Add Conway's Game of Life compute shader example.

examples/Makefile

@@ -489,7 +489,8 @@ SHADERS = \
     shaders/shaders_spotlight \
     shaders/shaders_hot_reloading \
     shaders/shaders_mesh_instancing \
-    shaders/shaders_multi_sample2d
+    shaders/shaders_multi_sample2d \
+    shaders/shaders_compute_gol
 
 AUDIO = \
     audio/audio_module_playing \

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

@@ -0,0 +1,58 @@
+// Game of Life logic shader
+#version 430
+
+#define GOL_WIDTH 768
+
+layout (local_size_x = 16, local_size_y = 16, local_size_x = 1) in;
+
+layout(std430, binding = 1) readonly restrict buffer golLayout {
+  uint golBuffer[]; // golBuffer[x, y] = golBuffer[x + gl_NumWorkGroups.x * y]
+};
+
+layout(std430, set = 1, 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 neighbour_count = 0;
+  uint x = gl_GlobalInvocationID.x;
+  uint y = gl_GlobalInvocationID.y;
+
+  // Top left
+  neighbour_count += fetchGol(x - 1, y - 1);
+  
+  // Top middle
+  neighbour_count += fetchGol(x, y - 1);
+  
+  // Top right
+  neighbour_count += fetchGol(x + 1, y - 1);
+  
+  // Left
+  neighbour_count += fetchGol(x - 1, y);
+
+  // Right
+  neighbour_count += fetchGol(x + 1, y);
+  
+  // Bottom left
+  neighbour_count += fetchGol(x - 1, y + 1);
+  
+  // Bottom middle
+  neighbour_count += fetchGol(x, y + 1);
+  
+  // Bottom right
+  neighbour_count += fetchGol(x + 1, y + 1);
+
+  if (neighbour_count == 3)
+    setGol(x, y, 1);
+  else if (neighbour_count == 2)
+    setGol(x, y, fetchGol(x, y));
+  else
+    setGol(x, y, 0);
+}

examples/shaders/resources/shaders/glsl430/golRender.glsl

@@ -0,0 +1,24 @@
+// Game of Life rendering shader
+// Just renders the content of the ssbo at binding 1 to screen.
+#version 430
+
+#define GOL_WIDTH 768
+
+out vec4 finalColor;
+in vec2 fragTexCoord;
+
+layout(std430, binding = 1) readonly buffer golLayout {
+  uint golBuffer[];
+};
+
+uniform vec2 res;
+
+void main()
+{
+  ivec2 coords = ivec2(fragTexCoord * res);
+
+  if (golBuffer[coords.x + coords.y * uvec2(res).x] == 1)
+    finalColor = vec4(1.0);
+  else
+    finalColor = vec4(0.0, 0.0, 0.0, 1.0);
+}

examples/shaders/resources/shaders/glsl430/golTransfert.glsl

@@ -0,0 +1,42 @@
+// Game of life transfert shader.
+#version 430
+#define GOL_WIDTH 768
+
+struct GolUpdateCmd {
+  uint x; // x coordinate of the gol command
+  uint y; // y coordinate of the gol command
+  uint w; // width of the filled zone
+  uint enabled; // whether to enable or disable zone
+};
+
+layout (local_size_x = 1, local_size_y = 1, local_size_x = 1) in;
+
+layout(std430, binding = 1) writeonly restrict buffer golBufferLayout {
+  uint golBuffer[]; // golBuffer[x, y] = golBuffer[x + GOL_WIDTH * y]
+};
+
+layout(std430, binding = 3) readonly restrict buffer golUpdateLayout {
+  uint count;
+  GolUpdateCmd commands[];
+};
+
+#define isInside(x, y) (((x) >= 0) && ((y) >= 0) && ((x) < GOL_WIDTH) && ((y) < GOL_WIDTH))
+#define getBufferIndex(x, y) ((x) + GOL_WIDTH * (y))
+
+void main()
+{
+  uint cmd_index = gl_GlobalInvocationID.x;
+  struct GolUpdateCmd cmd = commands[cmd_index];
+
+  for (uint x = cmd.x; x < (cmd.x + cmd.w); x++) {
+    for (uint y = cmd.y; y < (cmd.y + cmd.w); y++) {
+      if (isInside(x, y)) {
+        if (cmd.enabled != 0) {
+          atomicOr(golBuffer[getBufferIndex(x, y)], 1);
+        } else {
+          atomicAnd(golBuffer[getBufferIndex(x, y)], 0);
+        }
+      }
+    }
+  }
+}

