chore: Release lemur version 0.12.0

Cargo.toml

@@ -4,24 +4,24 @@ description = "An emulator for the Virtual Boy."
 repository = "https://git.virtual-boy.com/PVB/lemur"
 publish = false
 license = "MIT"
-version = "0.11.0"
+version = "0.12.0"
 edition = "2024"
 
 [dependencies]
 anyhow = "1"
 atoi = "2"
-audioadapter-buffers = "2"
+audioadapter-buffers = "3"
 atomic = "0.6"
 bitflags = { version = "2", features = ["serde"] }
 bytemuck = { version = "1", features = ["derive"] }
 clap = { version = "4", features = ["derive"] }
 cpal = { git = "https://github.com/sidit77/cpal.git", rev = "66ed6be" }
 directories = "6"
-egui = { version = "0.33", features = ["serde"] }
+egui = { version = "0.34", features = ["persistence", "serde"] }
-egui_extras = { version = "0.33", features = ["image"] }
+egui_extras = { version = "0.34", features = ["image"] }
-egui-notify = "0.21"
+egui-notify = "0.22"
-egui-winit = "0.33"
+egui-winit = "0.34"
-egui-wgpu = { version = "0.33", features = ["winit"] }
+egui-wgpu = { version = "0.34", features = ["winit"] }
 fxprof-processed-profile = "0.8"
 fixed = { version = "1.28", features = ["num-traits"] }
 gilrs = { version = "0.11", features = ["serde-serialize"] }
@@ -33,20 +33,20 @@ normpath = "1"
 notify = "8"
 num-derive = "0.4"
 num-traits = "0.2"
-object = "0.38"
+object = "0.39"
-oneshot = "0.1"
+oneshot = { version = "0.2", features = ["async", "std"] }
 pollster = "0.4"
 rand = "0.10"
 rfd = "0.17"
 rtrb = "0.3"
-rubato = "1"
+rubato = "2"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 thread-priority = "3"
 tokio = { version = "1", features = ["io-util", "macros", "net", "rt", "sync", "time"] }
 tracing = { version = "0.1", features = ["release_max_level_info"] }
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
-wgpu = "27"
+wgpu = "29"
 wholesym = "0.8"
 winit = { version = "0.30", features = ["serde"] }
 

build.Dockerfile

@@ -18,7 +18,7 @@ RUN apt-get update && \
     ln -s $(which ld64.lld-21) /usr/bin/ld64.lld && \
     SDK_VERSION=14.5 UNATTENDED=1 ENABLE_COMPILER_RT_INSTALL=1 TARGET_DIR=/osxcross ./build.sh
 
-FROM rust:1.93-bookworm
+FROM rust:1.94-bookworm
 ADD --chmod=644 "https://apt.llvm.org/llvm-snapshot.gpg.key" /etc/apt/trusted.gpg.d/apt.llvm.org.asc
 COPY llvm.sources /etc/apt/sources.list.d/llvm.sources
 COPY install-llvm.sh .

src/app.rs

@@ -1,35 +1,40 @@
-use std::{collections::HashSet, num::NonZero, sync::Arc, thread, time::Duration};
+use std::{
+    collections::hash_map::Entry,
+    num::NonZero,
+    sync::Arc,
+    thread,
+    time::{Duration, Instant},
+};
 
 use egui::{
-    Context, FontData, FontDefinitions, FontFamily, IconData, TextWrapMode, ViewportBuilder,
+    Context, FontData, FontDefinitions, FontFamily, IconData, PlatformOutput, RawInput,
-    ViewportCommand, ViewportId, ViewportInfo,
+    TextWrapMode, ViewportBuilder, ViewportCommand, ViewportEvent, ViewportId, ViewportIdMap,
-    ahash::{HashMap, HashMapExt},
+    ViewportIdSet, ViewportInfo, style::ScrollStyle,
-    style::ScrollStyle,
 };
+use egui_wgpu::winit::Painter;
+use egui_winit::EventResponse;
 use gilrs::{EventType, Gilrs};
 use tracing::{error, warn};
 use winit::{
     application::ApplicationHandler,
     event::WindowEvent,
-    event_loop::{ActiveEventLoop, EventLoopProxy},
+    event_loop::{ActiveEventLoop, ControlFlow, EventLoopProxy},
-    window::Window,
+    window::{Window, WindowId},
 };
 
 use crate::{
     config::CliArgs,
     controller::ControllerManager,
     emulator::{EmulatorClient, EmulatorCommand, SimId},
-    images::ImageProcessor,
+    images::ImageTextureLoader,
     input::{MappingProvider, ShortcutProvider},
     memory::MemoryClient,
     persistence::Persistence,
-    window::{
+    window::{AppWindow, ChildWindow, GameScreen, GameWindow, InitArgs},
-        AboutWindow, AppWindow, BgMapWindow, CharacterDataWindow, FrameBufferWindow, GameWindow,
-        GdbServerWindow, HotkeysWindow, InitArgs, InputWindow, ObjectWindow, ProfileWindow,
-        RegisterWindow, TerminalWindow, WorldWindow,
-    },
 };
 
+const EGUI_FILENAME: &str = "egui";
+
 fn load_icon() -> anyhow::Result<IconData> {
     let bytes = include_bytes!("../assets/lemur-256x256.png");
     let img = image::load_from_memory_with_format(bytes, image::ImageFormat::Png)?;
@@ -41,28 +46,24 @@ fn load_icon() -> anyhow::Result<IconData> {
     })
 }
 
+struct SharedViewportState {
+    viewport_info: ViewportIdMap<ViewportInfo>,
+    painter: Painter,
+    resized_viewport: Option<ViewportId>,
+}
+
 pub struct Application {
-    icon: Option<Arc<IconData>>,
-    wgpu: WgpuState,
     client: EmulatorClient,
-    proxy: EventLoopProxy<UserEvent>,
-    mappings: MappingProvider,
-    shortcuts: ShortcutProvider,
-    controllers: ControllerManager,
-    memory: Arc<MemoryClient>,
-    images: ImageProcessor,
     persistence: Persistence,
-    viewports: HashMap<ViewportId, Viewport>,
+    ctx: Context,
+    shared: SharedViewportState,
+    icon: Option<Arc<IconData>>,
+    app: GameWindow,
+    controllers: ControllerManager,
+    viewports: ViewportIdMap<ViewportManager>,
     focused: Option<ViewportId>,
-    init_debug_port: Option<u16>,
+    redraw_times: ViewportIdMap<Instant>,
-    init_profiling: bool,
+    initial_windows: Vec<ChildWindow>,
-    init_bgmap: bool,
-    init_chardata: bool,
-    init_objects: bool,
-    init_worlds: bool,
-    init_framebuffers: bool,
-    init_registers: bool,
-    init_terminal: bool,
 }
 
 impl Application {
@@ -78,132 +79,329 @@ impl Application {
         let shortcuts = ShortcutProvider::new(persistence.clone());
         let controllers = ControllerManager::new(client.clone(), &mappings);
         let memory = Arc::new(MemoryClient::new(client.clone()));
-        let images = ImageProcessor::new();
+        let images = Arc::new(ImageTextureLoader::new());
         {
             let mappings = mappings.clone();
             let proxy = proxy.clone();
             thread::spawn(|| process_gamepad_input(mappings, proxy));
         }
-        let app = Self {
+        let app = GameWindow::new(
-            icon,
+            ViewportId::ROOT,
-            wgpu,
+            client.clone(),
-            client,
+            proxy.clone(),
-            proxy,
+            persistence.clone(),
-            mappings,
+            shortcuts.clone(),
-            shortcuts,
+            &memory,
-            memory,
+            &images,
-            images,
+            mappings.clone(),
-            controllers,
+            SimId::Player1,
-            persistence,
+        );
-            viewports: HashMap::new(),
-            focused: None,
-            init_debug_port: args.debug_port,
-            init_profiling: args.profile,
-            init_bgmap: args.bgmap_data,
-            init_chardata: args.character_data,
-            init_objects: args.object_data,
-            init_worlds: args.worlds,
-            init_framebuffers: args.frame_buffers,
-            init_registers: args.registers,
-            init_terminal: args.terminal,
-        };
-        if args.player2 {
-            app.client
-                .send_command(EmulatorCommand::StartSecondSim(args.rom.clone()));
 
-            app.proxy
+        let ctx = Context::default();
-                .send_event(UserEvent::OpenPlayer2)
+        let data = persistence.load_config(EGUI_FILENAME).unwrap_or_default();
-                .expect("Failed to open Player 2 window");
+        ctx.data_mut(|d| *d = data);
+        let mut fonts = FontDefinitions::default();
+        fonts.font_data.insert(
+            "Selawik".into(),
+            Arc::new(FontData::from_static(include_bytes!(
+                "../assets/selawik.ttf"
+            ))),
+        );
+        fonts
+            .families
+            .get_mut(&FontFamily::Proportional)
+            .unwrap()
+            .insert(0, "Selawik".into());
+        ctx.set_fonts(fonts);
+        ctx.global_style_mut(|s| {
+            s.wrap_mode = Some(TextWrapMode::Extend);
+            s.visuals.menu_corner_radius = Default::default();
+            s.spacing.scroll = ScrollStyle::thin();
+        });
+        egui_extras::install_image_loaders(&ctx);
+        ctx.add_texture_loader(images.clone());
+        ctx.set_embed_viewports(false);
+        {
+            let proxy = proxy.clone();
+            ctx.set_request_repaint_callback(move |info| {
+                let _ = proxy.send_event(UserEvent::RequestRedraw(
+                    info.viewport_id,
+                    Instant::now() + info.delay,
+                ));
+            });
+        }
+
+        let wgpu_config = egui_wgpu::WgpuConfiguration {
+            present_mode: wgpu::PresentMode::AutoVsync,
+            wgpu_setup: egui_wgpu::WgpuSetup::Existing(egui_wgpu::WgpuSetupExisting {
+                instance: wgpu.instance.clone(),
+                adapter: wgpu.adapter.clone(),
+                device: wgpu.device.clone(),
+                queue: wgpu.queue.clone(),
+            }),
+            ..egui_wgpu::WgpuConfiguration::default()
+        };
+
+        let options = egui_wgpu::RendererOptions::default();
+        let painter = pollster::block_on(Painter::new(ctx.clone(), wgpu_config, false, options));
+
+        let mut initial_windows = vec![];
+        if let Some(port) = args.debug_port {
+            initial_windows.push(ChildWindow::Debugger { port: Some(port) });
+        }
+        if args.profile {
+            initial_windows.push(ChildWindow::Profiler { launch: true });
+        }
+        if args.character_data {
+            initial_windows.push(ChildWindow::CharacterData);
+        }
+        if args.bgmap_data {
+            initial_windows.push(ChildWindow::BgMap);
+        }
+        if args.object_data {
+            initial_windows.push(ChildWindow::Objects);
+        }
+        if args.worlds {
+            initial_windows.push(ChildWindow::Worlds);
+        }
+        if args.frame_buffers {
+            initial_windows.push(ChildWindow::FrameBuffers);
+        }
+        if args.registers {
+            initial_windows.push(ChildWindow::Registers);
+        }
+        if args.terminal {
+            initial_windows.push(ChildWindow::Terminal);
+        }
+        if args.player2 {
+            client.send_command(EmulatorCommand::StartSecondSim(args.rom.clone()));
+            initial_windows.push(ChildWindow::Player2);
+        }
+
+        Self {
+            client,
+            persistence,
+            ctx,
+            shared: SharedViewportState {
+                viewport_info: ViewportIdMap::default(),
+                painter,
+                resized_viewport: None,
+            },
+            icon,
+            app,
+            controllers,
+            viewports: ViewportIdMap::default(),
+            focused: None,
+            redraw_times: ViewportIdMap::default(),
+            initial_windows,
         }
-        app
     }
 
-    fn open(&mut self, event_loop: &ActiveEventLoop, window: Box<dyn AppWindow>) {
+    fn check_repaint(&mut self, event_loop: &ActiveEventLoop) {
-        let viewport_id = window.viewport_id();
+        let now = Instant::now();
-        if let Some(viewport) = self.viewports.get(&viewport_id) {
+        self.redraw_times.retain(|viewport_id, time| {
-            viewport.window.focus_window();
+            if *time > now {
-            return;
+                return true;
+            }
+            if let Some(viewport) = self.viewports.get(viewport_id) {
+                viewport.window.request_redraw();
+            }
+            false
+        });
+        if let Some(next_repaint_time) = self.redraw_times.values().min().copied() {
+            event_loop.set_control_flow(ControlFlow::WaitUntil(next_repaint_time));
         }
-        self.viewports.insert(
+    }
-            viewport_id,
+
-            Viewport::new(event_loop, &self.wgpu, self.icon.clone(), window),
+    fn repaint_all(&mut self, event_loop: &ActiveEventLoop) {
-        );
+        enum ViewportUpdate {
+            Keep {
+                recreate: bool,
+                builder: ViewportBuilder,
+                parent: ViewportId,
+                commands: Vec<ViewportCommand>,
+            },
+            Remove,
+        }
+        let mut updates = ViewportIdMap::<ViewportUpdate>::default();
+        for viewport in self.viewports.values() {
+            updates.insert(
+                viewport.id,
+                ViewportUpdate::Keep {
+                    recreate: false,
+                    builder: viewport.builder.clone(),
+                    parent: self
+                        .shared
+                        .viewport_info
+                        .get(&viewport.id)
+                        .and_then(|vp| vp.parent)
+                        .unwrap_or(ViewportId::ROOT),
+                    commands: vec![],
+                },
+            );
+        }
+
+        for viewport in self.viewports.values_mut() {
+            let mut input = viewport.take_egui_input();
+            if !self.shared.viewport_info.contains_key(&viewport.id) {
+                continue;
+            }
+            input.viewports = self.shared.viewport_info.clone();
+            let output = self.ctx.run_ui(input, |ui| {
+                if viewport.id == ViewportId::ROOT {
+                    self.app.show(ui);
+                } else if let Some(cb) = ui.viewport(|v| v.viewport_ui_cb.clone()) {
+                    cb(ui);
+                }
+            });
+            viewport.handle_platform_output(output.platform_output);
+            for (id, update) in updates.iter_mut() {
+                if !output.viewport_output.contains_key(id) {
+                    self.shared.viewport_info.remove(id);
+                    *update = ViewportUpdate::Remove;
+                }
+            }
+            for (id, mut vp) in output.viewport_output {
+                match updates.entry(id) {
+                    Entry::Vacant(e) => {
+                        e.insert(ViewportUpdate::Keep {
+                            recreate: true,
+                            builder: vp.builder,
+                            parent: vp.parent,
+                            commands: vp.commands,
+                        });
+                    }
+                    Entry::Occupied(e) => {
+                        let ViewportUpdate::Keep {
+                            recreate,
+                            builder,
+                            commands,
+                            ..
+                        } = e.into_mut()
+                        else {
+                            continue;
+                        };
+                        let (_, should_recreate) = builder.patch(vp.builder);
+                        *recreate |= should_recreate;
+                        commands.append(&mut vp.commands);
+                    }
+                }
+            }
+            let clipped_primitives = self.ctx.tessellate(output.shapes, output.pixels_per_point);
+            self.shared.painter.paint_and_update_textures(
+                viewport.id,
+                output.pixels_per_point,
+                [0.0, 0.0, 0.0, 0.0],
+                &clipped_primitives,
+                &output.textures_delta,
+                vec![],
+            );
+            viewport.window.pre_present_notify();
+        }
+        let mut active_viewports = ViewportIdSet::default();
+        for (id, update) in updates {
+            match update {
+                ViewportUpdate::Keep {
+                    recreate,
+                    builder,
+                    parent,
+                    commands,
+                } => {
+                    active_viewports.insert(id);
+                    let manager = self
+                        .viewports
+                        .remove(&id)
+                        .filter(|_| !recreate)
+                        .unwrap_or_else(|| {
+                            let manager = ViewportManager::new(
+                                &self.ctx,
+                                id,
+                                parent,
+                                event_loop,
+                                builder,
+                                &mut self.shared,
+                            );
+                            self.app.handle_init(
+                                id,
+                                InitArgs {
+                                    window: &manager.window,
+                                    render_state: &self.shared.painter.render_state().unwrap(),
+                                },
+                            );
+                            manager
+                        });
+                    manager.process_viewport_commands(commands, &mut self.shared);
+                    self.viewports.insert(id, manager);
+                }
+                ViewportUpdate::Remove => {
+                    self.viewports.remove(&id);
+                }
+            }
+        }
+        if !active_viewports.contains(&ViewportId::ROOT) {
+            event_loop.exit();
+        }
+        self.shared.painter.gc_viewports(&active_viewports);
     }
 }
 
