chore: Release lemur version 0.4.2

Reviewed-on: #4

Cargo.lock

@@ -427,6 +427,12 @@ version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ace50bade8e6234aa140d9a2f552bbee1db4d353f69b8217bc503490fc1a9f26"
 
+[[package]]
+name = "az"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7b7e4c2464d97fe331d41de9d5db0def0a96f4d823b8b32a2efd503578988973"
+
 [[package]]
 name = "backtrace"
 version = "0.3.74"
@@ -451,7 +457,7 @@ dependencies = [
  "bitflags 2.6.0",
  "cexpr",
  "clang-sys",
- "itertools",
+ "itertools 0.13.0",
  "proc-macro2",
  "quote",
  "regex",
@@ -834,6 +840,12 @@ version = "0.8.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d0a5c400df2834b80a4c3327b3aad3a4c4cd4de0629063962b03235697506a28"
 
+[[package]]
+name = "crunchy"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "43da5946c66ffcc7745f48db692ffbb10a83bfe0afd96235c5c2a4fb23994929"
+
 [[package]]
 name = "cursor-icon"
 version = "1.1.0"
@@ -1166,6 +1178,19 @@ dependencies = [
  "simd-adler32",
 ]
 
+[[package]]
+name = "fixed"
+version = "1.28.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85c6e0b89bf864acd20590dbdbad56f69aeb898abfc9443008fd7bd48b2cc85a"
+dependencies = [
+ "az",
+ "bytemuck",
+ "half",
+ "num-traits",
+ "typenum",
+]
+
 [[package]]
 name = "flate2"
 version = "1.0.35"
@@ -1443,6 +1468,16 @@ dependencies = [
  "bitflags 2.6.0",
 ]
 
+[[package]]
+name = "half"
+version = "2.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6dd08c532ae367adf81c312a4580bc67f1d0fe8bc9c460520283f4c0ff277888"
+dependencies = [
+ "cfg-if",
+ "crunchy",
+]
+
 [[package]]
 name = "hashbrown"
 version = "0.15.2"
@@ -1691,6 +1726,15 @@ dependencies = [
  "either",
 ]
 
+[[package]]
+name = "itertools"
+version = "0.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b192c782037fadd9cfa75548310488aabdbf3d2da73885b31bd0abd03351285"
+dependencies = [
+ "either",
+]
+
 [[package]]
 name = "itoa"
 version = "1.0.14"
@@ -1763,7 +1807,7 @@ checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
 
 [[package]]
 name = "lemur"
-version = "0.3.2"
+version = "0.4.2"
 dependencies = [
  "anyhow",
  "atoi",
@@ -1779,10 +1823,11 @@ dependencies = [
  "egui-wgpu",
  "egui-winit",
  "egui_extras",
+ "fixed",
  "gilrs",
  "hex",
  "image",
- "itertools",
+ "itertools 0.14.0",
  "num-derive",
  "num-traits",
  "oneshot",
@@ -3372,6 +3417,12 @@ dependencies = [
  "rustc-hash",
 ]
 
+[[package]]
+name = "typenum"
+version = "1.17.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "42ff0bf0c66b8238c6f3b578df37d0b7848e55df8577b3f74f92a69acceeb825"
+
 [[package]]
 name = "uds_windows"
 version = "1.1.0"

Cargo.toml

@@ -4,7 +4,7 @@ description = "An emulator for the Virtual Boy."
 repository = "https://git.virtual-boy.com/PVB/lemur"
 publish = false
 license = "MIT"
-version = "0.3.2"
+version = "0.4.2"
 edition = "2021"
 
 [dependencies]
@@ -21,10 +21,11 @@ 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"] }
+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 = "0.13"
+itertools = "0.14"
 num-derive = "0.4"
 num-traits = "0.2"
 oneshot = "0.1"

src/app.rs

@@ -17,13 +17,13 @@ use winit::{
 use crate::{
     controller::ControllerManager,
     emulator::{EmulatorClient, EmulatorCommand, SimId},
+    images::ImageProcessor,
     input::MappingProvider,
     memory::MemoryClient,
     persistence::Persistence,
-    vram::VramProcessor,
     window::{
-        AboutWindow, AppWindow, BgMapWindow, CharacterDataWindow, GameWindow, GdbServerWindow,
-        InputWindow, ObjectWindow,
+        AboutWindow, AppWindow, BgMapWindow, CharacterDataWindow, FrameBufferWindow, GameWindow,
+        GdbServerWindow, InputWindow, ObjectWindow, RegisterWindow, WorldWindow,
     },
 };
 
@@ -46,7 +46,7 @@ pub struct Application {
     mappings: MappingProvider,
     controllers: ControllerManager,
     memory: Arc<MemoryClient>,
-    vram: VramProcessor,
+    images: ImageProcessor,
     persistence: Persistence,
     viewports: HashMap<ViewportId, Viewport>,
     focused: Option<ViewportId>,
@@ -65,7 +65,7 @@ impl Application {
         let mappings = MappingProvider::new(persistence.clone());
         let controllers = ControllerManager::new(client.clone(), &mappings);
         let memory = Arc::new(MemoryClient::new(client.clone()));
-        let vram = VramProcessor::new();
+        let images = ImageProcessor::new();
         {
             let mappings = mappings.clone();
             let proxy = proxy.clone();
@@ -78,7 +78,7 @@ impl Application {
             proxy,
             mappings,
             memory,
-            vram,
+            images,
             controllers,
             persistence,
             viewports: HashMap::new(),
@@ -214,17 +214,29 @@ impl ApplicationHandler<UserEvent> for Application {
                 self.open(event_loop, Box::new(about));
             }
             UserEvent::OpenCharacterData(sim_id) => {
-                let vram = CharacterDataWindow::new(sim_id, &self.memory, &mut self.vram);
-                self.open(event_loop, Box::new(vram));
+                let chardata = CharacterDataWindow::new(sim_id, &self.memory, &mut self.images);
+                self.open(event_loop, Box::new(chardata));
             }
             UserEvent::OpenBgMap(sim_id) => {
-                let bgmap = BgMapWindow::new(sim_id, &self.memory, &mut self.vram);
+                let bgmap = BgMapWindow::new(sim_id, &self.memory, &mut self.images);
                 self.open(event_loop, Box::new(bgmap));
             }
             UserEvent::OpenObjects(sim_id) => {
-                let objects = ObjectWindow::new(sim_id, &self.memory, &mut self.vram);
+                let objects = ObjectWindow::new(sim_id, &self.memory, &mut self.images);
                 self.open(event_loop, Box::new(objects));
             }
+            UserEvent::OpenWorlds(sim_id) => {
+                let world = WorldWindow::new(sim_id, &self.memory, &mut self.images);
+                self.open(event_loop, Box::new(world));
+            }
+            UserEvent::OpenFrameBuffers(sim_id) => {
+                let world = FrameBufferWindow::new(sim_id, &self.memory, &mut self.images);
+                self.open(event_loop, Box::new(world));
+            }
+            UserEvent::OpenRegisters(sim_id) => {
+                let registers = RegisterWindow::new(sim_id, &self.memory);
+                self.open(event_loop, Box::new(registers));
+            }
             UserEvent::OpenDebugger(sim_id) => {
                 let debugger =
                     GdbServerWindow::new(sim_id, self.client.clone(), self.proxy.clone());
@@ -486,6 +498,9 @@ pub enum UserEvent {
     OpenCharacterData(SimId),
     OpenBgMap(SimId),
     OpenObjects(SimId),
+    OpenWorlds(SimId),
+    OpenFrameBuffers(SimId),
+    OpenRegisters(SimId),
     OpenDebugger(SimId),
     OpenInput,
     OpenPlayer2,

src/emulator.rs

@@ -291,6 +291,26 @@ impl Emulator {
         );
     }
 
+    fn frame_advance(&mut self) {
+        if self
+            .state
+            .compare_exchange(
+                EmulatorState::Paused,
+                EmulatorState::Stepping,
+                Ordering::AcqRel,
+                Ordering::Acquire,
+            )
+            .is_err_and(|s| s == EmulatorState::Running)
+        {
+            let _ = self.state.compare_exchange(
+                EmulatorState::Running,
+                EmulatorState::Stepping,
+                Ordering::AcqRel,
+                Ordering::Relaxed,
+            );
+        }
+    }
+
     fn 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();
@@ -366,6 +386,7 @@ impl Emulator {
         debugger.stop_reason = None;
         true
     }
+
     fn debug_step(&mut self, sim_id: SimId) {
         if self.debug_continue(sim_id) {
             let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
@@ -428,7 +449,7 @@ impl Emulator {
         // Don't emulate if the state is "paused", or if any sim is paused in the debugger
         let running = match state {
             EmulatorState::Paused => false,
-            EmulatorState::Running => true,
+            EmulatorState::Running | EmulatorState::Stepping => true,
             EmulatorState::Debugging => self.debuggers.values().all(|d| d.stop_reason.is_none()),
         };
         let p1_running = running && p1_state == SimState::Ready;
@@ -442,6 +463,10 @@ impl Emulator {
             self.sims[SimId::Player2.to_index()].emulate();
         }
 
+        if state == EmulatorState::Stepping {
+            self.state.store(EmulatorState::Paused, Ordering::Release);
+        }
+
         // Debug state
         if state == EmulatorState::Debugging {
             for sim_id in SimId::values() {
@@ -539,6 +564,9 @@ impl Emulator {
             EmulatorCommand::Resume => {
                 self.resume_sims();
             }
+            EmulatorCommand::FrameAdvance => {
+                self.frame_advance();
+            }
             EmulatorCommand::StartDebugging(sim_id, debugger) => {
                 self.start_debugging(sim_id, debugger);
             }
@@ -665,6 +693,7 @@ pub enum EmulatorCommand {
     StopSecondSim,
     Pause,
     Resume,
+    FrameAdvance,
     StartDebugging(SimId, DebugSender),
     StopDebugging(SimId),
     DebugInterrupt(SimId),
@@ -700,6 +729,7 @@ pub enum SimState {
 pub enum EmulatorState {
     Paused,
     Running,
+    Stepping,
     Debugging,
 }
 

src/graphics.rs

@@ -64,9 +64,7 @@ impl TextureSink {
             sample_count: 1,
             dimension: wgpu::TextureDimension::D2,
             format: TextureFormat::Rg8Unorm,
-            usage: TextureUsages::COPY_SRC
-                | TextureUsages::COPY_DST
-                | TextureUsages::TEXTURE_BINDING,
+            usage: TextureUsages::COPY_DST | TextureUsages::TEXTURE_BINDING,
             view_formats: &[TextureFormat::Rg8Unorm],
         };
         device.create_texture(&desc)

src/images.rs

@@ -13,11 +13,11 @@ use egui::{
 };
 use tokio::{sync::mpsc, time::timeout};
 
-pub struct VramProcessor {
-    sender: mpsc::UnboundedSender<Box<dyn VramRendererImpl>>,
+pub struct ImageProcessor {
+    sender: mpsc::UnboundedSender<Box<dyn ImageRendererImpl>>,
 }
 
-impl VramProcessor {
+impl ImageProcessor {
     pub fn new() -> Self {
         let (sender, receiver) = mpsc::unbounded_channel();
         thread::spawn(move || {
@@ -26,7 +26,7 @@ impl VramProcessor {
                 .build()
                 .unwrap()
                 .block_on(async move {
-                    let mut worker = VramProcessorWorker {
+                    let mut worker = ImageProcessorWorker {
                         receiver,
                         renderers: vec![],
                     };
@@ -36,39 +36,40 @@ impl VramProcessor {
         Self { sender }
     }
 
