Stop using nested viewports

src/app.rs

@@ -0,0 +1,329 @@
+use std::{collections::HashSet, num::NonZero, sync::Arc, thread};
+
+use egui::{
+    ahash::{HashMap, HashMapExt},
+    Context, TextWrapMode, ViewportBuilder, ViewportCommand, ViewportId, ViewportInfo,
+};
+use gilrs::{EventType, Gilrs};
+use winit::{
+    application::ApplicationHandler,
+    event::{KeyEvent, WindowEvent},
+    event_loop::{ActiveEventLoop, EventLoopProxy},
+    window::Window,
+};
+
+use crate::{
+    controller::ControllerManager,
+    emulator::{EmulatorClient, SimId},
+    input::MappingProvider,
+    window::{AppWindow, GameWindow, InputWindow},
+};
+
+pub struct Application {
+    client: EmulatorClient,
+    proxy: EventLoopProxy<UserEvent>,
+    mappings: MappingProvider,
+    controllers: ControllerManager,
+    viewports: HashMap<ViewportId, Viewport>,
+    focused: Option<ViewportId>,
+}
+
+impl Application {
+    pub fn new(client: EmulatorClient, proxy: EventLoopProxy<UserEvent>) -> Self {
+        let mappings = MappingProvider::new();
+        let controllers = ControllerManager::new(client.clone(), &mappings);
+        {
+            let mappings = mappings.clone();
+            let proxy = proxy.clone();
+            thread::spawn(|| process_gamepad_input(mappings, proxy));
+        }
+        Self {
+            client,
+            proxy,
+            mappings,
+            controllers,
+            viewports: HashMap::new(),
+            focused: None,
+        }
+    }
+
+    fn open(&mut self, event_loop: &ActiveEventLoop, window: Box<dyn AppWindow>) {
+        let viewport_id = window.viewport_id();
+        if self.viewports.contains_key(&viewport_id) {
+            return;
+        }
+        self.viewports
+            .insert(viewport_id, Viewport::new(event_loop, window));
+    }
+}
+
+impl ApplicationHandler<UserEvent> for Application {
+    fn resumed(&mut self, event_loop: &ActiveEventLoop) {
+        let app = GameWindow::new(self.client.clone(), self.proxy.clone(), SimId::Player1);
+        let wrapper = Viewport::new(event_loop, Box::new(app));
+        self.focused = Some(wrapper.id());
+        self.viewports.insert(wrapper.id(), wrapper);
+    }
+
+    fn window_event(
+        &mut self,
+        event_loop: &ActiveEventLoop,
+        window_id: winit::window::WindowId,
+        event: WindowEvent,
+    ) {
+        let Some(viewport) = self
+            .viewports
+            .values_mut()
+            .find(|v| v.window.id() == window_id)
+        else {
+            return;
+        };
+        let viewport_id = viewport.id();
+        match &event {
+            WindowEvent::KeyboardInput { event, .. } => {
+                self.controllers.handle_key_event(event);
+                viewport.handle_key_event(event);
+            }
+            WindowEvent::Focused(new_focused) => {
+                self.focused = new_focused.then_some(viewport_id);
+            }
+            _ => {}
+        }
+        match viewport.on_window_event(event) {
+            Some(Action::Redraw) => {
+                for viewport in self.viewports.values_mut() {
+                    viewport.redraw(event_loop);
+                }
+            }
+            Some(Action::Close) => {
+                self.viewports.remove(&viewport_id);
+                if viewport_id == ViewportId::ROOT {
+                    event_loop.exit();
+                }
+            }
+            None => {}
+        }
+    }
+
+    fn device_event(
+        &mut self,
+        _event_loop: &ActiveEventLoop,
+        _device_id: winit::event::DeviceId,
+        event: winit::event::DeviceEvent,
+    ) {
+        if let winit::event::DeviceEvent::MouseMotion { delta } = event {
+            let Some(viewport) = self
+                .focused
+                .as_ref()
+                .and_then(|id| self.viewports.get_mut(id))
+            else {
+                return;
+            };
+            viewport.state.on_mouse_motion(delta);
+        }
+    }
+
+    fn user_event(&mut self, event_loop: &ActiveEventLoop, event: UserEvent) {
+        match event {
+            UserEvent::GamepadEvent(event) => self.controllers.handle_gamepad_event(&event),
+            UserEvent::OpenInput => {
+                let input = InputWindow::new(self.mappings.clone());
+                self.open(event_loop, Box::new(input));
+            }
+            UserEvent::OpenPlayer2 => {