 impl ApplicationHandler<UserEvent> for Application {
     fn resumed(&mut self, event_loop: &ActiveEventLoop) {
-        if let Some(port) = self.init_debug_port {
+        let mut viewport_builder = self.app.initial_viewport();
-            let mut server =
+        if let Some(icon) = &self.icon {
-                GdbServerWindow::new(SimId::Player1, self.client.clone(), self.proxy.clone());
+            viewport_builder = viewport_builder.with_icon(icon.clone());
-            server.launch(port);
-            self.open(event_loop, Box::new(server));
         }
-        let app = GameWindow::new(
+        let manager = ViewportManager::new(
-            self.client.clone(),
+            &self.ctx,
-            self.proxy.clone(),
+            ViewportId::ROOT,
-            self.persistence.clone(),
+            ViewportId::ROOT,
-            self.shortcuts.clone(),
+            event_loop,
-            SimId::Player1,
+            viewport_builder,
+            &mut self.shared,
         );
-        self.open(event_loop, Box::new(app));
+        let render_state = self.shared.painter.render_state().unwrap();
-        let sim_id = SimId::Player1;
+        GameScreen::init_pipeline(&render_state);
-        if self.init_profiling {
+        self.app.handle_init(
-            let mut profiler = ProfileWindow::new(sim_id, self.client.clone());
+            ViewportId::ROOT,
-            profiler.launch();
+            InitArgs {
-            self.open(event_loop, Box::new(profiler));
+                window: &manager.window,
+                render_state: &render_state,
+            },
+        );
+        self.viewports.insert(ViewportId::ROOT, manager);
+        for window in std::mem::take(&mut self.initial_windows) {
+            self.app.open(window);
         }
-        if self.init_chardata {
+    }
-            let chardata = CharacterDataWindow::new(sim_id, &self.memory, &mut self.images);
+
-            self.open(event_loop, Box::new(chardata));
+    fn about_to_wait(&mut self, _event_loop: &ActiveEventLoop) {
-        }
+        if let Some(viewport) = self.viewports.get(&ViewportId::ROOT) {
-        if self.init_bgmap {
+            viewport.window.request_redraw();
-            let bgmap = BgMapWindow::new(sim_id, &self.memory, &mut self.images);
-            self.open(event_loop, Box::new(bgmap));
-        }
-        if self.init_objects {
-            let objects = ObjectWindow::new(sim_id, &self.memory, &mut self.images);
-            self.open(event_loop, Box::new(objects));
-        }
-        if self.init_worlds {
-            let world = WorldWindow::new(sim_id, &self.memory, &mut self.images);
-            self.open(event_loop, Box::new(world));
-        }
-        if self.init_framebuffers {
-            let fb = FrameBufferWindow::new(sim_id, &self.memory, &mut self.images);
-            self.open(event_loop, Box::new(fb));
-        }
-        if self.init_registers {
-            let registers = RegisterWindow::new(sim_id, &self.memory);
-            self.open(event_loop, Box::new(registers));
-        }
-        if self.init_terminal {
-            let terminal = TerminalWindow::new(sim_id, &self.client);
-            self.open(event_loop, Box::new(terminal));
         }
     }
 
     fn window_event(
         &mut self,
         event_loop: &ActiveEventLoop,
-        window_id: winit::window::WindowId,
+        window_id: WindowId,
         event: WindowEvent,
     ) {
         let Some(viewport) = self
             .viewports
             .values_mut()
-            .find(|v| v.window.id() == window_id)
+            .find(|v| v.has_window_id(window_id))
         else {
             return;
         };
-        let viewport_id = viewport.id();
+        let viewport_id = viewport.id;
-        let mut queue_redraw = false;
+        let (response, close_requested) = viewport.on_window_event(&event, &mut self.shared);
-        let mut inactive_viewports = HashSet::new();
+        if close_requested && viewport_id == ViewportId::ROOT {
-        let (consumed, action) = viewport.on_window_event(&event);
+            event_loop.exit();
-        if !consumed {
+        }
+        if !response.consumed {
             match event {
                 WindowEvent::KeyboardInput { event, .. } => {
-                    if !viewport.app.handle_key_event(&event) {
+                    if !self.app.handle_key_event(viewport_id, &event) {
                         self.controllers.handle_key_event(&event);
                     }
                 }
@@ -213,35 +411,10 @@ impl ApplicationHandler<UserEvent> for Application {
                 _ => {}
             }
         }
-        match action {
+        if response.repaint {
-            Some(Action::Redraw) => {
+            self.repaint_all(event_loop);
-                for viewport in self.viewports.values_mut() {
-                    match viewport.redraw(event_loop) {
-                        Some(Action::Redraw) => {
-                            queue_redraw = true;
-                        }
-                        Some(Action::Close) => {
-                            inactive_viewports.insert(viewport.id());
-                        }
-                        None => {}
-                    }
-                }
-            }
-            Some(Action::Close) => {
-                inactive_viewports.insert(viewport_id);
-            }
-            None => {}
-        }
-        self.viewports
-            .retain(|k, _| !inactive_viewports.contains(k));
-        match self.viewports.get(&ViewportId::ROOT) {
-            Some(viewport) => {
-                if queue_redraw {
-                    viewport.window.request_redraw();
-                }
-            }
-            None => event_loop.exit(),
         }
+        self.check_repaint(event_loop);
     }
 
     fn device_event(
@@ -258,99 +431,41 @@ impl ApplicationHandler<UserEvent> for Application {
             else {
                 return;
             };
-            viewport.state.on_mouse_motion(delta);
+            viewport.on_mouse_motion(delta);
         }
     }
 
     fn user_event(&mut self, event_loop: &ActiveEventLoop, event: UserEvent) {
         match event {
             UserEvent::GamepadEvent(event) => {
-                if let Some(viewport) = self
+                if !self
                     .focused
-                    .as_ref()
+                    .is_some_and(|id| self.app.handle_gamepad_event(id, &event))
-                    .and_then(|id| self.viewports.get_mut(id))
-                    && viewport.app.handle_gamepad_event(&event)
                 {
-                    return;
+                    self.controllers.handle_gamepad_event(&event);
                 }
-                self.controllers.handle_gamepad_event(&event);
             }
-            UserEvent::OpenAbout => {
+            UserEvent::Quit(sim_id) => match sim_id {
-                let about = AboutWindow;
+                SimId::Player1 => event_loop.exit(),
-                self.open(event_loop, Box::new(about));
+                SimId::Player2 => self.app.close(ChildWindow::Player2),
-            }
+            },
-            UserEvent::OpenCharacterData(sim_id) => {
+            UserEvent::RequestRedraw(viewport, when) => {
-                let chardata = CharacterDataWindow::new(sim_id, &self.memory, &mut self.images);
+                let scheduled = self.redraw_times.entry(viewport).or_insert(when);
-                self.open(event_loop, Box::new(chardata));
+                if *scheduled > when {
-            }
+                    *scheduled = when;
-            UserEvent::OpenBgMap(sim_id) => {
-                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.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 fb = FrameBufferWindow::new(sim_id, &self.memory, &mut self.images);
-                self.open(event_loop, Box::new(fb));
-            }
-            UserEvent::OpenRegisters(sim_id) => {
-                let registers = RegisterWindow::new(sim_id, &self.memory);
-                self.open(event_loop, Box::new(registers));
-            }
-            UserEvent::OpenTerminal(sim_id) => {
-                let terminal = TerminalWindow::new(sim_id, &self.client);
-                self.open(event_loop, Box::new(terminal));
-            }
-            UserEvent::OpenProfiler(sim_id) => {
-                let profile = ProfileWindow::new(sim_id, self.client.clone());
-                self.open(event_loop, Box::new(profile));
-            }
-            UserEvent::OpenDebugger(sim_id) => {
-                let debugger =
-                    GdbServerWindow::new(sim_id, self.client.clone(), self.proxy.clone());
-                self.open(event_loop, Box::new(debugger));
-            }
-            UserEvent::OpenInput => {
-                let input = InputWindow::new(self.mappings.clone());
-                self.open(event_loop, Box::new(input));
-            }
-            UserEvent::OpenHotkeys => {
-                let hotkeys = HotkeysWindow::new(self.shortcuts.clone());
-                self.open(event_loop, Box::new(hotkeys));
-            }
-            UserEvent::OpenPlayer2 => {
-                let p2 = GameWindow::new(
-                    self.client.clone(),
-                    self.proxy.clone(),
-                    self.persistence.clone(),
-                    self.shortcuts.clone(),
-                    SimId::Player2,
-                );
-                self.open(event_loop, Box::new(p2));
-            }
-            UserEvent::Quit(sim_id) => {
-                self.viewports
-                    .retain(|_, viewport| viewport.app.sim_id() != sim_id);
-                if !self.viewports.contains_key(&ViewportId::ROOT) {
-                    event_loop.exit();
                 }
             }
         }
-    }
+        self.check_repaint(event_loop);
-
-    fn about_to_wait(&mut self, _event_loop: &ActiveEventLoop) {
-        if let Some(viewport) = self.viewports.get(&ViewportId::ROOT) {
-            viewport.window.request_redraw();
-        }
     }
 
     fn exiting(&mut self, _event_loop: &ActiveEventLoop) {
+        if let Err(error) = self
+            .ctx
+            .data(|d| self.persistence.save_config(EGUI_FILENAME, d))
+        {
+            error!(%error, "could not save egui state.");
+        }
         let (sender, receiver) = oneshot::channel();
         if self.client.send_command(EmulatorCommand::Exit(sender))
             && let Err(error) = receiver.recv_timeout(Duration::from_secs(5))
@@ -385,9 +500,9 @@ impl WgpuState {
         #[cfg(windows)]
         let backends = wgpu::Backends::from_env()
             .unwrap_or((wgpu::Backends::PRIMARY | wgpu::Backends::GL) - wgpu::Backends::VULKAN);
-        let instance = wgpu::Instance::new(&wgpu::InstanceDescriptor {
+        let instance = wgpu::Instance::new(wgpu::InstanceDescriptor {
             backends,
-            ..wgpu::InstanceDescriptor::default()
+            ..wgpu::InstanceDescriptor::new_without_display_handle_from_env()
         });
 
         let adapter = pollster::block_on(instance.request_adapter(&wgpu::RequestAdapterOptions {
@@ -410,218 +525,109 @@ impl WgpuState {
     }
 }
 
-struct Viewport {
+struct ViewportManager {
-    painter: egui_wgpu::winit::Painter,
+    id: ViewportId,
-    ctx: Context,
-    info: ViewportInfo,
-    commands: Vec<ViewportCommand>,
-    builder: ViewportBuilder,
     window: Arc<Window>,
     state: egui_winit::State,
-    app: Box<dyn AppWindow>,
+    builder: ViewportBuilder,
 }
-impl Viewport {
+impl ViewportManager {
-    pub fn new(
+    fn new(
+        ctx: &Context,
+        viewport_id: ViewportId,
+        parent_id: ViewportId,
         event_loop: &ActiveEventLoop,
-        wgpu: &WgpuState,
+        builder: ViewportBuilder,
-        icon: Option<Arc<IconData>>,
+        shared: &mut SharedViewportState,
-        mut app: Box<dyn AppWindow>,
     ) -> Self {
-        let ctx = Context::default();
+        let window = Arc::new(egui_winit::create_window(ctx, event_loop, &builder).unwrap());
-        let mut fonts = FontDefinitions::default();
+        pollster::block_on(shared.painter.set_window(viewport_id, Some(window.clone()))).unwrap();
-        fonts.font_data.insert(
+        let state = egui_winit::State::new(
-            "Selawik".into(),
-            Arc::new(FontData::from_static(include_bytes!(
-                "../assets/selawik.ttf"
-            ))),
-        );
-        fonts
-            .families
-            .get_mut(&FontFamily::Proportional)
-            .unwrap()
-            .insert(0, "Selawik".into());
-        ctx.set_fonts(fonts);
-        ctx.style_mut(|s| {
-            s.wrap_mode = Some(TextWrapMode::Extend);
-            s.visuals.menu_corner_radius = Default::default();
-            s.spacing.scroll = ScrollStyle::thin();
-        });
-        egui_extras::install_image_loaders(&ctx);
-
-        let wgpu_config = egui_wgpu::WgpuConfiguration {
-            present_mode: wgpu::PresentMode::AutoVsync,
-            wgpu_setup: egui_wgpu::WgpuSetup::Existing(egui_wgpu::WgpuSetupExisting {
-                instance: wgpu.instance.clone(),
-                adapter: wgpu.adapter.clone(),
-                device: wgpu.device.clone(),
-                queue: wgpu.queue.clone(),
-            }),
-            ..egui_wgpu::WgpuConfiguration::default()
-        };
-
-        let options = egui_wgpu::RendererOptions::default();
-        let mut painter = pollster::block_on(egui_wgpu::winit::Painter::new(
             ctx.clone(),
-            wgpu_config,
+            viewport_id,
-            false,
+            event_loop,
-            options,
+            Some(window.scale_factor() as f32),
-        ));
+            event_loop.system_theme(),
+            shared.painter.max_texture_side(),
+        );
 
-        let mut info = ViewportInfo::default();
+        let mut info = ViewportInfo {
-        let mut builder = app.initial_viewport();
+            parent: Some(parent_id),
-        if let Some(icon) = icon {
+            ..ViewportInfo::default()
-            builder = builder.with_icon(icon);
-        }
-        let (window, state) = create_window_and_state(&ctx, event_loop, &builder, &mut painter);
-        egui_winit::update_viewport_info(&mut info, &ctx, &window, true);
-
-        let render_state = painter.render_state();
-        let args = InitArgs {
-            ctx: &ctx,
-            window: &window,
-            render_state: render_state.as_ref().unwrap(),
         };
-        app.on_init(args);
+        egui_winit::update_viewport_info(&mut info, ctx, &window, true);
+        shared.viewport_info.insert(viewport_id, info);
+
         Self {
-            painter,
+            id: viewport_id,
-            ctx,
-            info,
-            commands: vec![],
-            builder,
             window,
             state,
-            app,
+            builder,
         }
     }
 
