Actually produce profiler files

Reviewed-on: #6

Cargo.toml

@@ -4,8 +4,8 @@ description = "An emulator for the Virtual Boy."
 repository = "https://git.virtual-boy.com/PVB/lemur"
 publish = false
 license = "MIT"
-version = "0.4.2"
-edition = "2021"
+version = "0.7.1"
+edition = "2024"
 
 [dependencies]
 anyhow = "1"
@@ -15,35 +15,40 @@ bitflags = { version = "2", features = ["serde"] }
 bytemuck = { version = "1", features = ["derive"] }
 clap = { version = "4", features = ["derive"] }
 cpal = { git = "https://github.com/sidit77/cpal.git", rev = "66ed6be" }
-directories = "5"
-egui = { version = "0.30", features = ["serde"] }
-egui_extras = { version = "0.30", features = ["image"] }
-egui-toast = { git = "https://github.com/urholaukkarinen/egui-toast.git", rev = "d0bcf97" }
-egui-winit = "0.30"
-egui-wgpu = { version = "0.30", features = ["winit"] }
+directories = "6"
+egui = { version = "0.32", features = ["serde"] }
+egui_extras = { version = "0.32", features = ["image"] }
+egui-notify = "0.20"
+egui-winit = "0.32"
+egui-wgpu = { version = "0.32", features = ["winit"] }
+elf = "0.8"
+fxprof-processed-profile = "0.8"
 fixed = { version = "1.28", features = ["num-traits"] }
 gilrs = { version = "0.11", features = ["serde-serialize"] }
 hex = "0.4"
 image = { version = "0.25", default-features = false, features = ["png"] }
 itertools = "0.14"
+normpath = "1"
 num-derive = "0.4"
 num-traits = "0.2"
 oneshot = "0.1"
 pollster = "0.4"
-rfd = "0.15"
+rand = "0.9"
+rfd = { version = "0.15", default-features = false, features = ["xdg-portal", "async-std"]}
 rtrb = "0.3"
 rubato = "0.16"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
-thread-priority = "1"
+thread-priority = "2"
 tokio = { version = "1", features = ["io-util", "macros", "net", "rt", "sync", "time"] }
 tracing = { version = "0.1", features = ["release_max_level_info"] }
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
-wgpu = "23"
+wgpu = "25"
+wholesym = "0.8"
 winit = { version = "0.30", features = ["serde"] }
 
 [target.'cfg(windows)'.dependencies]
-windows = { version = "0.58", features = ["Win32_System_Threading"] }
+windows = { version = "0.61", features = ["Win32_System_Threading"] }
 
 [build-dependencies]
 cc = "1"

README.md

@@ -6,6 +6,8 @@ A Virtual Boy emulator built around the shrooms-vb core. Written in Rust, using
 
 Install the following dependencies:
  - `cargo` (via [rustup](https://rustup.rs/), the version from your package manager is too old)
+ - a C compiler (any will do, [the build script](https://docs.rs/cc/latest/cc/#compile-time-requirements) will find it automatically)
+ - (on linux) `libasound2-dev` and `libudev-dev`
 
 Run
 ```sh

build.Dockerfile

@@ -32,6 +32,5 @@ ENV PATH="/osxcross/bin:$PATH" \
     CARGO_TARGET_X86_64_APPLE_DARWIN_AR="llvm-ar-19" \
     CARGO_TARGET_AARCH64_APPLE_DARWIN_LINKER="oa64-clang" \
     CARGO_TARGET_AARCH64_APPLE_DARWIN_AR="llvm-ar-19" \
-    CROSS_COMPILE="setting-this-to-silence-a-warning-" \
     RC_PATH="llvm-rc-19" \
     MACOSX_DEPLOYMENT_TARGET="14.5"

build.rs

@@ -23,7 +23,9 @@ fn main() -> Result<(), Box<dyn Error>> {
         .define("VB_LITTLE_ENDIAN", None)
         .define("VB_SIGNED_PROPAGATE", None)
         .define("VB_DIV_GENERIC", None)
+        .define("VB_DIRECT_EXCEPTION", "on_exception")
         .define("VB_DIRECT_EXECUTE", "on_execute")
+        .define("VB_DIRECT_FETCH", "on_fetch")
         .define("VB_DIRECT_FRAME", "on_frame")
         .define("VB_DIRECT_READ", "on_read")
         .define("VB_DIRECT_WRITE", "on_write")

src/app.rs

@@ -1,9 +1,10 @@
 use std::{collections::HashSet, num::NonZero, sync::Arc, thread, time::Duration};
 
 use egui::{
-    ahash::{HashMap, HashMapExt},
     Context, FontData, FontDefinitions, FontFamily, IconData, TextWrapMode, ViewportBuilder,
     ViewportCommand, ViewportId, ViewportInfo,
+    ahash::{HashMap, HashMapExt},
+    style::ScrollStyle,
 };
 use gilrs::{EventType, Gilrs};
 use tracing::{error, warn};
@@ -18,12 +19,13 @@ use crate::{
     controller::ControllerManager,
     emulator::{EmulatorClient, EmulatorCommand, SimId},
     images::ImageProcessor,
-    input::MappingProvider,
+    input::{MappingProvider, ShortcutProvider},
     memory::MemoryClient,
     persistence::Persistence,
     window::{
         AboutWindow, AppWindow, BgMapWindow, CharacterDataWindow, FrameBufferWindow, GameWindow,
-        GdbServerWindow, InputWindow, ObjectWindow, RegisterWindow, WorldWindow,
+        GdbServerWindow, HotkeysWindow, InputWindow, ObjectWindow, ProfileWindow, RegisterWindow,
+        TerminalWindow, WorldWindow,
     },
 };
 
@@ -44,6 +46,7 @@ pub struct Application {
     client: EmulatorClient,
     proxy: EventLoopProxy<UserEvent>,
     mappings: MappingProvider,
+    shortcuts: ShortcutProvider,
     controllers: ControllerManager,
     memory: Arc<MemoryClient>,
     images: ImageProcessor,
@@ -51,6 +54,7 @@ pub struct Application {
     viewports: HashMap<ViewportId, Viewport>,
     focused: Option<ViewportId>,
     init_debug_port: Option<u16>,
+    init_profiling: bool,
 }
 
 impl Application {
@@ -58,11 +62,13 @@ impl Application {
         client: EmulatorClient,
         proxy: EventLoopProxy<UserEvent>,
         debug_port: Option<u16>,
+        profiling: bool,
     ) -> Self {
         let wgpu = WgpuState::new();
         let icon = load_icon().ok().map(Arc::new);
         let persistence = Persistence::new();
         let mappings = MappingProvider::new(persistence.clone());
+        let shortcuts = ShortcutProvider::new(persistence.clone());
         let controllers = ControllerManager::new(client.clone(), &mappings);
         let memory = Arc::new(MemoryClient::new(client.clone()));
         let images = ImageProcessor::new();
@@ -77,6 +83,7 @@ impl Application {
             client,
             proxy,
             mappings,
+            shortcuts,
             memory,
             images,
             controllers,
@@ -84,12 +91,14 @@ impl Application {
             viewports: HashMap::new(),
             focused: None,
             init_debug_port: debug_port,
+            init_profiling: profiling,
         }
     }
 
     fn open(&mut self, event_loop: &ActiveEventLoop, window: Box<dyn AppWindow>) {
         let viewport_id = window.viewport_id();
-        if self.viewports.contains_key(&viewport_id) {
+        if let Some(viewport) = self.viewports.get(&viewport_id) {
+            viewport.window.focus_window();
             return;
         }
         self.viewports.insert(
@@ -111,9 +120,15 @@ impl ApplicationHandler<UserEvent> for Application {
             self.client.clone(),
             self.proxy.clone(),
             self.persistence.clone(),
+            self.shortcuts.clone(),
             SimId::Player1,
         );
         self.open(event_loop, Box::new(app));
+        if self.init_profiling {
+            let mut profiler = ProfileWindow::new(SimId::Player1, self.client.clone());
+            profiler.launch();
+            self.open(event_loop, Box::new(profiler));
+        }
     }
 
     fn window_event(
@@ -237,6 +252,14 @@ impl ApplicationHandler<UserEvent> for Application {
                 let registers = RegisterWindow::new(sim_id, &self.memory);
                 self.open(event_loop, Box::new(registers));
             }
+            UserEvent::OpenTerminal(sim_id) => {
+                let terminal = TerminalWindow::new(sim_id, &self.client);
+                self.open(event_loop, Box::new(terminal));
+            }
+            UserEvent::OpenProfiler(sim_id) => {
+                let profile = ProfileWindow::new(sim_id, self.client.clone());
+                self.open(event_loop, Box::new(profile));
+            }
             UserEvent::OpenDebugger(sim_id) => {
                 let debugger =
                     GdbServerWindow::new(sim_id, self.client.clone(), self.proxy.clone());
@@ -246,11 +269,16 @@ impl ApplicationHandler<UserEvent> for Application {
                 let input = InputWindow::new(self.mappings.clone());
                 self.open(event_loop, Box::new(input));
             }
+            UserEvent::OpenHotkeys => {
+                let hotkeys = HotkeysWindow::new(self.shortcuts.clone());
+                self.open(event_loop, Box::new(hotkeys));
+            }
             UserEvent::OpenPlayer2 => {
                 let p2 = GameWindow::new(
                     self.client.clone(),
                     self.proxy.clone(),
                     self.persistence.clone(),
+                    self.shortcuts.clone(),
                     SimId::Player2,
                 );
                 self.open(event_loop, Box::new(p2));
@@ -282,10 +310,10 @@ impl ApplicationHandler<UserEvent> for Application {
 }
 
 struct WgpuState {
-    instance: Arc<wgpu::Instance>,
-    adapter: Arc<wgpu::Adapter>,
-    device: Arc<wgpu::Device>,
-    queue: Arc<wgpu::Queue>,
+    instance: wgpu::Instance,
+    adapter: wgpu::Adapter,
+    device: wgpu::Device,
+    queue: wgpu::Queue,
 }
 
 impl WgpuState {
@@ -293,21 +321,21 @@ impl WgpuState {
         #[allow(unused_variables)]
         let egui_wgpu::WgpuConfiguration {
             wgpu_setup:
-                egui_wgpu::WgpuSetup::CreateNew {
-                    supported_backends,
+                egui_wgpu::WgpuSetup::CreateNew(egui_wgpu::WgpuSetupCreateNew {
+                    instance_descriptor: wgpu::InstanceDescriptor { backends, .. },
                     device_descriptor,
                     ..
-                },
+                }),
             ..
         } = egui_wgpu::WgpuConfiguration::default()
         else {
             panic!("required fields not found")
         };
         #[cfg(windows)]
-        let supported_backends = wgpu::util::backend_bits_from_env()
+        let backends = wgpu::Backends::from_env()
             .unwrap_or((wgpu::Backends::PRIMARY | wgpu::Backends::GL) - wgpu::Backends::VULKAN);
-        let instance = wgpu::Instance::new(wgpu::InstanceDescriptor {
-            backends: supported_backends,
+        let instance = wgpu::Instance::new(&wgpu::InstanceDescriptor {
+            backends,
             ..wgpu::InstanceDescriptor::default()
         });
 
@@ -318,17 +346,14 @@ impl WgpuState {
         }))
         .expect("could not create adapter");
 
-        let trace_path = std::env::var("WGPU_TRACE");
-        let (device, queue) = pollster::block_on(adapter.request_device(
-            &(*device_descriptor)(&adapter),
-            trace_path.ok().as_ref().map(std::path::Path::new),
-        ))
-        .expect("could not request device");
+        let (device, queue) =
+            pollster::block_on(adapter.request_device(&(*device_descriptor)(&adapter)))
+                .expect("could not request device");
         Self {
-            instance: Arc::new(instance),
-            adapter: Arc::new(adapter),
-            device: Arc::new(device),
-            queue: Arc::new(queue),
+            instance,
+            adapter,
+            device,
+            queue,
         }
     }
 }
@@ -366,23 +391,30 @@ impl Viewport {
         ctx.set_fonts(fonts);
         ctx.style_mut(|s| {
             s.wrap_mode = Some(TextWrapMode::Extend);
-            s.visuals.menu_rounding = Default::default();
+            s.visuals.menu_corner_radius = Default::default();
+            s.spacing.scroll = ScrollStyle::thin();
         });
         egui_extras::install_image_loaders(&ctx);
 
         let wgpu_config = egui_wgpu::WgpuConfiguration {
             present_mode: wgpu::PresentMode::AutoNoVsync,
-            wgpu_setup: egui_wgpu::WgpuSetup::Existing {
+            wgpu_setup: egui_wgpu::WgpuSetup::Existing(egui_wgpu::WgpuSetupExisting {
                 instance: wgpu.instance.clone(),
                 adapter: wgpu.adapter.clone(),
                 device: wgpu.device.clone(),
                 queue: wgpu.queue.clone(),
-            },
+            }),
             ..egui_wgpu::WgpuConfiguration::default()
         };
 
-        let mut painter =
-            egui_wgpu::winit::Painter::new(ctx.clone(), wgpu_config, 1, None, false, true);
+        let mut painter = pollster::block_on(egui_wgpu::winit::Painter::new(
+            ctx.clone(),
+            wgpu_config,
+            1,
+            None,
+            false,
+            true,
+        ));
 
         let mut info = ViewportInfo::default();
         let mut builder = app.initial_viewport();
@@ -501,8 +533,11 @@ pub enum UserEvent {
     OpenWorlds(SimId),
     OpenFrameBuffers(SimId),
     OpenRegisters(SimId),
+    OpenTerminal(SimId),
+    OpenProfiler(SimId),
     OpenDebugger(SimId),
     OpenInput,
+    OpenHotkeys,
     OpenPlayer2,
     Quit(SimId),
 }

src/audio.rs

@@ -1,20 +1,22 @@
 use std::time::Duration;
 
-use anyhow::{bail, Result};
+use anyhow::{Result, bail};
 use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
 use itertools::Itertools;
-use rubato::{FftFixedInOut, Resampler};
+use rubato::{FastFixedOut, Resampler};
 use tracing::error;
 
 pub struct Audio {
     #[allow(unused)]
     stream: cpal::Stream,
-    sampler: FftFixedInOut<f32>,
+    sampler: FastFixedOut<f32>,
     input_buffer: Vec<Vec<f32>>,
     output_buffer: Vec<Vec<f32>>,
     sample_sink: rtrb::Producer<f32>,
 }
 
+const VB_FREQUENCY: usize = 41700;
+
 impl Audio {
     pub fn init() -> Result<Self> {
         let host = cpal::default_host();
@@ -28,7 +30,15 @@ impl Audio {
             bail!("No suitable output config available");
         };
         let mut config = config.with_max_sample_rate().config();
-        let sampler = FftFixedInOut::new(41700, config.sample_rate.0 as usize, 834, 2)?;
+        let resample_ratio = config.sample_rate.0 as f64 / VB_FREQUENCY as f64;
+        let chunk_size = (834.0 * resample_ratio) as usize;
+        let sampler = FastFixedOut::new(
+            resample_ratio,
+            64.0,
+            rubato::PolynomialDegree::Cubic,
+            chunk_size,
+            2,
+        )?;
         config.buffer_size = cpal::BufferSize::Fixed(sampler.output_frames_max() as u32);
 
         let input_buffer = sampler.input_buffer_allocate(true);
@@ -101,4 +111,10 @@ impl Audio {
             std::thread::sleep(Duration::from_micros(500));
         }
     }
+
+    pub fn set_speed(&mut self, speed: f64) -> Result<()> {
+        self.sampler
+            .set_resample_ratio_relative(1.0 / speed, false)?;
+        Ok(())
+    }
 }

src/controller.rs

@@ -1,6 +1,6 @@
 use std::sync::{Arc, RwLock};
 
-use gilrs::{ev::Code, Event as GamepadEvent, EventType, GamepadId};
+use gilrs::{Event as GamepadEvent, EventType, GamepadId, ev::Code};
 use winit::{
     event::{ElementState, KeyEvent},
     keyboard::PhysicalKey,

src/emulator.rs

@@ -1,31 +1,32 @@
 use std::{
     collections::HashMap,
     fmt::Display,
-    fs::{self, File},
-    io::{Read, Seek, SeekFrom, Write},
     path::{Path, PathBuf},
     sync::{
+        Arc, Weak,
         atomic::{AtomicBool, Ordering},
         mpsc::{self, RecvError, TryRecvError},
-        Arc, Weak,
     },
+    time::Duration,
 };
 
 use anyhow::Result;
 use atomic::Atomic;
 use bytemuck::NoUninit;
-use egui_toast::{Toast, ToastKind, ToastOptions};
+use egui_notify::Toast;
 use tracing::{error, warn};
 
 use crate::{
     audio::Audio,
+    emulator::cart::Cart,
     graphics::TextureSink,
     memory::{MemoryRange, MemoryRegion},
 };
-use shrooms_vb_core::{Sim, StopReason, EXPECTED_FRAME_SIZE};
-pub use shrooms_vb_core::{VBKey, VBRegister, VBWatchpointType};
+use shrooms_vb_core::{EXPECTED_FRAME_SIZE, Sim, StopReason};
+pub use shrooms_vb_core::{SimEvent, VBKey, VBRegister, VBWatchpointType};
 
 mod address_set;
+mod cart;
 mod shrooms_vb_core;
 
 #[derive(PartialEq, Eq, Hash, Clone, Copy, Debug)]
@@ -43,6 +44,13 @@ impl SimId {
             Self::Player2 => 1,
         }
     }
+    pub const fn from_index(index: usize) -> Option<Self> {
+        match index {
+            0 => Some(Self::Player1),
+            1 => Some(Self::Player2),
+            _ => None,
+        }
+    }
 }
 impl Display for SimId {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
@@ -53,43 +61,6 @@ impl Display for SimId {
     }
 }
 
-struct Cart {
-    rom_path: PathBuf,
-    rom: Vec<u8>,
-    sram_file: File,
-    sram: Vec<u8>,
-}
-
-impl Cart {
-    fn load(rom_path: &Path, sim_id: SimId) -> Result<Self> {
-        let rom = fs::read(rom_path)?;
-
-        let mut sram_file = File::options()
-            .read(true)
-            .write(true)
-            .create(true)
-            .truncate(false)
-            .open(sram_path(rom_path, sim_id))?;
