+        }
+    }
+
+    fn load_allocation(&mut self, ptr: *mut c_void) -> Option<Allocation> {
+        if ptr.is_null() {
+            return None;
+        }
+        let index = self
+            .allocations
+            .iter()
+            .enumerate()
+            .find_map(|(i, alloc)| std::ptr::addr_eq(alloc.ptr, ptr).then_some(i))?;
+        let allocation = self.allocations.remove(index);
+        Some(allocation)
+    }
+
+    fn store_allocation(&mut self, allocation: Allocation) -> *mut c_void {
+        let ptr = allocation.ptr;
+        self.allocations.push(allocation);
+        ptr.cast()
+    }
+}
+
+static VBU_ALLOC: LazyLock<Mutex<Reallocator>> =
+    LazyLock::new(|| Mutex::new(Reallocator::default()));
 
 #[unsafe(no_mangle)]
-unsafe fn vbu_realloc_shim(ptr: *mut c_void, new_size: usize) -> *mut c_void {
+#[allow(nonstandard_style)]
-    if !ptr.is_null() {
+unsafe fn VBU_MEMMGR(ptr: *mut c_void, new_size: usize) -> *mut c_void {
-        // not supporting proper realloc because it needs bookkeeping and it's unnecessary
+    let mut allocator = VBU_ALLOC.lock().unwrap();
-        return std::ptr::null_mut();
+    allocator.realloc(ptr, new_size)
-    }
-    let allocation = vec![0u8; new_size].into_boxed_slice();
-    Box::into_raw(allocation).cast()
 }
 
 #[link(name = "vb")]
@@ -25,7 +116,7 @@ pub fn rom_from_isx(bytes: &[u8]) -> Option<Vec<u8>> {
     if raw_rom.is_null() {
         return None;
     }
-    // SAFETY: the rom was allocated by vbu_realloc_shim, which created it from a Vec<u8>.
+    let bytes = VBU_ALLOC.lock().unwrap().load_allocation(raw_rom)?;
-    let rom = unsafe { Vec::from_raw_parts(raw_rom.cast(), rom_length, rom_length) };
+    assert_eq!(bytes.size, rom_length);
-    Some(rom)
+    Some(bytes.as_slice().to_vec())
 }

src/filesystem.rs

@@ -0,0 +1,167 @@
+use std::{
+    any::Any,
+    collections::{HashMap, hash_map::Entry},
+    fs,
+    ops::Deref,
+    path::PathBuf,
+    sync::{
+        Arc, Mutex, RwLock,
+        atomic::{AtomicU64, Ordering},
+    },
+};
+
+use anyhow::{Result, bail};
+use directories::ProjectDirs;
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone)]
+pub struct Persistence {
+    config_dir: Option<PathBuf>,
+    states: Arc<Mutex<HashMap<String, Arc<dyn Any + Send + Sync>>>>,
+}
+
+impl Persistence {
+    pub fn new() -> Self {
+        Self {
+            config_dir: init_config_dir(),
+            states: Arc::new(Mutex::new(HashMap::new())),
+        }
+    }
+
+    pub fn config<T: ConfigCompatible>(&self, file: &str) -> Config<T> {
+        let state = {
+            let mut lock = self.states.lock().unwrap();
+            match lock.entry(file.to_string()) {
+                Entry::Vacant(e) => {
+                    let path = self
+                        .config_dir
+                        .as_ref()
+                        .map(|p| p.join(file).with_extension("json"));
+                    let value = if let Some(p) = path.as_ref()
+                        && let Ok(bytes) = fs::read(p)
+                        && let Ok(v) = serde_json::from_slice(&bytes)
+                    {
+                        v
+                    } else {
+                        T::default()
+                    };
+
+                    let state = Arc::new(ConfigState {
+                        current: RwLock::new(value),
+                        version: AtomicU64::new(0),
+                        path,
+                    });
+                    e.insert(state.clone());
+                    state
+                }
+                Entry::Occupied(e) => e
+                    .get()
+                    .clone()
+                    .downcast()
+                    .expect("same config file accessed with two types"),
+            }
+        };
+        let value = state.current.read().unwrap().clone();
+        let version = state.version.load(Ordering::Relaxed);
+        Config {
+            value,
+            version,
+            state,
+        }
+    }
+
+    pub fn save_config<T: Serialize>(&self, file: &str, data: &T) -> Result<()> {
+        if let Some(config_dir) = self.config_dir.as_ref() {
+            let bytes = serde_json::to_vec_pretty(data)?;
+            let filename = 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(config_dir) = self.config_dir.as_ref() else {
+            bail!("config directory not found");
+        };
+        let filename = config_dir.join(file).with_extension("json");
+        let bytes = fs::read(filename)?;
+        Ok(serde_json::from_slice(&bytes)?)
+    }
+}
+
+fn init_config_dir() -> Option<PathBuf> {
+    let config_dir = project_dirs()?.config_dir().to_path_buf();
+    fs::create_dir_all(&config_dir).ok()?;
+    Some(config_dir)
+}
+
+pub fn init_data_dir() -> Option<PathBuf> {
+    let data_dir = project_dirs()?.data_dir().to_path_buf();
+    fs::create_dir_all(&data_dir).ok()?;
+    Some(data_dir)
+}
+
+fn project_dirs() -> Option<ProjectDirs> {
+    ProjectDirs::from("com", "virtual-boy", "Lemur")
+}
+
+pub trait ConfigCompatible:
+    Send + Sync + 'static + Clone + Default + Eq + Serialize + for<'a> Deserialize<'a>
+{
+}
+impl<T: Send + Sync + 'static + Clone + Default + Eq + Serialize + for<'a> Deserialize<'a>>
+    ConfigCompatible for T
+{
+}
+
+struct ConfigState<T> {
+    current: RwLock<T>,
+    version: AtomicU64,
+    path: Option<PathBuf>,
+}
+
+// A wrapper for a config struct, loaded from disk and referenced across the codebase.
+// Cheap to read, and lets you sync changes to all copies.
+pub struct Config<T> {
+    value: T,
+    version: u64,
+    state: Arc<ConfigState<T>>,
+}
+
+impl<T> Deref for Config<T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        &self.value
+    }
+}
+
+impl<T: ConfigCompatible> Config<T> {
+    pub fn refresh(&mut self) {
+        let version = self.state.version.load(Ordering::Relaxed);
+        if self.version == version {
+            return;
+        }
+        self.value = self.state.current.read().unwrap().clone();
+        self.version = version;
+    }
+
+    pub fn update(&mut self, mut update: impl FnMut(&mut T)) {
+        let mut new_value = self.value.clone();
+        update(&mut new_value);
+        if self.value == new_value {
+            return;
+        }
+
+        let mut current = self.state.current.write().unwrap();
+        update(&mut current);
+        if let Some(path) = &self.state.path
+            && let Ok(bytes) = serde_json::to_vec(&*current)
+        {
+            let _ = fs::write(path, bytes);
+        }
+        let version = self.state.version.fetch_add(1, Ordering::Relaxed) + 1;
+        self.value = current.clone();
+        self.version = version;
+    }
+}

src/images.rs

@@ -220,11 +220,7 @@ impl ImageBuffer {
     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(
+        self.pixels[index] = old + pixel;
-            old.r() + pixel.r(),
-            old.g() + pixel.g(),
-            old.b() + pixel.b(),
-        );
     }
 
     pub fn changed(&self, image: &ColorImage) -> bool {

src/input.rs

@@ -14,7 +14,7 @@ use winit::keyboard::{KeyCode, PhysicalKey};
 
 use crate::{
     emulator::{SimId, VBKey},
-    persistence::Persistence,
+    filesystem::Persistence,
 };
 
 #[derive(Clone, PartialEq, Eq, Hash)]

src/main.rs

@@ -15,7 +15,7 @@ use winit::event_loop::{ControlFlow, EventLoop};
 use crate::{
     config::{AppConfig, CliArgs, SimConfig},
     emulator::SimId,
-    persistence::Persistence,
+    filesystem::Persistence,
 };
 
 mod app;
@@ -24,12 +24,12 @@ mod config;
 mod controller;
 mod emulator;
 mod filepicker;
+mod filesystem;
 mod gdbserver;
 mod graphics;
 mod images;
 mod input;
 mod memory;
-mod persistence;
 mod profiler;
 mod window;
 