-    pub fn id(&self) -> ViewportId {
+    fn has_window_id(&self, window_id: WindowId) -> bool {
-        self.app.viewport_id()
+        self.window.id() == window_id
     }
 
-    pub fn on_window_event(&mut self, event: &WindowEvent) -> (bool, Option<Action>) {
+    fn on_mouse_motion(&mut self, delta: (f64, f64)) {
-        let response = self.state.on_window_event(&self.window, event);
+        self.state.on_mouse_motion(delta);
-        egui_winit::update_viewport_info(
+    }
-            &mut self.info,
-            self.state.egui_ctx(),
-            &self.window,
-            false,
-        );
 
-        let action = match event {
+    fn on_window_event(
-            WindowEvent::RedrawRequested => Some(Action::Redraw),
+        &mut self,
-            WindowEvent::CloseRequested => Some(Action::Close),
+        event: &WindowEvent,
-            WindowEvent::Resized(size) => {
+        shared: &mut SharedViewportState,
-                if let (Some(width), Some(height)) =
+    ) -> (EventResponse, bool) {
-                    (NonZero::new(size.width), NonZero::new(size.height))
+        if let WindowEvent::Resized(size) = event
-                {
+            && let (Some(width), Some(height)) =
-                    self.painter
+                (NonZero::new(size.width), NonZero::new(size.height))
-                        .on_window_resized(ViewportId::ROOT, width, height);
+        {
-                }
+            if shared.resized_viewport != Some(self.id) {
-                None
+                shared.resized_viewport = Some(self.id);
+                shared.painter.on_window_resize_state_change(self.id, true);
             }
-            _ if response.repaint => Some(Action::Redraw),
+            shared.painter.on_window_resized(self.id, width, height);
-            _ => None,
+        }
-        };
+        let response = self.state.on_window_event(&self.window, event);
-        (response.consumed, action)
+        let info = shared.viewport_info.get_mut(&self.id).unwrap();
+        if let WindowEvent::CloseRequested = event {
+            info.events.push(ViewportEvent::Close);
+        }
+        egui_winit::update_viewport_info(info, self.state.egui_ctx(), &self.window, false);
+        (response, info.close_requested())
     }
 
-    fn redraw(&mut self, event_loop: &ActiveEventLoop) -> Option<Action> {
+    fn take_egui_input(&mut self) -> RawInput {
-        let mut input = self.state.take_egui_input(&self.window);
+        self.state.take_egui_input(&self.window)
-        input.viewports = std::iter::once((ViewportId::ROOT, self.info.clone())).collect();
+    }
-        let mut output = self.ctx.run(input, |ctx| {
-            self.app.show(ctx);
-        });
-        let clipped_primitives = self.ctx.tessellate(output.shapes, output.pixels_per_point);
-        self.painter.paint_and_update_textures(
-            ViewportId::ROOT,
-            output.pixels_per_point,
-            [0.0, 0.0, 0.0, 0.0],
-            &clipped_primitives,
-            &output.textures_delta,
-            vec![],
-        );
 
+    fn handle_platform_output(&mut self, platform_output: PlatformOutput) {
         self.state
-            .handle_platform_output(&self.window, output.platform_output);
+            .handle_platform_output(&self.window, platform_output);
+    }
 
-        let Some(mut viewport_output) = output.viewport_output.remove(&ViewportId::ROOT) else {
+    fn process_viewport_commands(
-            return Some(Action::Close);
+        &self,
-        };
+        commands: Vec<ViewportCommand>,
-
+        shared: &mut SharedViewportState,
-        let (mut deferred_commands, recreate) = self.builder.patch(viewport_output.builder);
+    ) {
-        if recreate {
+        let info = shared.viewport_info.get_mut(&self.id).unwrap();
-            let (window, state) =
-                create_window_and_state(&self.ctx, event_loop, &self.builder, &mut self.painter);
-            egui_winit::update_viewport_info(&mut self.info, &self.ctx, &window, true);
-            self.window = window;
-            self.state = state;
-        }
-        self.commands.append(&mut deferred_commands);
-        self.commands.append(&mut viewport_output.commands);
         egui_winit::process_viewport_commands(
-            &self.ctx,
+            self.state.egui_ctx(),
-            &mut self.info,
+            info,
-            std::mem::take(&mut self.commands),
+            commands,
             &self.window,
             &mut vec![],
         );
-
-        if self.info.close_requested() {
-            Some(Action::Close)
-        } else {
-            Some(Action::Redraw)
-        }
-    }
-}
-
-impl Drop for Viewport {
-    fn drop(&mut self) {
-        self.app.on_destroy();
     }
 }
 
 #[derive(Debug)]
 pub enum UserEvent {
     GamepadEvent(gilrs::Event),
-    OpenAbout,
-    OpenCharacterData(SimId),
-    OpenBgMap(SimId),
-    OpenObjects(SimId),
-    OpenWorlds(SimId),
-    OpenFrameBuffers(SimId),
-    OpenRegisters(SimId),
-    OpenTerminal(SimId),
-    OpenProfiler(SimId),
-    OpenDebugger(SimId),
-    OpenInput,
-    OpenHotkeys,
-    OpenPlayer2,
     Quit(SimId),
-}
+    RequestRedraw(ViewportId, Instant),
-
-pub enum Action {
-    Redraw,
-    Close,
-}
-
-fn create_window_and_state(
-    ctx: &Context,
-    event_loop: &ActiveEventLoop,
-    builder: &ViewportBuilder,
-    painter: &mut egui_wgpu::winit::Painter,
-) -> (Arc<Window>, egui_winit::State) {
-    pollster::block_on(painter.set_window(ViewportId::ROOT, None)).unwrap();
-    let window = Arc::new(egui_winit::create_window(ctx, event_loop, builder).unwrap());
-    pollster::block_on(painter.set_window(ViewportId::ROOT, Some(window.clone()))).unwrap();
-    let state = egui_winit::State::new(
-        ctx.clone(),
-        ViewportId::ROOT,
-        event_loop,
-        Some(window.scale_factor() as f32),
-        event_loop.system_theme(),
-        painter.max_texture_side(),
-    );
-    (window, state)
 }
 
 fn process_gamepad_input(mappings: MappingProvider, proxy: EventLoopProxy<UserEvent>) {

src/config.rs

@@ -7,6 +7,7 @@ use crate::{emulator::SimId, persistence::Persistence, window::DisplayMode};
 use std::path::PathBuf;
 
 #[derive(Parser)]
+#[command(version, long_version = env!("CARGO_PKG_VERSION"))]
 pub struct CliArgs {
     /// The path to a virtual boy ROM to run.
     pub rom: Option<PathBuf>,

src/images.rs

@@ -1,5 +1,5 @@
 use std::{
-    collections::HashMap,
+    collections::{HashMap, hash_map::Entry},
     ops::Deref,
     sync::{Arc, Mutex, Weak},
     thread,
@@ -7,17 +7,21 @@ use std::{
 };
 
 use egui::{
-    Color32, ColorImage, TextureHandle, TextureOptions,
+    Color32, ColorImage, TextureHandle,
     epaint::ImageDelta,
+    generate_loader_id,
     load::{LoadError, SizedTexture, TextureLoader, TexturePoll},
 };
 use tokio::{sync::mpsc, time::timeout};
 
-pub struct ImageProcessor {
+use crate::emulator::SimId;
+
+pub struct ImageTextureLoader {
+    cache: Mutex<HashMap<String, ImageEntry>>,
     sender: mpsc::UnboundedSender<Box<dyn ImageRendererImpl>>,
 }
 
-impl ImageProcessor {
+impl ImageTextureLoader {
     pub fn new() -> Self {
         let (sender, receiver) = mpsc::unbounded_channel();
         thread::spawn(move || {
@@ -26,29 +30,52 @@ impl ImageProcessor {
                 .build()
                 .unwrap()
                 .block_on(async move {
-                    let mut worker = ImageProcessorWorker {
+                    let mut worker = ImageTextureLoaderWorker {
                         receiver,
                         renderers: vec![],
                     };
                     worker.run().await
                 })
         });
-        Self { sender }
+        Self {
+            cache: Mutex::new(HashMap::new()),
+            sender,
+        }
     }
 
     pub fn add<const N: usize, R: ImageRenderer<N> + 'static>(
         &self,
+        sim_id: SimId,
         renderer: R,
         params: R::Params,
-    ) -> ([ImageHandle; N], ImageParams<R::Params>) {
+    ) -> 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]| ImageBuffer::new(width, height));
+        {
+            let mut cache = self.cache.lock().unwrap();
+            for (name, state) in renderer.names().into_iter().zip(&states) {
+                let url = format!("vip://{sim_id}/{name}");
+                let entry = ImageEntry {
+                    size: state.size.map(|i| i as f32),
+                    data: Arc::downgrade(&state.sink),
+                    texture: None,
+                };
+                match cache.entry(url) {
+                    Entry::Vacant(e) => {
+                        e.insert(entry);
+                    }
+                    Entry::Occupied(mut e) => {
+                        // Only overwrite an old entry if that entry is dead.
+                        // Otherwise, we clear out the reference to a texture actually in use.
+                        if e.get().data.strong_count() == 0 {
+                            e.insert(entry);
+                        }
+                    }
+                }
+            }
+        }
         let sink = Arc::new(Mutex::new(params.clone()));
         let _ = self.sender.send(Box::new(ImageRendererWrapper {
             renderer,
@@ -56,20 +83,87 @@ impl ImageProcessor {
             images,
             states,
         }));
-        let params = ImageParams {
+        ImageParams {
             value: params,
             sink,
-        };
+        }
-        (handles, params)
     }
 }
 
-struct ImageProcessorWorker {
+impl TextureLoader for ImageTextureLoader {
+    fn id(&self) -> &str {
+        generate_loader_id!(ImageTextureLoader2)
+    }
+
+    fn load(
+        &self,
+        ctx: &egui::Context,
+        uri: &str,
+        texture_options: egui::TextureOptions,
+        _size_hint: egui::SizeHint,
+    ) -> Result<TexturePoll, LoadError> {
+        let mut cache = self.cache.lock().unwrap();
+        let Some(entry) = cache.get_mut(uri) else {
+            return Err(LoadError::NotSupported);
+        };
+        if texture_options != egui::TextureOptions::NEAREST {
+            return Err(LoadError::Loading(
+                "Only TextureOptions::NEAREST are supported".into(),
+            ));
+        }
+        let Some(data) = entry.data.upgrade() else {
+            cache.remove(uri);
+            return Err(LoadError::Loading("Backing loader no longer exists".into()));
+        };
+        match (data.lock().unwrap().take(), entry.texture.as_ref()) {
+            (Some(update), Some(handle)) => {
+                let delta = ImageDelta::full(update, texture_options);
+                ctx.tex_manager().write().set(handle.id(), delta);
+                let texture = SizedTexture::new(handle, entry.size);
+                Ok(TexturePoll::Ready { texture })
+            }
+            (Some(update), None) => {
+                let handle = ctx.load_texture(uri, update, texture_options);
+                let texture = SizedTexture::new(&handle, entry.size);
+                entry.texture.replace(handle);
+                Ok(TexturePoll::Ready { texture })
+            }
+            (None, Some(handle)) => {
+                let texture = SizedTexture::new(handle, entry.size);
+                Ok(TexturePoll::Ready { texture })
+            }
+            (None, None) => {
+                let size = entry.size.into();
+                Ok(TexturePoll::Pending { size: Some(size) })
+            }
+        }
+    }
+
+    fn forget(&self, uri: &str) {
+        let _ = uri;
+    }
+
+    fn forget_all(&self) {}
+
+    fn byte_size(&self) -> usize {
+        self.cache
+            .lock()
+            .unwrap()
+            .values()
+            .map(|entry| {
+                let [width, height] = entry.size;
+                width as usize * height as usize * 4
+            })
+            .sum()
+    }
+}
+
+struct ImageTextureLoaderWorker {
     receiver: mpsc::UnboundedReceiver<Box<dyn ImageRendererImpl>>,
     renderers: Vec<Box<dyn ImageRendererImpl>>,
 }
 
-impl ImageProcessorWorker {
+impl ImageTextureLoaderWorker {
     async fn run(&mut self) {
         loop {
             if self.renderers.is_empty() {
@@ -142,16 +236,10 @@ impl ImageBuffer {
     }
 }
 
-#[derive(Clone)]
+struct ImageEntry {
-pub struct ImageHandle {
     size: [f32; 2],
-    data: Arc<Mutex<Option<Arc<ColorImage>>>>,
+    data: Weak<Mutex<Option<Arc<ColorImage>>>>,
-}
+    texture: Option<TextureHandle>,
-
-impl ImageHandle {
-    fn pull(&mut self) -> Option<Arc<ColorImage>> {
-        self.data.lock().unwrap().take()
-    }
 }
 
 pub struct ImageParams<T> {
@@ -178,6 +266,7 @@ impl<T: Clone + Eq> ImageParams<T> {
 
 pub trait ImageRenderer<const N: usize>: Send {
     type Params: Clone + Send;
+    fn names(&self) -> [&str; N];
     fn sizes(&self) -> [[usize; 2]; N];
     fn render(&mut self, params: &Self::Params, images: &mut [ImageBuffer; N]);
 }
@@ -246,83 +335,3 @@ impl<const N: usize, R: ImageRenderer<N> + Send> ImageRendererImpl for ImageRend
         Ok(())
     }
 }
-
-pub struct ImageTextureLoader {
-    cache: Mutex<HashMap<String, (ImageHandle, Option<TextureHandle>)>>,
-}
-
-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));
-        }
-        Self {
-            cache: Mutex::new(cache),
-        }
-    }
-}
-
-impl TextureLoader for ImageTextureLoader {
-    fn id(&self) -> &str {
-        concat!(module_path!(), "ImageTextureLoader")
-    }
-
-    fn load(
-        &self,
-        ctx: &egui::Context,
-        uri: &str,
-        texture_options: TextureOptions,
-        _size_hint: egui::SizeHint,
-    ) -> Result<TexturePoll, LoadError> {
-        let mut cache = self.cache.lock().unwrap();
-        let Some((image, maybe_handle)) = cache.get_mut(uri) else {
-            return Err(LoadError::NotSupported);
-        };
-        if texture_options != TextureOptions::NEAREST {
-            return Err(LoadError::Loading(
-                "Only TextureOptions::NEAREST are supported".into(),
-            ));
-        }
-        match (image.pull(), maybe_handle.as_ref()) {
-            (Some(update), Some(handle)) => {
-                let delta = ImageDelta::full(update, texture_options);
-                ctx.tex_manager().write().set(handle.id(), delta);
-                let texture = SizedTexture::new(handle, image.size);
-                Ok(TexturePoll::Ready { texture })
-            }
-            (Some(update), None) => {
-                let handle = ctx.load_texture(uri, update, texture_options);
-                let texture = SizedTexture::new(&handle, image.size);
-                maybe_handle.replace(handle);
-                Ok(TexturePoll::Ready { texture })
-            }
-            (None, Some(handle)) => {
-                let texture = SizedTexture::new(handle, image.size);
-                Ok(TexturePoll::Ready { texture })
-            }
-            (None, None) => {
-                let size = image.size.into();
-                Ok(TexturePoll::Pending { size: Some(size) })
-            }
-        }
-    }
-
-    fn forget(&self, uri: &str) {
-        let _ = uri;
-    }
-
-    fn forget_all(&self) {}
-
-    fn byte_size(&self) -> usize {
-        self.cache
-            .lock()
-            .unwrap()
-            .values()
-            .map(|(image, _)| {
-                let [width, height] = image.size;
-                width as usize * height as usize * 4
-            })
-            .sum()
-    }
-}