-        sram_file.set_len(8 * 1024)?;
-
-        let mut sram = vec![];
-        sram_file.read_to_end(&mut sram)?;
-        Ok(Cart {
-            rom_path: rom_path.to_path_buf(),
-            rom,
-            sram_file,
-            sram,
-        })
-    }
-}
-
-fn sram_path(rom_path: &Path, sim_id: SimId) -> PathBuf {
-    match sim_id {
-        SimId::Player1 => rom_path.with_extension("p1.sram"),
-        SimId::Player2 => rom_path.with_extension("p2.sram"),
-    }
-}
-
 pub struct EmulatorBuilder {
     rom: Option<PathBuf>,
     commands: mpsc::Receiver<EmulatorCommand>,
@@ -166,11 +137,13 @@ pub struct Emulator {
     state: Arc<Atomic<EmulatorState>>,
     audio_on: Arc<[AtomicBool; 2]>,
     linked: Arc<AtomicBool>,
+    profilers: [Option<ProfileSender>; 2],
     renderers: HashMap<SimId, TextureSink>,
     messages: HashMap<SimId, mpsc::Sender<Toast>>,
     debuggers: HashMap<SimId, DebugInfo>,
+    stdouts: HashMap<SimId, mpsc::Sender<String>>,
     watched_regions: HashMap<MemoryRange, Weak<MemoryRegion>>,
-    eye_contents: Vec<u8>,
+    eye_contents: [Vec<u8>; 2],
     audio_samples: Vec<f32>,
     buffer: Vec<u8>,
 }
@@ -192,11 +165,13 @@ impl Emulator {
             state,
             audio_on,
             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],
+            eye_contents: [vec![0u8; 384 * 224 * 2], vec![0u8; 384 * 224 * 2]],
             audio_samples: Vec::with_capacity(EXPECTED_FRAME_SIZE),
             buffer: vec![],
         })
@@ -209,12 +184,12 @@ impl Emulator {
     }
 
     pub fn start_second_sim(&mut self, rom: Option<PathBuf>) -> Result<()> {
-        let rom_path = if let Some(path) = rom {
+        let file_path = if let Some(path) = rom {
             Some(path)
         } else {
-            self.carts[0].as_ref().map(|c| c.rom_path.clone())
+            self.carts[0].as_ref().map(|c| c.file_path.clone())
         };
-        let cart = match rom_path {
+        let cart = match file_path {
             Some(rom_path) => Some(Cart::load(&rom_path, SimId::Player2)?),
             None => None,
         };
@@ -228,8 +203,15 @@ impl Emulator {
 
         let index = sim_id.to_index();
         while self.sims.len() <= index {
+            let new_index = self.sims.len();
             self.sims.push(Sim::new());
-            self.sim_state[index].store(SimState::NoGame, Ordering::Release);
+            if self
+                .stdouts
+                .contains_key(&SimId::from_index(new_index).unwrap())
+            {
+                self.sims[new_index].watch_stdout(true);
+            }
+            self.sim_state[new_index].store(SimState::NoGame, Ordering::Release);
         }
         let sim = &mut self.sims[index];
         sim.reset();
@@ -238,6 +220,24 @@ impl Emulator {
             self.carts[index] = Some(cart);
             self.sim_state[index].store(SimState::Ready, Ordering::Release);
         }
+        let mut profiling = false;
+        if let Some(profiler) = self.profilers[sim_id.to_index()].as_ref() {
+            if let Some(cart) = self.carts[index].as_ref() {
+                if profiler
+                    .send(ProfileEvent::Start {
+                        file_path: cart.file_path.clone(),
+                    })
+                    .is_ok()
+                {
+                    sim.monitor_events(true);
+                    profiling = true;
+                }
+            }
+        }
+        if !profiling {
+            sim.monitor_events(false);
+        }
+
         if self.sim_state[index].load(Ordering::Acquire) == SimState::Ready {
             self.resume_sims();
         }
@@ -311,13 +311,16 @@ impl Emulator {
         }
     }
 
+    fn set_speed(&mut self, speed: f64) -> Result<()> {
+        self.audio.set_speed(speed)
+    }
+
     fn save_sram(&mut self, sim_id: SimId) -> Result<()> {
         let sim = self.sims.get_mut(sim_id.to_index());
         let cart = self.carts[sim_id.to_index()].as_mut();
         if let (Some(sim), Some(cart)) = (sim, cart) {
             sim.read_sram(&mut cart.sram);
-            cart.sram_file.seek(SeekFrom::Start(0))?;
-            cart.sram_file.write_all(&cart.sram)?;
+            cart.save_sram()?;
         }
         Ok(())
     }
@@ -332,6 +335,11 @@ impl Emulator {
         Ok(())
     }
 
+    fn start_profiling(&mut self, sim_id: SimId, sender: ProfileSender) -> Result<()> {
+        self.profilers[sim_id.to_index()] = Some(sender);
+        self.reset_sim(sim_id, None)
+    }
+
     fn start_debugging(&mut self, sim_id: SimId, sender: DebugSender) {
         if self.sim_state[sim_id.to_index()].load(Ordering::Acquire) != SimState::Ready {
             // Can't debug unless a game is connected
@@ -455,25 +463,57 @@ impl Emulator {
         let p1_running = running && p1_state == SimState::Ready;
         let p2_running = running && p2_state == SimState::Ready;
         let mut idle = !p1_running && !p2_running;
-        if p1_running && p2_running {
-            Sim::emulate_many(&mut self.sims);
-        } else if p1_running {
-            self.sims[SimId::Player1.to_index()].emulate();
-        } else if p2_running {
-            self.sims[SimId::Player2.to_index()].emulate();
+
+        let cycles = self.emulate(p1_running, p2_running);
+
+        // if we're profiling, track events
+        for ((sim, profiler), running) in self
+            .sims
+            .iter_mut()
+            .zip(self.profilers.iter_mut())
+            .zip([p1_running, p2_running])
+        {
+            if !running {
+                continue;
+            }
+            if let Some(p) = profiler {
+                if p.send(ProfileEvent::Update {
+                    cycles,
+                    event: sim.take_sim_event(),
+                })
+                .is_err()
+                {
+                    sim.monitor_events(false);
+                    *profiler = None;
+                }
+            }
         }
 
         if state == EmulatorState::Stepping {
             self.state.store(EmulatorState::Paused, Ordering::Release);
         }
 
+        // stdout
+        self.stdouts.retain(|sim_id, stdout| {
+            let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
+                return true;
+            };
+            if let Some(text) = sim.take_stdout() {
+                if stdout.send(text).is_err() {
+                    sim.watch_stdout(false);
+                    return false;
+                }
+            }
+            true
+        });
+
         // Debug state
         if state == EmulatorState::Debugging {
             for sim_id in SimId::values() {
                 let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
                     continue;
                 };
-                if let Some(reason) = sim.stop_reason() {
+                if let Some(reason) = sim.take_stop_reason() {
                     let stop_reason = match reason {
                         StopReason::Stepped => DebugStopReason::Trace,
                         StopReason::Watchpoint(watch, address) => {
@@ -494,9 +534,12 @@ impl Emulator {
             let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
                 continue;
             };
-            if sim.read_pixels(&mut self.eye_contents) {
+            if sim.read_pixels(&mut self.eye_contents[sim_id.to_index()]) {
                 idle = false;
-                if renderer.queue_render(&self.eye_contents).is_err() {
+                if renderer
+                    .queue_render(&self.eye_contents[sim_id.to_index()])
+                    .is_err()
+                {
                     self.renderers.remove(&sim_id);
                 }
             }
@@ -529,6 +572,19 @@ impl Emulator {
         idle
     }
 
+    fn emulate(&mut self, p1_running: bool, p2_running: bool) -> u32 {
+        const MAX_CYCLES: u32 = 20_000_000;
+        let mut cycles = MAX_CYCLES;
+        if p1_running && p2_running {
+            Sim::emulate_many(&mut self.sims, &mut cycles);
+        } else if p1_running {
+            self.sims[SimId::Player1.to_index()].emulate(&mut cycles);
+        } else if p2_running {
+            self.sims[SimId::Player2.to_index()].emulate(&mut cycles);
+        }
+        MAX_CYCLES - cycles
+    }
+
     fn handle_command(&mut self, command: EmulatorCommand) {
         match command {
             EmulatorCommand::ConnectToSim(sim_id, renderer, messages) => {
@@ -567,6 +623,16 @@ impl Emulator {
             EmulatorCommand::FrameAdvance => {
                 self.frame_advance();
             }
+            EmulatorCommand::SetSpeed(speed) => {
+                if let Err(error) = self.set_speed(speed) {
+                    self.report_error(SimId::Player1, format!("Error setting speed: {error}"));
+                }
+            }
+            EmulatorCommand::StartProfiling(sim_id, profiler) => {
+                if let Err(error) = self.start_profiling(sim_id, profiler) {
+                    self.report_error(SimId::Player1, format!("Error enaling profiler: {error}"));
+                }
+            }
             EmulatorCommand::StartDebugging(sim_id, debugger) => {
                 self.start_debugging(sim_id, debugger);
             }
@@ -636,6 +702,13 @@ impl Emulator {
                 };
                 sim.remove_watchpoint(address, length, watch);
             }
+            EmulatorCommand::WatchStdout(sim_id, stdout_sink) => {
+                self.stdouts.insert(sim_id, stdout_sink);
+                let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
+                    return;
+                };
+                sim.watch_stdout(true);
+            }
             EmulatorCommand::SetAudioEnabled(p1, p2) => {
                 self.audio_on[SimId::Player1.to_index()].store(p1, Ordering::Release);
                 self.audio_on[SimId::Player2.to_index()].store(p2, Ordering::Release);
@@ -656,6 +729,10 @@ impl Emulator {
                     sim.set_keys(keys);
                 }
             }
+            EmulatorCommand::Screenshot(sim_id, sender) => {
+                let contents = self.eye_contents[sim_id.to_index()].clone();
+                let _ = sender.send(contents);
+            }
             EmulatorCommand::Exit(done) => {
                 for sim_id in SimId::values() {
                     if let Err(error) = self.save_sram(sim_id) {
@@ -673,10 +750,8 @@ impl Emulator {
             .get(&sim_id)
             .or_else(|| self.messages.get(&SimId::Player1));
         if let Some(msg) = messages {
-            let toast = Toast::new()
-                .kind(ToastKind::Error)
-                .options(ToastOptions::default().duration_in_seconds(5.0))
-                .text(&message);
+            let mut toast = Toast::error(&message);
+            toast.duration(Some(Duration::from_secs(5)));
             if msg.send(toast).is_ok() {
                 return;
             }
@@ -694,6 +769,8 @@ pub enum EmulatorCommand {
     Pause,
     Resume,
     FrameAdvance,
+    SetSpeed(f64),
+    StartProfiling(SimId, ProfileSender),
     StartDebugging(SimId, DebugSender),
     StopDebugging(SimId),
     DebugInterrupt(SimId),
@@ -708,11 +785,13 @@ pub enum EmulatorCommand {
     RemoveBreakpoint(SimId, u32),
     AddWatchpoint(SimId, u32, usize, VBWatchpointType),
     RemoveWatchpoint(SimId, u32, usize, VBWatchpointType),
+    WatchStdout(SimId, mpsc::Sender<String>),
     SetAudioEnabled(bool, bool),
     Link,
     Unlink,
     Reset(SimId),
     SetKeys(SimId, VBKey),
+    Screenshot(SimId, oneshot::Sender<Vec<u8>>),
     Exit(oneshot::Sender<()>),
 }
 
@@ -733,6 +812,7 @@ pub enum EmulatorState {
     Debugging,
 }
 
+type ProfileSender = tokio::sync::mpsc::UnboundedSender<ProfileEvent>;
 type DebugSender = tokio::sync::mpsc::UnboundedSender<DebugEvent>;
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
@@ -756,6 +836,16 @@ pub enum DebugEvent {
     Stopped(DebugStopReason),
 }
 
+pub enum ProfileEvent {
+    Start {
+        file_path: PathBuf,
+    },
+    Update {
+        cycles: u32,
+        event: Option<SimEvent>,
+    },
+}
+
 #[derive(Clone)]
 pub struct EmulatorClient {
     queue: mpsc::Sender<EmulatorCommand>,

src/emulator/cart.rs

@@ -0,0 +1,81 @@
+use anyhow::Result;
+use rand::Rng;
+use std::{
+    fs::{self, File},
+    io::{Read, Seek as _, SeekFrom, Write as _},
+    path::{Path, PathBuf},
+};
+
+use crate::emulator::SimId;
+
+pub struct Cart {
+    pub file_path: PathBuf,
+    pub rom: Vec<u8>,
+    sram_file: File,
+    pub sram: Vec<u8>,
+}
+
+impl Cart {
+    pub fn load(file_path: &Path, sim_id: SimId) -> Result<Self> {
+        let rom = fs::read(file_path)?;
+        let rom = try_parse_elf(&rom).unwrap_or(rom);
+
+        let mut sram_file = File::options()
+            .read(true)
+            .write(true)
+            .create(true)
+            .truncate(false)
+            .open(sram_path(file_path, sim_id))?;
+
+        let sram = if sram_file.metadata()?.len() == 0 {
+            // new SRAM file, randomize the contents
+            let mut sram = vec![0; 16 * 1024];
+            let mut rng = rand::rng();
+            for dst in sram.iter_mut().step_by(2) {
+                *dst = rng.random();
+            }
+            sram
+        } else {
+            let mut sram = Vec::with_capacity(16 * 1024);
+            sram_file.read_to_end(&mut sram)?;
+            sram
+        };
+
+        Ok(Cart {
+            file_path: file_path.to_path_buf(),
+            rom,
+            sram_file,
+            sram,
+        })
+    }
+
+    pub fn save_sram(&mut self) -> Result<()> {
+        self.sram_file.seek(SeekFrom::Start(0))?;
+        self.sram_file.write_all(&self.sram)?;
+        Ok(())
+    }
+}
+
+fn try_parse_elf(data: &[u8]) -> Option<Vec<u8>> {
+    let parsed = elf::ElfBytes::<elf::endian::AnyEndian>::minimal_parse(data).ok()?;
+    let mut bytes = vec![];
+    let mut pstart = None;
+    for phdr in parsed.segments()? {
+        if phdr.p_filesz == 0 {
+            continue;
+        }
+        let start = pstart.unwrap_or(phdr.p_paddr);
+        pstart = Some(start);
+        bytes.resize((phdr.p_paddr - start) as usize, 0);
+        let data = parsed.segment_data(&phdr).ok()?;
+        bytes.extend_from_slice(data);
+    }
+    Some(bytes)
+}
+
+fn sram_path(file_path: &Path, sim_id: SimId) -> PathBuf {
+    match sim_id {
+        SimId::Player1 => file_path.with_extension("p1.sram"),
+        SimId::Player2 => file_path.with_extension("p2.sram"),
+    }
+}

src/emulator/shrooms_vb_core.rs

@@ -1,6 +1,6 @@
 use std::{ffi::c_void, ptr, slice};
 
-use anyhow::{anyhow, Result};
+use anyhow::{Result, anyhow};
 use bitflags::bitflags;
 use num_derive::{FromPrimitive, ToPrimitive};
 use serde::{Deserialize, Serialize};
@@ -71,8 +71,16 @@ pub enum VBWatchpointType {
     Access,
 }
 
+type OnException = extern "C" fn(sim: *mut VB, cause: *mut u16) -> c_int;
 type OnExecute =
     extern "C" fn(sim: *mut VB, address: u32, code: *const u16, length: c_int) -> c_int;
+type OnFetch = extern "C" fn(
+    sim: *mut VB,
+    fetch: c_int,
+    address: u32,
+    value: *mut i32,
+    cycles: *mut u32,
+) -> c_int;
 type OnFrame = extern "C" fn(sim: *mut VB) -> c_int;
 type OnRead = extern "C" fn(
     sim: *mut VB,
@@ -91,7 +99,7 @@ type OnWrite = extern "C" fn(
 ) -> c_int;
 
 #[link(name = "vb")]
-extern "C" {
+unsafe extern "C" {
     #[link_name = "vbEmulate"]
     fn vb_emulate(sim: *mut VB, cycles: *mut u32) -> c_int;
     #[link_name = "vbEmulateEx"]
@@ -135,8 +143,15 @@ extern "C" {
     fn vb_set_cart_ram(sim: *mut VB, sram: *mut c_void, size: u32) -> c_int;
     #[link_name = "vbSetCartROM"]
     fn vb_set_cart_rom(sim: *mut VB, rom: *mut c_void, size: u32) -> c_int;
+    #[link_name = "vbSetExceptionCallback"]
+    fn vb_set_exception_callback(
+        sim: *mut VB,
+        callback: Option<OnException>,
+    ) -> Option<OnException>;
     #[link_name = "vbSetExecuteCallback"]
     fn vb_set_execute_callback(sim: *mut VB, callback: Option<OnExecute>) -> Option<OnExecute>;
+    #[link_name = "vbSetFetchCallback"]
+    fn vb_set_fetch_callback(sim: *mut VB, callback: Option<OnFetch>) -> Option<OnFetch>;
     #[link_name = "vbSetFrameCallback"]
     fn vb_set_frame_callback(sim: *mut VB, callback: Option<OnFrame>) -> Option<OnFrame>;
     #[link_name = "vbSetKeys"]
@@ -170,7 +185,7 @@ extern "C" {
     fn vb_write(sim: *mut VB, address: u32, _type: VBDataType, value: i32) -> i32;
 }
 
-#[no_mangle]
+#[unsafe(no_mangle)]
 extern "C" fn on_frame(sim: *mut VB) -> c_int {
     // SAFETY: the *mut VB owns its userdata.
