REVIEWED: example: Compute shader Game-of-life

4 files changed, 294 insertions, 0 deletions

diff --git a/examples/others/resources/shaders/glsl430/gol.glsl b/examples/others/resources/shaders/glsl430/gol.glsl
new file mode 100644
index 00000000..c5dfe06b
--- /dev/null
+++ b/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);
+}
diff --git a/examples/others/resources/shaders/glsl430/gol_render.glsl b/examples/others/resources/shaders/glsl430/gol_render.glsl
new file mode 100644
index 00000000..97a1e99e
--- /dev/null
+++ b/examples/others/resources/shaders/glsl430/gol_render.glsl
@@ -0,0 +1,29 @@
+#version 430
+
+// Game of Life rendering shader
+// Just renders the content of the ssbo at binding 1 to screen
+
+#define GOL_WIDTH 768
+
+// Input vertex attributes (from vertex shader)
+in vec2 fragTexCoord;
+
+// Output fragment color
+out vec4 finalColor;
+
+// Input game of life grid.
+layout(std430, binding = 1) readonly buffer golLayout
+{
+    uint golBuffer[];
+};
+
+// Output resolution
+uniform vec2 resolution;
+
+void main()
+{
+    ivec2 coords = ivec2(fragTexCoord*resolution);
+
+    if ((golBuffer[coords.x + coords.y*uvec2(resolution).x]) == 1) finalColor = vec4(1.0);
+    else finalColor = vec4(0.0, 0.0, 0.0, 1.0);
+}
diff --git a/examples/others/resources/shaders/glsl430/gol_transfert.glsl b/examples/others/resources/shaders/glsl430/gol_transfert.glsl
new file mode 100644
index 00000000..a202338b
--- /dev/null
+++ b/examples/others/resources/shaders/glsl430/gol_transfert.glsl
@@ -0,0 +1,51 @@
+#version 430
+
+// Game of life transfert shader
+
+#define GOL_WIDTH 768
+
+// Game Of Life Update Command
+// NOTE: matches the structure defined on main program
+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
+};
+
+// Local compute unit size
+layout (local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+
+// Output game of life grid buffer
+layout(std430, binding = 1) buffer golBufferLayout
+{
+    uint golBuffer[]; // golBuffer[x, y] = golBuffer[x + GOL_WIDTH * y]
+};
+
+// Command buffer
+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 cmdIndex = gl_GlobalInvocationID.x;
+    GolUpdateCmd cmd = commands[cmdIndex];
+
+    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);
+            }
+        }
+    }
+}
diff --git a/examples/others/rlgl_compute_shader.c b/examples/others/rlgl_compute_shader.c
new file mode 100644
index 00000000..abc58934
--- /dev/null
+++ b/examples/others/rlgl_compute_shader.c
@@ -0,0 +1,173 @@
+/*******************************************************************************************
+*
+*   raylib [rlgl] example - compute shader - Conway's Game of Life
+*
+*   NOTE: This example requires raylib OpenGL 4.3 versions for compute shaders support,
+*         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) and reviewed by Ramon Santamaria (@raysan5)
+*
+*   Copyright (c) 2021 Teddy Astie (@tsnake41)
+*
+********************************************************************************************/
+
+#include "raylib.h"
+#include "rlgl.h"
+
+#include <stdlib.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
+
+// Maximum amount of queued draw commands (squares draw from mouse down events).