src/window.rs

@@ -1,9 +1,9 @@
 use std::sync::Arc;
 
 pub use about::AboutWindow;
-use egui::{Context, ViewportBuilder, ViewportId};
+use egui::{Ui, ViewportBuilder};
-pub use game::GameWindow;
+pub use game::{ChildWindow, GameWindow};
-pub use game_screen::DisplayMode;
+pub use game_screen::{DisplayMode, GameScreen};
 pub use gdb::GdbServerWindow;
 pub use hotkeys::HotkeysWindow;
 pub use input::InputWindow;
@@ -28,16 +28,17 @@ mod utils;
 mod vip;
 
 pub trait AppWindow {
-    fn viewport_id(&self) -> ViewportId;
     fn sim_id(&self) -> SimId {
         SimId::Player1
     }
+    fn image_url(&self, name: &str) -> String {
+        format!("vip://{}/{name}", self.sim_id())
+    }
     fn initial_viewport(&self) -> ViewportBuilder;
-    fn show(&mut self, ctx: &Context);
+    fn show(&mut self, ui: &mut Ui);
     fn on_init(&mut self, args: InitArgs) {
         let _ = args;
     }
-    fn on_destroy(&mut self) {}
     fn handle_key_event(&mut self, event: &KeyEvent) -> bool {
         let _ = event;
         false
@@ -49,7 +50,6 @@ pub trait AppWindow {
 }
 
 pub struct InitArgs<'a> {
-    pub ctx: &'a Context,
     pub window: &'a Arc<Window>,
     pub render_state: &'a egui_wgpu::RenderState,
 }

src/window/about.rs

@@ -1,22 +1,18 @@
-use egui::{CentralPanel, Context, Image, ViewportBuilder, ViewportId};
+use egui::{CentralPanel, Image, Ui, ViewportBuilder};
 
 use super::AppWindow;
 
 pub struct AboutWindow;
 
 impl AppWindow for AboutWindow {
-    fn viewport_id(&self) -> ViewportId {
-        ViewportId::from_hash_of("About")
-    }
-
     fn initial_viewport(&self) -> ViewportBuilder {
         ViewportBuilder::default()
             .with_title("About Lemur")
             .with_inner_size((300.0, 200.0))
     }
 
-    fn show(&mut self, ctx: &Context) {
+    fn show(&mut self, ui: &mut Ui) {
-        CentralPanel::default().show(ctx, |ui| {
+        CentralPanel::default().show_inside(ui, |ui| {
             ui.vertical_centered(|ui| {
                 ui.label("Lemur Virtual Boy Emulator");
                 ui.label(format!("Version {}", env!("CARGO_PKG_VERSION")));

src/window/game.rs

@@ -1,5 +1,6 @@
 use std::{
-    sync::{Arc, mpsc},
+    ops::{Deref, DerefMut},
+    sync::{Arc, Mutex, atomic::AtomicBool, mpsc},
     time::Duration,
 };
 
@@ -7,17 +8,23 @@ use crate::{
     app::UserEvent,
     config::{COLOR_PRESETS, SimConfig},
     emulator::{EmulatorClient, EmulatorCommand, EmulatorState, SimId, SimState},
-    input::{Command, ShortcutProvider},
+    images::ImageTextureLoader,
+    input::{Command, MappingProvider, ShortcutProvider},
+    memory::MemoryClient,
     persistence::Persistence,
-    window::InitArgs,
+    window::{
+        AboutWindow, BgMapWindow, CharacterDataWindow, FrameBufferWindow, GdbServerWindow,
+        HotkeysWindow, InitArgs, InputWindow, ObjectWindow, ProfileWindow, RegisterWindow,
+        TerminalWindow, WorldWindow, utils::UiData,
+    },
 };
 use anyhow::Context as _;
 use egui::{
-    Align2, Button, CentralPanel, Color32, Context, Frame, MenuBar, TopBottomPanel, Ui, Vec2,
+    Align2, Button, CentralPanel, Color32, Context, Frame, MenuBar, Panel, Ui, Vec2,
-    ViewportBuilder, ViewportCommand, ViewportId, Window,
+    ViewportBuilder, ViewportCommand, ViewportId, ViewportIdMap, Window,
 };
 use egui_notify::{Anchor, Toast, Toasts};
-use winit::event_loop::EventLoopProxy;
+use winit::{event::KeyEvent, event_loop::EventLoopProxy};
 
 use super::{
     AppWindow,
@@ -26,6 +33,7 @@ use super::{
 };
 
 pub struct GameWindow {
+    viewport_id: ViewportId,
     client: EmulatorClient,
     proxy: EventLoopProxy<UserEvent>,
     persistence: Persistence,
@@ -34,17 +42,29 @@ pub struct GameWindow {
     config: SimConfig,
     toasts: Toasts,
     screen: Option<GameScreen>,
-    messages: Option<mpsc::Receiver<Toast>>,
+    messages: mpsc::Receiver<Toast>,
+    message_sink: mpsc::Sender<Toast>,
     color_picker: Option<ColorPickerState>,
     window: Option<Arc<winit::window::Window>>,
+    memory: Arc<MemoryClient>,
+    images: Arc<ImageTextureLoader>,
+    mappings: MappingProvider,
+    children: ViewportIdMap<ChildWindowWrapper>,
+    child_sizes: UiData<ViewportIdMap<Vec2>>,
+    queued_children: Vec<ChildWindow>,
 }
 
 impl GameWindow {
+    #[expect(clippy::too_many_arguments)]
     pub fn new(
+        viewport_id: ViewportId,
         client: EmulatorClient,
         proxy: EventLoopProxy<UserEvent>,
         persistence: Persistence,
         shortcuts: ShortcutProvider,
+        memory: &Arc<MemoryClient>,
+        images: &Arc<ImageTextureLoader>,
+        mappings: MappingProvider,
         sim_id: SimId,
     ) -> Self {
         let config = SimConfig::load(&persistence, sim_id);
@@ -52,7 +72,9 @@ impl GameWindow {
             .with_anchor(Anchor::BottomLeft)
             .with_margin((10.0, 10.0).into())
             .reverse(true);
+        let (message_sink, messages) = mpsc::channel();
         Self {
+            viewport_id,
             client,
             proxy,
             persistence,
@@ -61,13 +83,150 @@ impl GameWindow {
             config,
             toasts,
             screen: None,
-            messages: None,
+            messages,
+            message_sink,
             color_picker: None,
             window: None,
+            memory: memory.clone(),
+            images: images.clone(),
+            mappings: mappings.clone(),
+            children: ViewportIdMap::default(),
+            child_sizes: UiData::new(),
+            queued_children: vec![],
         }
     }
 
-    fn show_menu(&mut self, ctx: &Context, ui: &mut Ui) {
+    pub fn open(&mut self, window: ChildWindow) {
+        // queue opening this child until our next render call,
+        // so that we get a chance to look up its size
+        self.queued_children.push(window);
+    }
+
+    pub fn close(&mut self, window: ChildWindow) {
+        let id = window.viewport_id(self.sim_id);
+        self.children.remove(&id);
+    }
+
+    fn do_open(&mut self, window: ChildWindow) {
+        let viewport_id = window.viewport_id(self.sim_id);
+        if self.children.contains_key(&viewport_id) {
+            return;
+        }
+        let child = match window {
+            ChildWindow::About => AppWrapper::of_dyn(AboutWindow),
+            ChildWindow::CharacterData => AppWrapper::of_dyn(CharacterDataWindow::new(
+                self.sim_id,
+                &self.memory,
+                &self.images,
+            )),
+            ChildWindow::BgMap => {
+                AppWrapper::of_dyn(BgMapWindow::new(self.sim_id, &self.memory, &self.images))
+            }
+            ChildWindow::Objects => {
+                AppWrapper::of_dyn(ObjectWindow::new(self.sim_id, &self.memory, &self.images))
+            }
+            ChildWindow::Worlds => {
+                AppWrapper::of_dyn(WorldWindow::new(self.sim_id, &self.memory, &self.images))
+            }
+            ChildWindow::FrameBuffers => AppWrapper::of_dyn(FrameBufferWindow::new(
+                self.sim_id,
+                &self.memory,
+                &self.images,
+            )),
+            ChildWindow::Registers => {
+                AppWrapper::of_dyn(RegisterWindow::new(self.sim_id, &self.memory))
+            }
+            ChildWindow::Terminal => {
+                AppWrapper::of_dyn(TerminalWindow::new(self.sim_id, &self.client))
+            }
+            ChildWindow::Profiler { launch } => {
+                let mut profile = ProfileWindow::new(self.sim_id, self.client.clone());
+                if launch {
+                    profile.launch();
+                }
+                AppWrapper::of_dyn(profile)
+            }
+            ChildWindow::Debugger { port } => {
+                let mut debugger =
+                    GdbServerWindow::new(self.sim_id, self.client.clone(), self.proxy.clone());
+                if let Some(port) = port {
+                    debugger.launch(port);
+                }
+                AppWrapper::of_dyn(debugger)
+            }
+            ChildWindow::Input => AppWrapper::of_dyn(InputWindow::new(self.mappings.clone())),
+            ChildWindow::Hotkeys => AppWrapper::of_dyn(HotkeysWindow::new(self.shortcuts.clone())),
+            ChildWindow::Player2 => {
+                if self.sim_id == SimId::Player2 {
+                    return;
+                }
+                AppWrapper::of_game(GameWindow::new(
+                    viewport_id,
+                    self.client.clone(),
+                    self.proxy.clone(),
+                    self.persistence.clone(),
+                    self.shortcuts.clone(),
+                    &self.memory,
+                    &self.images,
+                    self.mappings.clone(),
+                    SimId::Player2,
+                ))
+            }
+        };
+
+        let mut viewport = child.initial_viewport();
+        if let Some(size) = self.child_sizes.get(&viewport_id) {
+            viewport.inner_size = Some(*size);
+        }
+        self.children.insert(
+            viewport_id,
+            ChildWindowWrapper {
+                app: Arc::new(Mutex::new(child)),
+                updates: Some(viewport),
+                close_requested: Arc::new(AtomicBool::new(false)),
+            },
+        );
+    }
+
+    pub fn handle_init(&mut self, viewport_id: ViewportId, args: InitArgs) {
+        self.handle_event(viewport_id, |window| window.on_init(args))
+    }
+
+    pub fn handle_key_event(&mut self, viewport_id: ViewportId, event: &KeyEvent) -> bool {
+        self.handle_event(viewport_id, |window| window.handle_key_event(event))
+    }
+
+    pub fn handle_gamepad_event(&mut self, viewport_id: ViewportId, event: &gilrs::Event) -> bool {
+        self.handle_event(viewport_id, |window| window.handle_gamepad_event(event))
+    }
+
+    fn handle_event<F, R>(&mut self, viewport_id: ViewportId, cb: F) -> R
+    where
+        F: FnOnce(&mut dyn AppWindow) -> R,
+        R: Default,
+    {
+        let p2_viewport_id = ChildWindow::Player2.viewport_id(SimId::Player1);
+
+        if self.viewport_id == viewport_id {
+            cb(self)
+        } else if let Some(child) = self.children.get_mut(&viewport_id) {
+            cb(child.app.lock().unwrap().deref_mut().deref_mut())
+        } else if let Some(mut p2) = self
+            .children
+            .get_mut(&p2_viewport_id)
+            .map(|w| w.app.lock().unwrap())
+        {
+            if let AppWrapper::Game(g) = p2.deref_mut() {
+                g.handle_event(viewport_id, cb)
+            } else {
+                R::default()
+            }
+        } else {
+            R::default()
+        }
+    }
+
+    fn show_menu(&mut self, ui: &mut Ui) {
         let state = self.client.emulator_state();
         let is_ready = self.client.sim_state(self.sim_id) == SimState::Ready;
         let can_pause = is_ready && state == EmulatorState::Running;
@@ -208,7 +367,7 @@ impl GameWindow {
                 pollster::block_on(self.take_screenshot());
             }
         });
-        ui.menu_button("Options", |ui| self.show_options_menu(ctx, ui));
+        ui.menu_button("Options", |ui| self.show_options_menu(ui));
         ui.menu_button("Multiplayer", |ui| {
             let has_player_2 = self.client.sim_state(SimId::Player2) != SimState::Uninitialized;
             if self.sim_id == SimId::Player1
@@ -217,7 +376,7 @@ impl GameWindow {
             {
                 self.client
                     .send_command(EmulatorCommand::StartSecondSim(None));
-                self.proxy.send_event(UserEvent::OpenPlayer2).unwrap();
+                self.open(ChildWindow::Player2);
             }
             if has_player_2 {
                 let linked = self.client.are_sims_linked();
@@ -231,55 +390,37 @@ impl GameWindow {
         });
         ui.menu_button("Tools", |ui| {
             if ui.button("Terminal").clicked() {
-                self.proxy
+                self.open(ChildWindow::Terminal);
-                    .send_event(UserEvent::OpenTerminal(self.sim_id))
-                    .unwrap();
             }
             if ui.button("Profiler").clicked() {
-                self.proxy
+                self.open(ChildWindow::Profiler { launch: false });
-                    .send_event(UserEvent::OpenProfiler(self.sim_id))
-                    .unwrap();
             }
             if ui.button("GDB Server").clicked() {
-                self.proxy
+                self.open(ChildWindow::Debugger { port: None });
-                    .send_event(UserEvent::OpenDebugger(self.sim_id))
-                    .unwrap();
             }
             ui.separator();
             if ui.button("Character Data").clicked() {
-                self.proxy
+                self.open(ChildWindow::CharacterData);
-                    .send_event(UserEvent::OpenCharacterData(self.sim_id))
-                    .unwrap();
             }
             if ui.button("Background Maps").clicked() {
-                self.proxy
+                self.open(ChildWindow::BgMap);
-                    .send_event(UserEvent::OpenBgMap(self.sim_id))
-                    .unwrap();
             }
             if ui.button("Objects").clicked() {
-                self.proxy
+                self.open(ChildWindow::Objects);
-                    .send_event(UserEvent::OpenObjects(self.sim_id))
-                    .unwrap();
             }
             if ui.button("Worlds").clicked() {
-                self.proxy
+                self.open(ChildWindow::Worlds);
-                    .send_event(UserEvent::OpenWorlds(self.sim_id))
-                    .unwrap();
             }
             if ui.button("Frame Buffers").clicked() {
-                self.proxy
+                self.open(ChildWindow::FrameBuffers);
-                    .send_event(UserEvent::OpenFrameBuffers(self.sim_id))
-                    .unwrap();
             }
             if ui.button("Registers").clicked() {
-                self.proxy
+                self.open(ChildWindow::Registers);
-                    .send_event(UserEvent::OpenRegisters(self.sim_id))
-                    .unwrap();
             }
         });
         ui.menu_button("Help", |ui| {
             if ui.button("About").clicked() {
-                self.proxy.send_event(UserEvent::OpenAbout).unwrap();
+                self.open(ChildWindow::About);
             }
         });
     }
@@ -328,7 +469,7 @@ impl GameWindow {
         Ok(Some(path.display().to_string()))
     }
 