     // There is no way for the userdata to be null or otherwise invalid.
@@ -179,13 +194,23 @@ extern "C" fn on_frame(sim: *mut VB) -> c_int {
     1
 }
 
-#[no_mangle]
-extern "C" fn on_execute(sim: *mut VB, address: u32, _code: *const u16, _length: c_int) -> c_int {
+#[unsafe(no_mangle)]
+extern "C" fn on_execute(sim: *mut VB, address: u32, code: *const u16, length: c_int) -> c_int {
     // SAFETY: the *mut VB owns its userdata.
     // There is no way for the userdata to be null or otherwise invalid.
     let data: &mut VBState = unsafe { &mut *vb_get_user_data(sim).cast() };
 
-    let mut stopped = data.stop_reason.is_some();
+    if data.monitor.enabled {
+        // SAFETY: length is the length of code, in elements
+        let code = unsafe { slice::from_raw_parts(code, length as usize) };
+        if data.monitor.detect_event(sim, address, code) {
+            // Something interesting will happen after this instruction is run.
+            // The on_fetch callback will fire when it does.
+            unsafe { vb_set_fetch_callback(sim, Some(on_fetch)) };
+        }
+    }
+
+    let mut stopped = data.stop_reason.is_some() || data.monitor.event.is_some();
     if data.step_from.is_some_and(|s| s != address) {
         data.step_from = None;
         data.stop_reason = Some(StopReason::Stepped);
@@ -196,14 +221,45 @@ extern "C" fn on_execute(sim: *mut VB, address: u32, _code: *const u16, _length:
         stopped = true;
     }
 
-    if stopped {
-        1
-    } else {
-        0
-    }
+    if stopped { 1 } else { 0 }
 }
 
-#[no_mangle]
+#[unsafe(no_mangle)]
+extern "C" fn on_fetch(
+    sim: *mut VB,
+    _fetch: c_int,
+    _address: u32,
+    _value: *mut i32,
+    _cycles: *mut u32,
+) -> c_int {
+    // SAFETY: the *mut VB owns its userdata.
+    // There is no way for the userdata to be null or otherwise invalid.
+    let data: &mut VBState = unsafe { &mut *vb_get_user_data(sim).cast() };
+    data.monitor.event = data.monitor.queued_event.take();
+    unsafe { vb_set_exception_callback(sim, Some(on_exception)) };
+    unsafe { vb_set_fetch_callback(sim, None) };
+    1
+}
+
+#[unsafe(no_mangle)]
+extern "C" fn on_exception(sim: *mut VB, cause: *mut u16) -> c_int {
+    // SAFETY: the *mut VB owns its userdata.
+    // There is no way for the userdata to be null or otherwise invalid.
+    let data: &mut VBState = unsafe { &mut *vb_get_user_data(sim).cast() };
+    data.monitor.event = data.monitor.queued_event.take();
+    let cause = unsafe { *cause };
+    let pc = if cause == 0xff70 {
+        0xffffff60
+    } else {
+        (cause & 0xfff0) as u32 | 0xffff0000
+    };
+    data.monitor.queued_event = Some(SimEvent::Interrupt(cause, pc));
+    unsafe { vb_set_exception_callback(sim, None) };
+    unsafe { vb_set_fetch_callback(sim, Some(on_fetch)) };
+    if data.monitor.event.is_some() { 1 } else { 0 }
+}
+
+#[unsafe(no_mangle)]
 extern "C" fn on_read(
     sim: *mut VB,
     address: u32,
@@ -229,12 +285,12 @@ extern "C" fn on_read(
     0
 }
 
-#[no_mangle]
+#[unsafe(no_mangle)]
 extern "C" fn on_write(
     sim: *mut VB,
     address: u32,
     _type: VBDataType,
-    _value: *mut i32,
+    value: *mut i32,
     _cycles: *mut u32,
     _cancel: *mut c_int,
 ) -> c_int {
@@ -242,6 +298,14 @@ extern "C" fn on_write(
     // There is no way for the userdata to be null or otherwise invalid.
     let data: &mut VBState = unsafe { &mut *vb_get_user_data(sim).cast() };
 
+    // If we're monitoring stdout, track this write
+    if let Some(stdout) = data.stdout.as_mut() {
+        let normalized_hw_address = address & 0x0700003f;
+        if normalized_hw_address == 0x02000030 {
+            stdout.push(unsafe { *value } as u8);
+        }
+    }
+
     if let Some(start) = data.write_watchpoints.start_of_range_containing(address) {
         let watch = if data.read_watchpoints.contains(address) {
             VBWatchpointType::Access
@@ -256,6 +320,99 @@ extern "C" fn on_write(
     0
 }
 
+#[allow(dead_code)]
+#[derive(Debug)]
+pub enum SimEvent {
+    Call(u32),
+    Return,
+    Halt,
+    Interrupt(u16, u32),
+    Reti,
+}
+
+struct EventMonitor {
+    enabled: bool,
+    event: Option<SimEvent>,
+    queued_event: Option<SimEvent>,
+    just_halted: bool,
+}
+
+impl EventMonitor {
+    fn new() -> Self {
+        Self {
+            enabled: false,
+            event: None,
+            queued_event: None,
+            just_halted: false,
+        }
+    }
+
+    fn detect_event(&mut self, sim: *mut VB, address: u32, code: &[u16]) -> bool {
+        self.queued_event = self.do_detect_event(sim, address, code);
+        self.queued_event.is_some()
+    }
+
+    fn do_detect_event(&mut self, sim: *mut VB, address: u32, code: &[u16]) -> Option<SimEvent> {
+        const HALT_OPCODE: u16 = 0b011010;
+        const JAL_OPCODE: u16 = 0b101011;
+        const JMP_OPCODE: u16 = 0b000110;
+        const RETI_OPCODE: u16 = 0b011001;
+
+        const fn format_i_reg_1(code: &[u16]) -> u8 {
+            (code[0] & 0x1f) as u8
+        }
+
+        const fn format_iv_disp(code: &[u16]) -> i32 {
+            let value = ((code[0] & 0x3ff) as i32) << 16 | (code[1] as i32);
+            value << 6 >> 6
+        }
+
+        let opcode = code[0] >> 10;
+
+        if opcode == HALT_OPCODE {
+            if !self.just_halted {
+                self.just_halted = true;
+                self.event = Some(SimEvent::Halt);
+            } else {
+                self.just_halted = false;
+            }
+            // Don't _return_ an event, we want to emit this right away.
+            // If the CPU is halting, no other callbacks will run for a long time.
+            return None;
+        }
+
+        if opcode == JAL_OPCODE {
+            let disp = format_iv_disp(code);
+            if disp != 4 {
+                // JAL .+4 is how programs get r31 to a known value for indirect calls
+                // (which we detect later.)
+                // Any other JAL is a function call.
+                return Some(SimEvent::Call(address.wrapping_add_signed(disp)));
+            }
+        }
+
+        if opcode == JMP_OPCODE {
+            let jmp_reg = format_i_reg_1(code);
+            if jmp_reg == 31 {
+                // JMP[r31] is a return
+                return Some(SimEvent::Return);
+            }
+            let r31 = unsafe { vb_get_program_register(sim, 31) };
+            if r31 as u32 == address.wrapping_add(2) {
+                // JMP anywhere else, if r31 points to after the JMP, is an indirect call
+                let target = unsafe { vb_get_program_register(sim, jmp_reg as u32) };
+                return Some(SimEvent::Call(target as u32));
+            }
+        }
+
+        if opcode == RETI_OPCODE {
+            return Some(SimEvent::Reti);
+        }
+
+        None
+    }
+}
+
 const AUDIO_CAPACITY_SAMPLES: usize = 834 * 4;
 const AUDIO_CAPACITY_FLOATS: usize = AUDIO_CAPACITY_SAMPLES * 2;
 pub const EXPECTED_FRAME_SIZE: usize = 834 * 2;
@@ -263,15 +420,18 @@ pub const EXPECTED_FRAME_SIZE: usize = 834 * 2;
 struct VBState {
     frame_seen: bool,
     stop_reason: Option<StopReason>,
+    monitor: EventMonitor,
     step_from: Option<u32>,
     breakpoints: Vec<u32>,
     read_watchpoints: AddressSet,
     write_watchpoints: AddressSet,
+    stdout: Option<Vec<u8>>,
 }
 
 impl VBState {
     fn needs_execute_callback(&self) -> bool {
         self.step_from.is_some()
+            || self.monitor.enabled
             || !self.breakpoints.is_empty()
             || !self.read_watchpoints.is_empty()
             || !self.write_watchpoints.is_empty()
@@ -306,10 +466,12 @@ impl Sim {
         let state = VBState {
             frame_seen: false,
             stop_reason: None,
+            monitor: EventMonitor::new(),
             step_from: None,
             breakpoints: vec![],
             read_watchpoints: AddressSet::new(),
             write_watchpoints: AddressSet::new(),
+            stdout: None,
         };
         unsafe { vb_set_user_data(sim, Box::into_raw(Box::new(state)).cast()) };
         unsafe { vb_set_frame_callback(sim, Some(on_frame)) };
@@ -326,6 +488,23 @@ impl Sim {
         unsafe { vb_reset(self.sim) };
     }
 
+    pub fn monitor_events(&mut self, enabled: bool) {
+        let state = self.get_state();
+        state.monitor.enabled = enabled;
+        state.monitor.event = None;
+        state.monitor.queued_event = None;
+        if enabled {
+            unsafe { vb_set_execute_callback(self.sim, Some(on_execute)) };
+            unsafe { vb_set_exception_callback(self.sim, Some(on_exception)) };
+        } else {
+            if !state.needs_execute_callback() {
+                unsafe { vb_set_execute_callback(self.sim, None) };
+            }
+            unsafe { vb_set_exception_callback(self.sim, None) };
+            unsafe { vb_set_fetch_callback(self.sim, None) };
+        }
+    }
+
     pub fn load_cart(&mut self, mut rom: Vec<u8>, mut sram: Vec<u8>) -> Result<()> {
         self.unload_cart();
 
@@ -388,16 +567,14 @@ impl Sim {
         unsafe { vb_set_peer(self.sim, ptr::null_mut()) };
     }
 
-    pub fn emulate(&mut self) {
-        let mut cycles = 20_000_000;
-        unsafe { vb_emulate(self.sim, &mut cycles) };
+    pub fn emulate(&mut self, cycles: &mut u32) {
+        unsafe { vb_emulate(self.sim, cycles) };
     }
 
-    pub fn emulate_many(sims: &mut [Sim]) {
-        let mut cycles = 20_000_000;
+    pub fn emulate_many(sims: &mut [Sim], cycles: &mut u32) {
         let count = sims.len() as c_uint;
         let sims = sims.as_mut_ptr().cast();
-        unsafe { vb_emulate_ex(sims, count, &mut cycles) };
+        unsafe { vb_emulate_ex(sims, count, cycles) };
     }
 
     pub fn read_pixels(&mut self, buffers: &mut [u8]) -> bool {
@@ -568,7 +745,9 @@ impl Sim {
         state.write_watchpoints.remove(address, length);
         let needs_execute = state.needs_execute_callback();
         if state.write_watchpoints.is_empty() {
-            unsafe { vb_set_write_callback(self.sim, None) };
+            if state.stdout.is_none() {
+                unsafe { vb_set_write_callback(self.sim, None) };
+            }
             if !needs_execute {
                 unsafe { vb_set_execute_callback(self.sim, None) };
             }
@@ -590,12 +769,41 @@ impl Sim {
         data.breakpoints.clear();
         data.read_watchpoints.clear();
         data.write_watchpoints.clear();
+        let needs_write = data.stdout.is_some();
         unsafe { vb_set_read_callback(self.sim, None) };
-        unsafe { vb_set_write_callback(self.sim, None) };
+        if !needs_write {
+            unsafe { vb_set_write_callback(self.sim, None) };
+        }
         unsafe { vb_set_execute_callback(self.sim, None) };
     }
 
-    pub fn stop_reason(&mut self) -> Option<StopReason> {
+    pub fn watch_stdout(&mut self, watch: bool) {
+        let data = self.get_state();
+        if watch {
+            if data.stdout.is_none() {
+                data.stdout = Some(vec![]);
+                unsafe { vb_set_write_callback(self.sim, Some(on_write)) };
+            }
+        } else {
+            data.stdout.take();
+            if data.write_watchpoints.is_empty() {
+                unsafe { vb_set_write_callback(self.sim, None) };
+            }
+        }
+    }
+
+    pub fn take_stdout(&mut self) -> Option<String> {
+        let data = self.get_state();
+        let stdout = data.stdout.take()?;
+        let string = match String::from_utf8(stdout) {
+            Ok(str) => str,
+            Err(err) => String::from_utf8_lossy(err.as_bytes()).into_owned(),
+        };
+        data.stdout = Some(vec![]);
+        Some(string)
+    }
+
+    pub fn take_stop_reason(&mut self) -> Option<StopReason> {
         let data = self.get_state();
         let reason = data.stop_reason.take();
         if !data.needs_execute_callback() {
@@ -604,6 +812,11 @@ impl Sim {
         reason
     }
 
+    pub fn take_sim_event(&mut self) -> Option<SimEvent> {
+        let data = self.get_state();
+        data.monitor.event.take()
+    }
+
     fn get_state(&mut self) -> &mut VBState {
         // SAFETY: the *mut VB owns its userdata.
