Cleaner layer handling code

src/fill.wgsl

@@ -16,7 +16,7 @@ fn on_fragment(in: Varying) -> @location(0) u32 {
 	let x = bitcast<u32>(in.screen.x);
 	let y = bitcast<u32>(in.screen.y);
 	let rand = hash(hash(hash(SEED) ^ hash(x)) ^ hash(y));
-	return rand >> 31;
+	return rand >> 24;
 }
 
 fn hash(key : u32) -> u32 {

src/present.wgsl

@@ -16,5 +16,5 @@ fn on_vertex(@builtin(vertex_index) vi: u32) -> Varying {
 fn on_fragment(in: Varying) -> @location(0) vec4f {
 	let pos = vec2u(in.screen.xy);
 	let state = textureLoad(field, pos, 0).x;
-	return vec4f(f32(state));
+	return vec4f(f32(state) / 255.);
 }

src/step.wgsl

@@ -16,12 +16,25 @@ fn on_vertex(@builtin(vertex_index) vi: u32) -> Varying {
 
 @fragment
 fn on_fragment(in: Varying) -> @location(0) u32 {
-	let a = textureGather(0, field, smp, in.uv, vec2(0, 0));
+	let aa = textureGather(0, field, smp, in.uv, vec2(0, 0));
-	let b = textureGather(0, field, smp, in.uv, vec2(0, 1));
+	let ab = textureGather(0, field, smp, in.uv, vec2(0, 1));
-	let c = textureGather(0, field, smp, in.uv, vec2(1, 0));
+	let ba = textureGather(0, field, smp, in.uv, vec2(1, 0));
-	let d = textureGather(0, field, smp, in.uv, vec2(1, 1));
+	let bb = textureGather(0, field, smp, in.uv, vec2(1, 1));
-	let state = a.y;
+	let s = aa.y;
-	let n = a.x + a.z + a.w + b.x + b.y + c.y + c.z + d.y;
+	let a = vec4(aa.xzw, bb.y);
+	let b = vec4(ab.xy, ba.yz);
+	var ret = 0u;
+	for (var layer = 0u; layer < 8u; layer++) {
+		let s = s >> layer & 1u;
+		let a = a >> vec4(layer) & vec4(1u);
+		let b = b >> vec4(layer) & vec4(1u);
+		ret |= calc(s, a, b) << layer;
+	}
+	return ret;
+}
+
+fn calc(state: u32, a: vec4u, b: vec4u) -> u32 {
+	let n = dot(a, vec4(1u)) + dot(b, vec4(1u));
 	switch (n) {
 	case 2u: { return state; }
 	case 3u: { return 1u; }