-    fn show_options_menu(&mut self, ctx: &Context, ui: &mut Ui) {
+    fn show_options_menu(&mut self, ui: &mut Ui) {
         ui.menu_button("Video", |ui| {
             ui.menu_button("Screen Size", |ui| {
                 let current_dims = self.config.dimensions;
@@ -344,7 +485,7 @@ impl GameWindow {
                         .selectable_button((current_dims - dims).length() < 1.0, label)
                         .clicked()
                     {
-                        ctx.send_viewport_cmd(ViewportCommand::InnerSize(dims));
+                        ui.send_viewport_cmd(ViewportCommand::InnerSize(dims));
                     }
                 }
             });
@@ -374,7 +515,7 @@ impl GameWindow {
                 let new_proportions = display_mode.proportions();
                 let scale = new_proportions / old_proportions;
                 if scale != Vec2::new(1.0, 1.0) {
-                    ctx.send_viewport_cmd(ViewportCommand::InnerSize(current_dims * scale));
+                    ui.send_viewport_cmd(ViewportCommand::InnerSize(current_dims * scale));
                 }
 
                 self.update_config(|c| {
@@ -424,11 +565,11 @@ impl GameWindow {
         });
         ui.menu_button("Input", |ui| {
             if ui.button("Bind Inputs").clicked() {
-                self.proxy.send_event(UserEvent::OpenInput).unwrap();
+                self.open(ChildWindow::Input);
             }
         });
         if ui.button("Hotkeys").clicked() {
-            self.proxy.send_event(UserEvent::OpenHotkeys).unwrap();
+            self.open(ChildWindow::Hotkeys);
         }
     }
 
@@ -480,13 +621,6 @@ impl GameWindow {
 }
 
 impl AppWindow for GameWindow {
-    fn viewport_id(&self) -> ViewportId {
-        match self.sim_id {
-            SimId::Player1 => ViewportId::ROOT,
-            SimId::Player2 => ViewportId::from_hash_of("Player2"),
-        }
-    }
-
     fn sim_id(&self) -> SimId {
         self.sim_id
     }
@@ -497,23 +631,22 @@ impl AppWindow for GameWindow {
             .with_inner_size(self.config.dimensions)
     }
 
-    fn show(&mut self, ctx: &Context) {
+    fn show(&mut self, ui: &mut Ui) {
+        self.child_sizes.load(ui);
         let dimensions = {
-            let bounds = ctx.available_rect();
+            let bounds = ui.content_rect();
             bounds.max - bounds.min
         };
         self.update_config(|c| c.dimensions = dimensions);
 
-        if let Some(messages) = self.messages.as_mut() {
+        while let Ok(toast) = self.messages.try_recv() {
-            while let Ok(toast) = messages.try_recv() {
+            self.toasts.add(toast);
-                self.toasts.add(toast);
-            }
         }
-        TopBottomPanel::top("menubar")
+        Panel::top("menubar")
-            .exact_height(22.0)
+            .exact_size(22.0)
-            .show(ctx, |ui| {
+            .show_inside(ui, |ui| {
                 MenuBar::new().ui(ui, |ui| {
-                    self.show_menu(ctx, ui);
+                    self.show_menu(ui);
                 });
             });
         if self.color_picker.is_some() {
@@ -521,34 +654,61 @@ impl AppWindow for GameWindow {
                 .title_bar(false)
                 .resizable(false)
                 .anchor(Align2::CENTER_CENTER, Vec2::ZERO)
-                .show(ctx, |ui| {
+                .show(ui, |ui| {
                     self.show_color_picker(ui);
                 });
         }
-        let frame = Frame::central_panel(&ctx.style()).fill(Color32::BLACK);
+        let frame = Frame::central_panel(ui.style()).fill(Color32::BLACK);
-        CentralPanel::default().frame(frame).show(ctx, |ui| {
+        CentralPanel::default().frame(frame).show_inside(ui, |ui| {
             if let Some(screen) = self.screen.as_mut() {
                 screen.update(self.config.display_mode, self.config.colors);
                 ui.add(screen);
             }
         });
-        self.toasts.show(ctx);
+        self.toasts.show(ui);
+        for window in std::mem::take(&mut self.queued_children) {
+            self.do_open(window);
+        }
+        self.children.retain(|id, child| {
+            if child
+                .close_requested
+                .load(std::sync::atomic::Ordering::Relaxed)
+            {
+                return false;
+            }
+            let app = child.app.clone();
+            let viewport_builder = child.updates.take().unwrap_or_default();
+            let close_requested = child.close_requested.clone();
+            let size = ui.input_for(*id, |v| v.viewport_rect().size());
+            self.child_sizes.insert(*id, size);
+            ui.show_viewport_deferred(*id, viewport_builder, move |ui, _| {
+                app.lock().unwrap().show(ui);
+                if ui.input(|s| s.viewport().close_requested()) {
+                    close_requested.store(true, std::sync::atomic::Ordering::Relaxed);
+                }
+            });
+            true
+        });
+        self.child_sizes.save(ui);
+        ui.request_repaint_after(Duration::from_millis(10));
     }
 
     fn on_init(&mut self, args: InitArgs) {
-        let (screen, sink) = GameScreen::init(args.render_state);
+        if self.screen.is_none() {
-        let (message_sink, message_source) = mpsc::channel();
+            let (screen, sink) = GameScreen::init(args.render_state);
-        self.client.send_command(EmulatorCommand::ConnectToSim(
+            self.client.send_command(EmulatorCommand::ConnectToSim(
-            self.sim_id,
+                self.sim_id,
-            sink,
+                sink,
-            message_sink,
+                self.message_sink.clone(),
-        ));
+            ));
-        self.screen = Some(screen);
+            self.screen = Some(screen);
-        self.messages = Some(message_source);
+        }
         self.window = Some(args.window.clone());
     }
+}
 
-    fn on_destroy(&mut self) {
+impl Drop for GameWindow {
+    fn drop(&mut self) {
         if self.sim_id == SimId::Player2 {
             self.client.send_command(EmulatorCommand::StopSecondSim);
         }
@@ -561,3 +721,77 @@ struct ColorPickerState {
     just_opened: bool,
     unpause_on_close: bool,
 }
+
+struct ChildWindowWrapper {
+    app: Arc<Mutex<AppWrapper>>,
+    updates: Option<ViewportBuilder>,
+    close_requested: Arc<AtomicBool>,
+}
+enum AppWrapper {
+    Game(Box<GameWindow>),
+    Dyn(Box<dyn AppWindow + Send + 'static>),
+}
+impl AppWrapper {
+    fn of_game(game: GameWindow) -> Self {
+        Self::Game(Box::new(game))
+    }
+    fn of_dyn<T: AppWindow + Send + 'static>(inner: T) -> Self {
+        Self::Dyn(Box::new(inner))
+    }
+}
+impl Deref for AppWrapper {
+    type Target = dyn AppWindow + Send + 'static;
+    fn deref(&self) -> &Self::Target {
+        match self {
+            Self::Dyn(inner) => inner.as_ref(),
+            Self::Game(inner) => inner.as_ref(),
+        }
+    }
+}
+impl DerefMut for AppWrapper {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        match self {
+            Self::Dyn(inner) => inner.as_mut(),
+            Self::Game(inner) => inner.as_mut(),
+        }
+    }
+}
+
+#[derive(Debug)]
+pub enum ChildWindow {
+    About,
+    CharacterData,
+    BgMap,
+    Objects,
+    Worlds,
+    FrameBuffers,
+    Registers,
+    Terminal,
+    Profiler { launch: bool },
+    Debugger { port: Option<u16> },
+    Input,
+    Hotkeys,
+    Player2,
+}
+impl ChildWindow {
+    fn viewport_id(&self, sim_id: SimId) -> ViewportId {
+        ViewportId::from_hash_of(format!("{sim_id:?}{}", self.name()))
+    }
+    fn name(&self) -> &'static str {
+        match self {
+            Self::About => "About",
+            Self::CharacterData => "CharacterData",
+            Self::BgMap => "BgMap",
+            Self::Objects => "Objects",
+            Self::Worlds => "Worlds",
+            Self::FrameBuffers => "FrameBuffers",
+            Self::Registers => "Registers",
+            Self::Terminal => "Terminal",
+            Self::Profiler { .. } => "Profiler",
+            Self::Debugger { .. } => "Debugger",
+            Self::Input => "Input",
+            Self::Hotkeys => "Hotkeys",
+            Self::Player2 => "Player2",
+        }
+    }
+}

src/window/game_screen.rs

@@ -14,7 +14,7 @@ pub struct GameScreen {
 }
 
 impl GameScreen {
-    fn init_pipeline(render_state: &egui_wgpu::RenderState) {
+    pub fn init_pipeline(render_state: &egui_wgpu::RenderState) {
         let device = &render_state.device;
 
         let bind_group_layout = device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
@@ -53,8 +53,8 @@ impl GameScreen {
         let render_pipeline_layout =
             device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
                 label: Some("render pipeline layout"),
-                bind_group_layouts: &[&bind_group_layout],
+                bind_group_layouts: &[Some(&bind_group_layout)],
-                push_constant_ranges: &[],
+                immediate_size: 0,
             });
 
         let create_render_pipeline = |entry_point: &str| {
@@ -92,7 +92,7 @@ impl GameScreen {
                     mask: !0,
                     alpha_to_coverage_enabled: false,
                 },
-                multiview: None,
+                multiview_mask: None,
                 cache: None,
             })
         };
@@ -117,8 +117,6 @@ impl GameScreen {
     }
 
     pub fn init(render_state: &egui_wgpu::RenderState) -> (Self, TextureSink) {
-        Self::init_pipeline(render_state);
-
         let device = &render_state.device;
         let queue = &render_state.queue;
 

src/window/gdb.rs

@@ -1,4 +1,4 @@
-use egui::{Button, CentralPanel, TextEdit, ViewportBuilder, ViewportId};
+use egui::{Button, CentralPanel, TextEdit, ViewportBuilder};
 use winit::event_loop::EventLoopProxy;
 
 use crate::{
@@ -42,10 +42,6 @@ impl GdbServerWindow {
 }
 
 impl AppWindow for GdbServerWindow {
-    fn viewport_id(&self) -> ViewportId {
-        ViewportId::from_hash_of(format!("Debugger-{}", self.sim_id))
-    }
-
     fn sim_id(&self) -> SimId {
         self.sim_id
     }
@@ -56,10 +52,10 @@ impl AppWindow for GdbServerWindow {
             .with_inner_size((300.0, 200.0))
     }
 
-    fn show(&mut self, ctx: &egui::Context) {
+    fn show(&mut self, ui: &mut egui::Ui) {
         let port_num: Option<u16> = self.port_str.parse().ok();
         let status = self.server.status();
-        CentralPanel::default().show(ctx, |ui| {
+        CentralPanel::default().show_inside(ui, |ui| {
             ui.horizontal(|ui| {
                 if port_num.is_none() {
                     let style = ui.style_mut();

src/window/hotkeys.rs

@@ -1,6 +1,5 @@
 use egui::{
-    Button, CentralPanel, Context, Event, KeyboardShortcut, Label, Layout, Slider, Ui,
+    Button, CentralPanel, Event, KeyboardShortcut, Label, Layout, Slider, Ui, ViewportBuilder,
-    ViewportBuilder, ViewportId,
 };
 use egui_extras::{Column, TableBuilder};
 
@@ -125,18 +124,14 @@ impl HotkeysWindow {
 }
 
 impl AppWindow for HotkeysWindow {
-    fn viewport_id(&self) -> ViewportId {
-        ViewportId::from_hash_of("shortcuts")
-    }
-
     fn initial_viewport(&self) -> ViewportBuilder {
         ViewportBuilder::default()
             .with_title("Keyboard Shortcuts")
             .with_inner_size((400.0, 400.0))
     }
 
-    fn show(&mut self, ctx: &Context) {
+    fn show(&mut self, ui: &mut Ui) {
-        CentralPanel::default().show(ctx, |ui| {
+        CentralPanel::default().show_inside(ui, |ui| {
             ui.horizontal(|ui| {
                 if ui.button("Use defaults").clicked() {
                     self.shortcuts.reset();

src/window/input.rs

@@ -1,6 +1,4 @@
-use egui::{
+use egui::{Button, CentralPanel, Label, Layout, Panel, Ui, ViewportBuilder};
-    Button, CentralPanel, Context, Label, Layout, TopBottomPanel, Ui, ViewportBuilder, ViewportId,
-};
 use egui_extras::{Column, TableBuilder};
 use gilrs::{EventType, GamepadId};
 use std::sync::RwLock;
@@ -162,18 +160,14 @@ impl InputWindow {
 }
 
 impl AppWindow for InputWindow {
-    fn viewport_id(&self) -> ViewportId {
-        ViewportId::from_hash_of("input")
-    }
-
     fn initial_viewport(&self) -> ViewportBuilder {
         ViewportBuilder::default()
             .with_title("Bind Inputs")
             .with_inner_size((600.0, 400.0))
     }
 
-    fn show(&mut self, ctx: &Context) {
+    fn show(&mut self, ui: &mut Ui) {
-        TopBottomPanel::top("options").show(ctx, |ui| {
+        Panel::top("options").show_inside(ui, |ui| {
             ui.horizontal(|ui| {
                 let old_active_tab = self.active_tab;
                 ui.selectable_value(&mut self.active_tab, InputTab::Player1, "Player 1");
@@ -188,7 +182,7 @@ impl AppWindow for InputWindow {
                 }
             });
         });
-        CentralPanel::default().show(ctx, |ui| {
+        CentralPanel::default().show_inside(ui, |ui| {
             match self.active_tab {
                 InputTab::Player1 => self.show_key_bindings(ui, SimId::Player1),
                 InputTab::Player2 => self.show_key_bindings(ui, SimId::Player2),

src/window/profile.rs

@@ -1,7 +1,7 @@
 use std::{fs, sync::Arc, time::Duration};
 
 use anyhow::Result;
-use egui::{Button, CentralPanel, Checkbox, Label, ViewportBuilder, ViewportId};
+use egui::{Button, CentralPanel, Checkbox, Label, ViewportBuilder};
 use egui_notify::{Anchor, Toast, Toasts};
 use winit::window::Window;
 
@@ -82,10 +82,6 @@ impl ProfileWindow {
 }
 
 impl AppWindow for ProfileWindow {
-    fn viewport_id(&self) -> ViewportId {
-        ViewportId::from_hash_of(format!("Profile-{}", self.sim_id))
-    }
-
     fn sim_id(&self) -> SimId {
         self.sim_id
     }
@@ -96,10 +92,10 @@ impl AppWindow for ProfileWindow {
             .with_inner_size((300.0, 200.0))
     }
 
-    fn show(&mut self, ctx: &egui::Context) {
+    fn show(&mut self, ui: &mut egui::Ui) {
         let status = self.profiler.status();
         let recording = matches!(status, ProfilerStatus::Recording);
-        CentralPanel::default().show(ctx, |ui| {
+        CentralPanel::default().show_inside(ui, |ui| {
             ui.horizontal_wrapped(|ui| {
                 ui.spacing_mut().item_spacing.x = 0.0;
                 ui.add(
@@ -164,7 +160,7 @@ impl AppWindow for ProfileWindow {
                 _ => {}
             }
         });
-        self.toasts.show(ctx);
+        self.toasts.show(ui);
     }
 
     fn on_init(&mut self, args: InitArgs) {

src/window/terminal.rs

@@ -1,9 +1,6 @@
 use std::{collections::VecDeque, sync::mpsc};
 