         // There is no way for the userdata to be null or otherwise invalid.

src/gdbserver.rs

@@ -1,4 +1,4 @@
-use anyhow::{bail, Result};
+use anyhow::{Result, bail};
 use registers::REGISTERS;
 use request::{Request, RequestKind, RequestSource};
 use response::Response;
@@ -12,7 +12,7 @@ use tokio::{
     pin, select,
     sync::{mpsc, oneshot},
 };
-use tracing::{debug, enabled, error, info, Level};
+use tracing::{Level, debug, enabled, error, info};
 
 use crate::emulator::{
     DebugEvent, DebugStopReason, EmulatorClient, EmulatorCommand, SimId, VBWatchpointType,

src/gdbserver/registers.rs

@@ -12,7 +12,7 @@ impl RegisterInfo {
     pub fn to_description(&self) -> String {
         let mut string = format!("name:{}", self.name);
         if let Some(alt) = self.alt_name {
-            string.push_str(&format!(";alt-name:{}", alt));
+            string.push_str(&format!(";alt-name:{alt}"));
         }
         string.push_str(&format!(
             ";bitsize:32;offset:{};encoding:uint;format:hex;set:{};dwarf:{}",
@@ -21,7 +21,7 @@ impl RegisterInfo {
             self.dwarf
         ));
         if let Some(generic) = self.generic {
-            string.push_str(&format!(";generic:{}", generic));
+            string.push_str(&format!(";generic:{generic}"));
         }
         string
     }

src/gdbserver/request.rs

@@ -1,4 +1,4 @@
-use anyhow::{bail, Result};
+use anyhow::{Result, bail};
 use atoi::FromRadix16;
 use tokio::io::{AsyncRead, AsyncReadExt as _};
 

src/graphics.rs

@@ -1,15 +1,16 @@
 use std::{
     sync::{
+        Arc, Mutex, MutexGuard,
         atomic::{AtomicU64, Ordering},
-        mpsc, Arc, Mutex, MutexGuard,
+        mpsc,
     },
     thread,
 };
 
-use anyhow::{bail, Result};
+use anyhow::{Result, bail};
 use itertools::Itertools as _;
 use wgpu::{
-    Device, Extent3d, ImageCopyTexture, ImageDataLayout, Origin3d, Queue, Texture,
+    Device, Extent3d, Origin3d, Queue, TexelCopyBufferLayout, TexelCopyTextureInfo, Texture,
     TextureDescriptor, TextureFormat, TextureUsages, TextureView, TextureViewDescriptor,
 };
 
@@ -20,7 +21,7 @@ pub struct TextureSink {
 }
 
 impl TextureSink {
-    pub fn new(device: &Device, queue: Arc<Queue>) -> (Self, TextureView) {
+    pub fn new(device: &Device, queue: Queue) -> (Self, TextureView) {
         let texture = Self::create_texture(device);
         let view = texture.create_view(&TextureViewDescriptor::default());
         let buffers = Arc::new(BufferPool::new());
@@ -71,7 +72,7 @@ impl TextureSink {
     }
 
     fn write_texture(queue: &Queue, texture: &Texture, bytes: &[u8]) {
-        let texture = ImageCopyTexture {
+        let texture = TexelCopyTextureInfo {
             texture,
             mip_level: 0,
             origin: Origin3d::ZERO,
@@ -82,7 +83,7 @@ impl TextureSink {
             height: 224,
             depth_or_array_layers: 1,
         };
-        let data_layout = ImageDataLayout {
+        let data_layout = TexelCopyBufferLayout {
             offset: 0,
             bytes_per_row: Some(384 * 2),
             rows_per_image: Some(224),

src/images.rs

@@ -7,9 +7,9 @@ use std::{
 };
 
 use egui::{
+    Color32, ColorImage, TextureHandle, TextureOptions,
     epaint::ImageDelta,
     load::{LoadError, SizedTexture, TextureLoader, TexturePoll},
-    Color32, ColorImage, TextureHandle, TextureOptions,
 };
 use tokio::{sync::mpsc, time::timeout};
 
@@ -193,8 +193,8 @@ struct ImageState {
 impl ImageState {
     fn new(size: [usize; 2]) -> Self {
         let buffers = [
-            Arc::new(ColorImage::new(size, Color32::BLACK)),
-            Arc::new(ColorImage::new(size, Color32::BLACK)),
+            Arc::new(ColorImage::filled(size, Color32::BLACK)),
+            Arc::new(ColorImage::filled(size, Color32::BLACK)),
         ];
         let sink = buffers[0].clone();
         Self {

src/input.rs

@@ -1,12 +1,14 @@
 use std::{
-    collections::{hash_map::Entry, HashMap},
+    cmp::Ordering,
+    collections::{HashMap, hash_map::Entry},
     fmt::Display,
     str::FromStr,
-    sync::{Arc, RwLock},
+    sync::{Arc, Mutex, RwLock},
 };
 
 use anyhow::anyhow;
-use gilrs::{ev::Code, Axis, Button, Gamepad, GamepadId};
+use egui::{Event, Key, KeyboardShortcut, Modifiers};
+use gilrs::{Axis, Button, Gamepad, GamepadId, ev::Code};
 use serde::{Deserialize, Serialize};
 use winit::keyboard::{KeyCode, PhysicalKey};
 
@@ -225,7 +227,7 @@ impl Mappings for InputMapping {
         for (keyboard_key, keys) in &self.keys {
             let name = match keyboard_key {
                 PhysicalKey::Code(code) => format!("{code:?}"),
-                k => format!("{:?}", k),
+                k => format!("{k:?}"),
             };
             for key in keys.iter() {
                 results.entry(key).or_default().push(name.clone());
@@ -454,3 +456,315 @@ struct PersistedGamepadMapping {
     default_buttons: Vec<(Code, VBKey)>,
     default_axes: Vec<(Code, (VBKey, VBKey))>,
 }
+
+#[derive(Serialize, Deserialize)]
+pub struct Shortcut {
+    pub shortcut: KeyboardShortcut,
+    pub command: Command,
+}
+
+#[derive(Clone, Copy, Serialize, Deserialize, PartialEq, Eq, Hash)]
+pub enum Command {
+    OpenRom,
+    Quit,
+    FrameAdvance,
+    FastForward(u32),
+    Reset,
+    PauseResume,
+    Screenshot,
+    // if you update this, update Command::all and add a default
+}
+
+impl Command {
+    pub fn all() -> [Self; 7] {
+        [
+            Self::OpenRom,
+            Self::Quit,
+            Self::PauseResume,
+            Self::Reset,
+            Self::FrameAdvance,
+            Self::FastForward(0),
+            Self::Screenshot,
+        ]
+    }
+
+    pub fn name(self) -> &'static str {
+        match self {
+            Self::OpenRom => "Open ROM",
+            Self::Quit => "Exit",
+            Self::PauseResume => "Pause/Resume",
+            Self::Reset => "Reset",
+            Self::FrameAdvance => "Frame Advance",
+            Self::FastForward(_) => "Fast Forward",
+            Self::Screenshot => "Screenshot",
+        }
+    }
+}
+
+impl Display for Command {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(self.name())
+    }
+}
+
+struct Shortcuts {
+    all: Vec<(Command, KeyboardShortcut)>,
+    by_command: HashMap<Command, KeyboardShortcut>,
+}
+
+impl Default for Shortcuts {
+    fn default() -> Self {
+        let mut shortcuts = Shortcuts {
+            all: vec![],
+            by_command: HashMap::new(),
+        };
+        shortcuts.set(
+            Command::OpenRom,
+            KeyboardShortcut::new(Modifiers::COMMAND, Key::O),
+        );
+        shortcuts.set(
+            Command::Quit,
+            KeyboardShortcut::new(Modifiers::COMMAND, Key::Q),
+        );
+        shortcuts.set(
+            Command::PauseResume,
+            KeyboardShortcut::new(Modifiers::NONE, Key::F5),
+        );
+        shortcuts.set(
+            Command::Reset,
+            KeyboardShortcut::new(Modifiers::SHIFT, Key::F5),
+        );
+        shortcuts.set(
+            Command::FrameAdvance,
+            KeyboardShortcut::new(Modifiers::NONE, Key::F6),
+        );
+        shortcuts.set(
+            Command::FastForward(0),
+            KeyboardShortcut::new(Modifiers::NONE, Key::Space),
+        );
+        shortcuts.set(
+            Command::Screenshot,
+            KeyboardShortcut::new(Modifiers::NONE, Key::F12),
+        );
+        shortcuts
+    }
+}
+
+impl Shortcuts {
+    fn set(&mut self, command: Command, shortcut: KeyboardShortcut) {
+        if self.by_command.insert(command, shortcut).is_some() {
+            for (cmd, sht) in &mut self.all {
+                if *cmd == command {
+                    *sht = shortcut;
+                    break;
+                }
+            }
+        } else {
+            self.all.push((command, shortcut));
+        }
+        self.all.sort_by(|l, r| order_shortcut(l.1, r.1));
+    }
+
+    fn unset(&mut self, command: Command) {
+        if self.by_command.remove(&command).is_some() {
+            self.all.retain(|(c, _)| *c != command);
+        }
+    }
+
+    fn save(&self, saved: &mut PersistedSettings) {
+        for command in Command::all() {
+            let shortcut = self.by_command.get(&command).copied();
+            saved.shortcuts.push((command, shortcut));
+        }
+    }
+}
+
+fn order_shortcut(left: KeyboardShortcut, right: KeyboardShortcut) -> Ordering {
+    left.logical_key.cmp(&right.logical_key).then_with(|| {
+        specificity(left.modifiers)
+            .cmp(&specificity(right.modifiers))
+            .reverse()
+    })
+}
+
+fn specificity(modifiers: egui::Modifiers) -> usize {
+    let mut mods = 0;
+    if modifiers.alt {
+        mods += 1;
+    }
+    if modifiers.command || modifiers.ctrl {
+        mods += 1;
+    }
+    if modifiers.shift {
+        mods += 1;
+    }
+    mods
+}
+
+#[derive(Serialize, Deserialize, Default)]
+struct PersistedSettings {
+    shortcuts: Vec<(Command, Option<KeyboardShortcut>)>,
+    #[serde(default)]
+    ff_settings: FastForwardSettings,
+}
+
+#[derive(Default, Clone)]
+struct ShortcutState {
+    ff_toggled: bool,
+}
+
+#[derive(Default)]
+struct Settings {
+    shortcuts: Shortcuts,
+    ff_settings: FastForwardSettings,
+    state: ShortcutState,
+}
+
+impl Settings {
+    fn save(&self) -> PersistedSettings {
+        let mut saved = PersistedSettings {
+            shortcuts: vec![],
+            ff_settings: self.ff_settings.clone(),
+        };
+        self.shortcuts.save(&mut saved);
+        saved
+    }
+}
+
+#[derive(Clone)]
+pub struct ShortcutProvider {
+    persistence: Persistence,
+    settings: Arc<Mutex<Settings>>,
+}
+
+impl ShortcutProvider {
+    pub fn new(persistence: Persistence) -> Self {
+        let mut settings = Settings::default();
+        if let Ok(saved) = persistence.load_config::<PersistedSettings>("shortcuts") {
+            for (command, shortcut) in saved.shortcuts {
+                if let Some(shortcut) = shortcut {
+                    settings.shortcuts.set(command, shortcut);
+                } else {
+                    settings.shortcuts.unset(command);
+                }
+            }
+            settings.ff_settings = saved.ff_settings;
+        };
+        Self {
+            persistence,
+            settings: Arc::new(Mutex::new(settings)),
+        }
+    }
+
+    pub fn shortcut_for(&self, command: Command) -> Option<KeyboardShortcut> {
+        let lock = self.settings.lock().unwrap();
+        lock.shortcuts.by_command.get(&command).copied()
+    }
+
+    pub fn ff_settings(&self) -> FastForwardSettings {
+        let lock = self.settings.lock().unwrap();
+        lock.ff_settings.clone()
+    }
+
+    pub fn consume_all(&self, input: &mut egui::InputState) -> Vec<Command> {
+        let mut lock = self.settings.lock().unwrap();
+        let mut state = lock.state.clone();
+        let mut consumed = vec![];
+        for (command, shortcut) in &lock.shortcuts.all {
+            input.events.retain(|event| {
+                let Event::Key {
+                    key,
+                    pressed,
+                    repeat,
+                    modifiers,
+                    ..