-    pub fn add<const N: usize, R: VramRenderer<N> + 'static>(
+    pub fn add<const N: usize, R: ImageRenderer<N> + 'static>(
         &self,
         renderer: R,
-    ) -> ([VramImageHandle; N], VramParams<R::Params>) {
-        let states = renderer.sizes().map(VramRenderImageState::new);
-        let handles = states.clone().map(|state| VramImageHandle {
+        params: R::Params,
+    ) -> ([ImageHandle; N], ImageParams<R::Params>) {
+        let states = renderer.sizes().map(ImageState::new);
+        let handles = states.clone().map(|state| ImageHandle {
             size: state.size.map(|i| i as f32),
             data: state.sink,
         });
         let images = renderer
             .sizes()
-            .map(|[width, height]| VramImage::new(width, height));
-        let sink = Arc::new(Mutex::new(R::Params::default()));
-        let _ = self.sender.send(Box::new(VramRendererWrapper {
+            .map(|[width, height]| ImageBuffer::new(width, height));
+        let sink = Arc::new(Mutex::new(params.clone()));
+        let _ = self.sender.send(Box::new(ImageRendererWrapper {
             renderer,
             params: Arc::downgrade(&sink),
             images,
             states,
         }));
-        let params = VramParams {
-            value: R::Params::default(),
+        let params = ImageParams {
+            value: params,
             sink,
         };
         (handles, params)
     }
 }
 
-struct VramProcessorWorker {
-    receiver: mpsc::UnboundedReceiver<Box<dyn VramRendererImpl>>,
-    renderers: Vec<Box<dyn VramRendererImpl>>,
+struct ImageProcessorWorker {
+    receiver: mpsc::UnboundedReceiver<Box<dyn ImageRendererImpl>>,
+    renderers: Vec<Box<dyn ImageRendererImpl>>,
 }
 
-impl VramProcessorWorker {
+impl ImageProcessorWorker {
     async fn run(&mut self) {
         loop {
             if self.renderers.is_empty() {
@@ -99,33 +100,33 @@ impl VramProcessorWorker {
     }
 }
 
-pub struct VramImage {
-    size: [usize; 2],
-    shades: Vec<Color32>,
+pub struct ImageBuffer {
+    pub size: [usize; 2],
+    pub pixels: Vec<Color32>,
 }
 
-impl VramImage {
+impl ImageBuffer {
     pub fn new(width: usize, height: usize) -> Self {
         Self {
             size: [width, height],
-            shades: vec![Color32::BLACK; width * height],
+            pixels: vec![Color32::BLACK; width * height],
         }
     }
 
     pub fn clear(&mut self) {
-        for shade in self.shades.iter_mut() {
-            *shade = Color32::BLACK;
+        for pixel in self.pixels.iter_mut() {
+            *pixel = Color32::BLACK;
         }
     }
 
     pub fn write(&mut self, coords: (usize, usize), pixel: Color32) {
-        self.shades[coords.1 * self.size[0] + coords.0] = pixel;
+        self.pixels[coords.1 * self.size[0] + coords.0] = pixel;
     }
 
     pub fn add(&mut self, coords: (usize, usize), pixel: Color32) {
         let index = coords.1 * self.size[0] + coords.0;
-        let old = self.shades[index];
-        self.shades[index] = Color32::from_rgb(
+        let old = self.pixels[index];
+        self.pixels[index] = Color32::from_rgb(
             old.r() + pixel.r(),
             old.g() + pixel.g(),
             old.b() + pixel.b(),
@@ -133,32 +134,32 @@ impl VramImage {
     }
 
     pub fn changed(&self, image: &ColorImage) -> bool {
-        image.pixels.iter().zip(&self.shades).any(|(a, b)| a != b)
+        image.pixels.iter().zip(&self.pixels).any(|(a, b)| a != b)
     }
 
     pub fn read(&self, image: &mut ColorImage) {
-        image.pixels.copy_from_slice(&self.shades);
+        image.pixels.copy_from_slice(&self.pixels);
     }
 }
 
 #[derive(Clone)]
-pub struct VramImageHandle {
+pub struct ImageHandle {
     size: [f32; 2],
     data: Arc<Mutex<Option<Arc<ColorImage>>>>,
 }
 
-impl VramImageHandle {
+impl ImageHandle {
     fn pull(&mut self) -> Option<Arc<ColorImage>> {
         self.data.lock().unwrap().take()
     }
 }
 
-pub struct VramParams<T> {
+pub struct ImageParams<T> {
     value: T,
     sink: Arc<Mutex<T>>,
 }
 
-impl<T> Deref for VramParams<T> {
+impl<T> Deref for ImageParams<T> {
     type Target = T;
 
     fn deref(&self) -> &Self::Target {
@@ -166,7 +167,7 @@ impl<T> Deref for VramParams<T> {
     }
 }
 
-impl<T: Clone + Eq> VramParams<T> {
+impl<T: Clone + Eq> ImageParams<T> {
     pub fn write(&mut self, value: T) {
         if self.value != value {
             self.value = value.clone();
@@ -175,21 +176,21 @@ impl<T: Clone + Eq> VramParams<T> {
     }
 }
 
-pub trait VramRenderer<const N: usize>: Send {
-    type Params: Clone + Default + Send;
+pub trait ImageRenderer<const N: usize>: Send {
+    type Params: Clone + Send;
     fn sizes(&self) -> [[usize; 2]; N];
-    fn render(&mut self, params: &Self::Params, images: &mut [VramImage; N]);
+    fn render(&mut self, params: &Self::Params, images: &mut [ImageBuffer; N]);
 }
 
 #[derive(Clone)]
-struct VramRenderImageState {
+struct ImageState {
     size: [usize; 2],
     buffers: [Arc<ColorImage>; 2],
     last_buffer: usize,
     sink: Arc<Mutex<Option<Arc<ColorImage>>>>,
 }
 
-impl VramRenderImageState {
+impl ImageState {
     fn new(size: [usize; 2]) -> Self {
         let buffers = [
             Arc::new(ColorImage::new(size, Color32::BLACK)),
@@ -203,7 +204,7 @@ impl VramRenderImageState {
             sink: Arc::new(Mutex::new(Some(sink))),
         }
     }
-    fn try_send_update(&mut self, image: &VramImage) {
+    fn try_send_update(&mut self, image: &ImageBuffer) {
         let last = &self.buffers[self.last_buffer];
         if !image.changed(last) {
             return;
@@ -217,18 +218,18 @@ impl VramRenderImageState {
     }
 }
 
-struct VramRendererWrapper<const N: usize, R: VramRenderer<N>> {
+struct ImageRendererWrapper<const N: usize, R: ImageRenderer<N>> {
     renderer: R,
     params: Weak<Mutex<R::Params>>,
-    images: [VramImage; N],
-    states: [VramRenderImageState; N],
+    images: [ImageBuffer; N],
+    states: [ImageState; N],
 }
 
-trait VramRendererImpl: Send {
+trait ImageRendererImpl: Send {
     fn try_update(&mut self) -> Result<(), ()>;
 }
 
-impl<const N: usize, R: VramRenderer<N> + Send> VramRendererImpl for VramRendererWrapper<N, R> {
+impl<const N: usize, R: ImageRenderer<N> + Send> ImageRendererImpl for ImageRendererWrapper<N, R> {
     fn try_update(&mut self) -> Result<(), ()> {
         let params = match self.params.upgrade() {
             Some(params) => params.lock().unwrap().clone(),
@@ -246,12 +247,12 @@ impl<const N: usize, R: VramRenderer<N> + Send> VramRendererImpl for VramRendere
     }
 }
 
-pub struct VramTextureLoader {
-    cache: Mutex<HashMap<String, (VramImageHandle, Option<TextureHandle>)>>,
+pub struct ImageTextureLoader {
+    cache: Mutex<HashMap<String, (ImageHandle, Option<TextureHandle>)>>,
 }
 
-impl VramTextureLoader {
-    pub fn new(renderers: impl IntoIterator<Item = (String, VramImageHandle)>) -> Self {
+impl ImageTextureLoader {
+    pub fn new(renderers: impl IntoIterator<Item = (String, ImageHandle)>) -> Self {
         let mut cache = HashMap::new();
         for (key, image) in renderers {
             cache.insert(key, (image, None));
@@ -262,9 +263,9 @@ impl VramTextureLoader {
     }
 }
 
-impl TextureLoader for VramTextureLoader {
+impl TextureLoader for ImageTextureLoader {
     fn id(&self) -> &str {
-        concat!(module_path!(), "VramTextureLoader")
+        concat!(module_path!(), "ImageTextureLoader")
     }
 
     fn load(

src/main.rs

@@ -18,10 +18,10 @@ mod controller;
 mod emulator;
 mod gdbserver;
 mod graphics;
+mod images;
 mod input;
 mod memory;
 mod persistence;
-mod vram;
 mod window;
 
 #[derive(Parser)]

src/memory.rs

@@ -1,6 +1,7 @@
 use std::{
     collections::HashMap,
     fmt::Debug,
+    iter::FusedIterator,
     sync::{atomic::AtomicU64, Arc, Mutex, RwLock, RwLockReadGuard, TryLockError, Weak},
 };
 
@@ -97,8 +98,11 @@ macro_rules! primitive_memory_value_impl {
 }
 
 primitive_memory_value_impl!(u8, 1);
+primitive_memory_value_impl!(i8, 1);
 primitive_memory_value_impl!(u16, 2);
+primitive_memory_value_impl!(i16, 2);
 primitive_memory_value_impl!(u32, 4);
+primitive_memory_value_impl!(i32, 4);
 
 impl<const N: usize, T: MemoryValue> MemoryValue for [T; N] {
     #[inline]
@@ -117,7 +121,6 @@ impl<const N: usize, T: MemoryValue> MemoryValue for [T; N] {
 
 pub struct MemoryIter<'a, T> {
     bytes: &'a [u8],
-    index: usize,
     _phantom: std::marker::PhantomData<T>,
 }
 
@@ -125,7 +128,6 @@ impl<'a, T> MemoryIter<'a, T> {
     fn new(bytes: &'a [u8]) -> Self {
         Self {
             bytes,
-            index: 0,
             _phantom: std::marker::PhantomData,
         }
     }
@@ -136,15 +138,30 @@ impl<T: MemoryValue> Iterator for MemoryIter<'_, T> {
 
     #[inline]
     fn next(&mut self) -> Option<Self::Item> {
-        if self.index >= self.bytes.len() {
-            return None;
-        }
-        let bytes = &self.bytes[self.index..self.index + std::mem::size_of::<T>()];
-        self.index += std::mem::size_of::<T>();
+        let (bytes, rest) = self.bytes.split_at_checked(std::mem::size_of::<T>())?;
+        self.bytes = rest;
+        Some(T::from_bytes(bytes))
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let size = self.bytes.len() / std::mem::size_of::<T>();
+        (size, Some(size))
+    }
+}
+
+impl<T: MemoryValue> DoubleEndedIterator for MemoryIter<'_, T> {
+    fn next_back(&mut self) -> Option<Self::Item> {
+        let mid = self.bytes.len().checked_sub(std::mem::size_of::<T>())?;
+        // SAFETY: the checked_sub above is effectively a bounds check
+        let (rest, bytes) = unsafe { self.bytes.split_at_unchecked(mid) };
+        self.bytes = rest;
         Some(T::from_bytes(bytes))
     }
 }
 
