Introduce CanvasMaterial

src/canvas.rs

@@ -1,22 +1,42 @@
 use crate::grid;
-use bevy::prelude::*;
+use bevy::{
+    prelude::*,
+    reflect::TypeUuid,
+    render::render_resource::{AsBindGroup, ShaderRef},
+    sprite::{Material2d, Material2dPlugin, MaterialMesh2dBundle},
+};
 
 pub struct CanvasPlugin;
 
 impl Plugin for CanvasPlugin {
     fn build(&self, app: &mut App) {
-        app.add_startup_system(spawn_background);
+        app.add_plugin(Material2dPlugin::<CanvasMaterial>::default())
+            .add_startup_system(spawn_canvas);
     }
 }
 
-fn spawn_background(mut commands: Commands) {
+#[derive(AsBindGroup, TypeUuid, Clone)]
+#[uuid = "24f83f6e-e52d-41a6-bf1d-0e46e57a4995"]
+struct CanvasMaterial {}
+
+impl Material2d for CanvasMaterial {
+    fn fragment_shader() -> ShaderRef {
+        "canvas_shader.wgsl".into()
+    }
+}
+
+fn spawn_canvas(
+    mut commands: Commands,
+    mut mesh_assets: ResMut<Assets<Mesh>>,
+    mut canvas_material_assets: ResMut<Assets<CanvasMaterial>>,
+) {
     commands
-        .spawn(SpriteBundle {
-            sprite: Sprite {
-                color: Color::DARK_GRAY,
-                custom_size: Some(Vec2::splat(grid::SEGMENT_SIZE * f32::from(grid::SIZE))),
-                ..Default::default()
-            },
+        .spawn(MaterialMesh2dBundle {
+            mesh: mesh_assets.add(Mesh::from(shape::Quad::default())).into(),
+            material: canvas_material_assets.add(CanvasMaterial {}),
+            transform: Transform::from_scale(Vec3::splat(
+                grid::SEGMENT_SIZE * f32::from(grid::SIZE),
+            )),
             ..Default::default()
         })
         .insert(Name::new("Canvas"));