-use egui::{
+use egui::{Align, CentralPanel, FontFamily, Label, RichText, ScrollArea, Ui, ViewportBuilder};
-    Align, CentralPanel, Context, FontFamily, Label, RichText, ScrollArea, ViewportBuilder,
-    ViewportId,
-};
 
 use crate::emulator::{EmulatorClient, EmulatorCommand, SimId};
 
@@ -32,10 +29,6 @@ impl TerminalWindow {
 }
 
 impl AppWindow for TerminalWindow {
-    fn viewport_id(&self) -> ViewportId {
-        ViewportId::from_hash_of(format!("terminal-{}", self.sim_id))
-    }
-
     fn sim_id(&self) -> SimId {
         self.sim_id
     }
@@ -46,7 +39,7 @@ impl AppWindow for TerminalWindow {
             .with_inner_size((640.0, 480.0))
     }
 
-    fn show(&mut self, ctx: &Context) {
+    fn show(&mut self, ui: &mut Ui) {
         if let Ok(text) = self.receiver.try_recv() {
             let mut rest = text.as_str();
             while let Some(index) = rest.find('\n') {
@@ -61,7 +54,7 @@ impl AppWindow for TerminalWindow {
             }
             self.lines.back_mut().unwrap().push_str(rest);
         }
-        CentralPanel::default().show(ctx, |ui| {
+        CentralPanel::default().show_inside(ui, |ui| {
             ScrollArea::vertical()
                 .stick_to_bottom(true)
                 .auto_shrink([false, false])

src/window/utils.rs

@@ -1,6 +1,6 @@
 use std::{
     fmt::{Display, UpperHex},
-    ops::{Bound, RangeBounds},
+    ops::{Bound, Deref, DerefMut, RangeBounds},
     str::FromStr,
 };
 
@@ -8,7 +8,7 @@ use atoi::FromRadix16;
 use egui::{
     Align, Color32, CornerRadius, CursorIcon, Event, Frame, Key, Layout, Margin, Rect, Response,
     RichText, Sense, Shape, Stroke, StrokeKind, TextEdit, Ui, UiBuilder, Vec2, Widget, WidgetText,
-    ecolor::HexColor,
+    ecolor::HexColor, util::id_type_map::SerializableAny,
 };
 use num_traits::{CheckedAdd, CheckedSub, One};
 
@@ -409,3 +409,51 @@ impl ResponseExt for Response {
         self.clicked() || self.dragged()
     }
 }
+
+pub struct UiData<T> {
+    current: T,
+    prev: T,
+    loaded: bool,
+}
+
+impl<T> UiData<T>
+where
+    T: Default + PartialEq + SerializableAny,
+{
+    pub fn new() -> Self {
+        Self {
+            current: T::default(),
+            prev: T::default(),
+            loaded: false,
+        }
+    }
+
+    pub fn load(&mut self, ui: &Ui) {
+        if !self.loaded {
+            self.current = ui
+                .data_mut(|d| d.get_persisted(ui.id()))
+                .unwrap_or_default();
+            self.loaded = true;
+        }
+    }
+
+    pub fn save(&mut self, ui: &Ui) {
+        if self.current != self.prev {
+            ui.data_mut(|d| d.insert_persisted(ui.id(), self.current.clone()));
+            self.prev = self.current.clone();
+        }
+    }
+}
+
+impl<T> Deref for UiData<T> {
+    type Target = T;
+    fn deref(&self) -> &Self::Target {
+        &self.current
+    }
+}
+
+impl<T> DerefMut for UiData<T> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.current
+    }
+}

src/window/vip/bgmap.rs

@@ -1,53 +1,70 @@
 use std::sync::Arc;
 
 use egui::{
-    Align, CentralPanel, Checkbox, Color32, ComboBox, Context, Image, ScrollArea, Slider, TextEdit,
+    Align, CentralPanel, Checkbox, Color32, ComboBox, Image, ScrollArea, Slider, TextEdit,
-    TextureOptions, Ui, ViewportBuilder, ViewportId,
+    TextureOptions, Ui, ViewportBuilder,
 };
 use egui_extras::{Column, Size, StripBuilder, TableBuilder};
+use serde::{Deserialize, Serialize};
 
 use crate::{
     emulator::SimId,
-    images::{ImageBuffer, ImageParams, ImageProcessor, ImageRenderer, ImageTextureLoader},
+    images::{ImageBuffer, ImageParams, ImageRenderer, ImageTextureLoader},
     memory::{MemoryClient, MemoryView},
     window::{
-        AppWindow, InitArgs,
+        AppWindow,
-        utils::{NumberEdit, UiExt},
+        utils::{NumberEdit, UiData, UiExt},
     },
 };
 
 use super::utils::{self, CellData, CharacterGrid};
 
-pub struct BgMapWindow {
+#[derive(Clone, PartialEq, Serialize, Deserialize)]
-    sim_id: SimId,
+struct State {
-    loader: Arc<ImageTextureLoader>,
-    memory: Arc<MemoryClient>,
-    bgmaps: MemoryView,
     cell_index: usize,
     generic_palette: bool,
-    params: ImageParams<BgMapParams>,
     scale: f32,
     show_grid: bool,
 }
-
+impl Default for State {
-impl BgMapWindow {
+    fn default() -> 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) = images.add(renderer, BgMapParams::default());
-        let loader =
-            ImageTextureLoader::new([("vip://cell".into(), cell), ("vip://bgmap".into(), bgmap)]);
         Self {
-            sim_id,
+            cell_index: 0,
-            loader: Arc::new(loader),
+            generic_palette: false,
-            memory: memory.clone(),
-            bgmaps: memory.watch(sim_id, 0x00020000, 0x20000),
-            cell_index: params.cell_index,
-            generic_palette: params.generic_palette,
-            params,
             scale: 1.0,
             show_grid: false,
         }
     }
+}
+
+pub struct BgMapWindow {
+    sim_id: SimId,
+    memory: Arc<MemoryClient>,
+    bgmaps: MemoryView,
+    params: ImageParams<BgMapParams>,
+    state: UiData<State>,
+}
+
+impl BgMapWindow {
+    pub fn new(sim_id: SimId, memory: &Arc<MemoryClient>, images: &ImageTextureLoader) -> Self {
+        let state: UiData<State> = UiData::new();
+        let renderer = BgMapRenderer::new(sim_id, memory);
+        let params = images.add(
+            sim_id,
+            renderer,
+            BgMapParams {
+                cell_index: state.cell_index,
+                generic_palette: state.generic_palette,
+            },
+        );
+        Self {
+            sim_id,
+            memory: memory.clone(),
+            bgmaps: memory.watch(sim_id, 0x00020000, 0x20000),
+            params,
+            state,
+        }
+    }
 
     fn show_form(&mut self, ui: &mut Ui) {
         let row_height = ui.spacing().interact_size.y;
@@ -61,10 +78,11 @@ impl BgMapWindow {
                             ui.label("Map");
                         });
                         row.col(|ui| {
-                            let mut bgmap_index = self.cell_index / 4096;
+                            let mut bgmap_index = self.state.cell_index / 4096;
                             ui.add(NumberEdit::new(&mut bgmap_index).range(0..16));
-                            if bgmap_index != self.cell_index / 4096 {
+                            if bgmap_index != self.state.cell_index / 4096 {
-                                self.cell_index = (bgmap_index * 4096) + (self.cell_index % 4096);
+                                self.state.cell_index =
+                                    (bgmap_index * 4096) + (self.state.cell_index % 4096);
                             }
                         });
                     });
@@ -73,7 +91,7 @@ impl BgMapWindow {
                             ui.label("Cell");
                         });
                         row.col(|ui| {
-                            ui.add(NumberEdit::new(&mut self.cell_index).range(0..16 * 4096));
+                            ui.add(NumberEdit::new(&mut self.state.cell_index).range(0..16 * 4096));
                         });
                     });
                     body.row(row_height, |mut row| {
@@ -81,7 +99,7 @@ impl BgMapWindow {
                             ui.label("Address");
                         });
                         row.col(|ui| {
-                            let address = 0x00020000 + (self.cell_index * 2);
+                            let address = 0x00020000 + (self.state.cell_index * 2);
                             let mut address_str = format!("{address:08x}");
                             ui.add_enabled(
                                 false,
@@ -90,12 +108,12 @@ impl BgMapWindow {
                         });
                     });
                 });
-            let image = Image::new("vip://cell")
+            let image = Image::new(self.image_url("bgmap-cell"))
                 .maintain_aspect_ratio(true)
                 .texture_options(TextureOptions::NEAREST);
             ui.add(image);
             ui.section("Cell", |ui| {
-                let mut data = self.bgmaps.borrow().read::<u16>(self.cell_index);
+                let mut data = self.bgmaps.borrow().read::<u16>(self.state.cell_index);
                 let mut cell = CellData::parse(data);
                 TableBuilder::new(ui)
                     .column(Column::remainder())
@@ -138,7 +156,7 @@ impl BgMapWindow {
                         });
                     });
                 if cell.update(&mut data) {
-                    let address = 0x00020000 + (self.cell_index * 2);
+                    let address = 0x00020000 + (self.state.cell_index * 2);
                     self.memory.write(self.sim_id, address as u32, &data);
                 }
             });
@@ -146,37 +164,33 @@ impl BgMapWindow {
                 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)
+                    let slider = Slider::new(&mut self.state.scale, 1.0..=10.0)
                         .step_by(1.0)
                         .show_value(false);
                     ui.add(slider);
                 });
-                ui.checkbox(&mut self.show_grid, "Show grid");
+                ui.checkbox(&mut self.state.show_grid, "Show grid");
-                ui.checkbox(&mut self.generic_palette, "Generic palette");
+                ui.checkbox(&mut self.state.generic_palette, "Generic palette");
             });
         });
         self.params.write(BgMapParams {
-            cell_index: self.cell_index,
+            cell_index: self.state.cell_index,
-            generic_palette: self.generic_palette,
+            generic_palette: self.state.generic_palette,
         });
     }
 
     fn show_bgmap(&mut self, ui: &mut Ui) {
-        let grid = CharacterGrid::new("vip://bgmap")
+        let grid = CharacterGrid::new(self.image_url("bgmap"))
-            .with_scale(self.scale)
+            .with_scale(self.state.scale)
-            .with_grid(self.show_grid)
+            .with_grid(self.state.show_grid)
-            .with_selected(self.cell_index % 4096);
+            .with_selected(self.state.cell_index % 4096);
         if let Some(selected) = grid.show(ui) {
-            self.cell_index = (self.cell_index / 4096 * 4096) + selected;
+            self.state.cell_index = (self.state.cell_index / 4096 * 4096) + selected;
         }
     }
 }
 
 impl AppWindow for BgMapWindow {
-    fn viewport_id(&self) -> ViewportId {
-        ViewportId::from_hash_of(format!("bgmap-{}", self.sim_id))
-    }
-
     fn sim_id(&self) -> SimId {
         self.sim_id
     }
@@ -187,12 +201,9 @@ impl AppWindow for BgMapWindow {
             .with_inner_size((640.0, 480.0))
     }
 
-    fn on_init(&mut self, args: InitArgs) {
+    fn show(&mut self, ui: &mut Ui) {
-        args.ctx.add_texture_loader(self.loader.clone());
+        self.state.load(ui);
-    }
+        CentralPanel::default().show_inside(ui, |ui| {
-
-    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))
@@ -207,6 +218,7 @@ impl AppWindow for BgMapWindow {
                     })
             });
         });
+        self.state.save(ui);
     }
 }
 
@@ -300,6 +312,10 @@ impl BgMapRenderer {
 impl ImageRenderer<2> for BgMapRenderer {
     type Params = BgMapParams;
 
+    fn names(&self) -> [&str; 2] {
+        ["bgmap-cell", "bgmap"]
+    }
+
     fn sizes(&self) -> [[usize; 2]; 2] {
         [[8, 8], [8 * 64, 8 * 64]]
     }

src/window/vip/chardata.rs

@@ -1,19 +1,19 @@
-use std::{fmt::Display, sync::Arc};
+use std::fmt::Display;
 
 use egui::{
-    Align, CentralPanel, Color32, ComboBox, Context, Image, ScrollArea, Slider, TextEdit,
+    Align, CentralPanel, Color32, ComboBox, Image, ScrollArea, Slider, TextEdit, TextureOptions,
-    TextureOptions, Ui, Vec2, ViewportBuilder, ViewportId,
+    Ui, Vec2, ViewportBuilder,
 };
 use egui_extras::{Column, Size, StripBuilder, TableBuilder};
 use serde::{Deserialize, Serialize};
 
 use crate::{
     emulator::SimId,
-    images::{ImageBuffer, ImageParams, ImageProcessor, ImageRenderer, ImageTextureLoader},
+    images::{ImageBuffer, ImageParams, ImageRenderer, ImageTextureLoader},
     memory::{MemoryClient, MemoryView},
     window::{
-        AppWindow, InitArgs,
+        AppWindow,
-        utils::{NumberEdit, UiExt as _},
+        utils::{NumberEdit, UiData, UiExt as _},
     },
 };
 