@@ -60,14 +60,9 @@ fn set_panic_handler() {
 
         eprint!("{message}");
 
-        let Some(project_dirs) = directories::ProjectDirs::from("com", "virtual-boy", "Lemur")
+        let Some(data_dir) = filesystem::init_data_dir() else {
-        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()
@@ -98,7 +93,13 @@ fn main() -> Result<()> {
 
     let persistence = Persistence::new();
 
-    let (mut builder, client) = EmulatorBuilder::new();
+    let mut config = AppConfig::load(&persistence);
+    config.update(|c| c.apply_updates(&args));
+
+    let p1 = SimConfig::load(&persistence, SimId::Player1);
+    let p2 = SimConfig::load(&persistence, SimId::Player2);
+
+    let (mut builder, client) = EmulatorBuilder::new(config.save_data_location);
     if let Some(path) = &args.rom {
         builder = builder.with_rom(path);
     }
@@ -111,12 +112,6 @@ fn main() -> Result<()> {
     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;
 

src/memory.rs

@@ -37,7 +37,53 @@ impl MemoryClient {
                     .send_command(EmulatorCommand::WatchMemory(range, Arc::downgrade(&region)));
                 region
             });
-        MemoryView { region }
+        MemoryView {
+            region,
+            sim,
+            start,
+            length,
+        }
+    }
+
+    // Update an existing view to point to a new region of memory.
+    // If the old and new regions overlap, it'll retain any old values.
+    pub fn retarget(&self, view: &mut MemoryView, sim: SimId, start: u32, length: usize) {
+        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));
+                if view.range().overlaps(range) {
+                    let (old_index, new_index) = if start < view.start {
+                        (0, view.start as usize - start as usize)
+                    } else {
+                        (start as usize - view.start as usize, 0)
+                    };
+                    let len = (view.length - old_index).min(length - new_index);
+                    let mut new_data = vec![0u8; length];
+                    let old_data = view.borrow();
+                    for (dst, src) in new_data[new_index..(new_index + len)]
+                        .iter_mut()
+                        .zip(old_data.range::<u8>(old_index, len))
+                    {
+                        *dst = src;
+                    }
+                    drop(old_data);
+                    region.update(&new_data);
+                }
+                regions.insert(range, Arc::downgrade(&region));
+                self.client
+                    .send_command(EmulatorCommand::WatchMemory(range, Arc::downgrade(&region)));
+                region
+            });
+        *view = MemoryView {
+            region,
+            sim,
+            start,
+            length,
+        }
     }
 
     pub fn write<T: MemoryValue>(&self, sim: SimId, address: u32, data: &T) {
@@ -64,12 +110,23 @@ fn aligned_memory(start: u32, length: usize) -> BoxBytes {
 
 pub struct MemoryView {
     region: Arc<MemoryRegion>,
+    sim: SimId,
+    start: u32,
+    length: usize,
 }
 
 impl MemoryView {
     pub fn borrow(&self) -> MemoryRef<'_> {
         self.region.borrow()
     }
+
+    pub fn range(&self) -> MemoryRange {
+        MemoryRange {
+            sim: self.sim,
+            start: self.start,
+            length: self.length,
+        }
+    }
 }
 
 pub struct MemoryRef<'a> {
@@ -183,6 +240,14 @@ pub struct MemoryRange {
     pub length: usize,
 }
 
+impl MemoryRange {
+    pub fn overlaps(&self, other: MemoryRange) -> bool {
+        self.sim == other.sim
+            && (self.start as usize) < other.start as usize + other.length
+            && (other.start as usize) < self.start as usize + self.length
+    }
+}
+
 const BUFFERS: usize = 4;
 pub struct MemoryRegion {
     gens: [AtomicU64; BUFFERS],
@@ -195,10 +260,6 @@ impl Debug for MemoryRegion {
             .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 {

src/persistence.rs

@@ -1,46 +0,0 @@
-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/window.rs

@@ -7,6 +7,7 @@ pub use game_screen::{DisplayMode, GameScreen};
 pub use gdb::GdbServerWindow;
 pub use hotkeys::HotkeysWindow;
 pub use input::InputWindow;
+pub use memory::MemoryWindow;
 pub use profile::ProfileWindow;
 pub use terminal::TerminalWindow;
 pub use vip::{
@@ -22,6 +23,7 @@ mod game_screen;
 mod gdb;
 mod hotkeys;
 mod input;
+mod memory;
 mod profile;
 mod terminal;
 mod utils;

src/window/about.rs

@@ -12,7 +12,7 @@ impl AppWindow for AboutWindow {
     }
 
     fn show(&mut self, ui: &mut Ui) {
-        CentralPanel::default().show_inside(ui, |ui| {
+        CentralPanel::default().show(ui, |ui| {
             ui.vertical_centered(|ui| {
                 ui.label("Lemur Virtual Boy Emulator");
                 ui.label(format!("Version {}", env!("CARGO_PKG_VERSION")));

src/window/game.rs

@@ -7,17 +7,17 @@ use std::{
 
 use crate::{
     app::UserEvent,
-    config::{COLOR_PRESETS, SimConfig},
+    config::{AppConfig, COLOR_PRESETS, Config, SaveDataLocation, SimConfig},
     emulator::{EmulatorClient, EmulatorCommand, EmulatorState, SimId, SimState},
     filepicker::FilePicker,
+    filesystem::Persistence,
     images::ImageTextureLoader,
     input::{Command, MappingProvider, ShortcutProvider},
     memory::MemoryClient,
-    persistence::Persistence,
     window::{
         AboutWindow, BgMapWindow, CharacterDataWindow, FrameBufferWindow, GdbServerWindow,
-        HotkeysWindow, InitArgs, InputWindow, ObjectWindow, ProfileWindow, RegisterWindow,
+        HotkeysWindow, InitArgs, InputWindow, MemoryWindow, ObjectWindow, ProfileWindow,
-        TerminalWindow, WorldWindow, utils::UiData,
+        RegisterWindow, TerminalWindow, WorldWindow, utils::UiData,
     },
 };
 use anyhow::Context as _;
@@ -42,7 +42,7 @@ pub struct GameWindow {
     persistence: Persistence,
     shortcuts: ShortcutProvider,
     sim_id: SimId,
-    config: SimConfig,
+    config: Config<SimConfig>,
     toasts: Toasts,
     screen: Option<GameScreen>,
     messages: mpsc::Receiver<Toast>,
@@ -124,25 +124,39 @@ impl GameWindow {
             ChildWindow::CharacterData => AppWrapper::of_dyn(CharacterDataWindow::new(
                 self.sim_id,
                 &self.memory,
+                &self.persistence,
+                &self.images,
+            )),
+            ChildWindow::BgMap => AppWrapper::of_dyn(BgMapWindow::new(
+                self.sim_id,
+                &self.memory,
+                &self.persistence,
+                &self.images,
+            )),
+            ChildWindow::Objects => AppWrapper::of_dyn(ObjectWindow::new(
+                self.sim_id,
+                &self.memory,
+                &self.persistence,
+                &self.images,
+            )),
+            ChildWindow::Worlds => AppWrapper::of_dyn(WorldWindow::new(
+                self.sim_id,
+                &self.memory,
+                &self.persistence,
                 &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.persistence,
                 &self.images,
             )),
-            ChildWindow::Registers => {
+            ChildWindow::Registers => AppWrapper::of_dyn(RegisterWindow::new(
-                AppWrapper::of_dyn(RegisterWindow::new(self.sim_id, &self.memory))
+                self.sim_id,
-            }
+                &self.memory,
+                &self.persistence,
+            )),
+            ChildWindow::Memory => AppWrapper::of_dyn(MemoryWindow::new(self.sim_id, &self.memory)),
             ChildWindow::Terminal => {
                 AppWrapper::of_dyn(TerminalWindow::new(self.sim_id, &self.client))
             }
@@ -334,7 +348,7 @@ impl GameWindow {
             }
             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.config.update(|c| c.watch_rom = !watch_rom);
                 self.client
                     .send_command(EmulatorCommand::WatchRom(self.sim_id, !watch_rom));
             }
@@ -395,7 +409,7 @@ impl GameWindow {
             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);
+                self.config.update(|c| c.low_battery = !low_battery);
                 let _ = self
                     .proxy
                     .send_event(UserEvent::LowBattery(self.sim_id, !low_battery));
@@ -432,6 +446,9 @@ impl GameWindow {
             if ui.button("GDB Server").clicked() {
                 self.open(ChildWindow::Debugger { port: None });
             }
+            if ui.button("Memory").clicked() {
+                self.open(ChildWindow::Memory);
+            }
             ui.separator();
             if ui.button("Character Data").clicked() {
                 self.open(ChildWindow::CharacterData);
@@ -551,7 +568,7 @@ impl GameWindow {
                     ui.send_viewport_cmd(ViewportCommand::InnerSize(current_dims * scale));
                 }
 