+                let p2 = GameWindow::new(self.client.clone(), self.proxy.clone(), SimId::Player2);
+                self.open(event_loop, Box::new(p2));
+            }
+        }
+    }
+
+    fn about_to_wait(&mut self, _event_loop: &ActiveEventLoop) {
+        if let Some(viewport) = self.viewports.get(&ViewportId::ROOT) {
+            viewport.window.request_redraw();
+        }
+    }
+}
+
+struct Viewport {
+    painter: egui_wgpu::winit::Painter,
+    ctx: Context,
+    info: ViewportInfo,
+    commands: Vec<ViewportCommand>,
+    builder: ViewportBuilder,
+    window: Arc<Window>,
+    state: egui_winit::State,
+    app: Box<dyn AppWindow>,
+}
+impl Viewport {
+    pub fn new(event_loop: &ActiveEventLoop, mut app: Box<dyn AppWindow>) -> Self {
+        let mut painter = egui_wgpu::winit::Painter::new(
+            egui_wgpu::WgpuConfiguration::default(),
+            1,
+            None,
+            false,
+            true,
+        );
+
+        let ctx = Context::default();
+        ctx.style_mut(|s| {
+            s.wrap_mode = Some(TextWrapMode::Extend);
+            s.visuals.menu_rounding = Default::default();
+        });
+
+        let mut info = ViewportInfo::default();
+        let builder = app.initial_viewport();
+        let (window, state) = create_window_and_state(&ctx, event_loop, &builder, &mut painter);
+        egui_winit::update_viewport_info(&mut info, &ctx, &window, true);
+
+        app.on_init(painter.render_state().as_ref().unwrap());
+        Self {
+            painter,
+            ctx,
+            info,
+            commands: vec![],
+            builder,
+            window,
+            state,
+            app,
+        }
+    }
+
+    pub fn id(&self) -> ViewportId {
+        self.app.viewport_id()
+    }
+
+    pub fn on_window_event(&mut self, event: WindowEvent) -> Option<Action> {
+        let response = self.state.on_window_event(&self.window, &event);
+        egui_winit::update_viewport_info(
+            &mut self.info,
+            self.state.egui_ctx(),
+            &self.window,
+            false,
+        );
+
+        match event {
+            WindowEvent::RedrawRequested => Some(Action::Redraw),
+            WindowEvent::CloseRequested => Some(Action::Close),
+            WindowEvent::Resized(size) => {
+                let (Some(width), Some(height)) =
+                    (NonZero::new(size.width), NonZero::new(size.height))
+                else {
+                    return None;
+                };
+                self.painter
+                    .on_window_resized(ViewportId::ROOT, width, height);
+                None
+            }
+            _ if response.repaint => Some(Action::Redraw),
+            _ => None,
+        }
+    }
+
+    pub fn handle_key_event(&mut self, event: &KeyEvent) {
+        self.app.handle_key_event(event);
+    }
+
+    fn redraw(&mut self, event_loop: &ActiveEventLoop) -> Option<Action> {
+        let mut input = 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,
+            false,
+        );
+
+        self.state
+            .handle_platform_output(&self.window, output.platform_output);
+
+        let Some(viewport_output) = output.viewport_output.remove(&ViewportId::ROOT) else {
+            return Some(Action::Close);
+        };
+
+        let (mut deferred_commands, recreate) = self.builder.patch(viewport_output.builder);
+        if recreate {
+            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);
+        egui_winit::process_viewport_commands(
+            &self.ctx,
+            &mut self.info,
+            std::mem::take(&mut self.commands),
+            &self.window,
+            &mut HashSet::default(),
+        );
+
+        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),
+    OpenInput,
+    OpenPlayer2,
+}
+
+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>) {
+    let Ok(mut gilrs) = Gilrs::new() else {
+        eprintln!("could not connect gamepad listener");
+        return;
+    };
+    while let Some(event) = gilrs.next_event_blocking(None) {
+        if event.event == EventType::Connected {
+            let Some(gamepad) = gilrs.connected_gamepad(event.id) else {
+                continue;
+            };
+            mappings.map_gamepad(SimId::Player1, &gamepad);
+        }
+        if proxy.send_event(UserEvent::GamepadEvent(event)).is_err() {
+            // main thread has closed! we done
+            return;
+        }
+    }
+}