+                } = event
+                else {
+                    return true;
+                };
+                if shortcut.logical_key != *key || !shortcut.modifiers.contains(*modifiers) {
+                    return true;
+                }
+                if matches!(command, Command::FastForward(_)) {
+                    if *repeat {
+                        return true;
+                    }
+                    let sped_up = if lock.ff_settings.toggle {
+                        if !*pressed {
+                            return true;
+                        }
+                        state.ff_toggled = !state.ff_toggled;
+                        state.ff_toggled
+                    } else {
+                        *pressed
+                    };
+                    let speed = if sped_up { lock.ff_settings.speed } else { 1 };
+                    consumed.push(Command::FastForward(speed));
+                    false
+                } else {
+                    if !*pressed {
+                        return true;
+                    }
+                    consumed.push(*command);
+                    false
+                }
+            });
+        }
+        lock.state = state;
+        consumed
+    }
+
+    pub fn set(&self, command: Command, shortcut: KeyboardShortcut) {
+        let updated = {
+            let mut lock = self.settings.lock().unwrap();
+            lock.shortcuts.set(command, shortcut);
+            lock.save()
+        };
+        let _ = self.persistence.save_config("shortcuts", &updated);
+    }
+
+    pub fn unset(&self, command: Command) {
+        let updated = {
+            let mut lock = self.settings.lock().unwrap();
+            lock.shortcuts.unset(command);
+            lock.save()
+        };
+        let _ = self.persistence.save_config("shortcuts", &updated);
+    }
+
+    pub fn update_ff_settings(&self, ff_settings: FastForwardSettings) {
+        let updated = {
+            let mut lock = self.settings.lock().unwrap();
+            lock.ff_settings = ff_settings;
+            if !lock.ff_settings.toggle {
+                lock.state.ff_toggled = false;
+            }
+            lock.save()
+        };
+        let _ = self.persistence.save_config("shortcuts", &updated);
+    }
+
+    pub fn reset(&self) {
+        let updated = {
+            let mut lock = self.settings.lock().unwrap();
+            *lock = Settings::default();
+            lock.save()
+        };
+        let _ = self.persistence.save_config("shortcuts", &updated);
+    }
+}
+
+#[derive(Serialize, Deserialize, Clone)]
+pub struct FastForwardSettings {
+    pub toggle: bool,
+    pub speed: u32,
+}
+
+impl Default for FastForwardSettings {
+    fn default() -> Self {
+        Self {
+            toggle: false,
+            speed: 10,
+        }
+    }
+}

src/main.rs

@@ -3,13 +3,13 @@
 
 use std::{path::PathBuf, process, time::SystemTime};
 
-use anyhow::{bail, Result};
+use anyhow::{Result, bail};
 use app::Application;
 use clap::Parser;
 use emulator::EmulatorBuilder;
 use thread_priority::{ThreadBuilder, ThreadPriority};
 use tracing::error;
-use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt, EnvFilter, Layer};
+use tracing_subscriber::{EnvFilter, Layer, layer::SubscriberExt, util::SubscriberInitExt};
 use winit::event_loop::{ControlFlow, EventLoop};
 
 mod app;
@@ -22,6 +22,7 @@ mod images;
 mod input;
 mod memory;
 mod persistence;
+mod profiler;
 mod window;
 
 #[derive(Parser)]
@@ -31,6 +32,9 @@ struct Args {
     /// Start a GDB/LLDB debug server on this port.
     #[arg(short, long)]
     debug_port: Option<u16>,
+    /// Enable profiling a game
+    #[arg(short, long)]
+    profile: bool,
 }
 
 fn init_logger() {
@@ -44,9 +48,9 @@ fn set_panic_handler() {
     std::panic::set_hook(Box::new(|info| {
         let mut message = String::new();
         if let Some(msg) = info.payload().downcast_ref::<&str>() {
-            message += &format!("{}\n", msg);
+            message += &format!("{msg}\n");
         } else if let Some(msg) = info.payload().downcast_ref::<String>() {
-            message += &format!("{}\n", msg);
+            message += &format!("{msg}\n");
         }
         if let Some(location) = info.location() {
             message += &format!(
@@ -56,9 +60,9 @@ fn set_panic_handler() {
             );
         }
         let backtrace = std::backtrace::Backtrace::force_capture();
-        message += &format!("stack trace:\n{:#}\n", backtrace);
+        message += &format!("stack trace:\n{backtrace:#}\n");
 
-        eprint!("{}", message);
+        eprint!("{message}");
 
         let Some(project_dirs) = directories::ProjectDirs::from("com", "virtual-boy", "Lemur")
         else {
@@ -72,7 +76,7 @@ fn set_panic_handler() {
             .duration_since(SystemTime::UNIX_EPOCH)
             .unwrap()
             .as_millis();
-        let logfile_name = format!("crash-{}.txt", timestamp);
+        let logfile_name = format!("crash-{timestamp}.txt");
         let _ = std::fs::write(data_dir.join(logfile_name), message);
     }));
 }
@@ -106,6 +110,9 @@ fn main() -> Result<()> {
         }
         builder = builder.start_paused(true);
     }
+    if args.profile {
+        builder = builder.start_paused(true)
+    }
 
     ThreadBuilder::default()
         .name("Emulator".to_owned())
@@ -124,6 +131,11 @@ fn main() -> Result<()> {
     let event_loop = EventLoop::with_user_event().build().unwrap();
     event_loop.set_control_flow(ControlFlow::Poll);
     let proxy = event_loop.create_proxy();
-    event_loop.run_app(&mut Application::new(client, proxy, args.debug_port))?;
+    event_loop.run_app(&mut Application::new(
+        client,
+        proxy,
+        args.debug_port,
+        args.profile,
+    ))?;
     Ok(())
 }

src/memory.rs

@@ -2,7 +2,7 @@ use std::{
     collections::HashMap,
     fmt::Debug,
     iter::FusedIterator,
-    sync::{atomic::AtomicU64, Arc, Mutex, RwLock, RwLockReadGuard, TryLockError, Weak},
+    sync::{Arc, Mutex, RwLock, RwLockReadGuard, TryLockError, Weak, atomic::AtomicU64},
 };
 
 use bytemuck::BoxBytes;
@@ -223,7 +223,7 @@ impl MemoryRegion {
                 .iter()
                 .map(|i| i.load(std::sync::atomic::Ordering::Acquire))
                 .enumerate()
-                .max_by_key(|(_, gen)| *gen)
+                .max_by_key(|(_, g)| *g)
                 .map(|(i, _)| i)
                 .unwrap();
             let inner = match self.bufs[newest_index].try_read() {

src/persistence.rs

@@ -1,6 +1,6 @@
 use std::{fs, path::PathBuf};
 
-use anyhow::{bail, Result};
+use anyhow::{Result, bail};
 use directories::ProjectDirs;
 use serde::{Deserialize, Serialize};
 

src/profiler.rs

@@ -0,0 +1,235 @@
+use std::{
+    path::PathBuf,
+    sync::{Arc, Mutex},
+    thread,
+};
+
+use anyhow::Result;
+use tokio::{select, sync::mpsc};
+
+use crate::emulator::{EmulatorClient, EmulatorCommand, ProfileEvent, SimEvent, SimId};
+use recording::Recording;
+use state::ProgramState;
+
+mod recording;
+mod state;
+mod symbols;
+
+pub struct Profiler {
+    sim_id: SimId,
+    client: EmulatorClient,
+    status: Arc<Mutex<ProfilerStatus>>,
+    action: Option<mpsc::UnboundedSender<RecordingAction>>,
+    killer: Option<oneshot::Sender<()>>,
+}
+
+impl Profiler {
+    pub fn new(sim_id: SimId, client: EmulatorClient) -> Self {
+        Self {
+            sim_id,
+            client,
+            status: Arc::new(Mutex::new(ProfilerStatus::Disabled)),
+            action: None,
+            killer: None,
+        }
+    }
+
+    pub fn status(&self) -> ProfilerStatus {
+        self.status.lock().unwrap().clone()
+    }
+
+    pub fn enable(&mut self) {
+        let sim_id = self.sim_id;
+        let client = self.client.clone();
+        let status = self.status.clone();
+        let (action_tx, action_rx) = mpsc::unbounded_channel();
+        self.action = Some(action_tx);
+        let (killer_tx, killer_rx) = oneshot::channel();
+        self.killer = Some(killer_tx);
+        thread::spawn(move || {
+            tokio::runtime::Builder::new_current_thread()
+                .enable_all()
+                .build()
+                .unwrap()
+                .block_on(async move {
+                    select! {
+                        _ = run_profile(sim_id, client, status.clone(), action_rx) => {}
+                        _ = killer_rx => {
+                            *status.lock().unwrap() = ProfilerStatus::Disabled;
+                        }
+                    }
+                })
+        });
+    }
+
+    pub fn disable(&mut self) {
+        if let Some(killer) = self.killer.take() {
+            let _ = killer.send(());
+        }
+    }
+
+    pub fn start_recording(&mut self) {
+        if let Some(action) = &self.action {
+            let _ = action.send(RecordingAction::Start);
+        }
+    }
+
+    pub fn finish_recording(&mut self) -> oneshot::Receiver<Vec<u8>> {
+        let (tx, rx) = oneshot::channel();
+        if let Some(action) = &self.action {
+            let _ = action.send(RecordingAction::Finish(tx));
+        }
+        rx
+    }
+
+    pub fn cancel_recording(&mut self) {
+        if let Some(action) = &self.action {
+            let _ = action.send(RecordingAction::Cancel);
+        }
+    }
+}
+
+impl Drop for Profiler {
+    fn drop(&mut self) {
+        self.disable();
+    }
+}
+
+async fn run_profile(
+    sim_id: SimId,
+    client: EmulatorClient,
+    status: Arc<Mutex<ProfilerStatus>>,
+    mut action_source: mpsc::UnboundedReceiver<RecordingAction>,
+) {
+    let (profile_sync, mut profile_source) = mpsc::unbounded_channel();
+    client.send_command(EmulatorCommand::StartProfiling(sim_id, profile_sync));
+
+    *status.lock().unwrap() = ProfilerStatus::Enabled;
+
+    let mut session = ProfilerSession::new();
+    loop {
+        select! {
+            maybe_event = profile_source.recv() => {
+                let Some(event) = maybe_event else {
+                    break; // emulator thread disconnected
+                };
+                if let Err(error) = handle_event(event, &mut session).await {
+                    *status.lock().unwrap() = ProfilerStatus::Error(error.to_string());
+                    return;
+                }
+            }
+            maybe_action = action_source.recv() => {
+                let Some(action) = maybe_action else {
+                    break; // ui thread disconnected
+                };
+                handle_action(action, &mut session, &status);
+            }
+        }
+    }
+
+    *status.lock().unwrap() = ProfilerStatus::Disabled;
+}
+
+async fn handle_event(event: ProfileEvent, session: &mut ProfilerSession) -> Result<()> {
+    match event {
+        ProfileEvent::Start { file_path } => session.start_profiling(file_path).await,
+        ProfileEvent::Update { cycles, event } => {
+            session.track_elapsed_cycles(cycles)?;
+            if let Some(event) = event {
+                session.track_event(event)?;
+            }
+            Ok(())
+        }
+    }
+}
+
+fn handle_action(
+    action: RecordingAction,
+    session: &mut ProfilerSession,
+    status: &Mutex<ProfilerStatus>,
+) {
+    match action {
+        RecordingAction::Start => {
+            session.start_recording();
+            *status.lock().unwrap() = ProfilerStatus::Recording;
+        }
+        RecordingAction::Finish(rx) => {
+            if let Some(bytes) = session.finish_recording() {
+                let _ = rx.send(bytes);
+            }
+            *status.lock().unwrap() = ProfilerStatus::Enabled;
+        }
+        RecordingAction::Cancel => {
+            session.cancel_recording();
+            *status.lock().unwrap() = ProfilerStatus::Enabled;
+        }
+    }
+}
+
+#[derive(Clone)]
+pub enum ProfilerStatus {
+    Disabled,
+    Enabled,
+    Recording,
+    Error(String),
+}
+
+impl ProfilerStatus {
+    pub fn enabled(&self) -> bool {
+        matches!(self, Self::Enabled | Self::Recording)
+    }
+}
+
+enum RecordingAction {
+    Start,
+    Finish(oneshot::Sender<Vec<u8>>),
+    Cancel,
+}
+
+struct ProfilerSession {
+    program: Option<ProgramState>,
+    recording: Option<Recording>,
+}
+
+impl ProfilerSession {
+    fn new() -> Self {
+        Self {
+            program: None,
+            recording: None,
+        }
+    }
+
+    async fn start_profiling(&mut self, file_path: PathBuf) -> Result<()> {
+        self.program = Some(ProgramState::new(file_path).await?);
+        self.recording = None;
+        Ok(())
+    }
+
+    fn track_elapsed_cycles(&mut self, cycles: u32) -> Result<()> {
+        if let (Some(state), Some(recording)) = (&self.program, &mut self.recording) {
+            recording.track_elapsed_cycles(state, cycles);
+        }
+        Ok(())
+    }
+
+    fn track_event(&mut self, event: SimEvent) -> Result<()> {
+        if let Some(program) = &mut self.program {
+            program.track_event(event)?;
+        }
+        Ok(())
+    }
+
+    fn start_recording(&mut self) {
+        if let Some(program) = &self.program {
+            self.recording = Some(Recording::new(program));
+        }
+    }
+
+    fn finish_recording(&mut self) -> Option<Vec<u8>> {
+        self.recording.take().map(|r| r.finish())
+    }
+
+    fn cancel_recording(&mut self) {
+        self.recording.take();
+    }
+}

src/profiler/recording.rs

@@ -0,0 +1,114 @@
+use std::collections::HashMap;
+
+use fxprof_processed_profile::{
+    CategoryHandle, CpuDelta, Frame, FrameFlags, FrameInfo, ProcessHandle, Profile,
+    ReferenceTimestamp, SamplingInterval, StackHandle, ThreadHandle, Timestamp,
+};
+
+use crate::profiler::state::{ProgramState, RESET_CODE, StackFrame};
+
+pub struct Recording {
+    profile: Profile,
+    process: ProcessHandle,
+    threads: HashMap<u16, ThreadHandle>,
+    now: u64,
+}
+
+impl Recording {
+    pub fn new(state: &ProgramState) -> Self {
+        let symbol_file = state.symbol_file();
+
+        let name = &symbol_file.name();
+        let reference_timestamp = ReferenceTimestamp::from_millis_since_unix_epoch(0.0);
+        let interval = SamplingInterval::from_hz(20_000_000.0);
+        let mut profile = Profile::new(name, reference_timestamp, interval);
+
+        let process = profile.add_process(name, 1, Timestamp::from_nanos_since_reference(0));
+
+        let lib = profile.add_lib(symbol_file.library_info().clone());
+        profile.add_lib_mapping(process, lib, 0x00000000, 0xffffffff, 0);
+
+        let mut me = Self {
+            profile,
+            process,
+            threads: HashMap::new(),
+            now: 0,
+        };
+        me.track_elapsed_cycles(state, 0);
+        me
+    }
+
+    pub fn track_elapsed_cycles(&mut self, state: &ProgramState, cycles: u32) {
+        self.now += cycles as u64;
+        let timestamp = Timestamp::from_nanos_since_reference(self.now * 50);
+        let weight = 1;
+
+        let active_code = if let Some((code, frames)) = state.current_stack() {
+            let thread = *self.threads.entry(code).or_insert_with(|| {
+                let process = self.process;
+                let tid = code as u32;
+                let start_time = Timestamp::from_nanos_since_reference(self.now * 50);
+                let is_main = code == RESET_CODE;
+                let thread = self.profile.add_thread(process, tid, start_time, is_main);
+                self.profile
+                    .set_thread_name(thread, &thread_name_for_code(code));
+                thread
+            });
+
+            let stack = self.handle_for_stack(thread, frames);
+            let cpu_delta = CpuDelta::from_nanos((self.now - cycles as u64) * 50);
+            self.profile
+                .add_sample(thread, timestamp, stack, cpu_delta, weight);
+            Some(code)
+        } else {
+            None
+        };
+        for (code, thread) in &self.threads {
+            if active_code == Some(*code) {
+                continue;
+            }
+            self.profile
+                .add_sample_same_stack_zero_cpu(*thread, timestamp, weight);
+        }
+    }
+
+    pub fn finish(self) -> Vec<u8> {
+        serde_json::to_vec(&self.profile).expect("could not serialize profile")
+    }
+
+    fn handle_for_stack(
+        &mut self,
+        thread: ThreadHandle,
+        frames: &[StackFrame],
+    ) -> Option<StackHandle> {
+        self.profile.intern_stack_frames(
+            thread,
+            frames.iter().map(|f| FrameInfo {
+                frame: Frame::InstructionPointer(f.address as u64),
