REVIEWED: example: Compute shader Game-of-life

examples/others/resources/shaders/glsl430/gol.glsl

@@ -0,0 +1,41 @@
+#version 430
+
+// Game of Life logic shader
+
+#define GOL_WIDTH 768
+
+layout (local_size_x = 16, local_size_y = 16, local_size_z = 1) in;
+
+layout(std430, binding = 1) readonly restrict buffer golLayout {
+    uint golBuffer[];       // golBuffer[x, y] = golBuffer[x + gl_NumWorkGroups.x * y]
+};
+
+layout(std430, binding = 2) writeonly restrict buffer golLayout2 {
+    uint golBufferDest[];   // golBufferDest[x, y] = golBufferDest[x + gl_NumWorkGroups.x * y]
+};
+
+#define fetchGol(x, y) ((((x) < 0) || ((y) < 0) || ((x) > GOL_WIDTH) || ((y) > GOL_WIDTH)) \
+    ? (0) \
+    : golBuffer[(x) + GOL_WIDTH * (y)])
+
+#define setGol(x, y, value) golBufferDest[(x) + GOL_WIDTH*(y)] = value
+
+void main()
+{
+    uint neighbourCount = 0;
+    uint x = gl_GlobalInvocationID.x;
+    uint y = gl_GlobalInvocationID.y;
+
+    neighbourCount += fetchGol(x - 1, y - 1);   // Top left
+    neighbourCount += fetchGol(x, y - 1);       // Top middle
+    neighbourCount += fetchGol(x + 1, y - 1);   // Top right
+    neighbourCount += fetchGol(x - 1, y);       // Left
+    neighbourCount += fetchGol(x + 1, y);       // Right
+    neighbourCount += fetchGol(x - 1, y + 1);   // Bottom left
+    neighbourCount += fetchGol(x, y + 1);       // Bottom middle   
+    neighbourCount += fetchGol(x + 1, y + 1);   // Bottom right
+
+    if (neighbourCount == 3) setGol(x, y, 1);
+    else if (neighbourCount == 2) setGol(x, y, fetchGol(x, y));
+    else setGol(x, y, 0);
+}