src/application.rs

@@ -1,315 +0,0 @@
-use std::{
-    collections::{hash_map::Entry, HashMap, HashSet},
-    num::NonZero,
-    sync::Arc,
-};
-
-use winit::event_loop::EventLoopProxy;
-
-use crate::{emulator::EmulatorClient, window::WindowManager};
-
-pub struct Application {
-    client: EmulatorClient,
-    proxy: EventLoopProxy<UserEvent>,
-    state: Option<AppState>,
-}
-
-impl Application {
-    pub fn new(client: EmulatorClient, proxy: EventLoopProxy<UserEvent>) -> Self {
-        Self {
-            client,
-            proxy,
-            state: None,
-        }
-    }
-}
-
-impl winit::application::ApplicationHandler<UserEvent> for Application {
-    fn resumed(&mut self, event_loop: &winit::event_loop::ActiveEventLoop) {
-        self.state = Some(AppState::new(
-            self.client.clone(),
-            self.proxy.clone(),
-            event_loop,
-        ));
-    }
-
-    fn window_event(
-        &mut self,
-        event_loop: &winit::event_loop::ActiveEventLoop,
-        window_id: winit::window::WindowId,
-        event: winit::event::WindowEvent,
-    ) {
-        self.state
-            .as_mut()
-            .unwrap()
-            .window_event(event_loop, window_id, event);
-    }
-
-    fn device_event(
-        &mut self,
-        _event_loop: &winit::event_loop::ActiveEventLoop,
-        _device_id: winit::event::DeviceId,
-        event: winit::event::DeviceEvent,
-    ) {
-        self.state.as_mut().unwrap().device_event(event)
-    }
-
-    fn user_event(&mut self, _event_loop: &winit::event_loop::ActiveEventLoop, event: UserEvent) {
-        self.state.as_mut().unwrap().user_event(event);
-    }
-}
-
-struct AppState {
-    painter: egui_wgpu::winit::Painter,
-    ctx: egui::Context,
-    viewports: HashMap<egui::ViewportId, ViewportState>,
-    viewports_by_window: HashMap<winit::window::WindowId, egui::ViewportId>,
-    focused: Option<egui::ViewportId>,
-    screen: WindowManager,
-}
-impl AppState {
-    fn new(
-        client: EmulatorClient,
-        proxy: EventLoopProxy<UserEvent>,
-        event_loop: &winit::event_loop::ActiveEventLoop,
-    ) -> Self {
-        let mut painter = egui_wgpu::winit::Painter::new(
-            egui_wgpu::WgpuConfiguration::default(),
-            1,
-            None,
-            false,
-            true,
-        );
-        let ctx = egui::Context::default();
-        ctx.style_mut(|s| {
-            s.wrap_mode = Some(egui::TextWrapMode::Extend);
-            s.visuals.menu_rounding = Default::default();
-        });
-        ctx.set_embed_viewports(false);
-        {
-            let proxy = proxy.clone();
-            ctx.set_request_repaint_callback(move |info| {
-                proxy.send_event(UserEvent::RepaintRequested(info)).unwrap();
-            });
-        }
-
-        let mut screen = WindowManager::new(client, proxy);
-        let root_viewport = ViewportState::new(
-            egui::ViewportId::ROOT,
-            &ctx,
-            event_loop,
-            screen.initial_viewport(),
-            &mut painter,
-        );
-        screen.init_renderer(painter.render_state().as_ref().unwrap());
-
-        let mut viewports_by_window = HashMap::new();
-        viewports_by_window.insert(root_viewport.window.id(), egui::ViewportId::ROOT);
-        let mut viewports = HashMap::new();
-        viewports.insert(egui::ViewportId::ROOT, root_viewport);
-
-        Self {
-            painter,
-            ctx,
-            viewports,
-            viewports_by_window,
-            focused: Some(egui::ViewportId::ROOT),
-            screen,
-        }
-    }
-
-    fn window_event(
-        &mut self,
-        event_loop: &winit::event_loop::ActiveEventLoop,
-        window_id: winit::window::WindowId,
-        event: winit::event::WindowEvent,
-    ) {
-        let Some(&viewport_id) = self.viewports_by_window.get(&window_id) else {
-            return;
-        };
-        let Some(viewport) = self.viewports.get_mut(&viewport_id) else {
-            panic!("Unrecognized viewport");
-        };
-        viewport.on_window_event(&event);
-
-        match event {
-            winit::event::WindowEvent::KeyboardInput { event, .. } => {
-                self.screen.handle_key_event(event);
-            }
-            winit::event::WindowEvent::RedrawRequested => {
-                pollster::block_on(
-                    self.painter
-                        .set_window(viewport_id, Some(viewport.window.clone())),
-                )
-                .unwrap();
-                let cb = viewport.viewport_ui_cb.clone();
-                let mut input = viewport.state.take_egui_input(&viewport.window);
-                input.viewports = self
-                    .viewports
-                    .iter()
-                    .map(|(k, v)| (*k, v.info.clone()))
-                    .collect();
-                let output = self.ctx.run(input, |ctx| {
-                    if let Some(cb) = cb.as_deref() {
-                        cb(ctx)
-                    } else {
-                        self.screen.show(ctx)
-                    }
-                });
-                let clipped_primitives =
-                    self.ctx.tessellate(output.shapes, output.pixels_per_point);
-                self.painter.paint_and_update_textures(
-                    viewport_id,
-                    output.pixels_per_point,
-                    [0.0, 0.0, 0.0, 0.0],
-                    &clipped_primitives,
-                    &output.textures_delta,