+impl<T: MemoryValue> FusedIterator for MemoryIter<'_, T> {}
+
 impl MemoryRef<'_> {
     pub fn read<T: MemoryValue>(&self, index: usize) -> T {
         let from = index * size_of::<T>();
@@ -221,11 +238,10 @@ impl MemoryRegion {
     }
 
     pub fn update(&self, data: &[u8]) {
-        let gens: Vec<u64> = self
+        let gens = self
             .gens
-            .iter()
-            .map(|i| i.load(std::sync::atomic::Ordering::Acquire))
-            .collect();
+            .each_ref()
+            .map(|i| i.load(std::sync::atomic::Ordering::Acquire));
         let next_gen = gens.iter().max().unwrap() + 1;
         let indices = gens
             .into_iter()
@@ -247,7 +263,7 @@ impl MemoryRegion {
         /*
          * We have four buffers, and (at time of writing) only three threads interacting with memory:
          * - The UI thread, reading small regions of memory
-         * - The "vram renderer" thread, reading large regions of memory
+         * - The "image renderer" thread, reading large regions of memory
          * - The emulation thread, writing memory every so often
          * So it should be impossible for all four buffers to have a read lock at the same time,
          *  and (because readers always read the newest buffer) at least one of the oldest three

src/window.rs

@@ -3,7 +3,9 @@ use egui::{Context, ViewportBuilder, ViewportId};
 pub use game::GameWindow;
 pub use gdb::GdbServerWindow;
 pub use input::InputWindow;
-pub use vram::{BgMapWindow, CharacterDataWindow, ObjectWindow};
+pub use vip::{
+    BgMapWindow, CharacterDataWindow, FrameBufferWindow, ObjectWindow, RegisterWindow, WorldWindow,
+};
 use winit::event::KeyEvent;
 
 use crate::emulator::SimId;
@@ -14,7 +16,7 @@ mod game_screen;
 mod gdb;
 mod input;
 mod utils;
-mod vram;
+mod vip;
 
 pub trait AppWindow {
     fn viewport_id(&self) -> ViewportId;

src/window/game.rs

@@ -86,6 +86,7 @@ impl GameWindow {
             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() {
                     self.client.send_command(EmulatorCommand::Pause);
@@ -100,6 +101,14 @@ impl GameWindow {
                     .send_command(EmulatorCommand::Reset(self.sim_id));
                 ui.close_menu();
             }
+            ui.separator();
+            if ui
+                .add_enabled(can_frame_advance, Button::new("Frame Advance"))
+                .clicked()
+            {
+                self.client.send_command(EmulatorCommand::FrameAdvance);
+                ui.close_menu();
+            }
         });
         ui.menu_button("Options", |ui| self.show_options_menu(ctx, ui));
         ui.menu_button("Multiplayer", |ui| {
@@ -132,6 +141,7 @@ impl GameWindow {
                     .unwrap();
                 ui.close_menu();
             }
+            ui.separator();
             if ui.button("Character Data").clicked() {
                 self.proxy
                     .send_event(UserEvent::OpenCharacterData(self.sim_id))
@@ -150,6 +160,24 @@ impl GameWindow {
                     .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() {

src/window/utils.rs

@@ -1,15 +1,16 @@
 use std::{
-    fmt::Display,
+    fmt::{Display, UpperHex},
     ops::{Bound, RangeBounds},
     str::FromStr,
 };
 
+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,
 };
-use num_traits::PrimInt;
+use num_traits::{CheckedAdd, CheckedSub, One};
 
 pub trait UiExt {
     fn section(&mut self, title: impl Into<String>, add_contents: impl FnOnce(&mut Ui));
@@ -34,19 +35,24 @@ pub trait UiExt {
 
 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;
-        let res = frame.show(self, add_contents);
+        let res = self.push_id(&title, |ui| {
+            frame.show(ui, |ui| {
+                ui.set_max_width(ui.available_width());
+                add_contents(ui);
+            })
+        });
         let text = RichText::new(title).background_color(self.style().visuals.panel_fill);
         let old_rect = res.response.rect;
         let mut text_rect = old_rect;
         text_rect.min.x += 6.0;
-        let new_rect = self
-            .allocate_new_ui(UiBuilder::new().max_rect(text_rect), |ui| ui.label(text))
-            .response
-            .rect;
-        self.allocate_space((old_rect.max - new_rect.max) - (old_rect.min - new_rect.min));
+        self.allocate_new_ui(UiBuilder::new().max_rect(text_rect), |ui| ui.label(text));
+        if old_rect.width() > 0.0 {
+            self.advance_cursor_after_rect(old_rect);
+        }
     }
 
     fn selectable_button(&mut self, selected: bool, text: impl Into<WidgetText>) -> Response {
@@ -96,14 +102,49 @@ enum Direction {
     Down,
 }
 
-pub trait Number: PrimInt + Display + FromStr + Send + Sync + 'static {}
-impl<T: PrimInt + Display + FromStr + Send + Sync + 'static> Number for T {}
+pub trait Number:
+    Copy
+    + One
+    + CheckedAdd
+    + CheckedSub
+    + Eq
+    + Ord
+    + Display
+    + FromStr
+    + FromRadix16
+    + UpperHex
+    + Send
+    + Sync
+    + 'static
+{
+}
+impl<
+        T: Copy
+            + One
+            + CheckedAdd
+            + CheckedSub
+            + Eq
+            + Ord
+            + Display
+            + FromStr
+            + FromRadix16
+            + UpperHex
+            + Send
+            + Sync
+            + 'static,
+    > Number for T
+{
+}
 
 pub struct NumberEdit<'a, T: Number> {
     value: &'a mut T,
     increment: T,
+    precision: usize,
     min: Option<T>,
     max: Option<T>,
+    desired_width: Option<f32>,
+    arrows: bool,
+    hex: bool,
 }
 
 impl<'a, T: Number> NumberEdit<'a, T> {
@@ -111,11 +152,19 @@ impl<'a, T: Number> NumberEdit<'a, T> {
         Self {
             value,
             increment: T::one(),
+            precision: 3,
             min: None,
             max: None,
+            desired_width: None,
+            arrows: true,
+            hex: false,
         }
     }
 
+    pub fn precision(self, precision: usize) -> Self {
+        Self { precision, ..self }
+    }
+
     pub fn range(self, range: impl RangeBounds<T>) -> Self {
         let min = match range.start_bound() {
             Bound::Unbounded => None,
@@ -129,24 +178,57 @@ impl<'a, T: Number> NumberEdit<'a, T> {
         };
         Self { min, max, ..self }
     }
+
+    pub fn desired_width(self, desired_width: f32) -> Self {
+        Self {
+            desired_width: Some(desired_width),
+            ..self
+        }
+    }
+
+    pub fn arrows(self, arrows: bool) -> Self {
+        Self { arrows, ..self }
+    }
+
+    pub fn hex(self, hex: bool) -> Self {
+        Self { hex, ..self }
+    }
 }
 
 impl<T: Number> Widget for NumberEdit<'_, T> {
     fn ui(self, ui: &mut Ui) -> Response {
+        let id = ui.id();
+        let to_string = |val: &T| {
+            if self.hex {
+                format!("{val:.0$X}", self.precision)
+            } else {
+                format!("{val:.0$}", self.precision)
+            }
+        };
+        let from_string = |val: &str| {
+            if self.hex {
+                let bytes = val.as_bytes();
+                let (result, consumed) = T::from_radix_16(bytes);
+                (consumed == bytes.len()).then_some(result)
+            } else {
+                val.parse::<T>().ok()
+            }
+        };
+
         let (last_value, mut str, focus) = ui.memory(|m| {
             let (lv, s) = m
                 .data
-                .get_temp(ui.id())
-                .unwrap_or((*self.value, self.value.to_string()));
-            let focus = m.has_focus(ui.id());
+                .get_temp(id)
+                .unwrap_or((*self.value, to_string(self.value)));
+            let focus = m.has_focus(id);
             (lv, s, focus)
         });
         let mut stale = false;
         if *self.value != last_value {
-            str = self.value.to_string();
+            str = to_string(self.value);
             stale = true;
         }
-        let valid = str.parse().is_ok_and(|v: T| v == *self.value);
+        let valid = from_string(&str).is_some_and(|v: T| v == *self.value);
         let mut up_pressed = false;
         let mut down_pressed = false;
         if focus {
@@ -172,22 +254,37 @@ impl<T: Number> Widget for NumberEdit<'_, T> {
                 })
             });
         }
+        let mut desired_width = self
+            .desired_width
+            .unwrap_or_else(|| ui.spacing().text_edit_width);
+        if self.arrows {
+            desired_width -= 16.0;
+        }
         let text = TextEdit::singleline(&mut str)
             .horizontal_align(Align::Max)
-            .id(ui.id())
+            .id(id)
+            .desired_width(desired_width)
             .margin(Margin {
                 left: 4.0,
-                right: 20.0,
+                right: if self.arrows { 20.0 } else { 4.0 },
                 top: 2.0,
                 bottom: 2.0,
             });
-        let res = if valid {
+        let mut res = if valid {
             ui.add(text)
         } else {
             let message = match (self.min, self.max) {
-                (Some(min), Some(max)) => format!("Please enter a number between {min} and {max}."),
-                (Some(min), None) => format!("Please enter a number greater than {min}."),
-                (None, Some(max)) => format!("Please enter a number less than {max}."),
+                (Some(min), Some(max)) => format!(
+                    "Please enter a number between {} and {}.",
+                    to_string(&min),
+                    to_string(&max)
+                ),
+                (Some(min), None) => {
+                    format!("Please enter a number greater than {}.", to_string(&min))
+                }
+                (None, Some(max)) => {
+                    format!("Please enter a number less than {}.", to_string(&max))
+                }
                 (None, None) => "Please enter a number.".to_string(),
             };
             ui.scope(|ui| {
@@ -201,26 +298,28 @@ impl<T: Number> Widget for NumberEdit<'_, T> {
             .on_hover_text(message)
         };
 
-        let arrow_left = res.rect.max.x + 4.0;
-        let arrow_right = res.rect.max.x + 20.0;
-        let arrow_top = res.rect.min.y - 2.0;
-        let arrow_middle = (res.rect.min.y + res.rect.max.y) / 2.0;
-        let arrow_bottom = res.rect.max.y + 2.0;
-
         let mut delta = None;
-        let top_arrow_rect = Rect {
-            min: (arrow_left, arrow_top).into(),
-            max: (arrow_right, arrow_middle).into(),
-        };
-        if draw_arrow(ui, top_arrow_rect, true).clicked_or_dragged() || up_pressed {
-            delta = Some(Direction::Up);
-        }
-        let bottom_arrow_rect = Rect {
-            min: (arrow_left, arrow_middle).into(),
-            max: (arrow_right, arrow_bottom).into(),
-        };
-        if draw_arrow(ui, bottom_arrow_rect, false).clicked_or_dragged() || down_pressed {
-            delta = Some(Direction::Down);
+        if self.arrows {
+            let arrow_left = res.rect.max.x + 4.0;
+            let arrow_right = res.rect.max.x + 20.0;
+            let arrow_top = res.rect.min.y - 2.0;
+            let arrow_middle = (res.rect.min.y + res.rect.max.y) / 2.0;
+            let arrow_bottom = res.rect.max.y + 2.0;
+
+            let top_arrow_rect = Rect {
+                min: (arrow_left, arrow_top).into(),
+                max: (arrow_right, arrow_middle).into(),
+            };
+            if draw_arrow(ui, top_arrow_rect, true).clicked_or_dragged() || up_pressed {
+                delta = Some(Direction::Up);
+            }
+            let bottom_arrow_rect = Rect {
+                min: (arrow_left, arrow_middle).into(),
+                max: (arrow_right, arrow_bottom).into(),
+            };
+            if draw_arrow(ui, bottom_arrow_rect, false).clicked_or_dragged() || down_pressed {
+                delta = Some(Direction::Down);
+            }
         }
 