examples/shaders/shaders_compute_gol.c

@@ -0,0 +1,147 @@
+/*******************************************************************************************
+*
+*   raylib [shaders] example - Compute shaders Conway's Game of Life
+*
+*   NOTE: This example requires raylib OpenGL 4.3 versions for compute shaders support,
+*
+*   NOTE: Shaders used in this example are #version 430 (OpenGL 4.3).
+*
+*   This example has been created using raylib 4.0 (www.raylib.com)
+*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
+*
+*   Example contributed by Teddy Astie (@tsnake41)
+*
+*   Copyright (c) 2021 Teddy Astie (@tsnake41)
+*
+********************************************************************************************/
+
+#include <stdint.h>
+
+#include "raylib.h"
+#include "rlgl.h"
+
+// IMPORTANT: This must match gol*.glsl GOL_WIDTH constant.
+//            This must be a multiple of 16 (check golLogic compute dispatch).
+#define GOL_WIDTH 768
+
+#define SSBO_SIZE (sizeof(unsigned int) * GOL_WIDTH * GOL_WIDTH)
+
+// Maximum amount of queued draw commands (squares draw from mouse down events).
+#define MAX_BUFFERED_TRANSFERTS 128
+
+struct GolUpdateCmd {
+  unsigned int x; // x coordinate of the gol command
+  unsigned int y; // y coordinate of the gol command
+  unsigned int w; // width of the filled zone
+  unsigned int enabled; // whether to enable or disable zone
+};
+
+struct GolUpdateSSBO {
+  unsigned int count;
+  struct GolUpdateCmd commands[MAX_BUFFERED_TRANSFERTS];
+};
+
+int main(void)
+{
+  InitWindow(GOL_WIDTH, GOL_WIDTH, "raylib [shaders] example - compute shader gol");
+
+  const Vector2 resolution = { GOL_WIDTH, GOL_WIDTH };
+  unsigned int brush_size = 1;
+
+  // Game of Life logic compute shader
+  char *golLogicCode = LoadFileText("resources/shaders/glsl430/gol.glsl");
+  unsigned int golLogicShader = rlCompileShader(golLogicCode, RL_COMPUTE_SHADER);
+  unsigned int golLogicProgram = rlLoadComputeShaderProgram(golLogicShader);
+  MemFree(golLogicCode);
+
+  // Game of Life logic compute shader
+  Shader golRenderShader = LoadShader(NULL, "resources/shaders/glsl430/golRender.glsl");
+  int resUniformLoc = GetShaderLocation(golRenderShader, "res");
+
+  // Game of Life transfert shader
+  char *golTransfertCode = LoadFileText("resources/shaders/glsl430/golTransfert.glsl");
+  unsigned int golTransfertShader = rlCompileShader(golTransfertCode, RL_COMPUTE_SHADER);
+  unsigned int golTransfertProgram = rlLoadComputeShaderProgram(golTransfertShader);
+  MemFree(golTransfertCode);
+
+  // SSBOs
+  unsigned int ssboA = rlLoadShaderBuffer(SSBO_SIZE, NULL, RL_DYNAMIC_COPY);
+  unsigned int ssboB = rlLoadShaderBuffer(SSBO_SIZE, NULL, RL_DYNAMIC_COPY);
+
+  struct GolUpdateSSBO transfertBuffer;
+  transfertBuffer.count = 0;
+
+  int transfertSSBO = rlLoadShaderBuffer(sizeof(struct GolUpdateSSBO), NULL, RL_DYNAMIC_COPY);
+
+  Image whiteImage = GenImageColor(GOL_WIDTH, GOL_WIDTH, WHITE);
+  Texture whiteTex = LoadTextureFromImage(whiteImage);
+  UnloadImage(whiteImage);
+
+  while (!WindowShouldClose()) {
+    if (IsKeyPressed(KEY_UP))
+      brush_size *= 2;
+    else if (IsKeyPressed(KEY_DOWN) && brush_size != 1)
+      brush_size /= 2;
+
+    if ((IsMouseButtonDown(MOUSE_BUTTON_LEFT) || IsMouseButtonDown(MOUSE_BUTTON_RIGHT))
+      && transfertBuffer.count < MAX_BUFFERED_TRANSFERTS) {
+      // Buffer a new command
+      transfertBuffer.commands[transfertBuffer.count].x = GetMouseX();
+      transfertBuffer.commands[transfertBuffer.count].y = GetMouseY();
+      transfertBuffer.commands[transfertBuffer.count].w = brush_size;
+      transfertBuffer.commands[transfertBuffer.count].enabled = IsMouseButtonDown(MOUSE_BUTTON_LEFT);
+      transfertBuffer.count++;
+    } else if (transfertBuffer.count > 0) {
+      // Process transfert buffer
+
+      // Send SSBO buffer to GPU
+      rlUpdateShaderBufferElements(transfertSSBO, &transfertBuffer, sizeof(struct GolUpdateSSBO), 0);
+      // Process ssbo command
+      rlEnableShader(golTransfertProgram);
+      rlBindShaderBuffer(ssboA, 1);
+      rlBindShaderBuffer(transfertSSBO, 3);
+      rlComputeShaderDispatch(transfertBuffer.count, 1, 1); // each GPU unit will process a command
+      rlDisableShader();
+
+      transfertBuffer.count = 0;
+    } else {
+      // Process game of life logic
+      rlEnableShader(golLogicProgram);
+      rlBindShaderBuffer(ssboA, 1);
+      rlBindShaderBuffer(ssboB, 2);
+      rlComputeShaderDispatch(GOL_WIDTH / 16, GOL_WIDTH / 16, 1);
+      rlDisableShader();
+
+      // ssboA <-> ssboB
+      int temp = ssboA;
+      ssboA = ssboB;
+      ssboB = temp;
+    }
+
+    rlBindShaderBuffer(ssboA, 1);
+
+    BeginDrawing();
+
+    ClearBackground(BLANK);
+    SetShaderValue(golRenderShader, resUniformLoc, &resolution, SHADER_UNIFORM_VEC2);
+
+    BeginShaderMode(golRenderShader);
+    DrawTexture(whiteTex, 0, 0, WHITE);
+    EndShaderMode();
+
+    DrawFPS(0, 0);
+
+    EndDrawing();
+  }
+
+  rlUnloadShaderBuffer(ssboA);
+  rlUnloadShaderBuffer(ssboB);
+  rlUnloadShaderBuffer(transfertSSBO);
+  rlUnloadShaderProgram(golTransfertProgram);
+  rlUnloadShaderProgram(golLogicProgram);
+
+  UnloadTexture(whiteTex);
+  UnloadShader(golRenderShader);
+
+  CloseWindow();
+}