-                    false,
-                );
-
-                let mut live_viewports = HashSet::default();
-                for (id, output) in output.viewport_output {
-                    live_viewports.insert(id);
-                    let viewport = match self.viewports.entry(id) {
-                        Entry::Occupied(e) => e.into_mut(),
-                        Entry::Vacant(e) => {
-                            let mut v = ViewportState::new(
-                                id,
-                                &self.ctx,
-                                event_loop,
-                                output.builder,
-                                &mut self.painter,
-                            );
-                            v.viewport_ui_cb = output.viewport_ui_cb;
-                            self.viewports_by_window.insert(v.window.id(), id);
-                            e.insert(v)
-                        }
-                    };
-                    egui_winit::process_viewport_commands(
-                        &self.ctx,
-                        &mut viewport.info,
-                        output.commands,
-                        &viewport.window,
-                        &mut HashSet::default(),
-                    );
-                    if viewport.info.close_requested() {
-                        live_viewports.remove(&id);
-                    }
-                }
-                self.viewports.retain(|k, v| {
-                    if live_viewports.contains(k) {
-                        return true;
-                    }
-                    self.viewports_by_window.remove(&v.window.id());
-                    false
-                });
-                self.painter.gc_viewports(&live_viewports);
-                if !self.viewports.contains_key(&egui::ViewportId::ROOT) {
-                    event_loop.exit();
-                }
-            }
-            winit::event::WindowEvent::Resized(size) => {
-                let (Some(width), Some(height)) =
-                    (NonZero::new(size.width), NonZero::new(size.height))
-                else {
-                    return;
-                };
-                self.painter.on_window_resized(viewport_id, width, height);
-            }
-            winit::event::WindowEvent::Focused(new_focused) => {
-                self.focused = new_focused.then_some(viewport_id);
-            }
-            winit::event::WindowEvent::CloseRequested => {
-                if viewport_id == egui::ViewportId::ROOT {
-                    event_loop.exit();
-                } else if let Some(viewport) = self.viewports.get_mut(&viewport_id) {
-                    viewport.info.events.push(egui::ViewportEvent::Close);
-                    self.ctx.request_repaint_of(viewport_id);
-                    self.ctx.request_repaint_of(egui::ViewportId::ROOT);
-                }
-            }
-            _ => {}
-        }
-    }
-
-    fn device_event(&mut self, event: winit::event::DeviceEvent) {
-        if let winit::event::DeviceEvent::MouseMotion { delta } = event {
-            let Some(viewport) = self
-                .focused
-                .as_ref()
-                .and_then(|id| self.viewports.get_mut(id))
-            else {
-                return;
-            };
-            viewport.state.on_mouse_motion(delta);
-        }
-    }
-
-    fn user_event(&mut self, event: UserEvent) {
-        match event {
-            UserEvent::GamepadEvent(event) => self.screen.handle_gamepad_event(event),
-            UserEvent::RepaintRequested(info) => {
-                let Some(viewport) = self.viewports.get(&info.viewport_id) else {
-                    return;
-                };
-                viewport.window.request_redraw();
-            }
-        }
-    }
-}
-
-struct ViewportState {
-    info: egui::ViewportInfo,
-    state: egui_winit::State,
-    viewport_ui_cb: Option<Arc<egui::DeferredViewportUiCallback>>,
-    window: Arc<winit::window::Window>,
-}
-
-impl ViewportState {
-    fn new(
-        id: egui::ViewportId,
-        ctx: &egui::Context,
-        event_loop: &winit::event_loop::ActiveEventLoop,
-        viewport: egui::ViewportBuilder,
-        painter: &mut egui_wgpu::winit::Painter,
-    ) -> Self {
-        let mut info = egui::ViewportInfo::default();
-        let window = Arc::new(egui_winit::create_window(ctx, event_loop, &viewport).unwrap());
-        egui_winit::update_viewport_info(&mut info, ctx, &window, true);
-
-        pollster::block_on(painter.set_window(id, Some(window.clone()))).unwrap();
-        let state = egui_winit::State::new(
-            ctx.clone(),
-            id,
-            event_loop,
-            Some(window.scale_factor() as f32),
-            event_loop.system_theme(),
-            painter.max_texture_side(),
-        );
-        Self {
-            info,
-            state,
-            viewport_ui_cb: None,
-            window,
-        }
-    }
-
-    fn on_window_event(&mut self, event: &winit::event::WindowEvent) {
-        let response = self.state.on_window_event(&self.window, event);
-        if response.repaint {
-            self.window.request_redraw();
-        }
-        egui_winit::update_viewport_info(
-            &mut self.info,
-            self.state.egui_ctx(),
-            &self.window,
-            false,
-        );
-    }
-}
-
-#[derive(Debug)]
-pub enum UserEvent {
-    GamepadEvent(gilrs::Event),
-    RepaintRequested(egui::RequestRepaintInfo),
-}