         let in_range =
@@ -231,18 +330,24 @@ impl<T: Number> Widget for NumberEdit<'_, T> {
                 Direction::Down => self.value.checked_sub(&self.increment),
             };
             if let Some(new_value) = value.filter(in_range) {
+                if *self.value != new_value {
+                    res.mark_changed();
+                }
                 *self.value = new_value;
             }
-            str = self.value.to_string();
+            str = to_string(self.value);
             stale = true;
         } else if res.changed {
-            if let Some(new_value) = str.parse().ok().filter(in_range) {
+            if let Some(new_value) = from_string(&str).filter(in_range) {
+                if *self.value != new_value {
+                    res.mark_changed();
+                }
                 *self.value = new_value;
             }
             stale = true;
         }
         if stale {
-            ui.memory_mut(|m| m.data.insert_temp(ui.id(), (*self.value, str)));
+            ui.memory_mut(|m| m.data.insert_temp(id, (*self.value, str)));
         }
         res
     }

src/window/vip.rs

@@ -1,8 +1,14 @@
 mod bgmap;
 mod chardata;
+mod framebuffer;
 mod object;
+mod registers;
 mod utils;
+mod world;
 
 pub use bgmap::*;
 pub use chardata::*;
+pub use framebuffer::*;
 pub use object::*;
+pub use registers::*;
+pub use world::*;

src/window/vip/bgmap.rs

@@ -8,8 +8,8 @@ use egui_extras::{Column, Size, StripBuilder, TableBuilder};
 
 use crate::{
     emulator::SimId,
+    images::{ImageBuffer, ImageParams, ImageProcessor, ImageRenderer, ImageTextureLoader},
     memory::{MemoryClient, MemoryView},
-    vram::{VramImage, VramParams, VramProcessor, VramRenderer, VramTextureLoader},
     window::{
         utils::{NumberEdit, UiExt},
         AppWindow,
@@ -20,29 +20,29 @@ use super::utils::{self, CellData, CharacterGrid};
 
 pub struct BgMapWindow {
     sim_id: SimId,
-    loader: Arc<VramTextureLoader>,
+    loader: Arc<ImageTextureLoader>,
     memory: Arc<MemoryClient>,
     bgmaps: MemoryView,
     cell_index: usize,
     generic_palette: bool,
-    params: VramParams<BgMapParams>,
+    params: ImageParams<BgMapParams>,
     scale: f32,
     show_grid: bool,
 }
 
 impl BgMapWindow {
-    pub fn new(sim_id: SimId, memory: &Arc<MemoryClient>, vram: &mut VramProcessor) -> Self {
+    pub fn new(sim_id: SimId, memory: &Arc<MemoryClient>, images: &mut ImageProcessor) -> Self {
         let renderer = BgMapRenderer::new(sim_id, memory);
-        let ([cell, bgmap], params) = vram.add(renderer);
+        let ([cell, bgmap], params) = images.add(renderer, BgMapParams::default());
         let loader =
-            VramTextureLoader::new([("vram://cell".into(), cell), ("vram://bgmap".into(), bgmap)]);
+            ImageTextureLoader::new([("vip://cell".into(), cell), ("vip://bgmap".into(), bgmap)]);
         Self {
             sim_id,
             loader: Arc::new(loader),
             memory: memory.clone(),
-            bgmaps: memory.watch(sim_id, 0x00020000, 0x1d800),
-            cell_index: 0,
-            generic_palette: false,
+            bgmaps: memory.watch(sim_id, 0x00020000, 0x20000),
+            cell_index: params.cell_index,
+            generic_palette: params.generic_palette,
             params,
             scale: 1.0,
             show_grid: false,
@@ -62,7 +62,7 @@ impl BgMapWindow {
                         });
                         row.col(|ui| {
                             let mut bgmap_index = self.cell_index / 4096;
-                            ui.add(NumberEdit::new(&mut bgmap_index).range(0..14));
+                            ui.add(NumberEdit::new(&mut bgmap_index).range(0..16));
                             if bgmap_index != self.cell_index / 4096 {
                                 self.cell_index = (bgmap_index * 4096) + (self.cell_index % 4096);
                             }
@@ -90,7 +90,7 @@ impl BgMapWindow {
                         });
                     });
                 });
-            let image = Image::new("vram://cell")
+            let image = Image::new("vip://cell")
                 .maintain_aspect_ratio(true)
                 .texture_options(TextureOptions::NEAREST);
             ui.add(image);
@@ -162,7 +162,7 @@ impl BgMapWindow {
     }
 
     fn show_bgmap(&mut self, ui: &mut Ui) {
-        let grid = CharacterGrid::new("vram://bgmap")
+        let grid = CharacterGrid::new("vip://bgmap")
             .with_scale(self.scale)
             .with_grid(self.show_grid)
             .with_selected(self.cell_index % 4096);
@@ -195,7 +195,7 @@ impl AppWindow for BgMapWindow {
         CentralPanel::default().show(ctx, |ui| {
             ui.horizontal_top(|ui| {
                 StripBuilder::new(ui)
-                    .size(Size::relative(0.3))
+                    .size(Size::relative(0.3).at_most(200.0))
                     .size(Size::remainder())
                     .horizontal(|mut strip| {
                         strip.cell(|ui| {
@@ -227,13 +227,13 @@ impl BgMapRenderer {
     pub fn new(sim_id: SimId, memory: &MemoryClient) -> Self {
         Self {
             chardata: memory.watch(sim_id, 0x00078000, 0x8000),
-            bgmaps: memory.watch(sim_id, 0x00020000, 0x1d800),
+            bgmaps: memory.watch(sim_id, 0x00020000, 0x20000),
             brightness: memory.watch(sim_id, 0x0005f824, 8),
             palettes: memory.watch(sim_id, 0x0005f860, 16),
         }
     }
 
-    fn render_bgmap(&self, image: &mut VramImage, bgmap_index: usize, generic_palette: bool) {
+    fn render_bgmap(&self, image: &mut ImageBuffer, bgmap_index: usize, generic_palette: bool) {
         let chardata = self.chardata.borrow();
         let bgmaps = self.bgmaps.borrow();
         let brightness = self.brightness.borrow();
@@ -243,7 +243,7 @@ impl BgMapRenderer {
         let colors = if generic_palette {
             [utils::generic_palette(Color32::RED); 4]
         } else {
-            [0, 2, 4, 6].map(|i| utils::parse_palette(palettes.read(i), &brts, Color32::RED))
+            [0, 2, 4, 6].map(|i| utils::palette_colors(palettes.read(i), &brts, Color32::RED))
         };
 
         for (i, cell) in bgmaps.range::<u16>(bgmap_index * 4096, 4096).enumerate() {
@@ -266,7 +266,7 @@ impl BgMapRenderer {
         }
     }
 
-    fn render_bgmap_cell(&self, image: &mut VramImage, index: usize, generic_palette: bool) {
+    fn render_bgmap_cell(&self, image: &mut ImageBuffer, index: usize, generic_palette: bool) {
         let chardata = self.chardata.borrow();
         let bgmaps = self.bgmaps.borrow();
         let brightness = self.brightness.borrow();
@@ -286,7 +286,7 @@ impl BgMapRenderer {
         let palette = if generic_palette {
             utils::generic_palette(Color32::RED)
         } else {
-            utils::parse_palette(palettes.read(palette_index * 2), &brts, Color32::RED)
+            utils::palette_colors(palettes.read(palette_index * 2), &brts, Color32::RED)
         };
 
         for row in 0..8 {
@@ -297,14 +297,14 @@ impl BgMapRenderer {
     }
 }
 
-impl VramRenderer<2> for BgMapRenderer {
+impl ImageRenderer<2> for BgMapRenderer {
     type Params = BgMapParams;
 
     fn sizes(&self) -> [[usize; 2]; 2] {
         [[8, 8], [8 * 64, 8 * 64]]
     }
 
-    fn render(&mut self, params: &Self::Params, images: &mut [VramImage; 2]) {
+    fn render(&mut self, params: &Self::Params, images: &mut [ImageBuffer; 2]) {
         self.render_bgmap_cell(&mut images[0], params.cell_index, params.generic_palette);
         self.render_bgmap(
             &mut images[1],

src/window/vip/chardata.rs

@@ -9,8 +9,8 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     emulator::SimId,
+    images::{ImageBuffer, ImageParams, ImageProcessor, ImageRenderer, ImageTextureLoader},
     memory::{MemoryClient, MemoryView},
-    vram::{VramImage, VramParams, VramProcessor, VramRenderer, VramTextureLoader},
     window::{
         utils::{NumberEdit, UiExt as _},
         AppWindow,
@@ -20,7 +20,7 @@ use crate::{
 use super::utils::{self, CharacterGrid};
 
 #[derive(Debug, Default, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
-pub enum VramPalette {
+pub enum Palette {
     #[default]
     Generic,
     Bg0,
@@ -33,8 +33,8 @@ pub enum VramPalette {
     Obj3,
 }
 
-impl VramPalette {
-    pub const fn values() -> [VramPalette; 9] {
+impl Palette {
+    pub const fn values() -> [Palette; 9] {
         [
             Self::Generic,
             Self::Bg0,
@@ -63,7 +63,7 @@ impl VramPalette {
     }
 }
 
-impl Display for VramPalette {
+impl Display for Palette {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
             Self::Generic => f.write_str("Generic"),
@@ -81,23 +81,23 @@ impl Display for VramPalette {
 
 pub struct CharacterDataWindow {
     sim_id: SimId,
-    loader: Arc<VramTextureLoader>,
+    loader: Arc<ImageTextureLoader>,
     brightness: MemoryView,
     palettes: MemoryView,
-    palette: VramPalette,
+    palette: Palette,
     index: usize,
-    params: VramParams<CharDataParams>,
+    params: ImageParams<CharDataParams>,
     scale: f32,
     show_grid: bool,
 }
 
 impl CharacterDataWindow {
-    pub fn new(sim_id: SimId, memory: &MemoryClient, vram: &mut VramProcessor) -> Self {
+    pub fn new(sim_id: SimId, memory: &MemoryClient, images: &mut ImageProcessor) -> Self {
         let renderer = CharDataRenderer::new(sim_id, memory);
-        let ([char, chardata], params) = vram.add(renderer);
-        let loader = VramTextureLoader::new([
-            ("vram://char".into(), char),
-            ("vram://chardata".into(), chardata),
+        let ([char, chardata], params) = images.add(renderer, CharDataParams::default());
+        let loader = ImageTextureLoader::new([
+            ("vip://char".into(), char),
+            ("vip://chardata".into(), chardata),
         ]);
         Self {
             sim_id,
@@ -160,7 +160,7 @@ impl CharacterDataWindow {
                         });
                     });
                 });
-            let image = Image::new("vram://char")
+            let image = Image::new("vip://char")
                 .maintain_aspect_ratio(true)
                 .texture_options(TextureOptions::NEAREST);
             ui.add(image);
@@ -171,7 +171,7 @@ impl CharacterDataWindow {
                         .selected_text(self.palette.to_string())
                         .width(ui.available_width())
                         .show_ui(ui, |ui| {
-                            for palette in VramPalette::values() {
+                            for palette in Palette::values() {
                                 ui.selectable_value(
                                     &mut self.palette,
                                     palette,
@@ -222,11 +222,11 @@ impl CharacterDataWindow {
         let palette = self.palettes.borrow().read(offset);
         let brightnesses = self.brightness.borrow();
         let brts = brightnesses.read(0);
-        utils::parse_palette(palette, &brts, Color32::RED)
+        utils::palette_colors(palette, &brts, Color32::RED)
     }
 
     fn show_chardata(&mut self, ui: &mut Ui) {
-        let grid = CharacterGrid::new("vram://chardata")
+        let grid = CharacterGrid::new("vip://chardata")
             .with_scale(self.scale)
             .with_grid(self.show_grid)
             .with_selected(self.index);
@@ -259,7 +259,7 @@ impl AppWindow for CharacterDataWindow {
         CentralPanel::default().show(ctx, |ui| {
             ui.horizontal_top(|ui| {
                 StripBuilder::new(ui)
-                    .size(Size::relative(0.3))
+                    .size(Size::relative(0.3).at_most(200.0))
                     .size(Size::remainder())
                     .horizontal(|mut strip| {
                         strip.cell(|ui| {
@@ -276,13 +276,13 @@ impl AppWindow for CharacterDataWindow {
 