-                self.update_config(|c| {
+                self.config.update(|c| {
                     c.display_mode = display_mode;
                     c.dimensions = current_dims * scale;
                 });
@@ -559,7 +576,7 @@ impl GameWindow {
             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);
+                        self.config.update(|c| c.colors = preset);
                     }
                 }
                 ui.with_layout(ui.layout().with_cross_align(egui::Align::Center), |ui| {
@@ -589,7 +606,7 @@ impl GameWindow {
                 .selectable_button(self.config.audio_enabled, "Enabled")
                 .clicked()
             {
-                self.update_config(|c| c.audio_enabled = !c.audio_enabled);
+                self.config.update(|c| c.audio_enabled = !c.audio_enabled);
                 self.client.send_command(EmulatorCommand::SetAudioEnabled(
                     self.sim_id,
                     self.config.audio_enabled,
@@ -604,6 +621,36 @@ impl GameWindow {
         if ui.button("Hotkeys").clicked() {
             self.open(ChildWindow::Hotkeys);
         }
+        ui.menu_button("Save Data Location", |ui| {
+            let save_data_location = self.client.save_data_location();
+            let update_save_data_location = |new_location: SaveDataLocation| {
+                if new_location == save_data_location {
+                    return;
+                };
+                let mut app_config = AppConfig::load(&self.persistence);
+                app_config.update(|c| c.save_data_location = new_location);
+                self.client
+                    .send_command(EmulatorCommand::SetSaveDataLocation(new_location));
+            };
+            if ui
+                .selectable_button(
+                    save_data_location == SaveDataLocation::RomDirectory,
+                    "Same Directory as ROM",
+                )
+                .clicked()
+            {
+                update_save_data_location(SaveDataLocation::RomDirectory);
+            }
+            if ui
+                .selectable_button(
+                    save_data_location == SaveDataLocation::DataDirectory,
+                    "App Data Directory",
+                )
+                .clicked()
+            {
+                update_save_data_location(SaveDataLocation::DataDirectory);
+            }
+        });
     }
 
     fn show_color_picker(&mut self, ui: &mut Ui) {
@@ -631,19 +678,10 @@ impl GameWindow {
             self.color_picker = None;
         }
         if updated {
-            self.update_config(|c| c.colors = colors);
+            self.config.update(|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) {
@@ -670,6 +708,7 @@ impl AppWindow for GameWindow {
     }
 
     fn show(&mut self, ui: &mut Ui) {
+        self.config.refresh();
         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)));
@@ -700,7 +739,7 @@ impl AppWindow for GameWindow {
             bounds.max - bounds.min
         };
         let position = ui.input(|i| i.viewport().outer_rect.map(|r| r.min));
-        self.update_config(|c| {
+        self.config.update(|c| {
             c.dimensions = dimensions;
             c.position = position;
         });
@@ -708,9 +747,7 @@ impl AppWindow for GameWindow {
         while let Ok(toast) = self.messages.try_recv() {
             self.toasts.add(toast);
         }
-        Panel::top("menubar")
+        Panel::top("menubar").exact_size(22.0).show(ui, |ui| {
-            .exact_size(22.0)
-            .show_inside(ui, |ui| {
             MenuBar::new().ui(ui, |ui| {
                 self.show_menu(ui);
             });
@@ -725,7 +762,7 @@ impl AppWindow for GameWindow {
                 });
         }
         let frame = Frame::central_panel(ui.style()).fill(Color32::BLACK);
-        CentralPanel::default().frame(frame).show_inside(ui, |ui| {
+        CentralPanel::default().frame(frame).show(ui, |ui| {
             if let Some(screen) = self.screen.as_mut() {
                 screen.update(self.config.display_mode, self.config.colors);
                 ui.add(screen);
@@ -845,6 +882,7 @@ impl DerefMut for AppWrapper {
 pub enum ChildWindow {
     About,
     CharacterData,
+    Memory,
     BgMap,
     Objects,
     Worlds,
@@ -865,6 +903,7 @@ impl ChildWindow {
         match self {
             Self::About => "About",
             Self::CharacterData => "CharacterData",
+            Self::Memory => "Memory",
             Self::BgMap => "BgMap",
             Self::Objects => "Objects",
             Self::Worlds => "Worlds",

src/window/gdb.rs

@@ -55,7 +55,7 @@ impl AppWindow for GdbServerWindow {
     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| {
+        CentralPanel::default().show(ui, |ui| {
             ui.horizontal(|ui| {
                 if port_num.is_none() {
                     let style = ui.style_mut();

src/window/hotkeys.rs

@@ -131,7 +131,7 @@ impl AppWindow for HotkeysWindow {
     }
 
     fn show(&mut self, ui: &mut Ui) {
-        CentralPanel::default().show_inside(ui, |ui| {
+        CentralPanel::default().show(ui, |ui| {
             ui.horizontal(|ui| {
                 if ui.button("Use defaults").clicked() {
                     self.shortcuts.reset();

src/window/input.rs

@@ -70,7 +70,7 @@ impl InputWindow {
             .column(Column::remainder())
             .cell_layout(Layout::left_to_right(egui::Align::Center))
             .body(|mut body| {
-                for keys in KEY_NAMES.chunks_exact(2) {
+                for keys in KEY_NAMES.as_chunks::<2>().0 {
                     body.row(20.0, |mut row| {
                         for (key, name) in keys {
                             let binding = names.remove(key).map(|mut s| {
@@ -167,7 +167,7 @@ impl AppWindow for InputWindow {
     }
 
     fn show(&mut self, ui: &mut Ui) {
-        Panel::top("options").show_inside(ui, |ui| {
+        Panel::top("options").show(ui, |ui| {
             ui.horizontal(|ui| {
                 let old_active_tab = self.active_tab;
                 ui.selectable_value(&mut self.active_tab, InputTab::Player1, "Player 1");
@@ -182,7 +182,7 @@ impl AppWindow for InputWindow {
                 }
             });
         });
-        CentralPanel::default().show_inside(ui, |ui| {
+        CentralPanel::default().show(ui, |ui| {
             match self.active_tab {
                 InputTab::Player1 => self.show_key_bindings(ui, SimId::Player1),
                 InputTab::Player2 => self.show_key_bindings(ui, SimId::Player2),