+                category_pair: CategoryHandle::OTHER.into(),
+                flags: FrameFlags::empty(),
+            }),
+        )
+    }
+}
+
+fn thread_name_for_code(code: u16) -> std::borrow::Cow<'static, str> {
+    match code {
+        RESET_CODE => "Main".into(),
+        0xffd0 => "Duplexed exception".into(),
+        0xfe40 => "VIP interrupt".into(),
+        0xfe30 => "Communication interrupt".into(),
+        0xfe20 => "Game pak interrupt".into(),
+        0xfe10 => "Timer interrupt".into(),
+        0xfe00 => "Game pad interrupt".into(),
+        0xffc0 => "Address trap".into(),
+        0xffa0..0xffc0 => format!("Trap (vector {})", code - 0xffa0).into(),
+        0xff90 => "Illegal opcode exception".into(),
+        0xff80 => "Zero division exception".into(),
+        0xff60 => "Floating-point reserved operand exception".into(),
+        0xff70 => "Floating-point invalid operation exception".into(),
+        0xff68 => "Floating-point zero division exception".into(),
+        0xff64 => "Floating-point overflow exception".into(),
+        other => format!("Unrecognized handler (0x{other:04x})").into(),
+    }
+}

src/profiler/state.rs

@@ -0,0 +1,104 @@
+use std::{collections::HashMap, path::PathBuf};
+
+use anyhow::{Result, bail};
+
+use crate::{emulator::SimEvent, profiler::symbols::SymbolFile};
+
+pub struct ProgramState {
+    symbol_file: SymbolFile,
+    call_stacks: HashMap<u16, Vec<StackFrame>>,
+    context_stack: Vec<u16>,
+}
+
+pub struct StackFrame {
+    pub address: u32,
+}
+
+pub const RESET_CODE: u16 = 0xfff0;
+impl ProgramState {
+    pub async fn new(file_path: PathBuf) -> Result<Self> {
+        let symbol_file = SymbolFile::load(&file_path).await?;
+        let mut call_stacks = HashMap::new();
+        call_stacks.insert(
+            RESET_CODE,
+            vec![StackFrame {
+                address: 0xfffffff0,
+            }],
+        );
+        Ok(Self {
+            symbol_file,
+            call_stacks,
+            context_stack: vec![RESET_CODE],
+        })
+    }
+
+    pub fn symbol_file(&self) -> &SymbolFile {
+        &self.symbol_file
+    }
+
+    pub fn current_stack(&self) -> Option<(u16, &[StackFrame])> {
+        let code = self.context_stack.last()?;
+        let call_stack = self.call_stacks.get(code)?;
+        Some((*code, call_stack))
+    }
+
+    pub fn track_event(&mut self, event: SimEvent) -> Result<()> {
+        match event {
+            SimEvent::Call(address) => {
+                let Some(code) = self.context_stack.last() else {
+                    bail!("How did we call anything when we're halted?");
+                };
+                let Some(stack) = self.call_stacks.get_mut(code) else {
+                    bail!("missing stack {code:04x}");
+                };
+                stack.push(StackFrame { address });
+            }
+            SimEvent::Return => {
+                let Some(code) = self.context_stack.last() else {
+                    bail!("how did we return when we're halted?");
+                };
+                let Some(stack) = self.call_stacks.get_mut(code) else {
+                    bail!("missing stack {code:04x}");
+                };
+                if stack.pop().is_none() {
+                    bail!("returned from {code:04x} but stack was empty");
+                }
+                if stack.is_empty() {
+                    bail!("returned to oblivion");
+                }
+            }
+            SimEvent::Halt => {
+                let Some(RESET_CODE) = self.context_stack.pop() else {
+                    bail!("halted when not in an interrupt");
+                };
+            }
+            SimEvent::Interrupt(code, address) => {
+                // if the CPU was halted before, wake it up now
+                if self.context_stack.is_empty() {
+                    self.context_stack.push(RESET_CODE);
+                }
+
+                self.context_stack.push(code);
+                if self
+                    .call_stacks
+                    .insert(code, vec![StackFrame { address }])
+                    .is_some()
+                {
+                    bail!("{code:04x} fired twice");
+                }
+            }
+            SimEvent::Reti => {
+                let Some(code) = self.context_stack.pop() else {
+                    bail!("RETI when halted");
+                };
+                if code == RESET_CODE {
+                    bail!("RETI when not in interrupt");
+                }
+                if self.call_stacks.remove(&code).is_none() {
+                    bail!("{code:04x} popped but never called");
+                }
+            }
+        }
+        Ok(())
+    }
+}

src/profiler/symbols.rs

@@ -0,0 +1,67 @@
+use std::{path::Path, sync::Arc};
+
+use anyhow::Result;
+use fxprof_processed_profile::{LibraryInfo, Symbol, SymbolTable};
+use wholesym::{SymbolManager, samply_symbols::demangle_any};
+
+pub struct SymbolFile {
+    library_info: LibraryInfo,
+}
+
+impl SymbolFile {
+    pub async fn load(file_path: &Path) -> Result<Self> {
+        let normalized = normpath::PathExt::normalize(file_path)?;
+        let library_info =
+            SymbolManager::library_info_for_binary_at_path(normalized.as_path(), None).await?;
+
+        let symbol_manager = SymbolManager::with_config(Default::default());
+        let symbol_map = symbol_manager
+            .load_symbol_map_for_binary_at_path(normalized.as_path(), None)
+            .await?;
+
+        let name = library_info
+            .name
+            .or_else(|| {
+                normalized
+                    .file_name()
+                    .map(|n| n.to_string_lossy().into_owned())
+            })
+            .unwrap_or("game".to_string());
+        let debug_name = library_info.debug_name.unwrap_or_else(|| name.clone());
+        let path = library_info
+            .path
+            .unwrap_or_else(|| normalized.into_os_string().to_string_lossy().into_owned());
+        let debug_path = library_info.debug_path.unwrap_or_else(|| path.clone());
+        let debug_id = library_info.debug_id.unwrap_or_default();
+        let code_id = library_info.code_id.map(|id| id.to_string());
+        let arch = library_info.arch;
+        let symbols = symbol_map
+            .iter_symbols()
+            .map(|(address, name)| Symbol {
+                address: address + 0x07000000,
+                size: None,
+                name: demangle_any(&name),
+            })
+            .collect();
+        Ok(Self {
+            library_info: LibraryInfo {
+                name,
+                debug_name,
+                path,
+                debug_path,
+                debug_id,
+                code_id,
+                arch,
+                symbol_table: Some(Arc::new(SymbolTable::new(symbols))),
+            },
+        })
+    }
+
+    pub fn name(&self) -> &str {
+        &self.library_info.name
+    }
+
+    pub fn library_info(&self) -> &LibraryInfo {
+        &self.library_info
+    }
+}

src/window.rs

@@ -2,7 +2,10 @@ pub use about::AboutWindow;
 use egui::{Context, ViewportBuilder, ViewportId};
 pub use game::GameWindow;
 pub use gdb::GdbServerWindow;
+pub use hotkeys::HotkeysWindow;
 pub use input::InputWindow;
+pub use profile::ProfileWindow;
+pub use terminal::TerminalWindow;
 pub use vip::{
     BgMapWindow, CharacterDataWindow, FrameBufferWindow, ObjectWindow, RegisterWindow, WorldWindow,
 };
@@ -14,7 +17,10 @@ mod about;
 mod game;
 mod game_screen;
 mod gdb;
+mod hotkeys;
 mod input;
+mod profile;
+mod terminal;
 mod utils;
 mod vip;
 

src/window/game.rs

@@ -1,22 +1,24 @@
-use std::sync::mpsc;
+use std::{sync::mpsc, time::Duration};
 
 use crate::{
     app::UserEvent,
     emulator::{EmulatorClient, EmulatorCommand, EmulatorState, SimId, SimState},
+    input::{Command, ShortcutProvider},
     persistence::Persistence,
 };
+use anyhow::Context as _;
 use egui::{
-    menu, Align2, Button, CentralPanel, Color32, Context, Direction, Frame, TopBottomPanel, Ui,
-    Vec2, ViewportBuilder, ViewportCommand, ViewportId, Window,
+    Align2, Button, CentralPanel, Color32, Context, Frame, MenuBar, TopBottomPanel, Ui, Vec2,
+    ViewportBuilder, ViewportCommand, ViewportId, Window,
 };
-use egui_toast::{Toast, Toasts};
+use egui_notify::{Anchor, Toast, Toasts};
 use serde::{Deserialize, Serialize};
 use winit::event_loop::EventLoopProxy;
 
 use super::{
+    AppWindow,
     game_screen::{DisplayMode, GameScreen},
     utils::UiExt as _,
-    AppWindow,
 };
 
 const COLOR_PRESETS: [[Color32; 2]; 3] = [
@@ -38,8 +40,10 @@ pub struct GameWindow {
     client: EmulatorClient,
     proxy: EventLoopProxy<UserEvent>,
     persistence: Persistence,
+    shortcuts: ShortcutProvider,
     sim_id: SimId,
     config: GameConfig,
+    toasts: Toasts,
     screen: Option<GameScreen>,
     messages: Option<mpsc::Receiver<Toast>>,
     color_picker: Option<ColorPickerState>,
@@ -50,15 +54,22 @@ impl GameWindow {
         client: EmulatorClient,
         proxy: EventLoopProxy<UserEvent>,
         persistence: Persistence,
+        shortcuts: ShortcutProvider,
         sim_id: SimId,
     ) -> Self {
         let config = load_config(&persistence, sim_id);
+        let toasts = Toasts::new()
+            .with_anchor(Anchor::BottomLeft)
+            .with_margin((10.0, 10.0).into())
+            .reverse(true);
         Self {
             client,
             proxy,
             persistence,
+            shortcuts,
             sim_id,
             config,
+            toasts,
             screen: None,
             messages: None,
             color_picker: None,
@@ -66,8 +77,67 @@ impl GameWindow {
     }
 
     fn show_menu(&mut self, ctx: &Context, ui: &mut Ui) {
+        let state = self.client.emulator_state();
+        let is_ready = self.client.sim_state(self.sim_id) == SimState::Ready;
+        let can_pause = is_ready && state == EmulatorState::Running;
+        let can_resume = is_ready && state == EmulatorState::Paused;
+        let can_frame_advance = is_ready && state != EmulatorState::Debugging;
+
+        for command in ui.input_mut(|input| self.shortcuts.consume_all(input)) {
+            match command {
+                Command::OpenRom => {
+                    let rom = rfd::FileDialog::new()
+                        .add_filter("Virtual Boy ROMs", &["vb", "vbrom"])
+                        .pick_file();
+                    if let Some(path) = rom {
+                        self.client
+                            .send_command(EmulatorCommand::LoadGame(self.sim_id, path));
+                    }
+                }
+                Command::Quit => {
+                    let _ = self.proxy.send_event(UserEvent::Quit(self.sim_id));
+                }
+                Command::PauseResume => {
+                    if state == EmulatorState::Paused && can_resume {
+                        self.client.send_command(EmulatorCommand::Resume);
+                    }
+                    if state == EmulatorState::Running && can_pause {
+                        self.client.send_command(EmulatorCommand::Pause);
+                    }
+                }
+                Command::Reset => {
+                    if is_ready {
+                        self.client
+                            .send_command(EmulatorCommand::Reset(self.sim_id));
+                    }
+                }
+                Command::FrameAdvance => {
+                    if can_frame_advance {
+                        self.client.send_command(EmulatorCommand::FrameAdvance);
+                    }
+                }
+                Command::FastForward(speed) => {
+                    self.client
+                        .send_command(EmulatorCommand::SetSpeed(speed as f64));
+                }
+                Command::Screenshot => {
+                    let autopause = state == EmulatorState::Running && can_pause;
+                    if autopause {
+                        self.client.send_command(EmulatorCommand::Pause);
+                    }
+                    pollster::block_on(self.take_screenshot());
+                    if autopause {
+                        self.client.send_command(EmulatorCommand::Resume);
+                    }
+                }
+            }
+        }
+
         ui.menu_button("ROM", |ui| {
-            if ui.button("Open ROM").clicked() {
+            if ui
+                .add(self.button_for(ui.ctx(), "Open ROM", Command::OpenRom))
+                .clicked()
+            {
                 let rom = rfd::FileDialog::new()
                     .add_filter("Virtual Boy ROMs", &["vb", "vbrom"])
                     .pick_file();
@@ -75,39 +145,60 @@ impl GameWindow {
                     self.client
                         .send_command(EmulatorCommand::LoadGame(self.sim_id, path));
                 }
-                ui.close_menu();
             }
-            if ui.button("Quit").clicked() {
+            if ui
+                .add(self.button_for(ui.ctx(), "Quit", Command::Quit))
+                .clicked()
+            {
                 let _ = self.proxy.send_event(UserEvent::Quit(self.sim_id));
             }
         });
         ui.menu_button("Emulation", |ui| {
-            let state = self.client.emulator_state();
-            let is_ready = self.client.sim_state(self.sim_id) == SimState::Ready;
-            let can_pause = is_ready && state == EmulatorState::Running;
-            let can_resume = is_ready && state == EmulatorState::Paused;
-            let can_frame_advance = is_ready && state != EmulatorState::Debugging;
             if state == EmulatorState::Running {
-                if ui.add_enabled(can_pause, Button::new("Pause")).clicked() {
+                if ui
+                    .add_enabled(
+                        can_pause,
+                        self.button_for(ui.ctx(), "Pause", Command::PauseResume),
+                    )
+                    .clicked()
+                {
                     self.client.send_command(EmulatorCommand::Pause);
-                    ui.close_menu();
                 }
-            } else if ui.add_enabled(can_resume, Button::new("Resume")).clicked() {
+            } else if ui
+                .add_enabled(
+                    can_resume,
+                    self.button_for(ui.ctx(), "Resume", Command::PauseResume),
+                )
+                .clicked()
+            {
                 self.client.send_command(EmulatorCommand::Resume);
-                ui.close_menu();
             }
-            if ui.add_enabled(is_ready, Button::new("Reset")).clicked() {
+            if ui
+                .add_enabled(is_ready, self.button_for(ui.ctx(), "Reset", Command::Reset))
+                .clicked()
+            {
                 self.client
                     .send_command(EmulatorCommand::Reset(self.sim_id));
-                ui.close_menu();
             }
             ui.separator();
             if ui
-                .add_enabled(can_frame_advance, Button::new("Frame Advance"))
+                .add_enabled(
+                    can_frame_advance,
+                    self.button_for(ui.ctx(), "Frame Advance", Command::FrameAdvance),
+                )
                 .clicked()
             {
                 self.client.send_command(EmulatorCommand::FrameAdvance);
-                ui.close_menu();
+            }
+            ui.separator();
+            if ui
+                .add_enabled(
+                    is_ready,
+                    self.button_for(ui.ctx(), "Screenshot", Command::Screenshot),
+                )
+                .clicked()
+            {
+                pollster::block_on(self.take_screenshot());
             }
         });
         ui.menu_button("Options", |ui| self.show_options_menu(ctx, ui));
@@ -120,73 +211,113 @@ impl GameWindow {
                 self.client
                     .send_command(EmulatorCommand::StartSecondSim(None));
                 self.proxy.send_event(UserEvent::OpenPlayer2).unwrap();
-                ui.close_menu();
             }
             if has_player_2 {
                 let linked = self.client.are_sims_linked();
                 if linked && ui.button("Unlink").clicked() {
                     self.client.send_command(EmulatorCommand::Unlink);
-                    ui.close_menu();
                 }
                 if !linked && ui.button("Link").clicked() {
                     self.client.send_command(EmulatorCommand::Link);
-                    ui.close_menu();
                 }
             }
         });