+#define MAX_BUFFERED_TRANSFERTS 48
+
+// Game Of Life Update Command
+typedef 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
+} GolUpdateCmd;
+
+// Game Of Life Update Commands SSBO
+typedef struct GolUpdateSSBO {
+    unsigned int count;
+    GolUpdateCmd commands[MAX_BUFFERED_TRANSFERTS];
+} GolUpdateSSBO;
+
+int main(void)
+{
+    // Initialization
+    //--------------------------------------------------------------------------------------
+    InitWindow(GOL_WIDTH, GOL_WIDTH, "raylib [rlgl] example - compute shader - game of life");
+
+    const Vector2 resolution = { GOL_WIDTH, GOL_WIDTH };
+    unsigned int brushSize = 8;
+
+    // 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);
+    UnloadFileText(golLogicCode);
+
+    // Game of Life logic compute shader
+    Shader golRenderShader = LoadShader(NULL, "resources/shaders/glsl430/gol_render.glsl");
+    int resUniformLoc = GetShaderLocation(golRenderShader, "resolution");
+
+    // Game of Life transfert shader
+    char *golTransfertCode = LoadFileText("resources/shaders/glsl430/gol_transfert.glsl");
+    unsigned int golTransfertShader = rlCompileShader(golTransfertCode, RL_COMPUTE_SHADER);
+    unsigned int golTransfertProgram = rlLoadComputeShaderProgram(golTransfertShader);
+    UnloadFileText(golTransfertCode);
+
+    // SSBOs
+    unsigned int ssboA = rlLoadShaderBuffer(GOL_WIDTH*GOL_WIDTH*sizeof(unsigned int), NULL, RL_DYNAMIC_COPY);
+    unsigned int ssboB = rlLoadShaderBuffer(GOL_WIDTH*GOL_WIDTH*sizeof(unsigned int), NULL, RL_DYNAMIC_COPY);
+
+    struct GolUpdateSSBO transfertBuffer;
+    transfertBuffer.count = 0;
+
+    int transfertSSBO = rlLoadShaderBuffer(sizeof(struct GolUpdateSSBO), NULL, RL_DYNAMIC_COPY);
+
+    // Create a white texture of the size of the window to update 
+    // each pixel of the window using the fragment shader
+    Image whiteImage = GenImageColor(GOL_WIDTH, GOL_WIDTH, WHITE);
+    Texture whiteTex = LoadTextureFromImage(whiteImage);
+    UnloadImage(whiteImage);
+    //--------------------------------------------------------------------------------------
+
+    // Main game loop
+    while (!WindowShouldClose())
+    {
+        // Update
+        //----------------------------------------------------------------------------------
+        brushSize += (int)GetMouseWheelMove();
+
+        if ((IsMouseButtonDown(MOUSE_BUTTON_LEFT) || IsMouseButtonDown(MOUSE_BUTTON_RIGHT))
+            && (transfertBuffer.count < MAX_BUFFERED_TRANSFERTS))
+        {
+            // Buffer a new command
+            transfertBuffer.commands[transfertBuffer.count].x = GetMouseX() - brushSize/2;
+            transfertBuffer.commands[transfertBuffer.count].y = GetMouseY() - brushSize/2;
+            transfertBuffer.commands[transfertBuffer.count].w = brushSize;
+            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);
+        SetShaderValue(golRenderShader, resUniformLoc, &resolution, SHADER_UNIFORM_VEC2);
+        //----------------------------------------------------------------------------------
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        BeginDrawing();
+
+            ClearBackground(BLANK);
+
+            BeginShaderMode(golRenderShader);
+                DrawTexture(whiteTex, 0, 0, WHITE);
+            EndShaderMode();
+            
+            DrawRectangleLines(GetMouseX() - brushSize/2, GetMouseY() - brushSize/2, brushSize, brushSize, RED);
+
+            DrawText("Use Mouse wheel to increase/decrease brush size", 10, 10, 20, WHITE);
+            DrawFPS(GetScreenWidth() - 100, 10);
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    // De-Initialization
+    //--------------------------------------------------------------------------------------
+    // Unload shader buffers objects.
+    rlUnloadShaderBuffer(ssboA);
+    rlUnloadShaderBuffer(ssboB);
+    rlUnloadShaderBuffer(transfertSSBO);
+
+    // Unload compute shader programs
+    rlUnloadShaderProgram(golTransfertProgram);
+    rlUnloadShaderProgram(golLogicProgram);
+
+    UnloadTexture(whiteTex);            // Unload white texture
+    UnloadShader(golRenderShader);      // Unload rendering fragment shader
+
+    CloseWindow();                      // Close window and OpenGL context
+    //--------------------------------------------------------------------------------------
+
+    return 0;
+}