src/window/memory.rs

@@ -0,0 +1,447 @@
+use std::{fmt::LowerHex, sync::Arc};
+
+use egui::{
+    Align, CentralPanel, FontSelection, Label, Layout, Response, RichText, Separator, TextEdit, Ui,
+    ViewportBuilder, Widget, text::LayoutJob,
+};
+use egui_extras::{Column, Size, StripBuilder, TableBuilder};
+use itertools::Itertools;
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    emulator::SimId,
+    memory::{MemoryClient, MemoryRef, MemoryValue, MemoryView},
+    window::{AppWindow, utils::UiData},
+};
+
+#[derive(Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+enum ValueSize {
+    Byte,
+    Halfword,
+    Word,
+}
+impl ValueSize {
+    fn size(self) -> usize {
+        match self {
+            Self::Byte => 1,
+            Self::Halfword => 2,
+            Self::Word => 4,
+        }
+    }
+}
+
+struct HexEditResponse {
+    submitted: bool,
+    response: Response,
+}
+
+struct HexEdit<'a> {
+    text: &'a mut String,
+    button_label: &'static str,
+}
+
+impl<'a> HexEdit<'a> {
+    #[must_use]
+    fn new(text: &'a mut String, button_label: &'static str) -> Self {
+        Self { text, button_label }
+    }
+
+    fn show(self, ui: &mut Ui) -> HexEditResponse {
+        const HEX_WORD_WIDTH: f32 = 80.0;
+        let text_response = TextEdit::singleline(self.text)
+            .desired_width(HEX_WORD_WIDTH)
+            .ui(ui);
+        let button_response = ui.button(self.button_label);
+        let submitted = (text_response.lost_focus()
+            && text_response.ctx.input(|i| i.key_pressed(egui::Key::Enter)))
+            || button_response.clicked();
+        let response = text_response.union(button_response);
+        HexEditResponse {
+            submitted,
+            response,
+        }
+    }
+}
+
+impl Widget for HexEdit<'_> {
+    fn ui(self, ui: &mut Ui) -> egui::Response {
+        self.show(ui).response
+    }
+}
+
+#[derive(Clone, PartialEq, Serialize, Deserialize)]
+struct State {
+    address: u32,
+    value_size: ValueSize,
+}
+impl Default for State {
+    fn default() -> Self {
+        Self {
+            address: 0x05000000,
+            value_size: ValueSize::Byte,
+        }
+    }
+}
+
+pub struct MemoryWindow {
+    sim_id: SimId,
+    memory: Arc<MemoryClient>,
+    view: MemoryView,
+    scroll_to: Option<u32>,
+    jump_to: String,
+    editing_buffer: Vec<u8>,
+    state: UiData<State>,
+}
+
+impl MemoryWindow {
+    pub fn new(sim_id: SimId, memory: &Arc<MemoryClient>) -> Self {
+        let state: UiData<State> = UiData::new();
+        Self {
+            sim_id,
+            memory: memory.clone(),
+            view: memory.watch(sim_id, 0x0, 0),
+            scroll_to: None,
+            jump_to: String::new(),
+            editing_buffer: vec![],
+            state,
+        }
+    }
+
+    fn show_top_bar(&mut self, ui: &mut Ui) {
+        if ui
+            .radio_value(&mut self.state.value_size, ValueSize::Byte, "8-bit")
+            .clicked()
+        {
+            self.editing_buffer.clear();
+        }
+        if ui
+            .radio_value(&mut self.state.value_size, ValueSize::Halfword, "16-bit")
+            .clicked()
+        {
+            self.editing_buffer.clear();
+        }
+        if ui
+            .radio_value(&mut self.state.value_size, ValueSize::Word, "32-bit")
+            .clicked()
+        {
+            self.editing_buffer.clear();
+        }
+        self.state.address &= match self.state.value_size {
+            ValueSize::Byte => 0x07ffffff,
+            ValueSize::Halfword => 0x07fffffe,
+            ValueSize::Word => 0x07fffffc,
+        };
+        if HexEdit::new(&mut self.jump_to, "Jump to address")
+            .show(ui)
+            .submitted
+        {
+            let address_str = std::mem::take(&mut self.jump_to);
+            if let Ok(address) = u64::from_str_radix(&address_str, 16) {
+                let address = (address & 0x07ffffff) as u32;
+                self.state.address = address;
+                self.editing_buffer.clear();
+                self.scroll_to = Some(address);
+            }
+        }
+    }
+
+    fn show_memory(&mut self, ui: &mut Ui) {
+        let row_height_sans_spacing = ui.text_style_height(&egui::TextStyle::Monospace);
+        let max_height = ui.max_rect().height();
+
+        let something_has_focus = ui.memory(|m| m.focused().is_some());
+        let mut selected_changed = false;
+        ui.input(|i| {
+            if !i.focused || something_has_focus {
+                return;
+            }
+            let arrow_keys: [(egui::Key, i32); 4] = [
+                (egui::Key::ArrowUp, -0x10),
+                (egui::Key::ArrowDown, 0x10),
+                (egui::Key::ArrowLeft, -(self.state.value_size.size() as i32)),
+                (egui::Key::ArrowRight, self.state.value_size.size() as i32),
+            ];
+            for (key, delta) in arrow_keys {
+                if !selected_changed && i.key_pressed(key) {
+                    self.state.address = self.state.address.wrapping_add_signed(delta) & 0x07ffffff;
+                    self.editing_buffer.clear();
+                    selected_changed = true;
+                }
+            }
+            if !self.editing_buffer.is_empty() && i.key_pressed(egui::Key::Enter) {
+                let full_size = self.state.value_size.size() * 2;
+                while self.editing_buffer.len() < full_size {
+                    self.editing_buffer.insert(0, 0);
+                }
+            }
+        });
+
+        let mut table = TableBuilder::new(ui)
+            .column(Column::auto())
+            .column(Column::initial(0.0))
+            .column(Column::auto())
+            .column(Column::initial(0.0))
+            .column(Column::remainder())
+            .max_scroll_height(max_height)
+            .animate_scrolling(false);
+
+        if let Some(scroll_to) = self.scroll_to.take() {
+            table = table.scroll_to_row(
+                (scroll_to as usize / 0x10).saturating_sub(2),
+                Some(Align::Min),
+            );
+        }
+
+        table.body(|body| {
+            let total_rows = 0x00800000; // whole 27-bit non-mirrored address space, with 16 bytes per row
+            let range = self.view.range();
+            let current_start = range.start as usize;
+            let current_length = range.length;
+            let rows = self.view.borrow();
+            let mut new_start = None;
+            let mut new_length = 0;
+
+            body.rows(row_height_sans_spacing, total_rows, |mut row| {
+                let address = row.index() * 0x10;
+                let offset = address
+                    .checked_sub(current_start)
+                    .filter(|offset| offset + 0x10 <= current_length);
+
+                if new_start.is_none() {
+                    new_start = Some(address);
+                }
+                new_length += 0x10;
+                row.col(|ui| {
+                    let label = Label::new(RichText::new(format!("{address:08x}")).monospace());
+                    if ui.add(label).clicked() {
+                        self.state.address = address as u32;
+                        self.editing_buffer.clear();
+                        selected_changed = true;
+                    };
+                });
+                row.col(|ui| {
+                    ui.separator();
+                });
+                row.col(|ui| {
+                    if let Some(offset) = offset {
+                        fn show_memory<T: MemoryValue + LowerHex>(
+                            ui: &mut Ui,
+                            rows: &MemoryRef,
+                            (start, offset): (usize, usize),
+                            selected: u32,
+                            memory: &MemoryClient,
+                            sim: SimId,
+                            buffer: &mut Vec<u8>,
+                        ) -> Option<u32> {
+                            let mut new_selected = None;
+                            for (i, value) in rows
+                                .range::<T>(offset / size_of::<T>(), 0x10 / size_of::<T>())
+                                .enumerate()
+                            {
+                                let address = (start + offset + i * size_of::<T>()) as u32;
+                                let mut job = LayoutJob::default();
+
+                                let rich_text = |value: &str| {
+                                    let text = RichText::new(value).monospace();
+                                    if address == selected {
+                                        text.background_color(ui.visuals().selection.bg_fill)
+                                            .color(ui.visuals().selection.stroke.color)
+                                    } else {
+                                        text
+                                    }
+                                };
+
+                                let edit_len = if address == selected { buffer.len() } else { 0 };
+
+                                if edit_len > 0 {
+                                    let buffer_str =
+                                        buffer.iter().map(|d| format!("{d:x}")).join("");
+                                    let text = rich_text(&buffer_str).underline();
+                                    text.append_to(
+                                        &mut job,
+                                        ui.style(),
+                                        FontSelection::default(),
+                                        Align::Center,
+                                    );
+                                }
+
+                                let val_str = format!("{value:08x}")
+                                    .split_off(8 - size_of::<T>() * 2 + edit_len);
+                                let text = rich_text(&val_str);
+                                text.append_to(
+                                    &mut job,
+                                    ui.style(),
+                                    FontSelection::default(),
+                                    Align::Center,
+                                );
+
+                                let response = ui.label(job);
+                                if response.clicked() {
+                                    new_selected = Some(address);
+                                }
+                                if ui.memory(|m| m.focused().is_none())
+                                    && ui.input(|i| i.focused)
+                                    && address == selected
+                                {
+                                    const KEYS: [egui::Key; 16] = [
+                                        egui::Key::Num0,
+                                        egui::Key::Num1,
+                                        egui::Key::Num2,
+                                        egui::Key::Num3,
+                                        egui::Key::Num4,
+                                        egui::Key::Num5,
+                                        egui::Key::Num6,
+                                        egui::Key::Num7,
+                                        egui::Key::Num8,
+                                        egui::Key::Num9,
+                                        egui::Key::A,
+                                        egui::Key::B,
+                                        egui::Key::C,
+                                        egui::Key::D,
+                                        egui::Key::E,
+                                        egui::Key::F,
+                                    ];
+                                    let pressed = ui.input(|i| {
+                                        for (index, key) in KEYS.into_iter().enumerate() {
+                                            if i.key_pressed(key) {
+                                                return Some(index as u8);
+                                            }
+                                        }
+                                        None
+                                    });
+                                    if let Some(value) = pressed {
+                                        buffer.push(value);
+                                    }
+                                    if buffer.len() == size_of::<T>() * 2 {
+                                        let bytes = buffer
+                                            .chunks(2)
+                                            .map(|letters| (letters[0] << 4) | letters[1])
+                                            .rev()
+                                            .collect::<Vec<u8>>();
+                                        let data = T::from_bytes(&bytes);
+                                        memory.write(sim, address, &data);
+                                        new_selected = Some(
+                                            address.wrapping_add(size_of::<T>() as u32)
+                                                & 0x07ffffff,
+                                        );
+                                    }
+                                }
+                            }
+                            new_selected
+                        }
+                        let selected = match self.state.value_size {
+                            ValueSize::Byte => show_memory::<u8>(
+                                ui,
+                                &rows,
+                                (current_start, offset),
+                                self.state.address,
+                                &self.memory,
+                                self.sim_id,
+                                &mut self.editing_buffer,
+                            ),
+                            ValueSize::Halfword => show_memory::<u16>(
+                                ui,
+                                &rows,
+                                (current_start, offset),
+                                self.state.address,
+                                &self.memory,
+                                self.sim_id,
+                                &mut self.editing_buffer,
+                            ),
+                            ValueSize::Word => show_memory::<u32>(
+                                ui,
+                                &rows,
+                                (current_start, offset),
+                                self.state.address,
+                                &self.memory,
+                                self.sim_id,
+                                &mut self.editing_buffer,
+                            ),
+                        };
+                        if let Some(selected) = selected {
+                            self.state.address = selected;
+                            selected_changed = true;
+                        }
+                    };
+                    if selected_changed {
+                        self.editing_buffer.clear();
+                    }
+                });
+                row.col(|ui| {
+                    ui.separator();
+                });
+                row.col(|ui| {
+                    if let Some(offset) = offset {
+                        let printable: String = rows
+                            .range::<u8>(offset, 0x10)
+                            .map(|c| {
+                                if (32..128).contains(&c) {
+                                    c as char
+                                } else {
+                                    '.'
+                                }
+                            })
+                            .collect();
+                        ui.label(RichText::new(printable).monospace());
+                    }
+                });
+            });
+            drop(rows);
+            if let Some(start) = new_start
+                && (start != current_start || new_length != current_length)
+            {
+                self.memory
+                    .retarget(&mut self.view, self.sim_id, start as u32, new_length);
+            }
+        });
+
+        if selected_changed && self.scroll_to.is_none() {
+            let range = self.view.range();
+            if self.state.address < range.start {
+                self.scroll_to = Some(self.state.address);
+            } else if let Some(delta) = self
+                .state
+                .address
+                .checked_sub(range.start + range.length as u32 - 0x20)
+            {
+                self.scroll_to = Some(range.start + delta + 0x40);
+            }
+        }
+    }
+}
+
+impl AppWindow for MemoryWindow {
+    fn sim_id(&self) -> Option<SimId> {
+        Some(self.sim_id)
+    }
+
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title("Memory")
+            .with_inner_size((640.0, 480.0))
+    }
+
+    fn show(&mut self, ui: &mut Ui) {
+        let row_height =
+            ui.text_style_height(&egui::TextStyle::Monospace) + ui.spacing().item_spacing.y;
+        let table_height = ui.available_height() - (row_height * 2.5);
+        if self.state.load(ui) {
+            self.scroll_to = Some(self.state.address);
+        }
+        CentralPanel::default().show(ui, |ui| {
+            StripBuilder::new(ui)
+                .size(Size::exact(row_height))
+                .size(Size::initial(0.0))
+                .size(Size::exact(table_height))
+                .cell_layout(Layout::left_to_right(Align::Center))
+                .vertical(|mut strip| {
+                    strip.cell(|ui| self.show_top_bar(ui));
+                    strip.cell(|ui| {
+                        Separator::default().horizontal().ui(ui);
+                    });
+                    strip.cell(|ui| self.show_memory(ui));
+                });
+        });
+        self.state.save(ui);
+    }
+}

