Temporal dithering

src/bin/wireframe/main.rs

@@ -199,7 +199,7 @@ impl<'a> State<'a> {
 					required_features: wgpu::Features::PUSH_CONSTANTS
 						| wgpu::Features::TEXTURE_ADAPTER_SPECIFIC_FORMAT_FEATURES,
 					required_limits: wgpu::Limits {
-						max_push_constant_size: 16,
+						max_push_constant_size: 20,
 						..wgpu::Limits::default()
 					},
 					memory_hints: Default::default(),

src/bin/wireframe/mesh.wgsl

@@ -7,6 +7,7 @@ var<uniform> camera: CameraUniform;
 
 struct MeshUniform {
 	color: vec4<f32>,
+	seed: u32,
 }
 var<push_constant> mesh: MeshUniform;
 
@@ -50,7 +51,7 @@ fn fs_main(in: VertexOutput) -> FragmentOutput {
 	var y = bitcast<u32>(in.clip_position.y);
 	var z = bitcast<u32>(in.clip_position.z);
 	var alpha = in.vertex_color.w;
-	var seed = hash(hash(hash(x) ^ y) ^ z);
+	var seed = hash(hash(hash(mesh.seed ^ x) ^ y) ^ z);
 	var mask = 0u;
 	for (var sample = 0u; sample < 8u; sample++) {
 		var threshold = f32(hash(seed ^ sample)) / 0x1p32;

src/bin/wireframe/meshes.rs

@@ -15,6 +15,7 @@ struct Vertex {
 #[derive(Copy, Clone, Pod, Zeroable)]
 struct PushConsts {
 	pub color: [f32; 4],
+	pub seed: u32,
 }
 
 #[derive(Copy, Clone)]
@@ -23,15 +24,16 @@ pub struct Attrs {
 }
 
 impl Attrs {
-	fn consts(&self) -> PushConsts {
+	fn consts(&self, seed: u32) -> PushConsts {
 		PushConsts {
 			color: self.color.to_array(),
+			seed,
 		}
 	}
 }
 
 pub struct Mesh {
-	consts: PushConsts,
+	attrs: Attrs,
 	npoints: u32,
 	buf: wgpu::Buffer,
 }
@@ -64,7 +66,7 @@ impl Mesh {
 			usage: wgpu::BufferUsages::VERTEX,
 		});
 		Mesh {
-			consts: attrs.consts(),
+			attrs,
 			npoints: data.len() as u32,
 			buf,
 		}
@@ -157,10 +159,12 @@ impl Renderer {
 		cam_bind: &wgpu::BindGroup,
 		meshes: impl Iterator<Item = &'a Mesh>,
 	) {
+		let seed = rand::random();
 		pass.set_pipeline(&self.pipeline);
 		pass.set_bind_group(0, cam_bind, &[]);
 		for mesh in meshes {
-			pass.set_push_constants(wgpu::ShaderStages::VERTEX, 0, bytes_of(&mesh.consts));
+			let consts = mesh.attrs.consts(seed);
+			pass.set_push_constants(wgpu::ShaderStages::VERTEX, 0, bytes_of(&consts));
 			pass.set_vertex_buffer(0, mesh.buf.slice(..));
 			pass.draw(0..mesh.npoints, 0..1);
 		}