 #[derive(Serialize, Deserialize, Clone, PartialEq, Eq, Hash)]
 enum CharDataResource {
-    Character { palette: VramPalette, index: usize },
-    CharacterData { palette: VramPalette },
+    Character { palette: Palette, index: usize },
+    CharacterData { palette: Palette },
 }
 
 #[derive(Clone, Default, PartialEq, Eq)]
 struct CharDataParams {
-    palette: VramPalette,
+    palette: Palette,
     index: usize,
 }
 
@@ -292,14 +292,14 @@ struct CharDataRenderer {
     palettes: MemoryView,
 }
 
-impl VramRenderer<2> for CharDataRenderer {
+impl ImageRenderer<2> for CharDataRenderer {
     type Params = CharDataParams;
 
     fn sizes(&self) -> [[usize; 2]; 2] {
         [[8, 8], [16 * 8, 128 * 8]]
     }
 
-    fn render(&mut self, params: &Self::Params, image: &mut [VramImage; 2]) {
+    fn render(&mut self, params: &Self::Params, image: &mut [ImageBuffer; 2]) {
         self.render_character(&mut image[0], params.palette, params.index);
         self.render_character_data(&mut image[1], params.palette);
     }
@@ -314,7 +314,7 @@ impl CharDataRenderer {
         }
     }
 
-    fn render_character(&self, image: &mut VramImage, palette: VramPalette, index: usize) {
+    fn render_character(&self, image: &mut ImageBuffer, palette: Palette, index: usize) {
         if index >= 2048 {
             return;
         }
@@ -329,7 +329,7 @@ impl CharDataRenderer {
         }
     }
 
-    fn render_character_data(&self, image: &mut VramImage, palette: VramPalette) {
+    fn render_character_data(&self, image: &mut ImageBuffer, palette: Palette) {
         let palette = self.load_palette(palette);
         let chardata = self.chardata.borrow();
         for (row, pixels) in chardata.range::<u16>(0, 8 * 2048).enumerate() {
@@ -344,13 +344,13 @@ impl CharDataRenderer {
         }
     }
 
-    fn load_palette(&self, palette: VramPalette) -> [Color32; 4] {
+    fn load_palette(&self, palette: Palette) -> [Color32; 4] {
         let Some(offset) = palette.offset() else {
             return utils::GENERIC_PALETTE.map(|p| utils::shade(p, Color32::RED));
         };
         let palette = self.palettes.borrow().read(offset);
         let brightnesses = self.brightness.borrow();
         let brts = brightnesses.read(0);
-        utils::parse_palette(palette, &brts, Color32::RED)
+        utils::palette_colors(palette, &brts, Color32::RED)
     }
 }

src/window/vip/framebuffer.rs

@@ -0,0 +1,267 @@
+use std::sync::Arc;
+
+use egui::{
+    Align, CentralPanel, Color32, Context, Image, ScrollArea, Slider, TextEdit, TextureOptions, Ui,
+    ViewportBuilder, ViewportId,
+};
+use egui_extras::{Column, Size, StripBuilder, TableBuilder};
+
+use crate::{
+    emulator::SimId,
+    images::{ImageBuffer, ImageParams, ImageProcessor, ImageRenderer, ImageTextureLoader},
+    memory::{MemoryClient, MemoryView},
+    window::{
+        utils::{NumberEdit, UiExt as _},
+        AppWindow,
+    },
+};
+
+use super::utils;
+
+pub struct FrameBufferWindow {
+    sim_id: SimId,
+    loader: Arc<ImageTextureLoader>,
+    index: usize,
+    left: bool,
+    right: bool,
+    generic_palette: bool,
+    params: ImageParams<FrameBufferParams>,
+    scale: f32,
+}
+
+impl FrameBufferWindow {
+    pub fn new(sim_id: SimId, memory: &MemoryClient, images: &mut ImageProcessor) -> Self {
+        let initial_params = FrameBufferParams {
+            index: 0,
+            left: true,
+            right: true,
+            generic_palette: false,
+            left_color: Color32::from_rgb(0xff, 0x00, 0x00),
+            right_color: Color32::from_rgb(0x00, 0xc6, 0xf0),
+        };
+        let renderer = FrameBufferRenderer::new(sim_id, memory);
+        let ([buffer], params) = images.add(renderer, initial_params);
+        let loader = ImageTextureLoader::new([("vip://buffer".into(), buffer)]);
+        Self {
+            sim_id,
+            loader: Arc::new(loader),
+            index: params.index,
+            left: params.left,
+            right: params.right,
+            generic_palette: params.generic_palette,
+            params,
+            scale: 2.0,
+        }
+    }
+
+    fn show_form(&mut self, ui: &mut Ui) {
+        let row_height = ui.spacing().interact_size.y;
+        ui.vertical(|ui| {
+            TableBuilder::new(ui)
+                .column(Column::auto())
+                .column(Column::remainder())
+                .body(|mut body| {
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("Index");
+                        });
+                        row.col(|ui| {
+                            ui.add(NumberEdit::new(&mut self.index).range(0..2));
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("Left");
+                        });
+                        row.col(|ui| {
+                            let address = self.index * 0x00008000;
+                            let mut address_str = format!("{address:08x}");
+                            ui.add_enabled(
+                                false,
+                                TextEdit::singleline(&mut address_str).horizontal_align(Align::Max),
+                            );
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("Right");
+                        });
+                        row.col(|ui| {
+                            let address = self.index * 0x00008000 + 0x00010000;
+                            let mut address_str = format!("{address:08x}");
+                            ui.add_enabled(
+                                false,
+                                TextEdit::singleline(&mut address_str).horizontal_align(Align::Max),
+                            );
+                        });
+                    });
+                });
+            ui.section("Display", |ui| {
+                ui.horizontal(|ui| {
+                    ui.label("Scale");
+                    ui.spacing_mut().slider_width = ui.available_width();
+                    let slider = Slider::new(&mut self.scale, 1.0..=10.0)
+                        .step_by(1.0)
+                        .show_value(false);
+                    ui.add(slider);
+                });
+                TableBuilder::new(ui)
+                    .columns(Column::remainder(), 2)
+                    .body(|mut body| {
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.checkbox(&mut self.left, "Left");
+                            });
+                            row.col(|ui| {
+                                ui.checkbox(&mut self.right, "Right");
+                            });
+                        });
+                    });
+                ui.checkbox(&mut self.generic_palette, "Generic colors");
+            });
+        });
+
+        self.params.write(FrameBufferParams {
+            index: self.index,
+            left: self.left,
+            right: self.right,
+            generic_palette: self.generic_palette,
+            ..*self.params
+        });
+    }
+
+    fn show_buffers(&mut self, ui: &mut Ui) {
+        let image = Image::new("vip://buffer")
+            .fit_to_original_size(self.scale)
+            .texture_options(TextureOptions::NEAREST);
+        ui.add(image);
+    }
+}
+
+impl AppWindow for FrameBufferWindow {
+    fn viewport_id(&self) -> ViewportId {
+        ViewportId::from_hash_of(format!("framebuffer-{}", self.sim_id))
+    }
+
+    fn sim_id(&self) -> SimId {
+        self.sim_id
+    }
+
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title(format!("Frame Buffers ({})", self.sim_id))
+            .with_inner_size((640.0, 480.0))
+    }
+
+    fn on_init(&mut self, ctx: &Context, _render_state: &egui_wgpu::RenderState) {
+        ctx.add_texture_loader(self.loader.clone());
+    }
+
+    fn show(&mut self, ctx: &Context) {
+        CentralPanel::default().show(ctx, |ui| {
+            ui.horizontal_top(|ui| {
+                StripBuilder::new(ui)
+                    .size(Size::relative(0.3).at_most(200.0))
+                    .size(Size::remainder())
+                    .horizontal(|mut strip| {
+                        strip.cell(|ui| {
+                            ScrollArea::vertical().show(ui, |ui| self.show_form(ui));
+                        });
+                        strip.cell(|ui| {
+                            ScrollArea::both().show(ui, |ui| self.show_buffers(ui));
+                        });
+                    });
+            });
+        });
+    }
+}
+
+#[derive(Clone, PartialEq, Eq)]
+struct FrameBufferParams {
+    index: usize,
+    left: bool,
+    right: bool,
+    generic_palette: bool,
+    left_color: Color32,
+    right_color: Color32,
+}
+
+struct FrameBufferRenderer {
+    buffers: [MemoryView; 4],
+    brightness: MemoryView,
+}
+
+impl FrameBufferRenderer {
+    fn new(sim_id: SimId, memory: &MemoryClient) -> Self {
+        Self {
+            buffers: [
+                memory.watch(sim_id, 0x00000000, 0x6000),
+                memory.watch(sim_id, 0x00008000, 0x6000),
+                memory.watch(sim_id, 0x00010000, 0x6000),
+                memory.watch(sim_id, 0x00018000, 0x6000),
+            ],
+            brightness: memory.watch(sim_id, 0x0005f824, 8),
+        }
+    }
+}
+
+impl ImageRenderer<1> for FrameBufferRenderer {
+    type Params = FrameBufferParams;
+
+    fn sizes(&self) -> [[usize; 2]; 1] {
+        [[384, 224]]
+    }
+
+    fn render(&mut self, params: &Self::Params, images: &mut [ImageBuffer; 1]) {
+        let image = &mut images[0];
+
+        let left_buffer = self.buffers[params.index].borrow();
+        let right_buffer = self.buffers[2 + params.index].borrow();
+
+        let colors = if params.generic_palette {
+            [
+                utils::generic_palette(params.left_color),
+                utils::generic_palette(params.right_color),
+            ]
+        } else {
+            let brts = self.brightness.borrow().read::<[u8; 8]>(0);
+            let shades = utils::parse_shades(&brts);
+            [
+                shades.map(|s| utils::shade(s, params.left_color)),
+                shades.map(|s| utils::shade(s, params.right_color)),
+            ]
+        };
+
+        let left_cols = left_buffer.range::<u8>(0, 0x6000);
+        let right_cols = right_buffer.range::<u8>(0, 0x6000);
+        for (index, (left, right)) in left_cols.zip(right_cols).enumerate() {
+            let top = (index % 64) * 4;
+            if top >= 224 {
+                continue;
+            }
+
+            let pixels = [0, 2, 4, 6].map(|i| {
+                let left = if params.left {
+                    colors[0][(left >> i) as usize & 0x3]
+                } else {
+                    Color32::BLACK
+                };
+                let right = if params.right {
+                    colors[1][(right >> i) as usize & 0x3]
+                } else {
+                    Color32::BLACK
+                };
+                Color32::from_rgb(
+                    left.r() + right.r(),
+                    left.g() + right.g(),
+                    left.b() + right.b(),
+                )
+            });
+            let x = index / 64;
+            for (i, pixel) in pixels.into_iter().enumerate() {
+                let y = top + i;
+                image.write((x, y), pixel);
+            }
+        }
+    }
+}

src/window/vip/object.rs

@@ -8,8 +8,8 @@ use egui_extras::{Column, Size, StripBuilder, TableBuilder};
 
 use crate::{
     emulator::SimId,
+    images::{ImageBuffer, ImageParams, ImageProcessor, ImageRenderer, ImageTextureLoader},
     memory::{MemoryClient, MemoryView},
-    vram::{VramImage, VramParams, VramProcessor, VramRenderer, VramTextureLoader},
     window::{
         utils::{NumberEdit, UiExt as _},
         AppWindow,
@@ -20,28 +20,34 @@ use super::utils::{self, Object};
 