src/window/profile.rs

@@ -94,7 +94,7 @@ impl AppWindow for ProfileWindow {
     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| {
+        CentralPanel::default().show(ui, |ui| {
             ui.horizontal_wrapped(|ui| {
                 ui.spacing_mut().item_spacing.x = 0.0;
                 ui.add(

src/window/terminal.rs

@@ -54,7 +54,7 @@ impl AppWindow for TerminalWindow {
             }
             self.lines.back_mut().unwrap().push_str(rest);
         }
-        CentralPanel::default().show_inside(ui, |ui| {
+        CentralPanel::default().show(ui, |ui| {
             ScrollArea::vertical()
                 .stick_to_bottom(true)
                 .auto_shrink([false, false])

src/window/utils.rs

@@ -432,13 +432,15 @@ where
         }
     }
 
-    pub fn load(&mut self, ui: &Ui) {
+    pub fn load(&mut self, ui: &Ui) -> bool {
+        let just_loaded = !self.loaded;
         if !self.loaded {
             self.current = ui
                 .data_mut(|d| d.get_persisted(ui.id()))
                 .unwrap_or_default();
             self.loaded = true;
         }
+        just_loaded
     }
 
     pub fn save(&mut self, ui: &Ui) {

src/window/vip/bgmap.rs

@@ -1,14 +1,16 @@
 use std::sync::Arc;
 
 use egui::{
-    Align, CentralPanel, Checkbox, Color32, ComboBox, Image, ScrollArea, Slider, TextEdit,
+    Align, CentralPanel, Checkbox, ComboBox, Image, ScrollArea, Slider, TextEdit, TextureOptions,
-    TextureOptions, Ui, ViewportBuilder,
+    Ui, ViewportBuilder,
 };
 use egui_extras::{Column, Size, StripBuilder, TableBuilder};
 use serde::{Deserialize, Serialize};
 
 use crate::{
+    config::{Config, SimConfig},
     emulator::SimId,
+    filesystem::Persistence,
     images::{ImageBuffer, ImageParams, ImageRenderer, ImageTextureLoader},
     memory::{MemoryClient, MemoryView},
     window::{
@@ -46,9 +48,14 @@ pub struct BgMapWindow {
 }
 
 impl BgMapWindow {
-    pub fn new(sim_id: SimId, memory: &Arc<MemoryClient>, images: &ImageTextureLoader) -> Self {
+    pub fn new(
+        sim_id: SimId,
+        memory: &Arc<MemoryClient>,
+        persistence: &Persistence,
+        images: &ImageTextureLoader,
+    ) -> Self {
         let state: UiData<State> = UiData::new();
-        let renderer = BgMapRenderer::new(sim_id, memory);
+        let renderer = BgMapRenderer::new(sim_id, persistence, memory);
         let params = images.add(
             sim_id,
             renderer,
@@ -203,7 +210,7 @@ impl AppWindow for BgMapWindow {
 