         ui.menu_button("Tools", |ui| {
+            if ui.button("Terminal").clicked() {
+                self.proxy
+                    .send_event(UserEvent::OpenTerminal(self.sim_id))
+                    .unwrap();
+            }
+            if ui.button("Profiler").clicked() {
+                self.proxy
+                    .send_event(UserEvent::OpenProfiler(self.sim_id))
+                    .unwrap();
+            }
             if ui.button("GDB Server").clicked() {
                 self.proxy
                     .send_event(UserEvent::OpenDebugger(self.sim_id))
                     .unwrap();
-                ui.close_menu();
             }
             ui.separator();
             if ui.button("Character Data").clicked() {
                 self.proxy
                     .send_event(UserEvent::OpenCharacterData(self.sim_id))
                     .unwrap();
-                ui.close_menu();
             }
             if ui.button("Background Maps").clicked() {
                 self.proxy
                     .send_event(UserEvent::OpenBgMap(self.sim_id))
                     .unwrap();
-                ui.close_menu();
             }
             if ui.button("Objects").clicked() {
                 self.proxy
                     .send_event(UserEvent::OpenObjects(self.sim_id))
                     .unwrap();
-                ui.close_menu();
             }
             if ui.button("Worlds").clicked() {
                 self.proxy
                     .send_event(UserEvent::OpenWorlds(self.sim_id))
                     .unwrap();
-                ui.close_menu();
             }
             if ui.button("Frame Buffers").clicked() {
                 self.proxy
                     .send_event(UserEvent::OpenFrameBuffers(self.sim_id))
                     .unwrap();
-                ui.close_menu();
             }
             if ui.button("Registers").clicked() {
                 self.proxy
                     .send_event(UserEvent::OpenRegisters(self.sim_id))
                     .unwrap();
-                ui.close_menu();
             }
         });
         ui.menu_button("Help", |ui| {
             if ui.button("About").clicked() {
                 self.proxy.send_event(UserEvent::OpenAbout).unwrap();
-                ui.close_menu();
             }
         });
     }
 
+    async fn take_screenshot(&mut self) {
+        match self.try_take_screenshot().await {
+            Ok(Some(path)) => {
+                let mut toast = Toast::info(format!("Saved to {path}"));
+                toast.duration(Some(Duration::from_secs(5)));
+                self.toasts.add(toast);
+            }
+            Ok(None) => {}
+            Err(error) => {
+                let mut toast = Toast::error(format!("{error:#}"));
+                toast.duration(Some(Duration::from_secs(5)));
+                self.toasts.add(toast);
+            }
+        }
+    }
+
+    async fn try_take_screenshot(&self) -> anyhow::Result<Option<String>> {
+        let (tx, rx) = oneshot::channel();
+        self.client
+            .send_command(EmulatorCommand::Screenshot(self.sim_id, tx));
+        let bytes = rx.await.context("Could not take screenshot")?;
+        let file = rfd::FileDialog::new()
+            .add_filter("PNG images", &["png"])
+            .set_file_name("screenshot.png")
+            .save_file();
+        let Some(path) = file else {
+            return Ok(None);
+        };
+        if bytes.len() != 384 * 224 * 2 {
+            anyhow::bail!("Unexpected screenshot size");
+        }
+        let mut screencap = image::GrayImage::new(384 * 2, 224);
+        for (index, pixel) in bytes.into_iter().enumerate() {
+            let x = (index / 2) % 384 + ((index % 2) * 384);
+            let y = (index / 2) / 384;
+            screencap.put_pixel(x as u32, y as u32, image::Luma([pixel]));
+        }
+        screencap.save(&path).context("Could not save screenshot")?;
+        Ok(Some(path.display().to_string()))
+    }
+
     fn show_options_menu(&mut self, ctx: &Context, ui: &mut Ui) {
         ui.menu_button("Video", |ui| {
             ui.menu_button("Screen Size", |ui| {
@@ -204,7 +335,6 @@ impl GameWindow {
                         .clicked()
                     {
                         ctx.send_viewport_cmd(ViewportCommand::InnerSize(dims));
-                        ui.close_menu();
                     }
                 }
             });
@@ -241,13 +371,11 @@ impl GameWindow {
                     c.display_mode = display_mode;
                     c.dimensions = current_dims * scale;
                 });
-                ui.close_menu();
             });
             ui.menu_button("Colors", |ui| {
                 for preset in COLOR_PRESETS {
                     if ui.color_pair_button(preset[0], preset[1]).clicked() {
                         self.update_config(|c| c.colors = preset);
-                        ui.close_menu();
                     }
                 }
                 ui.with_layout(ui.layout().with_cross_align(egui::Align::Center), |ui| {
@@ -268,7 +396,6 @@ impl GameWindow {
                             just_opened: true,
                             unpause_on_close: is_running,
                         });
-                        ui.close_menu();
                     }
                 });
             });
@@ -279,20 +406,20 @@ impl GameWindow {
             if ui.selectable_button(p1_enabled, "Player 1").clicked() {
                 self.client
                     .send_command(EmulatorCommand::SetAudioEnabled(!p1_enabled, p2_enabled));
-                ui.close_menu();
             }
             if ui.selectable_button(p2_enabled, "Player 2").clicked() {
                 self.client
                     .send_command(EmulatorCommand::SetAudioEnabled(p1_enabled, !p2_enabled));
-                ui.close_menu();
             }
         });
         ui.menu_button("Input", |ui| {
             if ui.button("Bind Inputs").clicked() {
                 self.proxy.send_event(UserEvent::OpenInput).unwrap();
-                ui.close_menu();
             }
         });
+        if ui.button("Hotkeys").clicked() {
+            self.proxy.send_event(UserEvent::OpenHotkeys).unwrap();
+        }
     }
 
     fn show_color_picker(&mut self, ui: &mut Ui) {
@@ -334,6 +461,14 @@ impl GameWindow {
         }
         self.config = new_config;
     }
+
+    fn button_for(&self, ctx: &Context, text: &str, command: Command) -> Button {
+        let button = Button::new(text);
+        match self.shortcuts.shortcut_for(command) {
+            Some(shortcut) => button.shortcut_text(ctx.format_shortcut(&shortcut)),
+            None => button,
+        }
+    }
 }
 
 fn config_filename(sim_id: SimId) -> &'static str {
@@ -379,18 +514,15 @@ impl AppWindow for GameWindow {
         };
         self.update_config(|c| c.dimensions = dimensions);
 
-        let mut toasts = Toasts::new()
-            .anchor(Align2::LEFT_BOTTOM, (10.0, 10.0))
-            .direction(Direction::BottomUp);
         if let Some(messages) = self.messages.as_mut() {
             while let Ok(toast) = messages.try_recv() {
-                toasts.add(toast);
+                self.toasts.add(toast);
             }
         }
         TopBottomPanel::top("menubar")
             .exact_height(22.0)
             .show(ctx, |ui| {
-                menu::bar(ui, |ui| {
+                MenuBar::new().ui(ui, |ui| {
                     self.show_menu(ctx, ui);
                 });
             });
@@ -410,7 +542,7 @@ impl AppWindow for GameWindow {
                 ui.add(screen);
             }
         });
-        toasts.show(ctx);
+        self.toasts.show(ctx);
     }
 
     fn on_init(&mut self, _ctx: &Context, render_state: &egui_wgpu::RenderState) {

src/window/game_screen.rs

@@ -2,7 +2,7 @@ use std::{collections::HashMap, sync::Arc};
 
 use egui::{Color32, Rgba, Vec2, Widget};
 use serde::{Deserialize, Serialize};
-use wgpu::{util::DeviceExt as _, BindGroup, BindGroupLayout, Buffer, RenderPipeline};
+use wgpu::{BindGroup, BindGroupLayout, Buffer, RenderPipeline, util::DeviceExt as _};
 
 use crate::graphics::TextureSink;
 
@@ -71,7 +71,7 @@ impl GameScreen {
                     module: &shader,
                     entry_point: Some(entry_point),
                     targets: &[Some(wgpu::ColorTargetState {
-                        format: wgpu::TextureFormat::Bgra8Unorm,
+                        format: render_state.target_format,
                         blend: Some(wgpu::BlendState::REPLACE),
                         write_mask: wgpu::ColorWrites::ALL,
                     })],

src/window/hotkeys.rs

@@ -0,0 +1,150 @@
+use egui::{
+    Button, CentralPanel, Context, Event, KeyboardShortcut, Label, Layout, Slider, Ui,
+    ViewportBuilder, ViewportId,
+};
+use egui_extras::{Column, TableBuilder};
+
+use crate::input::{Command, ShortcutProvider};
+
+use super::{AppWindow, utils::UiExt};
+
+pub struct HotkeysWindow {
+    shortcuts: ShortcutProvider,
+    now_binding: Option<Command>,
+}
+
+impl HotkeysWindow {
+    pub fn new(shortcuts: ShortcutProvider) -> Self {
+        Self {
+            shortcuts,
+            now_binding: None,
+        }
+    }
+
+    fn show_shortcuts(&mut self, ui: &mut Ui) {
+        let row_height = ui.spacing().interact_size.y;
+        ui.section("Shortcuts", |ui| {
+            let width = ui.available_width() - 16.0;
+            TableBuilder::new(ui)
+                .column(Column::exact(width * 0.3))
+                .column(Column::exact(width * 0.5))
+                .column(Column::exact(width * 0.2))
+                .cell_layout(Layout::left_to_right(egui::Align::Center))
+                .body(|mut body| {
+                    for command in Command::all() {
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.add_sized(ui.available_size(), Label::new(command.name()));
+                            });
+                            row.col(|ui| {
+                                let button = if self.now_binding == Some(command) {
+                                    Button::new("Binding...")
+                                } else if let Some(shortcut) = self.shortcuts.shortcut_for(command)
+                                {
+                                    Button::new(ui.ctx().format_shortcut(&shortcut))
+                                } else {
+                                    Button::new("")
+                                };
+                                if ui.add_sized(ui.available_size(), button).clicked() {
+                                    self.now_binding = Some(command);
+                                }
+                            });
+                            row.col(|ui| {
+                                if ui
+                                    .add_sized(ui.available_size(), Button::new("Clear"))
+                                    .clicked()
+                                {
+                                    self.shortcuts.unset(command);
+                                    self.now_binding = None;
+                                }
+                            });
+                        });
+                    }
+                });
+        });
+        if let Some(command) = self.now_binding {
+            if let Some(shortcut) = ui.input_mut(|i| {
+                i.events.iter().find_map(|event| match event {
+                    Event::Key {
+                        key,
+                        pressed: true,
+                        modifiers,
+                        ..
+                    } => Some(KeyboardShortcut::new(*modifiers, *key)),
+                    _ => None,
+                })
+            }) {
+                self.shortcuts.set(command, shortcut);
+                self.now_binding = None;
+            }
+        }
+    }
+
+    fn show_ff_settings(&mut self, ui: &mut Ui) {
+        let row_height = ui.spacing().interact_size.y;
+        ui.section("Fast Forward", |ui| {
+            let width = ui.available_width() - 8.0;
+            let mut ff_settings = self.shortcuts.ff_settings();
+            let mut updated = false;
+            TableBuilder::new(ui)
+                .column(Column::exact(width * 0.5))
+                .column(Column::exact(width * 0.5))
+                .body(|mut body| {
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("Treat button as toggle");
+                        });
+                        row.col(|ui| {
+                            if ui.checkbox(&mut ff_settings.toggle, "").changed() {
+                                updated = true;
+                            }
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("Speed multiplier");
+                        });
+                        row.col(|ui| {
+                            if ui
+                                .add_sized(
+                                    ui.available_size(),
+                                    Slider::new(&mut ff_settings.speed, 1..=15),
+                                )
+                                .changed()
+                            {
+                                updated = true;
+                            }
+                        });
+                    });
+                });
+            if updated {
+                self.shortcuts.update_ff_settings(ff_settings);
+            }
+        });
+    }
+}
+
+impl AppWindow for HotkeysWindow {
+    fn viewport_id(&self) -> ViewportId {
+        ViewportId::from_hash_of("shortcuts")
+    }
+
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title("Keyboard Shortcuts")
+            .with_inner_size((400.0, 400.0))
+    }
+
+    fn show(&mut self, ctx: &Context) {
+        CentralPanel::default().show(ctx, |ui| {
+            ui.horizontal(|ui| {
+                if ui.button("Use defaults").clicked() {
+                    self.shortcuts.reset();
+                }
+            });
+            ui.separator();
+            self.show_shortcuts(ui);
+            self.show_ff_settings(ui);
+        });
+    }
+}

src/window/profile.rs

@@ -0,0 +1,126 @@
+use std::{fs, time::Duration};
+
+use anyhow::Result;
+use egui::{Button, CentralPanel, Checkbox, ViewportBuilder, ViewportId};
+use egui_notify::{Anchor, Toast, Toasts};
+
+use crate::{
+    emulator::{EmulatorClient, SimId},
+    profiler::{Profiler, ProfilerStatus},
+    window::AppWindow,
+};
+
+pub struct ProfileWindow {
+    sim_id: SimId,
+    profiler: Profiler,
+    toasts: Toasts,
+}
+
+impl ProfileWindow {
+    pub fn new(sim_id: SimId, client: EmulatorClient) -> Self {
+        Self {
+            sim_id,
+            profiler: Profiler::new(sim_id, client),
+            toasts: Toasts::new()
+                .with_anchor(Anchor::BottomLeft)
+                .with_margin((10.0, 10.0).into())
+                .reverse(true),
+        }
+    }
+
+    pub fn launch(&mut self) {
+        self.profiler.enable();
+    }
+
+    fn finish_recording(&mut self) {
+        match self.try_finish_recording() {
+            Ok(Some(path)) => {
+                let mut toast = Toast::info(format!("Saved to {path}"));
+                toast.duration(Some(Duration::from_secs(5)));
+                self.toasts.add(toast);
+            }
+            Ok(None) => {}
+            Err(error) => {
+                let mut toast = Toast::error(format!("{error:#}"));
+                toast.duration(Some(Duration::from_secs(5)));
+                self.toasts.add(toast);
+            }
+        }
+    }
+
+    fn try_finish_recording(&mut self) -> Result<Option<String>> {
+        let bytes_receiver = self.profiler.finish_recording();
+        let file = rfd::FileDialog::new()
+            .add_filter("Profiler files", &["json"])
+            .set_file_name("profile.json")
+            .save_file();
+        if let Some(path) = file {
+            let bytes = pollster::block_on(bytes_receiver)?;
+            fs::write(&path, bytes)?;
+            Ok(Some(path.display().to_string()))
+        } else {
+            self.profiler.cancel_recording();
+            Ok(None)
+        }
+    }
+}
+
+impl AppWindow for ProfileWindow {
+    fn viewport_id(&self) -> ViewportId {
+        ViewportId::from_hash_of(format!("Profile-{}", self.sim_id))
+    }
+
+    fn sim_id(&self) -> SimId {
+        self.sim_id
+    }
+
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title(format!("Profiler ({})", self.sim_id))
+            .with_inner_size((300.0, 200.0))
+    }
+
+    fn show(&mut self, ctx: &egui::Context) {
+        let status = self.profiler.status();