src/main.rs

@@ -1,13 +1,13 @@
 use std::{path::PathBuf, process};
 
 use anyhow::Result;
-use application::Application;
+use app::Application;
 use clap::Parser;
 use emulator::EmulatorBuilder;
 use thread_priority::{ThreadBuilder, ThreadPriority};
 use winit::event_loop::{ControlFlow, EventLoop};
 
-mod application;
+mod app;
 mod audio;
 mod controller;
 mod emulator;

src/window.rs

@@ -1,157 +1,21 @@
-use std::{
-    sync::{
-        atomic::{AtomicBool, Ordering},
-        Arc, Mutex,
-    },
-    thread,
-};
-
 use egui::{Context, ViewportBuilder, ViewportId};
-use game::GameWindow;
-use game_screen::GameScreen;
-use gilrs::{EventType, Gilrs};
-use input::InputWindow;
-use winit::{event::KeyEvent, event_loop::EventLoopProxy};
-
-use crate::{
-    application::UserEvent,
-    controller::ControllerManager,
-    emulator::{EmulatorClient, EmulatorCommand, SimId},
-    input::MappingProvider,
-};
+pub use game::GameWindow;
+pub use input::InputWindow;
+use winit::event::KeyEvent;
 
 mod game;
 mod game_screen;
 mod input;
 
