Color according to generation

src/game-of-life.compute.wgsl

@@ -13,17 +13,22 @@ fn getCell(x: i32, y: i32) -> u32 {
     return current[getIndex(x, y)];
 }
 
+fn isAlive(x: i32, y: i32) -> u32 {
+    return u32(current[getIndex(x, y)] > 0u);
+}
+
 fn countNeighbors(x: i32, y: i32) -> u32 {
-    return getCell(x - 1, y - 1) + getCell(x, y - 1) + getCell(x + 1, y - 1) + getCell(x - 1, y) + getCell(x + 1, y) + getCell(x - 1, y + 1) + getCell(x, y + 1) + getCell(x + 1, y + 1);
+    return isAlive(x - 1, y - 1) + isAlive(x, y - 1) + isAlive(x + 1, y - 1) + isAlive(x - 1, y) + isAlive(x + 1, y) + isAlive(x - 1, y + 1) + isAlive(x, y + 1) + isAlive(x + 1, y + 1);
 }
 
 @compute @workgroup_size(8, 8)
 fn main(@builtin(global_invocation_id) grid: vec3<u32>) {
     let x = i32(grid.x);
     let y = i32(grid.y);
     let n = countNeighbors(x, y);
+    let current_generation = getCell(x, y);
+    let cell_lives = current_generation >= 1u;
     let will_be_born = u32(((1 << n) & rule.x) > 0);
-    let will_survive = u32(((1 << n) & rule.y) > 0);
-    let cell_lives = getCell(x, y) == 1u;
+    let will_survive = u32(((1 << n) & rule.y) > 0) * (1u + current_generation);
     next[getIndex(x, y)] = select(will_be_born, will_survive, cell_lives);
 } 

src/game-of-life.render.wgsl

@@ -12,14 +12,34 @@ fn vertex_main(@builtin(instance_index) i: u32, @location(0) cell: u32, @locatio
     let x = (f32(i % w + pos.x) / f32(w) - 0.5) * 2. * f32(w) / f32(w);
     let y = (f32((i - (i % w)) / w + pos.y) / f32(h) - 0.5) * 2. * f32(h) / f32(h);
 
-    let c = f32(i) / f32(size.x * size.y);
-    let r = f32(cell) * f32(i % w) / f32(w);
-    let g = f32(cell) * f32(i / w) / f32(h);
-    let b = f32(cell) * (1. - max(g, r));
-    return Out(vec4<f32>(x, y, 0., 1.), vec3(r, g, b));
+    let max_age_for_color: u32 = 10u;
+    let intensity = 1.0 - f32(min(cell, max_age_for_color)) / f32(max_age_for_color);
+
+    let rgb = select(vec3(0., 0., 0.), spectral_bruton(intensity), cell > 0u);
+    return Out(vec4<f32>(x, y, 0., 1.), rgb);
 }
 
 @fragment
 fn fragment_main(@location(0) cell: vec3<f32>) -> @location(0) vec4<f32> {
     return vec4<f32>(cell, 1.0);
 }
+
+fn spectral_bruton(w: f32) -> vec3<f32> {
+    if w < 0.15 {
+        // return vec3<f32>(-(w - 0.15) / 0.15, 0.0, 1.0);
+        return vec3<f32>(0.0, 1.0, -(w - 0.325) / (0.325 - 0.275));
+    } else if w >= 0.15 && w < 0.275 {
+        //return vec3<f32>(0.0, (w - 0.15) / (0.275 - 0.15), 1.0);
+        return vec3<f32>(0.0, 1.0, -(w - 0.325) / (0.325 - 0.275));
+    } else if w >= 0.275 && w < 0.325 {
+        return vec3<f32>(0.0, 1.0, -(w - 0.325) / (0.325 - 0.275));
+    } else if w >= 0.325 && w < 0.5 {
+        return vec3<f32>((w - 0.325) / (0.5 - 0.325), 1.0, 0.0);
+    } else if w >= 0.5 && w < 0.6625 {
+        return vec3<f32>(1.0, -(w - 0.6625) / (0.6625 - 0.5), 0.0);
+    } else if w >= 0.6625 {
+        return vec3<f32>(1.0, 0.0, 0.0);
+    } else {
+        return vec3<f32>(0.0, 0.0, 0.0);
+    }
+}