 pub struct ObjectWindow {
     sim_id: SimId,
-    loader: Arc<VramTextureLoader>,
+    loader: Arc<ImageTextureLoader>,
     memory: Arc<MemoryClient>,
     objects: MemoryView,
     index: usize,
     generic_palette: bool,
-    params: VramParams<ObjectParams>,
+    params: ImageParams<ObjectParams>,
     scale: f32,
 }
 
 impl ObjectWindow {
-    pub fn new(sim_id: SimId, memory: &Arc<MemoryClient>, vram: &mut VramProcessor) -> Self {
+    pub fn new(sim_id: SimId, memory: &Arc<MemoryClient>, images: &mut ImageProcessor) -> Self {
+        let initial_params = ObjectParams {
+            index: 0,
+            generic_palette: false,
+            left_color: Color32::from_rgb(0xff, 0x00, 0x00),
+            right_color: Color32::from_rgb(0x00, 0xc6, 0xf0),
+        };
         let renderer = ObjectRenderer::new(sim_id, memory);
-        let ([zoom, full], params) = vram.add(renderer);
+        let ([zoom, full], params) = images.add(renderer, initial_params);
         let loader =
-            VramTextureLoader::new([("vram://zoom".into(), zoom), ("vram://full".into(), full)]);
+            ImageTextureLoader::new([("vip://zoom".into(), zoom), ("vip://full".into(), full)]);
         Self {
             sim_id,
             loader: Arc::new(loader),
             memory: memory.clone(),
             objects: memory.watch(sim_id, 0x0003e000, 0x2000),
-            index: 0,
-            generic_palette: false,
+            index: params.index,
+            generic_palette: params.generic_palette,
             params,
             scale: 1.0,
         }
@@ -76,7 +82,7 @@ impl ObjectWindow {
                         });
                     });
                 });
-            let image = Image::new("vram://zoom")
+            let image = Image::new("vip://zoom")
                 .maintain_aspect_ratio(true)
                 .texture_options(TextureOptions::NEAREST);
             ui.add(image);
@@ -175,12 +181,12 @@ impl ObjectWindow {
         self.params.write(ObjectParams {
             index: self.index,
             generic_palette: self.generic_palette,
-            ..ObjectParams::default()
+            ..*self.params
         });
     }
 
     fn show_object(&mut self, ui: &mut Ui) {
-        let image = Image::new("vram://full")
+        let image = Image::new("vip://full")
             .fit_to_original_size(self.scale)
             .texture_options(TextureOptions::NEAREST);
         ui.add(image);
@@ -210,7 +216,7 @@ impl AppWindow for ObjectWindow {
         CentralPanel::default().show(ctx, |ui| {
             ui.horizontal_top(|ui| {
                 StripBuilder::new(ui)
-                    .size(Size::relative(0.3))
+                    .size(Size::relative(0.3).at_most(200.0))
                     .size(Size::remainder())
                     .horizontal(|mut strip| {
                         strip.cell(|ui| {
@@ -233,17 +239,6 @@ struct ObjectParams {
     right_color: Color32,
 }
 
-impl Default for ObjectParams {
-    fn default() -> Self {
-        Self {
-            index: 0,
-            generic_palette: false,
-            left_color: Color32::from_rgb(0xff, 0x00, 0x00),
-            right_color: Color32::from_rgb(0x00, 0xc6, 0xf0),
-        }
-    }
-}
-
 enum Eye {
     Left,
     Right,
@@ -266,7 +261,13 @@ impl ObjectRenderer {
         }
     }
 
-    fn render_object(&self, image: &mut VramImage, params: &ObjectParams, use_pos: bool, eye: Eye) {
+    fn render_object(
+        &self,
+        image: &mut ImageBuffer,
+        params: &ObjectParams,
+        use_pos: bool,
+        eye: Eye,
+    ) {
         let chardata = self.chardata.borrow();
         let objects = self.objects.borrow();
         let brightness = self.brightness.borrow();
@@ -302,7 +303,7 @@ impl ObjectRenderer {
         let palette = if params.generic_palette {
             utils::generic_palette(color)
         } else {
-            utils::parse_palette(palettes.read(8 + obj.data.palette_index * 2), &brts, color)
+            utils::palette_colors(palettes.read(8 + obj.data.palette_index * 2), &brts, color)
         };
 
         for row in 0..8 {
@@ -323,14 +324,14 @@ impl ObjectRenderer {
     }
 }
 
-impl VramRenderer<2> for ObjectRenderer {
+impl ImageRenderer<2> for ObjectRenderer {
     type Params = ObjectParams;
 
     fn sizes(&self) -> [[usize; 2]; 2] {
         [[8, 8], [384, 224]]
     }
 
-    fn render(&mut self, params: &Self::Params, images: &mut [VramImage; 2]) {
+    fn render(&mut self, params: &Self::Params, images: &mut [ImageBuffer; 2]) {
         images[0].clear();
         self.render_object(&mut images[0], params, false, Eye::Left);
         self.render_object(&mut images[0], params, false, Eye::Right);