-pub struct WindowManager {
-    p1: GameWindow,
-    p2: Arc<Mutex<GameWindow>>,
-    client: EmulatorClient,
-    input: ChildWindow<InputWindow>,
-    controllers: ControllerManager,
-}
-impl WindowManager {
-    pub fn new(client: EmulatorClient, proxy: EventLoopProxy<UserEvent>) -> Self {
-        let mappings = MappingProvider::new();
-        let controllers = ControllerManager::new(client.clone(), &mappings);
-        {
-            let mappings = mappings.clone();
-            thread::spawn(|| process_gamepad_input(mappings, proxy));
-        }
-        let input = ChildWindow::new(InputWindow::new(mappings));
-        let p1 = GameWindow::new(client.clone(), SimId::Player1, input.open.clone());
-        let p2 = GameWindow::new(client.clone(), SimId::Player2, input.open.clone());
-        Self {
-            p1,
-            p2: Arc::new(Mutex::new(p2)),
-            client,
-            input,
-            controllers,
-        }
-    }
-
-    pub fn init_renderer(&mut self, render_state: &egui_wgpu::RenderState) {
-        GameScreen::init_pipeline(render_state);
-        self.p2.lock().unwrap().init_renderer(render_state);
-        self.p1.init_renderer(render_state);
-    }
-
-    pub fn initial_viewport(&self) -> ViewportBuilder {
-        self.p1.initial_viewport()
-    }
-
-    pub fn show(&mut self, ctx: &Context) {
-        self.p1.show(ctx);
-        self.input.show(ctx);
-        if self.client.has_player_2() {
-            let (viewport_id, viewport) = {
-                let p2 = self.p2.lock().unwrap();
-                (p2.viewport_id(), p2.initial_viewport())
-            };
-            let client = self.client.clone();
-            let p2 = self.p2.clone();
-            ctx.show_viewport_deferred(viewport_id, viewport, move |ctx, _| {
-                p2.lock().unwrap().show(ctx);
-                if ctx.input(|i| i.viewport().close_requested()) {
-                    client.send_command(EmulatorCommand::StopSecondSim);
-                }
-            });
-        }
-    }
-
-    pub fn handle_key_event(&mut self, event: winit::event::KeyEvent) {
-        self.controllers.handle_key_event(&event);
-        self.input.handle_key_event(&event);
-    }
-
-    pub fn handle_gamepad_event(&mut self, event: gilrs::Event) {
-        self.controllers.handle_gamepad_event(&event);
-    }
-}
-
-fn process_gamepad_input(mappings: MappingProvider, proxy: EventLoopProxy<UserEvent>) {
-    let Ok(mut gilrs) = Gilrs::new() else {
-        eprintln!("could not connect gamepad listener");
-        return;
-    };
-    while let Some(event) = gilrs.next_event_blocking(None) {
-        if event.event == EventType::Connected {
-            let Some(gamepad) = gilrs.connected_gamepad(event.id) else {
-                continue;
-            };
-            mappings.map_gamepad(SimId::Player1, &gamepad);
-        }
-        if proxy.send_event(UserEvent::GamepadEvent(event)).is_err() {
-            // main thread has closed! we done
-            return;
-        }
-    }
-}
-
-trait AppWindow {
+pub trait AppWindow {
     fn viewport_id(&self) -> ViewportId;
     fn initial_viewport(&self) -> ViewportBuilder;
     fn show(&mut self, ctx: &Context);
+    fn on_init(&mut self, render_state: &egui_wgpu::RenderState) {
+        let _ = render_state;
+    }
+    fn on_destroy(&mut self) {}
     fn handle_key_event(&mut self, event: &KeyEvent) {
         let _ = event;
     }
 }
-
-struct ChildWindow<T: AppWindow> {
-    pub open: Arc<AtomicBool>,
-    window: Arc<Mutex<T>>,
-}
-impl<T: AppWindow + Send + 'static> ChildWindow<T> {
-    fn new(window: T) -> Self {
-        Self {
-            open: Arc::new(AtomicBool::new(false)),
-            window: Arc::new(Mutex::new(window)),
-        }
-    }
-
-    fn show(&self, ctx: &Context) {
-        if !self.open.load(Ordering::Relaxed) {
-            return;
-        }
-        let (viewport_id, viewport) = {
-            let window = self.window.lock().unwrap();
-            (window.viewport_id(), window.initial_viewport())
-        };
-        let open = self.open.clone();
-        let window = self.window.clone();
-        ctx.show_viewport_deferred(viewport_id, viewport, move |ctx, _| {
-            window.lock().unwrap().show(ctx);
-            if ctx.input(|i| i.viewport().close_requested()) {
-                open.store(false, Ordering::Relaxed);
-                ctx.request_repaint();
-            }
-        });
-    }
-
-    fn handle_key_event(&self, event: &KeyEvent) {
-        if self.open.load(Ordering::Relaxed) {
-            self.window.lock().unwrap().handle_key_event(event);
-        }
-    }
-}

