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