src/window/vip/registers.rs

@@ -0,0 +1,819 @@
+use std::sync::Arc;
+
+use egui::{
+    Align, Button, CentralPanel, Checkbox, Color32, Context, Direction, Label, Layout, ScrollArea,
+    TextEdit, Ui, ViewportBuilder, ViewportId,
+};
+use egui_extras::{Column, Size, StripBuilder, TableBuilder};
+
+use crate::{
+    emulator::SimId,
+    memory::{MemoryClient, MemoryRef, MemoryValue, MemoryView},
+    window::{
+        utils::{NumberEdit, UiExt},
+        AppWindow,
+    },
+};
+
+use super::utils;
+
+pub struct RegisterWindow {
+    sim_id: SimId,
+    memory: Arc<MemoryClient>,
+    registers: MemoryView,
+}
+
+impl RegisterWindow {
+    pub fn new(sim_id: SimId, memory: &Arc<MemoryClient>) -> Self {
+        Self {
+            sim_id,
+            memory: memory.clone(),
+            registers: memory.watch(sim_id, 0x0005f800, 0x72),
+        }
+    }
+
+    fn show_interrupts(&mut self, ui: &mut Ui) {
+        let row_height = self.row_height(ui);
+        let [mut raw_intpnd, mut raw_intenb] = self.read_address(0x0005f800);
+        let mut intenb = InterruptReg::parse(raw_intenb);
+        let mut intpnd = InterruptReg::parse(raw_intpnd);
+        ui.section("Interrupt", |ui| {
+            let width = ui.available_width();
+            let xspace = ui.spacing().item_spacing.x;
+            ui.with_layout(Layout::top_down_justified(Align::Center), |ui| {
+                TableBuilder::new(ui)
+                    .id_salt("raw_values")
+                    .columns(Column::exact(width * 0.5 - xspace), 2)
+                    .cell_layout(Layout::left_to_right(Align::Max))
+                    .body(|mut body| {
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.label("INTENB");
+                            });
+                            row.col(|ui| {
+                                let mut text = format!("{raw_intenb:04x}");
+                                ui.add_sized(
+                                    ui.available_size(),
+                                    TextEdit::singleline(&mut text).horizontal_align(Align::Max),
+                                );
+                            });
+                        });
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.label("INTPND");
+                            });
+                            row.col(|ui| {
+                                let mut text = format!("{raw_intpnd:04x}");
+                                ui.add_enabled(
+                                    false,
+                                    TextEdit::singleline(&mut text).horizontal_align(Align::Max),
+                                );
+                            });
+                        });
+                    });
+                ui.add_space(8.0);
+                TableBuilder::new(ui)
+                    .id_salt("flags")
+                    .column(Column::exact(width * 0.5 - xspace))
+                    .columns(Column::exact(width * 0.25 - xspace), 2)
+                    .cell_layout(Layout::left_to_right(Align::Center).with_main_align(Align::RIGHT))
+                    .body(|mut body| {
+                        body.row(row_height, |mut row| {
+                            row.col(|_ui| {});
+                            row.col(|ui| {
+                                ui.add_sized(ui.available_size(), Label::new("ENB"));
+                            });
+                            row.col(|ui| {
+                                ui.add_sized(ui.available_size(), Label::new("PND"));
+                            });
+                        });
+                        let mut add_row = |label: &str, enb: &mut bool, pnd: &mut bool| {
+                            body.row(row_height, |mut row| {
+                                row.col(|ui| {
+                                    ui.label(label);
+                                });
+                                row.col(|ui| {
+                                    let space =
+                                        (ui.available_width() - ui.spacing().icon_width) / 2.0;
+                                    ui.add_space(space);
+                                    ui.checkbox(enb, "");
+                                });
+                                row.col(|ui| {
+                                    let space =
+                                        (ui.available_width() - ui.spacing().icon_width) / 2.0;
+                                    ui.add_space(space);
+                                    ui.checkbox(pnd, "");
+                                });
+                            });
+                        };
+                        add_row("TIMEERR", &mut intenb.timeerr, &mut intpnd.timeerr);
+                        add_row("XPEND", &mut intenb.xpend, &mut intpnd.xpend);
+                        add_row("SBHIT", &mut intenb.sbhit, &mut intpnd.sbhit);
+                        add_row("FRAMESTART", &mut intenb.framestart, &mut intpnd.framestart);
+                        add_row("GAMESTART", &mut intenb.gamestart, &mut intpnd.gamestart);
+                        add_row("RFBEND", &mut intenb.rfbend, &mut intpnd.rfbend);
+                        add_row("LFBEND", &mut intenb.lfbend, &mut intpnd.lfbend);
+                        add_row("SCANERR", &mut intenb.scanerr, &mut intpnd.scanerr);
+                    });
+            });
+            ui.allocate_space(ui.available_size());
+        });
+        if intpnd.update(&mut raw_intpnd) {
+            self.memory.write(self.sim_id, 0x0005f800, &raw_intpnd);
+        }
+        if intenb.update(&mut raw_intenb) {
+            self.memory.write(self.sim_id, 0x0005f802, &raw_intenb);
+        }
+    }
+
+    fn show_display_status(&mut self, ui: &mut Ui) {
+        let row_height = self.row_height(ui);
+        let mut raw_dpstts = self.read_address(0x0005f820);
+        let mut dpstts = DisplayReg::parse(raw_dpstts);
+        ui.section("Display", |ui| {
+            let width = ui.available_width();
+            TableBuilder::new(ui)
+                .column(Column::exact(width * 0.5))
+                .column(Column::exact(width * 0.5))
+                .cell_layout(Layout::left_to_right(Align::Max))
+                .body(|mut body| {
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("DPSTTS");
+                        });
+                        row.col(|ui| {
+                            let mut value_str = format!("{raw_dpstts:04x}");
+                            ui.add_enabled(
+                                false,
+                                TextEdit::singleline(&mut value_str).horizontal_align(Align::Max),
+                            );
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.add_enabled(true, Checkbox::new(&mut dpstts.lock, "LOCK"));
+                        });
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut dpstts.r1bsy, "R1BSY"));
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.add_enabled(true, Checkbox::new(&mut dpstts.synce, "SYNCE"));
+                        });
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut dpstts.l1bsy, "L1BSY"));
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.add_enabled(true, Checkbox::new(&mut dpstts.re, "RE"));
+                        });
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut dpstts.r0bsy, "R0BSY"));
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut dpstts.fclk, "FCLK"));
+                        });
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut dpstts.l0bsy, "L0BSY"));
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut dpstts.scanrdy, "SCANRDY"));
+                        });
+                        row.col(|ui| {
+                            ui.add_enabled(true, Checkbox::new(&mut dpstts.disp, "DISP"));
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|_ui| {});
+                        row.col(|ui| {
+                            if ui
+                                .add(Button::new("DPRST").min_size(ui.available_size()))
+                                .clicked()
+                            {
+                                dpstts.dprst = true;
+                            }
+                        });
+                    });
+                });
+            ui.allocate_space(ui.available_size());
+        });
+        if dpstts.update(&mut raw_dpstts) {
+            self.memory.write(self.sim_id, 0x0005f822, &raw_dpstts);
+        }
+    }
+
+    fn show_drawing_status(&mut self, ui: &mut Ui) {
+        let row_height = self.row_height(ui);
+        let [mut raw_xpstts, raw_xpctrl] = self.read_address(0x0005f840);
+        let mut xpstts = DrawingReg::parse(raw_xpstts);
+        ui.section("Drawing", |ui| {
+            let width = ui.available_width();
+            TableBuilder::new(ui)
+                .column(Column::exact(width * 0.5))
+                .column(Column::exact(width * 0.5))
+                .cell_layout(Layout::left_to_right(Align::Max))
+                .body(|mut body| {
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("XPCTRL");
+                        });
+                        row.col(|ui| {
+                            let mut value_str = format!("{raw_xpctrl:04x}");
+                            ui.add_enabled(
+                                false,
+                                TextEdit::singleline(&mut value_str).horizontal_align(Align::Max),
+                            );
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("XPSTTS");
+                        });
+                        row.col(|ui| {
+                            let mut value_str = format!("{raw_xpstts:04x}");
+                            ui.add_enabled(
+                                false,
+                                TextEdit::singleline(&mut value_str).horizontal_align(Align::Max),
+                            );
+                        });
+                    });
+                    /*
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("SBCMP");
+                        });
+                        row.col(|ui| {
+                            let old_value = xpctrl.sbcmp;
+                            ui.add_enabled(true, NumberEdit::new(&mut xpctrl.sbcmp).range(0..32));
+                            cmp_changed = xpctrl.sbcmp != old_value;
+                        });
+                    });
+                     */
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("SBCOUNT");
+                        });
+                        row.col(|ui| {
+                            ui.add_enabled(
+                                false,
+                                NumberEdit::new(&mut xpstts.sbcount)
+                                    .arrows(false)
+                                    .range(0..32),
+                            );
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut xpstts.sbout, "SBOUT"));
+                        });
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut xpstts.f1bsy, "F1BSY"));
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut xpstts.f0bsy, "F0BSY"));
+                        });
+                        row.col(|ui| {
+                            ui.add_enabled(false, Checkbox::new(&mut xpstts.overtime, "OVERTIME"));
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.add_enabled(true, Checkbox::new(&mut xpstts.xpen, "XPEN"));
+                        });
+                        row.col(|ui| {
+                            if ui
+                                .add(Button::new("XPRST").min_size(ui.available_size()))
+                                .clicked()
+                            {
+                                xpstts.xprst = true;
+                            }
+                        });
+                    });
+                });
+            ui.allocate_space(ui.available_size());
+        });
+        if xpstts.update(&mut raw_xpstts) {
+            xpstts.update(&mut raw_xpstts);
+            self.memory.write(self.sim_id, 0x0005f842, &raw_xpstts);
+        }
+    }
+
+    fn show_colors(&mut self, ui: &mut Ui) {
+        let row_height = self.row_height(ui);
+        let registers = self.registers.borrow();
+        ui.section("Colors", |ui| {
+            let width = ui.available_width();
+            let xspace = ui.spacing().item_spacing.x;
+            TableBuilder::new(ui)
+                .column(Column::exact(width * 0.2 - xspace))
+                .columns(Column::exact(width * 0.20 - xspace), 4)
+                .cell_layout(Layout::left_to_right(Align::Max))
+                .body(|mut body| {
+                    body.row(row_height, |mut row| {
+                        row.col(|_ui| {});
+                        row.col(|_ui| {});
+                        row.col(|ui| {
+                            ui.with_layout(
+                                Layout::centered_and_justified(Direction::LeftToRight),
+                                |ui| ui.label("1"),
+                            );
+                        });
+                        row.col(|ui| {
+                            ui.with_layout(
+                                Layout::centered_and_justified(Direction::LeftToRight),
+                                |ui| ui.label("2"),
+                            );
+                        });
+                        row.col(|ui| {
+                            ui.with_layout(
+                                Layout::centered_and_justified(Direction::LeftToRight),
+                                |ui| ui.label("3"),
+                            );
+                        });
+                    });
+                    let mut brts: [u16; 3] = [
+                        read_address(&registers, 0x0005f824),
+                        read_address(&registers, 0x0005f826),
+                        read_address(&registers, 0x0005f828),
+                    ];
+                    body.row(row_height, |mut row| {
+                        let mut stale = false;
+                        row.col(|ui| {
+                            ui.label("BRT");
+                        });
+                        row.col(|_ui| {});
+                        for brt in brts.iter_mut() {
+                            row.col(|ui| {
+                                if ui
+                                    .add(NumberEdit::new(brt).range(0..256).arrows(false).hex(true))
+                                    .changed()
+                                {
+                                    stale = true;
+                                }
+                            });
+                        }
+                        if stale {
+                            self.memory.write(self.sim_id, 0x0005f824, &brts);
+                        }
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|_ui| {});
+                        for shade in utils::parse_brts(&brts, Color32::RED) {
+                            row.col(|ui| {
+                                ui.painter().rect_filled(
+                                    ui.available_rect_before_wrap(),
+                                    0.0,
+                                    shade,
+                                );
+                            });
+                        }
+                    });
+                    let mut palettes = read_address::<[u16; 8]>(&registers, 0x0005f860);
+                    let mut add_row = |name: &str, address: u32, value: &mut u16| {
+                        let mut c1 = (*value >> 2) & 0x03;
+                        let mut c2 = (*value >> 4) & 0x03;
+                        let mut c3 = (*value >> 6) & 0x03;
+                        let mut stale = false;
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.label(name);
+                            });
+                            row.col(|ui| {
+                                if ui
+                                    .add(
+                                        NumberEdit::new(value)
+                                            .range(0..256)
+                                            .desired_width(width * 0.2)
+                                            .arrows(false)
+                                            .hex(true),
+                                    )
+                                    .changed()
+                                {
+                                    stale = true;
+                                };
+                            });
+                            row.col(|ui| {
+                                if ui
+                                    .add(
+                                        NumberEdit::new(&mut c1)
+                                            .range(0..4)
+                                            .desired_width(ui.available_width() - xspace),
+                                    )
+                                    .changed()
+                                {
+                                    *value = (*value & 0xfff3) | (c1 << 2);
+                                    stale = true;
+                                }
+                            });
+                            row.col(|ui| {
+                                if ui
+                                    .add(
+                                        NumberEdit::new(&mut c2)
+                                            .range(0..4)
+                                            .desired_width(ui.available_width() - xspace),
+                                    )
+                                    .changed()
+                                {
+                                    *value = (*value & 0xffcf) | (c2 << 4);
+                                    stale = true;
+                                }
+                            });
+                            row.col(|ui| {
+                                if ui
+                                    .add(
+                                        NumberEdit::new(&mut c3)
+                                            .range(0..4)
+                                            .desired_width(ui.available_width() - xspace),
+                                    )
+                                    .changed()
+                                {
+                                    *value = (*value & 0xff3f) | (c3 << 6);
+                                    stale = true;
+                                }
+                            });
+                        });
+                        if stale {
+                            self.memory.write(self.sim_id, address, value);
+                        }
+                    };
+
+                    add_row("GPLT0", 0x0005f860, &mut palettes[0]);
+                    add_row("GPLT1", 0x0005f862, &mut palettes[1]);
+                    add_row("GPLT2", 0x0005f864, &mut palettes[2]);
+                    add_row("GPLT3", 0x0005f866, &mut palettes[3]);
+                    add_row("JPLT0", 0x0005f868, &mut palettes[4]);
+                    add_row("JPLT1", 0x0005f86a, &mut palettes[5]);
+                    add_row("JPLT2", 0x0005f86c, &mut palettes[6]);
+                    add_row("JPLT3", 0x0005f86e, &mut palettes[7]);
+
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("BKCOL");
+                        });
+                        row.col(|ui| {
+                            let mut bkcol: u16 = read_address(&registers, 0x0005f870);
+                            if ui
+                                .add(
+                                    NumberEdit::new(&mut bkcol)
+                                        .range(0..4)
+                                        .desired_width(ui.available_width() - xspace),
+                                )
+                                .changed()
+                            {
+                                self.memory.write(self.sim_id, 0x0005f870, &bkcol);
+                            }
+                        });
+                        row.col(|_ui| {});
+                        row.col(|ui| {
+                            ui.label("REST");
+                        });
+                        row.col(|ui| {
+                            let mut rest: u16 = read_address(&registers, 0x0005f82a);
+                            if ui
+                                .add(
+                                    NumberEdit::new(&mut rest)
+                                        .range(0..256)
+                                        .arrows(false)
+                                        .hex(true),
+                                )
+                                .changed()
+                            {
+                                self.memory.write(self.sim_id, 0x0005f82a, &rest);
+                            }
+                        });
+                    });
+                });
+
+            ui.allocate_space(ui.available_size_before_wrap());
+        });
+    }
+
+    fn show_objects(&mut self, ui: &mut Ui) {
+        let row_height = self.row_height(ui);
+        ui.section("Objects", |ui| {
+            let width = ui.available_width();
+            let xspace = ui.spacing().item_spacing.x;
+            TableBuilder::new(ui)
+                .column(Column::exact(width * 0.3 - xspace))
+                .column(Column::exact(width * 0.3 - xspace))
+                .column(Column::exact(width * 0.4 - xspace))
+                .cell_layout(Layout::left_to_right(Align::Center).with_main_align(Align::RIGHT))
+                .body(|mut body| {
+                    body.row(row_height, |mut row| {
+                        row.col(|_ui| {});
+                        row.col(|ui| {
+                            ui.add_sized(ui.available_size(), Label::new("Start"));
+                        });
+                        row.col(|ui| {
+                            ui.add_sized(ui.available_size(), Label::new("End"));
+                        });
+                    });
+                    let mut spts = self.read_address::<[u16; 4]>(0x0005f848);
+                    let prevs = std::iter::once(0u16).chain(spts.map(|i| (i + 1) & 0x03ff));
+                    let mut changed = false;
+                    for (index, (spt, prev)) in spts.iter_mut().zip(prevs).enumerate() {
+                        body.row(row_height, |mut row| {
+                            row.col(|ui| {
+                                ui.label(format!("SPT{index}"));
+                            });
+                            row.col(|ui| {
+                                ui.with_layout(Layout::right_to_left(Align::Center), |ui| {
+                                    ui.label(prev.to_string());
+                                });
+                            });
+                            row.col(|ui| {
+                                if ui.add(NumberEdit::new(spt).range(0..1024)).changed() {
+                                    changed = true;
+                                }
+                            });
+                        });
+                    }
+                    if changed {
+                        self.memory.write(self.sim_id, 0x0005f848, &spts);
+                    }
+                });
+            ui.allocate_space(ui.available_size_before_wrap());
+        });
+    }
+
+    fn show_misc(&mut self, ui: &mut Ui) {
+        let row_height = self.row_height(ui);
+        let registers = self.registers.borrow();
+        ui.section("Misc.", |ui| {
+            let width = ui.available_width();
+            let xspace = ui.spacing().item_spacing.x;
+            TableBuilder::new(ui)
+                .column(Column::exact(width * 0.5 - xspace))
+                .column(Column::exact(width * 0.5 - xspace))
+                .cell_layout(Layout::left_to_right(Align::Center).with_main_align(Align::RIGHT))
+                .body(|mut body| {
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("FRMCYC");
+                        });
+                        row.col(|ui| {
+                            let mut frmcyc = read_address::<u16>(&registers, 0x0005f82e);
+                            ui.with_layout(Layout::right_to_left(Align::Center), |ui| {
+                                if ui.add(NumberEdit::new(&mut frmcyc).range(0..32)).changed() {
+                                    self.memory.write(self.sim_id, 0x0005f82e, &frmcyc);
+                                }
+                            });
+                        });
+                    });
+                    let mut cta = read_address::<u16>(&registers, 0x0005f830);
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("CTA");
+                        });
+                        row.col(|ui| {
+                            ui.with_layout(Layout::right_to_left(Align::Center), |ui| {
+                                ui.add_enabled(
+                                    false,
+                                    NumberEdit::new(&mut cta).arrows(false).hex(true),
+                                );
+                            });
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("CTA_L");
+                        });
+                        row.col(|ui| {
+                            let mut cta_l = cta & 0xff;
+                            ui.with_layout(Layout::right_to_left(Align::Center), |ui| {
+                                ui.add_enabled(
+                                    false,
+                                    NumberEdit::new(&mut cta_l).arrows(false).hex(true),
+                                );
+                            });
+                        });
+                    });
+                    body.row(row_height, |mut row| {
+                        row.col(|ui| {
+                            ui.label("CTA_R");
+                        });
+                        row.col(|ui| {
+                            let mut cta_r = (cta >> 8) & 0xff;
+                            ui.with_layout(Layout::right_to_left(Align::Center), |ui| {
+                                ui.add_enabled(
+                                    false,
+                                    NumberEdit::new(&mut cta_r).arrows(false).hex(true),
+                                );
+                            });
+                        });
+                    });
+                });
+            ui.allocate_space(ui.available_size_before_wrap());
+        });
+    }
+
+    fn row_height(&self, ui: &mut Ui) -> f32 {
+        ui.spacing().interact_size.y + ui.style().visuals.selection.stroke.width
+    }
+
+    fn read_address<T: MemoryValue>(&self, address: usize) -> T {
+        read_address(&self.registers.borrow(), address)
+    }
+}
+
+fn read_address<T: MemoryValue>(registers: &MemoryRef, address: usize) -> T {
+    let index = (address - 0x0005f800) / size_of::<T>();
+    registers.read(index)
+}
+
+impl AppWindow for RegisterWindow {
+    fn viewport_id(&self) -> ViewportId {
+        ViewportId::from_hash_of(format!("registers-{}", self.sim_id))
+    }
+
+    fn sim_id(&self) -> SimId {
+        self.sim_id
+    }
+
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title(format!("Registers ({})", self.sim_id))
+            .with_inner_size((800.0, 480.0))
+    }
+
+    fn show(&mut self, ctx: &Context) {
+        CentralPanel::default().show(ctx, |ui| {
+            ScrollArea::vertical().show(ui, |ui| {
+                ui.horizontal_top(|ui| {
+                    let width = ui.available_width();
+                    let xspace = ui.spacing().item_spacing.x;
+                    StripBuilder::new(ui)
+                        .size(Size::exact(width * 0.25 - xspace))
+                        .size(Size::exact(width * 0.225 - xspace))
+                        .size(Size::exact(width * 0.325 - xspace))
+                        .size(Size::exact(width * 0.2 - xspace))
+                        .horizontal(|mut strip| {
+                            strip.cell(|ui| {
+                                self.show_interrupts(ui);
+                            });
+                            strip.strip(|nested| {
+                                nested.sizes(Size::remainder(), 2).vertical(|mut strip| {
+                                    strip.cell(|ui| {
+                                        self.show_display_status(ui);
+                                    });
+                                    strip.cell(|ui| {
+                                        self.show_drawing_status(ui);
+                                    });
+                                });
+                            });
+                            strip.cell(|ui| {
+                                self.show_colors(ui);
+                            });
+                            strip.strip(|nested| {
+                                nested.sizes(Size::remainder(), 2).vertical(|mut strip| {
+                                    strip.cell(|ui| {
+                                        self.show_objects(ui);
+                                    });
+                                    strip.cell(|ui| {
+                                        self.show_misc(ui);
+                                    });
+                                });
+                            });
+                        });
+                });
+            });
+        });
+    }
+}
+
+struct InterruptReg {
+    timeerr: bool,
+    xpend: bool,
+    sbhit: bool,
+    framestart: bool,
+    gamestart: bool,
+    rfbend: bool,
+    lfbend: bool,
+    scanerr: bool,
+}
+
+impl InterruptReg {
+    fn parse(value: u16) -> Self {
+        Self {
+            timeerr: value & 0x8000 != 0,
+            xpend: value & 0x4000 != 0,
+            sbhit: value & 0x2000 != 0,
+            framestart: value & 0x0010 != 0,
+            gamestart: value & 0x0008 != 0,
+            rfbend: value & 0x0004 != 0,
+            lfbend: value & 0x0002 != 0,
+            scanerr: value & 0x0001 != 0,
+        }
+    }
+
+    fn update(&self, value: &mut u16) -> bool {
+        let new_value = (*value & 0x1fe0)
+            | if self.timeerr { 0x8000 } else { 0x0000 }
+            | if self.xpend { 0x4000 } else { 0x0000 }
+            | if self.sbhit { 0x2000 } else { 0x0000 }
+            | if self.framestart { 0x0010 } else { 0x0000 }
+            | if self.gamestart { 0x0008 } else { 0x0000 }
+            | if self.rfbend { 0x0004 } else { 0x0000 }
+            | if self.lfbend { 0x0002 } else { 0x0000 }
+            | if self.scanerr { 0x0001 } else { 0x0000 };
+        let changed = *value != new_value;
+        *value = new_value;
+        changed
+    }
+}
+
+struct DisplayReg {
+    lock: bool,
+    synce: bool,
+    re: bool,
+    fclk: bool,
+    scanrdy: bool,
+    r1bsy: bool,
+    l1bsy: bool,
+    r0bsy: bool,
+    l0bsy: bool,
+    disp: bool,
+    dprst: bool,
+}
+
+impl DisplayReg {
+    fn parse(value: u16) -> Self {
+        Self {
+            lock: value & 0x0400 != 0,
+            synce: value & 0x0200 != 0,
+            re: value & 0x0100 != 0,
+            fclk: value & 0x0080 != 0,
+            scanrdy: value & 0x0040 != 0,
+            r1bsy: value & 0x0020 != 0,
+            l1bsy: value & 0x0010 != 0,
+            r0bsy: value & 0x0008 != 0,
+            l0bsy: value & 0x0004 != 0,
+            disp: value & 0x0002 != 0,
+            dprst: value & 0x0001 != 0,
+        }
+    }
+
+    fn update(&self, value: &mut u16) -> bool {
+        let new_value = (*value & 0xf800)
+            | if self.lock { 0x0400 } else { 0x0000 }
+            | if self.synce { 0x0200 } else { 0x0000 }
+            | if self.re { 0x0100 } else { 0x0000 }
+            | if self.fclk { 0x0080 } else { 0x0000 }
+            | if self.scanrdy { 0x0040 } else { 0x0000 }
+            | if self.r1bsy { 0x0020 } else { 0x0000 }
+            | if self.l1bsy { 0x0010 } else { 0x0000 }
+            | if self.r0bsy { 0x0008 } else { 0x0000 }
+            | if self.l0bsy { 0x0004 } else { 0x0000 }
+            | if self.disp { 0x0002 } else { 0x0000 }
+            | if self.dprst { 0x0001 } else { 0x0000 };
+        let changed = *value != new_value;
+        *value = new_value;
+        changed
+    }
+}
+
+struct DrawingReg {
+    sbout: bool,
+    sbcount: u8,
+    overtime: bool,
+    f1bsy: bool,
+    f0bsy: bool,
+    xpen: bool,
+    xprst: bool,
+}
+
+impl DrawingReg {
+    fn parse(value: u16) -> Self {
+        Self {
+            sbout: value & 0x8000 != 0,
+            sbcount: (value >> 8) as u8 & 0x1f,
+            overtime: value & 0x0010 != 0,
+            f1bsy: value & 0x0008 != 0,
+            f0bsy: value & 0x0004 != 0,
+            xpen: value & 0x0002 != 0,
+            xprst: value & 0x0001 != 0,
+        }
+    }
+
+    fn update(&self, value: &mut u16) -> bool {
+        let new_value = (*value & 0x60e0)
+            | if self.sbout { 0x8000 } else { 0x0000 }
+            | (((self.sbcount & 0x1f) as u16) << 8)
+            | if self.overtime { 0x0010 } else { 0x0000 }
+            | if self.f1bsy { 0x0008 } else { 0x0000 }
+            | if self.f0bsy { 0x0004 } else { 0x0000 }
+            | if self.xpen { 0x0002 } else { 0x0000 }
+            | if self.xprst { 0x0001 } else { 0x0000 };
+        let changed = *value != new_value;
+        *value = new_value;
+        changed
+    }
+}