src/window/game.rs

@@ -1,40 +1,32 @@
-use std::sync::{
-    atomic::{AtomicBool, Ordering},
-    Arc,
+use crate::{
+    app::UserEvent,
+    emulator::{EmulatorClient, EmulatorCommand, SimId},
 };
-
-use crate::emulator::{EmulatorClient, EmulatorCommand, SimId};
 use egui::{
     menu, Button, CentralPanel, Color32, Context, Response, TopBottomPanel, Ui, ViewportBuilder,
     ViewportCommand, ViewportId, WidgetText,
 };
+use winit::event_loop::EventLoopProxy;
 
 use super::{game_screen::GameScreen, AppWindow};
 
 pub struct GameWindow {
     client: EmulatorClient,
+    proxy: EventLoopProxy<UserEvent>,
     sim_id: SimId,
-    input_window_open: Arc<AtomicBool>,
     screen: Option<GameScreen>,
 }
 
 impl GameWindow {
-    pub fn new(client: EmulatorClient, sim_id: SimId, input_window_open: Arc<AtomicBool>) -> Self {
+    pub fn new(client: EmulatorClient, proxy: EventLoopProxy<UserEvent>, sim_id: SimId) -> Self {
         Self {
             client,
+            proxy,
             sim_id,
-            input_window_open,
             screen: None,
         }
     }
 
-    pub fn init_renderer(&mut self, render_state: &egui_wgpu::RenderState) {
-        let (screen, sink) = GameScreen::init(render_state);
-        self.client
-            .send_command(EmulatorCommand::SetRenderer(self.sim_id, sink));
-        self.screen = Some(screen)
-    }
-
     fn show_menu(&mut self, ctx: &Context, ui: &mut Ui) {
         ui.menu_button("ROM", |ui| {
             if ui.button("Open ROM").clicked() {
@@ -101,7 +93,7 @@ impl GameWindow {
         });
         ui.menu_button("Input", |ui| {
             if ui.button("Bind Inputs").clicked() {
-                self.input_window_open.store(true, Ordering::Relaxed);
+                self.proxy.send_event(UserEvent::OpenInput).unwrap();
                 ui.close_menu();
             }
         });
@@ -112,6 +104,7 @@ impl GameWindow {
             {
                 self.client
                     .send_command(EmulatorCommand::StartSecondSim(None));
+                self.proxy.send_event(UserEvent::OpenPlayer2).unwrap();
                 ui.close_menu();
             }
             if self.client.has_player_2() {
@@ -157,6 +150,19 @@ impl AppWindow for GameWindow {
             }
         });
     }
+
+    fn on_init(&mut self, render_state: &egui_wgpu::RenderState) {
+        let (screen, sink) = GameScreen::init(render_state);
+        self.client
+            .send_command(EmulatorCommand::SetRenderer(self.sim_id, sink));
+        self.screen = Some(screen)
+    }
+
+    fn on_destroy(&mut self) {
+        if self.sim_id == SimId::Player2 {
+            self.client.send_command(EmulatorCommand::StopSecondSim);
+        }
+    }
 }
 
 trait UiExt {

src/window/game_screen.rs

@@ -10,7 +10,7 @@ pub struct GameScreen {
 }
 
 impl GameScreen {
-    pub fn init_pipeline(render_state: &egui_wgpu::RenderState) {
+    fn init_pipeline(render_state: &egui_wgpu::RenderState) {
         let device = &render_state.device;
 
         let bind_group_layout = device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
@@ -101,6 +101,8 @@ 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;