     fn show(&mut self, ui: &mut Ui) {
         self.state.load(ui);
-        CentralPanel::default().show_inside(ui, |ui| {
+        CentralPanel::default().show(ui, |ui| {
             ui.horizontal_top(|ui| {
                 StripBuilder::new(ui)
                     .size(Size::relative(0.3).at_most(200.0))
@@ -229,6 +236,7 @@ struct BgMapParams {
 }
 
 struct BgMapRenderer {
+    config: Config<SimConfig>,
     chardata: MemoryView,
     bgmaps: MemoryView,
     brightness: MemoryView,
@@ -236,8 +244,9 @@ struct BgMapRenderer {
 }
 
 impl BgMapRenderer {
-    pub fn new(sim_id: SimId, memory: &MemoryClient) -> Self {
+    pub fn new(sim_id: SimId, persistence: &Persistence, memory: &MemoryClient) -> Self {
         Self {
+            config: SimConfig::load(persistence, sim_id),
             chardata: memory.watch(sim_id, 0x00078000, 0x8000),
             bgmaps: memory.watch(sim_id, 0x00020000, 0x20000),
             brightness: memory.watch(sim_id, 0x0005f824, 8),
@@ -246,6 +255,8 @@ impl BgMapRenderer {
     }
 
     fn render_bgmap(&self, image: &mut ImageBuffer, bgmap_index: usize, generic_palette: bool) {
+        let color = self.config.colors[0];
+
         let chardata = self.chardata.borrow();
         let bgmaps = self.bgmaps.borrow();
         let brightness = self.brightness.borrow();
@@ -253,9 +264,9 @@ impl BgMapRenderer {
 
         let brts = brightness.read::<[u8; 8]>(0);
         let colors = if generic_palette {
-            [utils::generic_palette(Color32::RED); 4]
+            [utils::generic_palette(color); 4]
         } else {
-            [0, 2, 4, 6].map(|i| utils::palette_colors(palettes.read(i), &brts, Color32::RED))
+            [0, 2, 4, 6].map(|i| utils::palette_colors(palettes.read(i), &brts, color))
         };
 
         for (i, cell) in bgmaps.range::<u16>(bgmap_index * 4096, 4096).enumerate() {
@@ -279,6 +290,8 @@ impl BgMapRenderer {
     }
 
     fn render_bgmap_cell(&self, image: &mut ImageBuffer, index: usize, generic_palette: bool) {
+        let color = self.config.colors[0];
+
         let chardata = self.chardata.borrow();
         let bgmaps = self.bgmaps.borrow();
         let brightness = self.brightness.borrow();
@@ -296,9 +309,9 @@ impl BgMapRenderer {
         } = CellData::parse(cell);
         let char = chardata.read::<[u16; 8]>(char_index);
         let palette = if generic_palette {
-            utils::generic_palette(Color32::RED)
+            utils::generic_palette(color)
         } else {
-            utils::palette_colors(palettes.read(palette_index * 2), &brts, Color32::RED)
+            utils::palette_colors(palettes.read(palette_index * 2), &brts, color)
         };
 
         for row in 0..8 {
@@ -321,6 +334,7 @@ impl ImageRenderer<2> for BgMapRenderer {
     }
 
     fn render(&mut self, params: &Self::Params, images: &mut [ImageBuffer; 2]) {
+        self.config.refresh();
         self.render_bgmap_cell(&mut images[0], params.cell_index, params.generic_palette);
         self.render_bgmap(
             &mut images[1],

src/window/vip/chardata.rs

@@ -8,7 +8,9 @@ use egui_extras::{Column, Size, StripBuilder, TableBuilder};
 use serde::{Deserialize, Serialize};
 
 use crate::{
+    config::{Config, SimConfig},
     emulator::SimId,
+    filesystem::Persistence,
     images::{ImageBuffer, ImageParams, ImageRenderer, ImageTextureLoader},
     memory::{MemoryClient, MemoryView},
     window::{
@@ -99,6 +101,7 @@ impl Default for State {
 
 pub struct CharacterDataWindow {
     sim_id: SimId,
+    config: Config<SimConfig>,
     brightness: MemoryView,
     palettes: MemoryView,
     params: ImageParams<CharDataParams>,
@@ -106,7 +109,13 @@ pub struct CharacterDataWindow {
 }
 
 impl CharacterDataWindow {
-    pub fn new(sim_id: SimId, memory: &MemoryClient, images: &ImageTextureLoader) -> Self {
+    pub fn new(
+        sim_id: SimId,
+        memory: &MemoryClient,
+        persistence: &Persistence,
+        images: &ImageTextureLoader,
+    ) -> Self {
+        let config = SimConfig::load(persistence, sim_id);
         let state: UiData<State> = UiData::new();
         let renderer = CharDataRenderer::new(sim_id, memory);
         let params = images.add(
@@ -115,10 +124,12 @@ impl CharacterDataWindow {
             CharDataParams {
                 palette: state.palette,
                 index: state.index,
+                color: config.colors[0],
             },
         );
         Self {
             sim_id,
+            config,
             brightness: memory.watch(sim_id, 0x0005f824, 8),
             palettes: memory.watch(sim_id, 0x0005f860, 16),
             params,
@@ -226,17 +237,19 @@ impl CharacterDataWindow {
         self.params.write(CharDataParams {
             palette: self.state.palette,
             index: self.state.index,
+            color: self.config.colors[0],
         });
     }
 
     fn load_palette_colors(&self) -> [Color32; 4] {
+        let color = self.config.colors[0];
         let Some(offset) = self.state.palette.offset() else {
-            return utils::generic_palette(Color32::RED);
+            return utils::generic_palette(color);
         };
         let palette = self.palettes.borrow().read(offset);
         let brightnesses = self.brightness.borrow();
         let brts = brightnesses.read(0);
-        utils::palette_colors(palette, &brts, Color32::RED)
+        utils::palette_colors(palette, &brts, color)
     }
 
     fn show_chardata(&mut self, ui: &mut Ui) {
@@ -262,8 +275,9 @@ impl AppWindow for CharacterDataWindow {
     }
 
     fn show(&mut self, ui: &mut Ui) {
+        self.config.refresh();
         self.state.load(ui);
-        CentralPanel::default().show_inside(ui, |ui| {
+        CentralPanel::default().show(ui, |ui| {
             ui.horizontal_top(|ui| {
                 StripBuilder::new(ui)
                     .size(Size::relative(0.3).at_most(200.0))
@@ -286,8 +300,8 @@ impl AppWindow for CharacterDataWindow {
 struct CharDataParams {
     palette: Palette,
     index: usize,
+    color: Color32,
 }
-
 struct CharDataRenderer {
     chardata: MemoryView,
     brightness: MemoryView,
@@ -306,8 +320,8 @@ impl ImageRenderer<2> for CharDataRenderer {
     }
 
     fn render(&mut self, params: &Self::Params, image: &mut [ImageBuffer; 2]) {
-        self.render_character(&mut image[0], params.palette, params.index);
+        self.render_character(&mut image[0], params.palette, params.index, params.color);
-        self.render_character_data(&mut image[1], params.palette);
+        self.render_character_data(&mut image[1], params.palette, params.color);
     }
 }
 
@@ -320,11 +334,17 @@ impl CharDataRenderer {
         }
     }
 
-    fn render_character(&self, image: &mut ImageBuffer, palette: Palette, index: usize) {
+    fn render_character(
+        &self,
+        image: &mut ImageBuffer,
+        palette: Palette,
+        index: usize,
+        color: Color32,
+    ) {
         if index >= 2048 {
             return;
         }
-        let palette = self.load_palette(palette);
+        let palette = self.load_palette(palette, color);
         let chardata = self.chardata.borrow();
         let character = chardata.range::<u16>(index * 8, 8);
         for (row, pixels) in character.enumerate() {
@@ -335,8 +355,8 @@ impl CharDataRenderer {
         }
     }
 