src/window/vip/utils.rs

@@ -1,33 +1,52 @@
 use egui::{Color32, Image, ImageSource, Response, Sense, TextureOptions, Ui, Widget};
 
-pub const GENERIC_PALETTE: [u8; 4] = [0, 64, 128, 255];
+pub const GENERIC_PALETTE: [u8; 4] = [0, 32, 64, 128];
 
 pub fn shade(brt: u8, color: Color32) -> Color32 {
-    color.gamma_multiply(brt as f32 / 255.0)
+    let corrected = if brt > 132 {
+        255.0
+    } else {
+        (brt as f32 * 255.0 / 133.0).round()
+    };
+    color.gamma_multiply(corrected / 255.0)
 }
 
 pub fn generic_palette(color: Color32) -> [Color32; 4] {
     GENERIC_PALETTE.map(|brt| shade(brt, color))
 }
 
-pub fn parse_palette(palette: u8, brts: &[u8; 8], color: Color32) -> [Color32; 4] {
-    let shades = [
-        Color32::BLACK,
-        shade(brts[0], color),
-        shade(brts[2], color),
-        shade(
-            brts[0].saturating_add(brts[2]).saturating_add(brts[4]),
-            color,
-        ),
-    ];
+pub const fn parse_palette(palette: u8) -> [u8; 4] {
+    [
+        0,
+        (palette >> 2) & 0x03,
+        (palette >> 4) & 0x03,
+        (palette >> 6) & 0x03,
+    ]
+}
+
+pub const fn parse_shades(brts: &[u8; 8]) -> [u8; 4] {
+    [
+        0,
+        brts[0],
+        brts[2],
+        brts[0].saturating_add(brts[2]).saturating_add(brts[4]),
+    ]
+}
+
+pub fn parse_brts(brts: &[u16; 3], color: Color32) -> [Color32; 4] {
     [
         Color32::BLACK,
-        shades[(palette >> 2) as usize & 0x03],
-        shades[(palette >> 4) as usize & 0x03],
-        shades[(palette >> 6) as usize & 0x03],
+        shade(brts[0] as u8, color),
+        shade(brts[1] as u8, color),
+        shade((brts[0] + brts[1] + brts[2]) as u8, color),
     ]
 }
 
+pub fn palette_colors(palette: u8, brts: &[u8; 8], color: Color32) -> [Color32; 4] {
+    let colors = parse_shades(brts).map(|s| shade(s, color));
+    parse_palette(palette).map(|p| colors[p as usize])
+}
+
 pub struct Object {
     pub x: i16,
     pub lon: bool,
@@ -129,6 +148,12 @@ pub fn read_char_row(
     })
 }
 
+pub fn read_char_pixel(char: &[u16; 8], hflip: bool, vflip: bool, row: usize, col: usize) -> u8 {
+    let pixels = if vflip { char[7 - row] } else { char[row] };
+    let pixel = if hflip { 7 - col } else { col } << 1;
+    ((pixels >> pixel) & 0x3) as u8
+}
+
 pub struct CharacterGrid<'a> {
     source: ImageSource<'a>,
     scale: f32,