@@ -79,38 +79,52 @@ impl Display for Palette {
     }
 }
 
-pub struct CharacterDataWindow {
+#[derive(Clone, PartialEq, Serialize, Deserialize)]
-    sim_id: SimId,
+struct State {
-    loader: Arc<ImageTextureLoader>,
-    brightness: MemoryView,
-    palettes: MemoryView,
     palette: Palette,
     index: usize,
-    params: ImageParams<CharDataParams>,
     scale: f32,
     show_grid: bool,
 }
-
+impl Default for State {
-impl CharacterDataWindow {
+    fn default() -> Self {
-    pub fn new(sim_id: SimId, memory: &MemoryClient, images: &mut ImageProcessor) -> Self {
-        let renderer = CharDataRenderer::new(sim_id, memory);
-        let ([char, chardata], params) = images.add(renderer, CharDataParams::default());
-        let loader = ImageTextureLoader::new([
-            ("vip://char".into(), char),
-            ("vip://chardata".into(), chardata),
-        ]);
         Self {
-            sim_id,
+            palette: Palette::default(),
-            loader: Arc::new(loader),
+            index: 0,
-            brightness: memory.watch(sim_id, 0x0005f824, 8),
-            palettes: memory.watch(sim_id, 0x0005f860, 16),
-            palette: params.palette,
-            index: params.index,
-            params,
             scale: 4.0,
             show_grid: true,
         }
     }
+}
+
+pub struct CharacterDataWindow {
+    sim_id: SimId,
+    brightness: MemoryView,
+    palettes: MemoryView,
+    params: ImageParams<CharDataParams>,
+    state: UiData<State>,
+}
+
+impl CharacterDataWindow {
+    pub fn new(sim_id: SimId, memory: &MemoryClient, images: &ImageTextureLoader) -> Self {
+        let state: UiData<State> = UiData::new();
+        let renderer = CharDataRenderer::new(sim_id, memory);
+        let params = images.add(
+            sim_id,
+            renderer,
+            CharDataParams {
+                palette: state.palette,
+                index: state.index,
+            },
+        );
+        Self {
+            sim_id,
+            brightness: memory.watch(sim_id, 0x0005f824, 8),
+            palettes: memory.watch(sim_id, 0x0005f860, 16),
+            params,
+            state,
+        }
+    }
 
     fn show_form(&mut self, ui: &mut Ui) {
         let row_height = ui.spacing().interact_size.y;
@@ -124,7 +138,7 @@ impl CharacterDataWindow {
                             ui.label("Index");
                         });
                         row.col(|ui| {
-                            ui.add(NumberEdit::new(&mut self.index).range(0..2048));
+                            ui.add(NumberEdit::new(&mut self.state.index).range(0..2048));
                         });
                     });
                     body.row(row_height, |mut row| {
@@ -132,11 +146,11 @@ impl CharacterDataWindow {
                             ui.label("Address");
                         });
                         row.col(|ui| {
-                            let address = match self.index {
+                            let address = match self.state.index {
-                                0x000..0x200 => 0x00060000 + self.index * 16,
+                                0x000..0x200 => 0x00060000 + self.state.index * 16,
-                                0x200..0x400 => 0x000e0000 + (self.index - 0x200) * 16,
+                                0x200..0x400 => 0x000e0000 + (self.state.index - 0x200) * 16,
-                                0x400..0x600 => 0x00160000 + (self.index - 0x400) * 16,
+                                0x400..0x600 => 0x00160000 + (self.state.index - 0x400) * 16,
-                                0x600..0x800 => 0x001e0000 + (self.index - 0x600) * 16,
+                                0x600..0x800 => 0x001e0000 + (self.state.index - 0x600) * 16,
                                 _ => unreachable!("can't happen"),
                             };
                             let mut address_str = format!("{address:08x}");
@@ -151,7 +165,7 @@ impl CharacterDataWindow {
                             ui.label("Mirror");
                         });
                         row.col(|ui| {
-                            let mirror = 0x00078000 + (self.index * 16);
+                            let mirror = 0x00078000 + (self.state.index * 16);
                             let mut mirror_str = format!("{mirror:08x}");
                             ui.add_enabled(
                                 false,
@@ -160,7 +174,7 @@ impl CharacterDataWindow {
                         });
                     });
                 });
-            let image = Image::new("vip://char")
+            let image = Image::new(self.image_url("chardata-char"))
                 .maintain_aspect_ratio(true)
                 .texture_options(TextureOptions::NEAREST);
             ui.add(image);
@@ -168,12 +182,12 @@ impl CharacterDataWindow {
                 ui.horizontal(|ui| {
                     ui.label("Palette");
                     ComboBox::from_id_salt("palette")
-                        .selected_text(self.palette.to_string())
+                        .selected_text(self.state.palette.to_string())
                         .width(ui.available_width())
                         .show_ui(ui, |ui| {
                             for palette in Palette::values() {
                                 ui.selectable_value(
-                                    &mut self.palette,
+                                    &mut self.state.palette,
                                     palette,
                                     palette.to_string(),
                                 );
@@ -200,23 +214,23 @@ impl CharacterDataWindow {
                 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)
+                    let slider = Slider::new(&mut self.state.scale, 1.0..=10.0)
                         .step_by(1.0)
                         .show_value(false);
                     ui.add(slider);
                 });
-                ui.checkbox(&mut self.show_grid, "Show grid");
+                ui.checkbox(&mut self.state.show_grid, "Show grid");
             });
         });
 
         self.params.write(CharDataParams {
-            palette: self.palette,
+            palette: self.state.palette,
-            index: self.index,
+            index: self.state.index,
         });
     }
 
     fn load_palette_colors(&self) -> [Color32; 4] {
-        let Some(offset) = self.palette.offset() else {
+        let Some(offset) = self.state.palette.offset() else {
             return utils::generic_palette(Color32::RED);
         };
         let palette = self.palettes.borrow().read(offset);
@@ -226,21 +240,17 @@ impl CharacterDataWindow {
     }
 
     fn show_chardata(&mut self, ui: &mut Ui) {
-        let grid = CharacterGrid::new("vip://chardata")
+        let grid = CharacterGrid::new(self.image_url("chardata"))
-            .with_scale(self.scale)
+            .with_scale(self.state.scale)
-            .with_grid(self.show_grid)
+            .with_grid(self.state.show_grid)
-            .with_selected(self.index);
+            .with_selected(self.state.index);
         if let Some(selected) = grid.show(ui) {
-            self.index = selected;
+            self.state.index = selected;
         }
     }
 }
 
 impl AppWindow for CharacterDataWindow {
-    fn viewport_id(&self) -> ViewportId {
-        ViewportId::from_hash_of(format!("chardata-{}", self.sim_id))
-    }
-
     fn sim_id(&self) -> SimId {
         self.sim_id
     }
@@ -251,12 +261,9 @@ impl AppWindow for CharacterDataWindow {
             .with_inner_size((640.0, 480.0))
     }
 
-    fn on_init(&mut self, args: InitArgs) {
+    fn show(&mut self, ui: &mut Ui) {
-        args.ctx.add_texture_loader(self.loader.clone());
+        self.state.load(ui);
-    }
+        CentralPanel::default().show_inside(ui, |ui| {
-
-    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))
@@ -271,10 +278,11 @@ impl AppWindow for CharacterDataWindow {
                     });
             });
         });
+        self.state.save(ui);
     }
 }
 
-#[derive(Clone, Default, PartialEq, Eq)]
+#[derive(Clone, PartialEq, Eq)]
 struct CharDataParams {
     palette: Palette,
     index: usize,
@@ -289,6 +297,10 @@ struct CharDataRenderer {
 impl ImageRenderer<2> for CharDataRenderer {
     type Params = CharDataParams;
 
+    fn names(&self) -> [&str; 2] {
+        ["chardata-char", "chardata"]
+    }
+
     fn sizes(&self) -> [[usize; 2]; 2] {
         [[8, 8], [16 * 8, 128 * 8]]
     }

src/window/vip/framebuffer.rs

@@ -1,56 +1,68 @@
-use std::sync::Arc;
-
 use egui::{
-    Align, CentralPanel, Color32, Context, Image, ScrollArea, Slider, TextEdit, TextureOptions, Ui,
+    Align, CentralPanel, Color32, Image, ScrollArea, Slider, TextEdit, TextureOptions, Ui,
-    ViewportBuilder, ViewportId,
+    ViewportBuilder,
 };
 use egui_extras::{Column, Size, StripBuilder, TableBuilder};
+use serde::{Deserialize, Serialize};
 
 use crate::{
     emulator::SimId,
-    images::{ImageBuffer, ImageParams, ImageProcessor, ImageRenderer, ImageTextureLoader},
+    images::{ImageBuffer, ImageParams, ImageRenderer, ImageTextureLoader},
     memory::{MemoryClient, MemoryView},
     window::{
-        AppWindow, InitArgs,
+        AppWindow,
-        utils::{NumberEdit, UiExt as _},
+        utils::{NumberEdit, UiData, UiExt as _},
     },
 };
 
 use super::utils;
 
-pub struct FrameBufferWindow {
+#[derive(Clone, PartialEq, Serialize, Deserialize)]
-    sim_id: SimId,
+struct State {
-    loader: Arc<ImageTextureLoader>,
     index: usize,
     left: bool,
     right: bool,
     generic_palette: bool,
-    params: ImageParams<FrameBufferParams>,
     scale: f32,
 }
-
+impl Default for State {
-impl FrameBufferWindow {
+    fn default() -> Self {
-    pub fn new(sim_id: SimId, memory: &MemoryClient, images: &mut ImageProcessor) -> Self {
+        Self {
-        let initial_params = FrameBufferParams {
             index: 0,
             left: true,
             right: true,
             generic_palette: false,
-            left_color: Color32::from_rgb(0xff, 0x00, 0x00),
+            scale: 2.0,
-            right_color: Color32::from_rgb(0x00, 0xc6, 0xf0),
+        }
-        };
+    }
+}
+
+pub struct FrameBufferWindow {
+    sim_id: SimId,
+    params: ImageParams<FrameBufferParams>,
+    state: UiData<State>,
+}
+
+impl FrameBufferWindow {
+    pub fn new(sim_id: SimId, memory: &MemoryClient, images: &ImageTextureLoader) -> Self {
+        let state: UiData<State> = UiData::new();
         let renderer = FrameBufferRenderer::new(sim_id, memory);
-        let ([buffer], params) = images.add(renderer, initial_params);
+        let params = images.add(
-        let loader = ImageTextureLoader::new([("vip://buffer".into(), buffer)]);
+            sim_id,
+            renderer,
+            FrameBufferParams {
+                index: state.index,
+                left: state.left,
+                right: state.right,
+                generic_palette: state.generic_palette,
+                left_color: Color32::from_rgb(0xff, 0x00, 0x00),
+                right_color: Color32::from_rgb(0x00, 0xc6, 0xf0),
+            },
+        );
         Self {
             sim_id,
-            loader: Arc::new(loader),
-            index: params.index,
-            left: params.left,
-            right: params.right,
-            generic_palette: params.generic_palette,
             params,
-            scale: 2.0,
+            state,
         }
     }
 
@@ -66,7 +78,7 @@ impl FrameBufferWindow {
                             ui.label("Index");
                         });
                         row.col(|ui| {
-                            ui.add(NumberEdit::new(&mut self.index).range(0..2));
+                            ui.add(NumberEdit::new(&mut self.state.index).range(0..2));
                         });
                     });
                     body.row(row_height, |mut row| {
@@ -74,7 +86,7 @@ impl FrameBufferWindow {
                             ui.label("Left");
                         });
                         row.col(|ui| {
-                            let address = self.index * 0x00008000;
+                            let address = self.state.index * 0x00008000;
                             let mut address_str = format!("{address:08x}");
                             ui.add_enabled(
                                 false,
@@ -87,7 +99,7 @@ impl FrameBufferWindow {
                             ui.label("Right");
                         });
                         row.col(|ui| {
-                            let address = self.index * 0x00008000 + 0x00010000;
+                            let address = self.state.index * 0x00008000 + 0x00010000;
                             let mut address_str = format!("{address:08x}");
                             ui.add_enabled(
                                 false,
@@ -100,7 +112,7 @@ impl FrameBufferWindow {
                 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)
+                    let slider = Slider::new(&mut self.state.scale, 1.0..=10.0)
                         .step_by(1.0)
                         .show_value(false);
                     ui.add(slider);
@@ -110,39 +122,35 @@ impl FrameBufferWindow {
                     .body(|mut body| {
                         body.row(row_height, |mut row| {
                             row.col(|ui| {
-                                ui.checkbox(&mut self.left, "Left");
+                                ui.checkbox(&mut self.state.left, "Left");
                             });
                             row.col(|ui| {
-                                ui.checkbox(&mut self.right, "Right");
+                                ui.checkbox(&mut self.state.right, "Right");
                             });
                         });
                     });
-                ui.checkbox(&mut self.generic_palette, "Generic colors");
+                ui.checkbox(&mut self.state.generic_palette, "Generic colors");
             });
         });
 
         self.params.write(FrameBufferParams {
-            index: self.index,
+            index: self.state.index,
-            left: self.left,
+            left: self.state.left,
-            right: self.right,
+            right: self.state.right,
-            generic_palette: self.generic_palette,
+            generic_palette: self.state.generic_palette,
             ..*self.params
         });
     }
 
     fn show_buffers(&mut self, ui: &mut Ui) {
-        let image = Image::new("vip://buffer")
+        let image = Image::new(self.image_url("buffer"))
-            .fit_to_original_size(self.scale)
+            .fit_to_original_size(self.state.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
     }
@@ -153,12 +161,9 @@ impl AppWindow for FrameBufferWindow {
             .with_inner_size((640.0, 480.0))
     }
 
-    fn on_init(&mut self, args: InitArgs) {
+    fn show(&mut self, ui: &mut Ui) {
-        args.ctx.add_texture_loader(self.loader.clone());
+        self.state.load(ui);
-    }
+        CentralPanel::default().show_inside(ui, |ui| {
-
-    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))
@@ -173,6 +178,7 @@ impl AppWindow for FrameBufferWindow {
                     });
             });
         });
+        self.state.save(ui);
     }
 }
 
@@ -208,6 +214,10 @@ impl FrameBufferRenderer {
 impl ImageRenderer<1> for FrameBufferRenderer {
     type Params = FrameBufferParams;
 
+    fn names(&self) -> [&str; 1] {
+        ["buffer"]
+    }
+
     fn sizes(&self) -> [[usize; 2]; 1] {
         [[384, 224]]
     }

src/window/vip/object.rs

@@ -1,55 +1,68 @@
 use std::sync::Arc;
 
 use egui::{
-    Align, CentralPanel, Checkbox, Color32, ComboBox, Context, Image, ScrollArea, Slider, TextEdit,
+    Align, CentralPanel, Checkbox, Color32, ComboBox, Image, ScrollArea, Slider, TextEdit,
-    TextureOptions, Ui, ViewportBuilder, ViewportId,
+    TextureOptions, Ui, ViewportBuilder,
 };
 use egui_extras::{Column, Size, StripBuilder, TableBuilder};
+use serde::{Deserialize, Serialize};
 
 use crate::{
     emulator::SimId,
-    images::{ImageBuffer, ImageParams, ImageProcessor, ImageRenderer, ImageTextureLoader},
+    images::{ImageBuffer, ImageParams, ImageRenderer, ImageTextureLoader},
     memory::{MemoryClient, MemoryView},
     window::{
-        AppWindow, InitArgs,
+        AppWindow,
-        utils::{NumberEdit, UiExt as _},
+        utils::{NumberEdit, UiData, UiExt as _},
     },
 };
 
 use super::utils::{self, Object};
 
-pub struct ObjectWindow {
+#[derive(Clone, PartialEq, Serialize, Deserialize)]
-    sim_id: SimId,
+struct State {
-    loader: Arc<ImageTextureLoader>,
-    memory: Arc<MemoryClient>,
-    objects: MemoryView,
     index: usize,
     generic_palette: bool,
-    params: ImageParams<ObjectParams>,
     scale: f32,
 }
+impl Default for State {
+    fn default() -> Self {
+        Self {
+            index: 0,
+            generic_palette: false,
+            scale: 1.0,
+        }
+    }
+}
+
+pub struct ObjectWindow {
+    sim_id: SimId,
+    memory: Arc<MemoryClient>,
+    objects: MemoryView,
+    params: ImageParams<ObjectParams>,
+    state: UiData<State>,
+}
 
 impl ObjectWindow {
-    pub fn new(sim_id: SimId, memory: &Arc<MemoryClient>, images: &mut ImageProcessor) -> Self {
+    pub fn new(sim_id: SimId, memory: &Arc<MemoryClient>, images: &ImageTextureLoader) -> Self {
-        let initial_params = ObjectParams {
+        let state: UiData<State> = UiData::new();
-            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) = images.add(renderer, initial_params);
+        let params = images.add(
-        let loader =
+            sim_id,
-            ImageTextureLoader::new([("vip://zoom".into(), zoom), ("vip://full".into(), full)]);
+            renderer,
+            ObjectParams {
+                index: state.index,
+                generic_palette: state.generic_palette,
+                left_color: Color32::from_rgb(0xff, 0x00, 0x00),
+                right_color: Color32::from_rgb(0x00, 0xc6, 0xf0),
+            },
+        );
         Self {
             sim_id,
-            loader: Arc::new(loader),
             memory: memory.clone(),
             objects: memory.watch(sim_id, 0x0003e000, 0x2000),
-            index: params.index,
-            generic_palette: params.generic_palette,
             params,
-            scale: 1.0,
+            state,
         }
     }
 
