Support choosing colors

src/window/game_screen.rs

@@ -1,13 +1,15 @@
 use std::{collections::HashMap, sync::Arc};
 
-use egui::Widget;
-use wgpu::{util::DeviceExt as _, BindGroup, BindGroupLayout, RenderPipeline};
+use egui::{Color32, Rgba, Widget};
+use wgpu::{util::DeviceExt as _, BindGroup, BindGroupLayout, Buffer, RenderPipeline};
 
 use crate::graphics::TextureSink;
 
 pub struct GameScreen {
     bind_group: Arc<BindGroup>,
-    pub display_mode: DisplayMode,
+    color_buffer: Arc<Buffer>,
+    display_mode: DisplayMode,
+    colors: Colors,
 }
 
 impl GameScreen {
@@ -117,12 +119,12 @@ impl GameScreen {
 
         let (sink, texture_view) = TextureSink::new(device, queue.clone());
         let sampler = device.create_sampler(&wgpu::SamplerDescriptor::default());
-        let colors = Colors {
-            left: [1.0, 0.0, 0.0, 1.0],
-            right: [0.0, 0.7734375, 0.9375, 1.0],
-        };
+        let colors = Colors::new(
+            Color32::from_rgb(0xff, 0x00, 0x00),
+            Color32::from_rgb(0x00, 0xc6, 0xf0),
+        );
 
-        let color_buf = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
+        let color_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
             label: Some("colors"),
             contents: bytemuck::bytes_of(&colors),
             usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
@@ -145,7 +147,7 @@ impl GameScreen {
                 },
                 wgpu::BindGroupEntry {
                     binding: 2,
-                    resource: color_buf.as_entire_binding(),
+                    resource: color_buffer.as_entire_binding(),
                 },
             ],
         });
@@ -153,11 +155,18 @@ impl GameScreen {
         (
             Self {
                 bind_group: Arc::new(bind_group),
+                color_buffer: Arc::new(color_buffer),
                 display_mode: DisplayMode::Anaglyph,
+                colors,
             },
             sink,
         )
     }
+
+    pub fn update(&mut self, display_mode: DisplayMode, colors: [Color32; 2]) {
+        self.display_mode = display_mode;
+        self.colors = Colors::new(colors[0], colors[1]);
+    }
 }
 
 impl Widget for &mut GameScreen {
@@ -167,7 +176,9 @@ impl Widget for &mut GameScreen {
             response.rect,
             GameScreenCallback {
                 bind_group: self.bind_group.clone(),
+                color_buffer: self.color_buffer.clone(),
                 display_mode: self.display_mode,
+                colors: self.colors,
             },
         );
         ui.painter().add(callback);
@@ -177,10 +188,23 @@ impl Widget for &mut GameScreen {
 
 struct GameScreenCallback {
     bind_group: Arc<BindGroup>,
+    color_buffer: Arc<Buffer>,
     display_mode: DisplayMode,
+    colors: Colors,
 }
 
 impl egui_wgpu::CallbackTrait for GameScreenCallback {
+    fn prepare(
+        &self,
+        _device: &wgpu::Device,
+        queue: &wgpu::Queue,
+        _screen_descriptor: &egui_wgpu::ScreenDescriptor,
+        _egui_encoder: &mut wgpu::CommandEncoder,
+        _callback_resources: &mut egui_wgpu::CallbackResources,
+    ) -> Vec<wgpu::CommandBuffer> {
+        queue.write_buffer(&self.color_buffer, 0, bytemuck::bytes_of(&self.colors));
+        vec![]
+    }
     fn paint(
         &self,
         info: egui::PaintCallbackInfo,
@@ -217,8 +241,16 @@ struct SharedGameScreenResources {
 #[derive(Clone, Copy, bytemuck::Pod, bytemuck::Zeroable)]
 #[repr(C)]
 struct Colors {
-    left: [f32; 4],
-    right: [f32; 4],
+    left: Rgba,
+    right: Rgba,
+}
+impl Colors {
+    fn new(left: Color32, right: Color32) -> Self {
+        Self {
+            left: left.into(),
+            right: right.into(),
+        }
+    }
 }
 
 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]