+        let recording = matches!(status, ProfilerStatus::Recording);
+        CentralPanel::default().show(ctx, |ui| {
+            let mut enabled = status.enabled();
+            let enabled_checkbox = Checkbox::new(&mut enabled, "Profiling enabled?");
+            if ui.add_enabled(!recording, enabled_checkbox).changed() {
+                if enabled {
+                    self.profiler.enable();
+                } else {
+                    self.profiler.disable();
+                }
+            }
+
+            ui.horizontal(|ui| {
+                if !recording {
+                    let record_button = Button::new("Record");
+                    let can_record = matches!(status, ProfilerStatus::Enabled);
+                    if ui.add_enabled(can_record, record_button).clicked() {
+                        self.profiler.start_recording();
+                    }
+                } else {
+                    if ui.button("Finish recording").clicked() {
+                        self.finish_recording();
+                    }
+                    if ui.button("Cancel recording").clicked() {
+                        self.profiler.cancel_recording();
+                    }
+                }
+            });
+
+            match &status {
+                ProfilerStatus::Recording => {
+                    ui.label("Recording...");
+                }
+                ProfilerStatus::Error(message) => {
+                    ui.label(message);
+                }
+                _ => {}
+            }
+        });
+        self.toasts.show(ctx);
+    }
+}

src/window/terminal.rs

@@ -0,0 +1,79 @@
+use std::{collections::VecDeque, sync::mpsc};
+
+use egui::{
+    Align, CentralPanel, Context, FontFamily, Label, RichText, ScrollArea, ViewportBuilder,
+    ViewportId,
+};
+
+use crate::emulator::{EmulatorClient, EmulatorCommand, SimId};
+
+use super::AppWindow;
+
+const SCROLLBACK: usize = 1000;
+
+pub struct TerminalWindow {
+    sim_id: SimId,
+    receiver: mpsc::Receiver<String>,
+    lines: VecDeque<String>,
+}
+
+impl TerminalWindow {
+    pub fn new(sim_id: SimId, client: &EmulatorClient) -> Self {
+        let (sender, receiver) = mpsc::channel();
+        client.send_command(EmulatorCommand::WatchStdout(sim_id, sender));
+        let mut lines = VecDeque::new();
+        lines.push_back(String::new());
+        Self {
+            sim_id,
+            receiver,
+            lines,
+        }
+    }
+}
+
+impl AppWindow for TerminalWindow {
+    fn viewport_id(&self) -> ViewportId {
+        ViewportId::from_hash_of(format!("terminal-{}", self.sim_id))
+    }
+
+    fn sim_id(&self) -> SimId {
+        self.sim_id
+    }
+
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title(format!("Terminal ({})", self.sim_id))
+            .with_inner_size((640.0, 480.0))
+    }
+
+    fn show(&mut self, ctx: &Context) {
+        if let Ok(text) = self.receiver.try_recv() {
+            let mut rest = text.as_str();
+            while let Some(index) = rest.find('\n') {
+                let (line, lines) = rest.split_at(index);
+                let current = self.lines.back_mut().unwrap();
+                current.push_str(line);
+                self.lines.push_back(String::new());
+                if self.lines.len() > SCROLLBACK {
+                    self.lines.pop_front();
+                }
+                rest = &lines[1..];
+            }
+            self.lines.back_mut().unwrap().push_str(rest);
+        }
+        CentralPanel::default().show(ctx, |ui| {
+            ScrollArea::vertical()
+                .stick_to_bottom(true)
+                .auto_shrink([false, false])
+                .animated(false)
+                .show(ui, |ui| {
+                    for line in &self.lines {
+                        let label = Label::new(RichText::new(line).family(FontFamily::Monospace))
+                            .halign(Align::LEFT)
+                            .wrap();
+                        ui.add(label);
+                    }
+                });
+        });
+    }
+}

src/window/utils.rs

@@ -6,9 +6,9 @@ use std::{
 
 use atoi::FromRadix16;
 use egui::{
-    ecolor::HexColor, Align, Color32, CursorIcon, Event, Frame, Key, Layout, Margin, Rect,
-    Response, RichText, Rounding, Sense, Shape, Stroke, TextEdit, Ui, UiBuilder, Vec2, Widget,
-    WidgetText,
+    Align, Color32, CornerRadius, CursorIcon, Event, Frame, Key, Layout, Margin, Rect, Response,
+    RichText, Sense, Shape, Stroke, StrokeKind, TextEdit, Ui, UiBuilder, Vec2, Widget, WidgetText,
+    ecolor::HexColor,
 };
 use num_traits::{CheckedAdd, CheckedSub, One};
 
@@ -37,8 +37,8 @@ impl UiExt for Ui {
     fn section(&mut self, title: impl Into<String>, add_contents: impl FnOnce(&mut Ui)) {
         let title: String = title.into();
         let mut frame = Frame::group(self.style());
-        frame.outer_margin.top += 10.0;
-        frame.inner_margin.top += 2.0;
+        frame.outer_margin.top += 10;
+        frame.inner_margin.top += 2;
         let res = self.push_id(&title, |ui| {
             frame.show(ui, |ui| {
                 ui.set_max_width(ui.available_width());
@@ -49,7 +49,7 @@ impl UiExt for Ui {
         let old_rect = res.response.rect;
         let mut text_rect = old_rect;
         text_rect.min.x += 6.0;
-        self.allocate_new_ui(UiBuilder::new().max_rect(text_rect), |ui| ui.label(text));
+        self.scope_builder(UiBuilder::new().max_rect(text_rect), |ui| ui.label(text));
         if old_rect.width() > 0.0 {
             self.advance_cursor_after_rect(old_rect);
         }
@@ -73,7 +73,8 @@ impl UiExt for Ui {
         self.painter().rect_filled(right_rect, 0.0, right);
 
         let style = self.style().interact(&response);
-        self.painter().rect_stroke(rect, 0.0, style.fg_stroke);
+        self.painter()
+            .rect_stroke(rect, 0.0, style.fg_stroke, StrokeKind::Inside);
         response
     }
 
@@ -119,20 +120,20 @@ pub trait Number:
 {
 }
 impl<
-        T: Copy
-            + One
-            + CheckedAdd
-            + CheckedSub
-            + Eq
-            + Ord
-            + Display
-            + FromStr
-            + FromRadix16
-            + UpperHex
-            + Send
-            + Sync
-            + 'static,
-    > Number for T
+    T: Copy
+        + One
+        + CheckedAdd
+        + CheckedSub
+        + Eq
+        + Ord
+        + Display
+        + FromStr
+        + FromRadix16
+        + UpperHex
+        + Send
+        + Sync
+        + 'static,
+> Number for T
 {
 }
 
@@ -265,10 +266,10 @@ impl<T: Number> Widget for NumberEdit<'_, T> {
             .id(id)
             .desired_width(desired_width)
             .margin(Margin {
-                left: 4.0,
-                right: if self.arrows { 20.0 } else { 4.0 },
-                top: 2.0,
-                bottom: 2.0,
+                left: 4,
+                right: if self.arrows { 20 } else { 4 },
+                top: 2,
+                bottom: 2,
             });
         let mut res = if valid {
             ui.add(text)
@@ -337,7 +338,7 @@ impl<T: Number> Widget for NumberEdit<'_, T> {
             }
             str = to_string(self.value);
             stale = true;
-        } else if res.changed {
+        } else if res.changed() {
             if let Some(new_value) = from_string(&str).filter(in_range) {
                 if *self.value != new_value {
                     res.mark_changed();
@@ -355,27 +356,20 @@ impl<T: Number> Widget for NumberEdit<'_, T> {
 
 fn draw_arrow(ui: &mut Ui, rect: Rect, up: bool) -> Response {
     let arrow_res = ui
-        .allocate_rect(
-            rect,
-            Sense {
-                click: true,
-                drag: true,
-                focusable: false,
-            },
-        )
+        .allocate_rect(rect, Sense::all())
         .on_hover_cursor(CursorIcon::Default);
     let visuals = ui.style().visuals.widgets.style(&arrow_res);
     let painter = ui.painter_at(arrow_res.rect);
 
     let rounding = if up {
-        Rounding {
-            ne: 2.0,
-            ..Rounding::ZERO
+        CornerRadius {
+            ne: 2,
+            ..CornerRadius::ZERO
         }
     } else {
-        Rounding {
-            se: 2.0,
-            ..Rounding::ZERO
+        CornerRadius {
+            se: 2,
+            ..CornerRadius::ZERO
         }
     };
     painter.rect_filled(arrow_res.rect, rounding, visuals.bg_fill);

src/window/vip/bgmap.rs

@@ -11,8 +11,8 @@ use crate::{
     images::{ImageBuffer, ImageParams, ImageProcessor, ImageRenderer, ImageTextureLoader},
     memory::{MemoryClient, MemoryView},
     window::{
-        utils::{NumberEdit, UiExt},
         AppWindow,
+        utils::{NumberEdit, UiExt},
     },
 };
 

src/window/vip/chardata.rs

@@ -12,8 +12,8 @@ use crate::{
     images::{ImageBuffer, ImageParams, ImageProcessor, ImageRenderer, ImageTextureLoader},
     memory::{MemoryClient, MemoryView},
     window::{
-        utils::{NumberEdit, UiExt as _},
         AppWindow,
+        utils::{NumberEdit, UiExt as _},
     },
 };
 

src/window/vip/framebuffer.rs

@@ -11,8 +11,8 @@ use crate::{
     images::{ImageBuffer, ImageParams, ImageProcessor, ImageRenderer, ImageTextureLoader},
     memory::{MemoryClient, MemoryView},
     window::{
-        utils::{NumberEdit, UiExt as _},
         AppWindow,
+        utils::{NumberEdit, UiExt as _},
     },
 };
 

src/window/vip/object.rs

@@ -11,8 +11,8 @@ use crate::{
     images::{ImageBuffer, ImageParams, ImageProcessor, ImageRenderer, ImageTextureLoader},
     memory::{MemoryClient, MemoryView},
     window::{
-        utils::{NumberEdit, UiExt as _},
         AppWindow,
+        utils::{NumberEdit, UiExt as _},
     },
 };
 

src/window/vip/registers.rs

@@ -10,8 +10,8 @@ use crate::{
     emulator::SimId,
     memory::{MemoryClient, MemoryRef, MemoryValue, MemoryView},
     window::{
-        utils::{NumberEdit, UiExt},
         AppWindow,
+        utils::{NumberEdit, UiExt},
     },
 };
 

src/window/vip/utils.rs

@@ -124,7 +124,7 @@ impl CellData {
     }
 
     pub fn update(&self, source: &mut u16) -> bool {
-        let new_value = (self.palette_index as u16) << 14
+        let new_value = ((self.palette_index as u16) << 14)
             | if self.hflip { 0x2000 } else { 0x0000 }
             | if self.vflip { 0x1000 } else { 0x0000 }
             | (self.char_index as u16 & 0x07ff)
@@ -222,12 +222,12 @@ impl Widget for CharacterGrid<'_> {
             for x in (1..grid_width_cells).map(|i| (i as f32) * cell_size) {
                 let p1 = (res.rect.min.x + x, res.rect.min.y).into();
                 let p2 = (res.rect.min.x + x, res.rect.max.y).into();
-                painter.line(vec![p1, p2], stroke);
+                painter.line_segment([p1, p2], stroke);
             }
             for y in (1..grid_height_cells).map(|i| (i as f32) * cell_size) {
                 let p1 = (res.rect.min.x, res.rect.min.y + y).into();
                 let p2 = (res.rect.max.x, res.rect.min.y + y).into();
-                painter.line(vec![p1, p2], stroke);
+                painter.line_segment([p1, p2], stroke);
             }
         }
         if let Some(selected) = self.selected {

src/window/vip/world.rs

@@ -6,8 +6,8 @@ use egui::{
 };
 use egui_extras::{Column, Size, StripBuilder, TableBuilder};
 use fixed::{
-    types::extra::{U3, U9},
     FixedI32,
+    types::extra::{U3, U9},
 };
 use num_derive::{FromPrimitive, ToPrimitive};
 use num_traits::{FromPrimitive, ToPrimitive};
@@ -17,12 +17,12 @@ use crate::{
     images::{ImageBuffer, ImageParams, ImageProcessor, ImageRenderer, ImageTextureLoader},
     memory::{MemoryClient, MemoryRef, MemoryView},
     window::{
-        utils::{NumberEdit, UiExt as _},
         AppWindow,
+        utils::{NumberEdit, UiExt as _},
     },
 };
 
-use super::utils::{self, shade, CellData, Object};
+use super::utils::{self, CellData, Object, shade};
 
 pub struct WorldWindow {
     sim_id: SimId,
@@ -33,6 +33,7 @@ pub struct WorldWindow {
     index: usize,
     param_index: usize,
     generic_palette: bool,
+    show_extents: bool,
     params: ImageParams<WorldParams>,
     scale: f32,
 }
@@ -57,6 +58,7 @@ impl WorldWindow {
             index: params.index,
             param_index: 0,
             generic_palette: params.generic_palette,
+            show_extents: false,
             params,
             scale: 1.0,
         }
@@ -413,6 +415,7 @@ impl WorldWindow {
                     ui.add(slider);
                 });
                 ui.checkbox(&mut self.generic_palette, "Generic palette");
+                ui.checkbox(&mut self.show_extents, "Show extents");
             });
         });
         self.params.write(WorldParams {
@@ -426,7 +429,82 @@ impl WorldWindow {
         let image = Image::new("vip://world")
             .fit_to_original_size(self.scale)
             .texture_options(TextureOptions::NEAREST);
-        ui.add(image);
+        let res = ui.add(image);
+        if self.show_extents {
+            let world = {
+                let worlds = self.worlds.borrow();
+                let data = worlds.read(self.index);
+                World::parse(&data)
+            };
+            if world.header.mode == WorldMode::Object {
+                return;
+            }
+
+            let lx1 = (world.dst_x - world.dst_parallax) as f32 * self.scale;
+            let lx2 = lx1 + world.width as f32 * self.scale;
+            let rx1 = (world.dst_x + world.dst_parallax) as f32 * self.scale;
+            let rx2 = rx1 + world.width as f32 * self.scale;
+            let y1 = world.dst_y as f32 * self.scale;
+            let y2 = y1 + world.height as f32 * self.scale;
+
+            let left_color = self.params.left_color;
+            let right_color = self.params.right_color;
+            let both_color = Color32::from_rgb(
+                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(
+                    vec![
+                        res.rect.min + (x1, y1).into(),
+                        res.rect.min + (x2, y1).into(),
+                        res.rect.min + (x2, y2).into(),
+                        res.rect.min + (x1, y2).into(),
+                        res.rect.min + (x1, y1).into(),
+                    ],
+                    (2.0, color),
+                )
+            };
+
+            match (world.header.lon, world.header.ron) {
+                (false, false) => {}
+                (true, false) => {
+                    draw_rect(lx1, lx2, left_color);
+                }
+                (false, true) => {
+                    draw_rect(rx1, rx2, right_color);
+                }
+                (true, true) if world.dst_parallax == 0 => {
+                    draw_rect(lx1, lx2, both_color);
+                }
+                (true, true) => {
+                    draw_rect(lx1, lx2, left_color);
+                    draw_rect(rx1, rx2, right_color);
+                    let (x1, x2) = if world.dst_parallax < 0 {
+                        (lx1, rx2)
+                    } else {
+                        (rx1, lx2)
+                    };
+                    painter.line_segment(
+                        [
+                            res.rect.min + (x1, y1).into(),
+                            res.rect.min + (x2 + 1.0, y1).into(),
+                        ],
+                        (2.0, both_color),
+                    );
+                    painter.line_segment(
+                        [
+                            res.rect.min + (x1, y2).into(),
+                            res.rect.min + (x2 + 1.0, y2).into(),
+                        ],
+                        (2.0, both_color),
+                    );
+                }
+            }
+        }
     }
 }
 
@@ -442,7 +520,7 @@ impl AppWindow for WorldWindow {
     fn initial_viewport(&self) -> ViewportBuilder {
         ViewportBuilder::default()
             .with_title(format!("Worlds ({})", self.sim_id))
-            .with_inner_size((640.0, 500.0))
+            .with_inner_size((640.0, 520.0))
     }
 
     fn on_init(&mut self, ctx: &Context, _render_state: &egui_wgpu::RenderState) {
@@ -870,7 +948,7 @@ impl WorldHeader {
         let new_value = (*source & 0x0030)
             | if self.lon { 0x8000 } else { 0x0000 }
             | if self.ron { 0x4000 } else { 0x0000 }
-            | self.mode.to_u16().unwrap() << 12
+            | (self.mode.to_u16().unwrap() << 12)
             | ((self.scx as u16) << 10)
             | ((self.scy as u16) << 8)
             | if self.over { 0x0080 } else { 0x0000 }