@@ -65,7 +78,7 @@ impl ObjectWindow {
                             ui.label("Index");
                         });
                         row.col(|ui| {
-                            ui.add(NumberEdit::new(&mut self.index).range(0..1024));
+                            ui.add(NumberEdit::new(&mut self.state.index).range(0..1024));
                         });
                     });
                     body.row(row_height, |mut row| {
@@ -73,7 +86,7 @@ impl ObjectWindow {
                             ui.label("Address");
                         });
                         row.col(|ui| {
-                            let address = 0x3e000 + self.index * 8;
+                            let address = 0x3e000 + self.state.index * 8;
                             let mut address_str = format!("{address:08x}");
                             ui.add_enabled(
                                 false,
@@ -82,12 +95,12 @@ impl ObjectWindow {
                         });
                     });
                 });
-            let image = Image::new("vip://zoom")
+            let image = Image::new(self.image_url("object-zoom"))
                 .maintain_aspect_ratio(true)
                 .texture_options(TextureOptions::NEAREST);
             ui.add(image);
             ui.section("Properties", |ui| {
-                let mut object = self.objects.borrow().read::<[u16; 4]>(self.index);
+                let mut object = self.objects.borrow().read::<[u16; 4]>(self.state.index);
                 let mut obj = Object::parse(object);
                 TableBuilder::new(ui)
                     .column(Column::remainder())
@@ -162,7 +175,7 @@ impl ObjectWindow {
                         });
                     });
                 if obj.update(&mut object) {
-                    let address = 0x3e000 + self.index * 8;
+                    let address = 0x3e000 + self.state.index * 8;
                     self.memory.write(self.sim_id, address as u32, &object);
                 }
             });
@@ -170,34 +183,30 @@ impl ObjectWindow {
                 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)
+                    let slider = Slider::new(&mut self.state.scale, 1.0..=10.0)
                         .step_by(1.0)
                         .show_value(false);
                     ui.add(slider);
                 });
-                ui.checkbox(&mut self.generic_palette, "Generic palette");
+                ui.checkbox(&mut self.state.generic_palette, "Generic palette");
             });
         });
         self.params.write(ObjectParams {
-            index: self.index,
+            index: self.state.index,
-            generic_palette: self.generic_palette,
+            generic_palette: self.state.generic_palette,
             ..*self.params
         });
     }
 
     fn show_object(&mut self, ui: &mut Ui) {
-        let image = Image::new("vip://full")
+        let image = Image::new(self.image_url("object-full"))
-            .fit_to_original_size(self.scale)
+            .fit_to_original_size(self.state.scale)
             .texture_options(TextureOptions::NEAREST);
         ui.add(image);
     }
 }
 
 impl AppWindow for ObjectWindow {
-    fn viewport_id(&self) -> egui::ViewportId {
-        ViewportId::from_hash_of(format!("object-{}", self.sim_id))
-    }
-
     fn sim_id(&self) -> SimId {
         self.sim_id
     }
@@ -208,12 +217,9 @@ impl AppWindow for ObjectWindow {
             .with_inner_size((640.0, 500.0))
     }
 
-    fn on_init(&mut self, args: InitArgs) {
+    fn show(&mut self, ui: &mut Ui) {
-        args.ctx.add_texture_loader(self.loader.clone());
+        self.state.load(ui);
-    }
+        CentralPanel::default().show_inside(ui, |ui| {
-
-    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))
@@ -228,6 +234,7 @@ impl AppWindow for ObjectWindow {
                     });
             });
         });
+        self.state.save(ui);
     }
 }
 
@@ -327,6 +334,10 @@ impl ObjectRenderer {
 impl ImageRenderer<2> for ObjectRenderer {
     type Params = ObjectParams;
 
+    fn names(&self) -> [&str; 2] {
+        ["object-zoom", "object-full"]
+    }
+
     fn sizes(&self) -> [[usize; 2]; 2] {
         [[8, 8], [384, 224]]
     }

src/window/vip/registers.rs

@@ -1,8 +1,8 @@
 use std::sync::Arc;
 
 use egui::{
-    Align, Button, CentralPanel, Checkbox, Color32, Context, Direction, Label, Layout, ScrollArea,
+    Align, Button, CentralPanel, Checkbox, Color32, Direction, Label, Layout, ScrollArea, TextEdit,
-    TextEdit, Ui, ViewportBuilder, ViewportId,
+    Ui, ViewportBuilder,
 };
 use egui_extras::{Column, Size, StripBuilder, TableBuilder};
 
@@ -630,10 +630,6 @@ fn read_address<T: MemoryValue>(registers: &MemoryRef, address: usize) -> T {
 }
 
 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
     }
@@ -644,8 +640,8 @@ impl AppWindow for RegisterWindow {
             .with_inner_size((800.0, 480.0))
     }
 
-    fn show(&mut self, ctx: &Context) {
+    fn show(&mut self, ui: &mut Ui) {
-        CentralPanel::default().show(ctx, |ui| {
+        CentralPanel::default().show_inside(ui, |ui| {
             ScrollArea::vertical().show(ui, |ui| {
                 ui.horizontal_top(|ui| {
                     let width = ui.available_width();

src/window/vip/world.rs

@@ -1,8 +1,8 @@
 use std::{fmt::Display, sync::Arc};
 
 use egui::{
-    Align, CentralPanel, Checkbox, Color32, ComboBox, Context, Image, ScrollArea, Slider, TextEdit,
+    Align, CentralPanel, Checkbox, Color32, ComboBox, Image, ScrollArea, Slider, TextEdit,
-    TextureOptions, Ui, ViewportBuilder, ViewportId,
+    TextureOptions, Ui, ViewportBuilder,
 };
 use egui_extras::{Column, Size, StripBuilder, TableBuilder};
 use fixed::{
@@ -11,56 +11,70 @@ use fixed::{
 };
 use num_derive::{FromPrimitive, ToPrimitive};
 use num_traits::{FromPrimitive, ToPrimitive};
+use serde::{Deserialize, Serialize};
 
 use crate::{
     emulator::SimId,
-    images::{ImageBuffer, ImageParams, ImageProcessor, ImageRenderer, ImageTextureLoader},
+    images::{ImageBuffer, ImageParams, ImageRenderer, ImageTextureLoader},
     memory::{MemoryClient, MemoryRef, MemoryView},
     window::{
-        AppWindow, InitArgs,
+        AppWindow,
-        utils::{NumberEdit, UiExt as _},
+        utils::{NumberEdit, UiData, UiExt as _},
     },
 };
 
 use super::utils::{self, CellData, Object, shade};
 
-pub struct WorldWindow {
+#[derive(Clone, PartialEq, Serialize, Deserialize)]
-    sim_id: SimId,
+struct State {
-    loader: Arc<ImageTextureLoader>,
-    memory: Arc<MemoryClient>,
-    worlds: MemoryView,
-    bgmaps: MemoryView,
     index: usize,
     param_index: usize,
     generic_palette: bool,
     show_extents: bool,
-    params: ImageParams<WorldParams>,
     scale: f32,
 }
+impl Default for State {
+    fn default() -> Self {
+        Self {
+            index: 31,
+            param_index: 0,
+            generic_palette: false,
+            show_extents: false,
+            scale: 1.0,
+        }
+    }
+}
+
+pub struct WorldWindow {
+    sim_id: SimId,
+    memory: Arc<MemoryClient>,
+    worlds: MemoryView,
+    bgmaps: MemoryView,
+    params: ImageParams<WorldParams>,
+    state: UiData<State>,
+}
 
 impl WorldWindow {
-    pub fn new(sim_id: SimId, memory: &Arc<MemoryClient>, images: &mut ImageProcessor) -> Self {
+    pub fn new(sim_id: SimId, memory: &Arc<MemoryClient>, images: &ImageTextureLoader) -> Self {
-        let initial_params = WorldParams {
+        let state: UiData<State> = UiData::new();
-            index: 31,
-            generic_palette: false,
-            left_color: Color32::from_rgb(0xff, 0x00, 0x00),
-            right_color: Color32::from_rgb(0x00, 0xc6, 0xf0),
-        };
         let renderer = WorldRenderer::new(sim_id, memory);
-        let ([world], params) = images.add(renderer, initial_params);
+        let params = images.add(
-        let loader = ImageTextureLoader::new([("vip://world".into(), world)]);
+            sim_id,
+            renderer,
+            WorldParams {
+                index: state.index,
+                generic_palette: state.generic_palette,
+                left_color: Color32::from_rgb(0xff, 0x00, 0x00),
+                right_color: Color32::from_rgb(0x00, 0xc6, 0xf0),
+            },
+        );
         Self {
             sim_id,
-            loader: Arc::new(loader),
             memory: memory.clone(),
             worlds: memory.watch(sim_id, 0x0003d800, 0x400),
             bgmaps: memory.watch(sim_id, 0x00020000, 0x20000),
-            index: params.index,
-            param_index: 0,
-            generic_palette: params.generic_palette,
-            show_extents: false,
             params,
-            scale: 1.0,
+            state,
         }
     }
 
@@ -76,7 +90,7 @@ impl WorldWindow {
                             ui.label("Index");
                         });
                         row.col(|ui| {
-                            ui.add(NumberEdit::new(&mut self.index).range(0..32));
+                            ui.add(NumberEdit::new(&mut self.state.index).range(0..32));
                         });
                     });
                     body.row(row_height, |mut row| {
@@ -84,7 +98,7 @@ impl WorldWindow {
                             ui.label("Address");
                         });
                         row.col(|ui| {
-                            let address = 0x0003d800 + self.index * 32;
+                            let address = 0x0003d800 + self.state.index * 32;
                             let mut address_str = format!("{address:08x}");
                             ui.add_enabled(
                                 false,
@@ -95,7 +109,7 @@ impl WorldWindow {
                 });
             let mut data = {
                 let worlds = self.worlds.borrow();
-                worlds.read(self.index)
+                worlds.read(self.state.index)
             };
             let mut world = World::parse(&data);
             ui.section("Properties", |ui| {
@@ -275,7 +289,7 @@ impl WorldWindow {
                     });
             });
             if world.update(&mut data) {
-                let address = 0x0003d800 + self.index * 32;
+                let address = 0x0003d800 + self.state.index * 32;
                 self.memory.write(self.sim_id, address as u32, &data);
             }
             if world.header.mode == WorldMode::HBias {
@@ -290,10 +304,12 @@ impl WorldWindow {
                                 });
                                 row.col(|ui| {
                                     let max = world.height.max(8) as usize;
-                                    ui.add(NumberEdit::new(&mut self.param_index).range(0..max));
+                                    ui.add(
+                                        NumberEdit::new(&mut self.state.param_index).range(0..max),
+                                    );
                                 });
                             });
-                            let base = (world.param_base + self.param_index * 2) & 0x1ffff;
+                            let base = (world.param_base + self.state.param_index * 2) & 0x1ffff;
                             let mut param = HBiasParam::load(&self.bgmaps.borrow(), base);
                             body.row(row_height, |mut row| {
                                 row.col(|ui| {
@@ -340,10 +356,12 @@ impl WorldWindow {
                                 });
                                 row.col(|ui| {
                                     let max = world.height.max(1) as usize;
-                                    ui.add(NumberEdit::new(&mut self.param_index).range(0..max));
+                                    ui.add(
+                                        NumberEdit::new(&mut self.state.param_index).range(0..max),
+                                    );
                                 });
                             });
-                            let base = (world.param_base + self.param_index * 8) & 0x1ffff;
+                            let base = (world.param_base + self.state.param_index * 8) & 0x1ffff;
                             let mut param = AffineParam::load(&self.bgmaps.borrow(), base);
                             body.row(row_height, |mut row| {
                                 row.col(|ui| {
@@ -403,49 +421,49 @@ impl WorldWindow {
                         });
                 });
             } else {
-                self.param_index = 0;
+                self.state.param_index = 0;
             }
             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)
+                    let slider = Slider::new(&mut self.state.scale, 1.0..=10.0)
                         .step_by(1.0)
                         .show_value(false);
                     ui.add(slider);
                 });
-                ui.checkbox(&mut self.generic_palette, "Generic palette");
+                ui.checkbox(&mut self.state.generic_palette, "Generic palette");
-                ui.checkbox(&mut self.show_extents, "Show extents");
+                ui.checkbox(&mut self.state.show_extents, "Show extents");
             });
         });
         self.params.write(WorldParams {
-            index: self.index,
+            index: self.state.index,
-            generic_palette: self.generic_palette,
+            generic_palette: self.state.generic_palette,
             ..*self.params
         });
     }
 
     fn show_world(&mut self, ui: &mut Ui) {
-        let image = Image::new("vip://world")
+        let image = Image::new(self.image_url("world"))
-            .fit_to_original_size(self.scale)
+            .fit_to_original_size(self.state.scale)
             .texture_options(TextureOptions::NEAREST);
         let res = ui.add(image);
-        if self.show_extents {
+        if self.state.show_extents {
             let world = {
                 let worlds = self.worlds.borrow();
-                let data = worlds.read(self.index);
+                let data = worlds.read(self.state.index);
                 World::parse(&data)
             };
             if world.header.mode == WorldMode::Object {
                 return;
             }
 
-            let lx1 = (world.dst_x - world.dst_parallax) as f32 * self.scale;
+            let lx1 = (world.dst_x - world.dst_parallax) as f32 * self.state.scale;
-            let lx2 = lx1 + world.width as f32 * self.scale;
+            let lx2 = lx1 + world.width as f32 * self.state.scale;
-            let rx1 = (world.dst_x + world.dst_parallax) as f32 * self.scale;
+            let rx1 = (world.dst_x + world.dst_parallax) as f32 * self.state.scale;
-            let rx2 = rx1 + world.width as f32 * self.scale;
+            let rx2 = rx1 + world.width as f32 * self.state.scale;
-            let y1 = world.dst_y as f32 * self.scale;
+            let y1 = world.dst_y as f32 * self.state.scale;
-            let y2 = y1 + world.height as f32 * self.scale;
+            let y2 = y1 + world.height as f32 * self.state.scale;
 
             let left_color = self.params.left_color;
             let right_color = self.params.right_color;
@@ -509,10 +527,6 @@ impl WorldWindow {
 }
 
 impl AppWindow for WorldWindow {
-    fn viewport_id(&self) -> ViewportId {
-        ViewportId::from_hash_of(format!("world-{}", self.sim_id))
-    }
-
     fn sim_id(&self) -> SimId {
         self.sim_id
     }
@@ -523,12 +537,9 @@ impl AppWindow for WorldWindow {
             .with_inner_size((640.0, 520.0))
     }
 
-    fn on_init(&mut self, args: InitArgs) {
+    fn show(&mut self, ui: &mut Ui) {
-        args.ctx.add_texture_loader(self.loader.clone());
+        self.state.load(ui);
-    }
+        CentralPanel::default().show_inside(ui, |ui| {
-
-    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))
@@ -543,6 +554,7 @@ impl AppWindow for WorldWindow {
                     });
             });
         });
+        self.state.save(ui);
     }
 }
 
@@ -779,6 +791,10 @@ impl WorldRenderer {
 impl ImageRenderer<1> for WorldRenderer {
     type Params = WorldParams;
 
+    fn names(&self) -> [&str; 1] {
+        ["world"]
+    }
+
     fn sizes(&self) -> [[usize; 2]; 1] {
         [[384, 224]]
     }