-    fn render_character_data(&self, image: &mut ImageBuffer, palette: Palette) {
+    fn render_character_data(&self, image: &mut ImageBuffer, palette: Palette, color: Color32) {
-        let palette = self.load_palette(palette);
+        let palette = self.load_palette(palette, color);
         let chardata = self.chardata.borrow();
         for (row, pixels) in chardata.range::<u16>(0, 8 * 2048).enumerate() {
             let char_index = row / 8;
@@ -350,13 +370,13 @@ impl CharDataRenderer {
         }
     }
 
-    fn load_palette(&self, palette: Palette) -> [Color32; 4] {
+    fn load_palette(&self, palette: Palette, color: Color32) -> [Color32; 4] {
         let Some(offset) = palette.offset() else {
-            return utils::GENERIC_PALETTE.map(|p| utils::shade(p, Color32::RED));
+            return utils::GENERIC_PALETTE.map(|p| utils::shade(p, color));
         };
         let palette = self.palettes.borrow().read(offset);
         let brightnesses = self.brightness.borrow();
         let brts = brightnesses.read(0);
-        utils::palette_colors(palette, &brts, Color32::RED)
+        utils::palette_colors(palette, &brts, color)
     }
 }

src/window/vip/framebuffer.rs

@@ -6,7 +6,9 @@ use egui_extras::{Column, Size, StripBuilder, TableBuilder};
 use serde::{Deserialize, Serialize};
 
 use crate::{
+    config::{Config, SimConfig},
     emulator::SimId,
+    filesystem::Persistence,
     images::{ImageBuffer, ImageParams, ImageRenderer, ImageTextureLoader},
     memory::{MemoryClient, MemoryView},
     window::{
@@ -44,9 +46,14 @@ pub struct FrameBufferWindow {
 }
 
 impl FrameBufferWindow {
-    pub fn new(sim_id: SimId, memory: &MemoryClient, images: &ImageTextureLoader) -> Self {
+    pub fn new(
+        sim_id: SimId,
+        memory: &MemoryClient,
+        persistence: &Persistence,
+        images: &ImageTextureLoader,
+    ) -> Self {
         let state: UiData<State> = UiData::new();
-        let renderer = FrameBufferRenderer::new(sim_id, memory);
+        let renderer = FrameBufferRenderer::new(sim_id, memory, persistence);
         let params = images.add(
             sim_id,
             renderer,
@@ -55,8 +62,6 @@ impl FrameBufferWindow {
                 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 {
@@ -138,7 +143,6 @@ impl FrameBufferWindow {
             left: self.state.left,
             right: self.state.right,
             generic_palette: self.state.generic_palette,
-            ..*self.params
         });
     }
 
@@ -163,7 +167,7 @@ impl AppWindow for FrameBufferWindow {
 
     fn show(&mut self, ui: &mut Ui) {
         self.state.load(ui);
-        CentralPanel::default().show_inside(ui, |ui| {
+        CentralPanel::default().show(ui, |ui| {
             ui.horizontal_top(|ui| {
                 StripBuilder::new(ui)
                     .size(Size::relative(0.3).at_most(200.0))
@@ -188,18 +192,18 @@ struct FrameBufferParams {
     left: bool,
     right: bool,
     generic_palette: bool,
-    left_color: Color32,
-    right_color: Color32,
 }
 
 struct FrameBufferRenderer {
+    config: Config<SimConfig>,
     buffers: [MemoryView; 4],
     brightness: MemoryView,
 }
 
 impl FrameBufferRenderer {
-    fn new(sim_id: SimId, memory: &MemoryClient) -> Self {
+    fn new(sim_id: SimId, memory: &MemoryClient, persistence: &Persistence) -> Self {
         Self {
+            config: SimConfig::load(persistence, sim_id),
             buffers: [
                 memory.watch(sim_id, 0x00000000, 0x6000),
                 memory.watch(sim_id, 0x00008000, 0x6000),
@@ -223,6 +227,7 @@ impl ImageRenderer<1> for FrameBufferRenderer {
     }
 
     fn render(&mut self, params: &Self::Params, images: &mut [ImageBuffer; 1]) {
+        self.config.refresh();
         let image = &mut images[0];
 
         let left_buffer = self.buffers[params.index].borrow();
@@ -230,15 +235,15 @@ impl ImageRenderer<1> for FrameBufferRenderer {
 
         let colors = if params.generic_palette {
             [
-                utils::generic_palette(params.left_color),
+                utils::generic_palette(self.config.colors[0]),
-                utils::generic_palette(params.right_color),
+                utils::generic_palette(self.config.colors[1]),
             ]
         } 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, self.config.colors[0])),
-                shades.map(|s| utils::shade(s, params.right_color)),
+                shades.map(|s| utils::shade(s, self.config.colors[1])),
             ]
         };
 
@@ -261,11 +266,7 @@ impl ImageRenderer<1> for FrameBufferRenderer {
                 } else {
                     Color32::BLACK
                 };
-                Color32::from_rgb(
+                left + right
-                    left.r() + right.r(),
-                    left.g() + right.g(),
-                    left.b() + right.b(),
-                )
             });
             let x = index / 64;
             for (i, pixel) in pixels.into_iter().enumerate() {

src/window/vip/object.rs

@@ -1,14 +1,16 @@
 use std::sync::Arc;
 
 use egui::{
-    Align, CentralPanel, Checkbox, Color32, ComboBox, Image, ScrollArea, Slider, TextEdit,
+    Align, CentralPanel, Checkbox, ComboBox, Image, ScrollArea, Slider, TextEdit, TextureOptions,
-    TextureOptions, Ui, ViewportBuilder,
+    Ui, ViewportBuilder,
 };
 use egui_extras::{Column, Size, StripBuilder, TableBuilder};
 use serde::{Deserialize, Serialize};
 
 use crate::{
+    config::{Config, SimConfig},
     emulator::SimId,
+    filesystem::Persistence,
     images::{ImageBuffer, ImageParams, ImageRenderer, ImageTextureLoader},
     memory::{MemoryClient, MemoryView},
     window::{
@@ -44,17 +46,20 @@ pub struct ObjectWindow {
 }
 
 impl ObjectWindow {
-    pub fn new(sim_id: SimId, memory: &Arc<MemoryClient>, images: &ImageTextureLoader) -> Self {
+    pub fn new(
+        sim_id: SimId,
+        memory: &Arc<MemoryClient>,
+        persistence: &Persistence,
+        images: &ImageTextureLoader,
+    ) -> Self {
         let state: UiData<State> = UiData::new();
-        let renderer = ObjectRenderer::new(sim_id, memory);
+        let renderer = ObjectRenderer::new(sim_id, memory, persistence);
         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 {
@@ -194,7 +199,6 @@ impl ObjectWindow {
         self.params.write(ObjectParams {
             index: self.state.index,
             generic_palette: self.state.generic_palette,
-            ..*self.params
         });
     }
 
@@ -219,7 +223,7 @@ impl AppWindow for ObjectWindow {
 
     fn show(&mut self, ui: &mut Ui) {
         self.state.load(ui);
-        CentralPanel::default().show_inside(ui, |ui| {
+        CentralPanel::default().show(ui, |ui| {
             ui.horizontal_top(|ui| {
                 StripBuilder::new(ui)
                     .size(Size::relative(0.3).at_most(200.0))
@@ -242,8 +246,6 @@ impl AppWindow for ObjectWindow {
 struct ObjectParams {
     index: usize,
     generic_palette: bool,
-    left_color: Color32,
-    right_color: Color32,
 }
 
 enum Eye {
@@ -252,6 +254,7 @@ enum Eye {
 }
 
 struct ObjectRenderer {
+    config: Config<SimConfig>,
     chardata: MemoryView,
     objects: MemoryView,
     brightness: MemoryView,
@@ -259,8 +262,9 @@ struct ObjectRenderer {
 }
 
 impl ObjectRenderer {
-    pub fn new(sim_id: SimId, memory: &MemoryClient) -> Self {
+    pub fn new(sim_id: SimId, memory: &MemoryClient, persistence: &Persistence) -> Self {
         Self {
+            config: SimConfig::load(persistence, sim_id),
             chardata: memory.watch(sim_id, 0x00078000, 0x8000),
             objects: memory.watch(sim_id, 0x0003e000, 0x2000),
             brightness: memory.watch(sim_id, 0x0005f824, 8),
@@ -302,8 +306,8 @@ impl ObjectRenderer {
         };
 
         let color = match eye {
-            Eye::Left => params.left_color,
+            Eye::Left => self.config.colors[0],
-            Eye::Right => params.right_color,
+            Eye::Right => self.config.colors[1],
         };
 
         let char = chardata.read::<[u16; 8]>(obj.data.char_index);
@@ -343,6 +347,7 @@ impl ImageRenderer<2> for ObjectRenderer {
     }
 
     fn render(&mut self, params: &Self::Params, images: &mut [ImageBuffer; 2]) {
+        self.config.refresh();
         images[0].clear();
         self.render_object(&mut images[0], params, false, Eye::Left);
         self.render_object(&mut images[0], params, false, Eye::Right);

src/window/vip/registers.rs

@@ -1,13 +1,15 @@
 use std::sync::Arc;
 
 use egui::{
-    Align, Button, CentralPanel, Checkbox, Color32, Direction, Label, Layout, ScrollArea, TextEdit,
+    Align, Button, CentralPanel, Checkbox, Direction, Label, Layout, ScrollArea, TextEdit, Ui,
-    Ui, ViewportBuilder,
+    ViewportBuilder,
 };
 use egui_extras::{Column, Size, StripBuilder, TableBuilder};
 
 use crate::{
+    config::{Config, SimConfig},
     emulator::SimId,
+    filesystem::Persistence,
     memory::{MemoryClient, MemoryRef, MemoryValue, MemoryView},
     window::{
         AppWindow,
@@ -19,14 +21,16 @@ use super::utils;
 
 pub struct RegisterWindow {
     sim_id: SimId,
+    config: Config<SimConfig>,
     memory: Arc<MemoryClient>,
     registers: MemoryView,
 }
 
 impl RegisterWindow {
-    pub fn new(sim_id: SimId, memory: &Arc<MemoryClient>) -> Self {
+    pub fn new(sim_id: SimId, memory: &Arc<MemoryClient>, persistence: &Persistence) -> Self {
         Self {
             sim_id,
+            config: SimConfig::load(persistence, sim_id),
             memory: memory.clone(),
             registers: memory.watch(sim_id, 0x0005f800, 0x72),
         }
@@ -366,7 +370,7 @@ impl RegisterWindow {
                     });
                     body.row(row_height, |mut row| {
                         row.col(|_ui| {});
-                        for shade in utils::parse_brts(&brts, Color32::RED) {
+                        for shade in utils::parse_brts(&brts, self.config.colors[0]) {
                             row.col(|ui| {
                                 ui.painter().rect_filled(
                                     ui.available_rect_before_wrap(),
@@ -641,7 +645,8 @@ impl AppWindow for RegisterWindow {
     }
 
     fn show(&mut self, ui: &mut Ui) {
-        CentralPanel::default().show_inside(ui, |ui| {
+        self.config.refresh();
+        CentralPanel::default().show(ui, |ui| {
             ScrollArea::vertical().show(ui, |ui| {
                 ui.horizontal_top(|ui| {
                     let width = ui.available_width();

src/window/vip/utils.rs

@@ -1,6 +1,7 @@
 use egui::{Color32, Image, ImageSource, Response, Sense, TextureOptions, Ui, Widget};
 
 pub const GENERIC_PALETTE: [u8; 4] = [0, 32, 64, 128];
+const COLOR_TRANSPARENT: Color32 = Color32::from_rgb(0x25, 0x25, 0x25);
 
 pub fn shade(brt: u8, color: Color32) -> Color32 {
     let corrected = if brt > 132 {
@@ -44,7 +45,9 @@ pub fn parse_brts(brts: &[u16; 3], color: Color32) -> [Color32; 4] {
 
 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])
+    let mut palette_colors = parse_palette(palette).map(|p| colors[p as usize]);
+    palette_colors[0] = COLOR_TRANSPARENT;
+    palette_colors
 }
 
 pub struct Object {

src/window/vip/world.rs

@@ -14,7 +14,9 @@ use num_traits::{FromPrimitive, ToPrimitive};
 use serde::{Deserialize, Serialize};
 
 use crate::{
+    config::{Config, SimConfig},
     emulator::SimId,
+    filesystem::Persistence,
     images::{ImageBuffer, ImageParams, ImageRenderer, ImageTextureLoader},
     memory::{MemoryClient, MemoryRef, MemoryView},
     window::{
@@ -47,6 +49,7 @@ impl Default for State {
 
 pub struct WorldWindow {
     sim_id: SimId,
+    config: Config<SimConfig>,
     memory: Arc<MemoryClient>,
     worlds: MemoryView,
     bgmaps: MemoryView,
@@ -55,7 +58,13 @@ pub struct WorldWindow {
 }
 
 impl WorldWindow {
-    pub fn new(sim_id: SimId, memory: &Arc<MemoryClient>, images: &ImageTextureLoader) -> Self {
+    pub fn new(
+        sim_id: SimId,
+        memory: &Arc<MemoryClient>,
+        persistence: &Persistence,
+        images: &ImageTextureLoader,
+    ) -> Self {
+        let config = SimConfig::load(persistence, sim_id);
         let state: UiData<State> = UiData::new();
         let renderer = WorldRenderer::new(sim_id, memory);
         let params = images.add(
@@ -64,12 +73,13 @@ impl WorldWindow {
             WorldParams {
                 index: state.index,
                 generic_palette: state.generic_palette,
-                left_color: Color32::from_rgb(0xff, 0x00, 0x00),
+                left_color: config.colors[0],
-                right_color: Color32::from_rgb(0x00, 0xc6, 0xf0),
+                right_color: config.colors[1],
             },
         );
         Self {
             sim_id,
+            config,
             memory: memory.clone(),
             worlds: memory.watch(sim_id, 0x0003d800, 0x400),
             bgmaps: memory.watch(sim_id, 0x00020000, 0x20000),
@@ -467,12 +477,7 @@ impl WorldWindow {
 
             let left_color = self.params.left_color;
             let right_color = self.params.right_color;
-            let both_color = Color32::from_rgb(
+            let both_color = left_color + right_color;
-                left_color.r() + right_color.r(),
-                left_color.g() + right_color.g(),
-                left_color.b() + right_color.b(),
-            );
-
             let painter = ui.painter();
             let draw_rect = |x1: f32, x2: f32, color: Color32| {
                 painter.line(
@@ -538,8 +543,14 @@ impl AppWindow for WorldWindow {
     }
 
     fn show(&mut self, ui: &mut Ui) {
+        self.config.refresh();
+        self.params.write(WorldParams {
+            left_color: self.config.colors[0],
+            right_color: self.config.colors[1],
+            ..*self.params
+        });
         self.state.load(ui);
-        CentralPanel::default().show_inside(ui, |ui| {
+        CentralPanel::default().show(ui, |ui| {
             ui.horizontal_top(|ui| {
                 StripBuilder::new(ui)
                     .size(Size::relative(0.3).at_most(200.0))
@@ -686,11 +697,7 @@ impl WorldRenderer {
         for (dst, shades) in image.pixels.iter_mut().zip(self.buffer.iter()) {
             let left = colors[0][shades[0] as usize];
             let right = colors[1][shades[1] as usize];
-            *dst = Color32::from_rgb(
+            *dst = left + right;
-                left.r() + right.r(),
-                left.g() + right.g(),
-                left.b() + right.b(),
-            )
         }
     }
 
@@ -944,7 +951,7 @@ impl WorldHeader {
         let ron = data & 0x4000 != 0;
         let mode = WorldMode::from_u16((data >> 12) & 0x3).unwrap();
         let scx = (data >> 10) as u32 & 0x03;
-        let scy = (data >> 10) as u32 & 0x03;
+        let scy = (data >> 8) as u32 & 0x03;
         let over = data & 0x0080 != 0;
         let end = data & 0x0040 != 0;
         let base = (data & 0x000f) as usize;