/******************************************************************************************* * * raylib [shaders] example - mandelbrot set * * Example complexity rating: [★★★☆] 3/4 * * NOTE: This example requires raylib OpenGL 3.3 or ES2 versions for shaders support, * OpenGL 1.1 does not support shaders, recompile raylib to OpenGL 3.3 version * * NOTE: Shaders used in this example are #version 330 (OpenGL 3.3) * * Example originally created with raylib 5.6, last time updated with raylib 5.6 * * Example contributed by Jordi Santonja (@JordSant) * Based on previous work by Josh Colclough (@joshcol9232) * * Example licensed under an unmodified zlib/libpng license, which is an OSI-certified, * BSD-like license that allows static linking with closed source software * * Copyright (c) 2025 Jordi Santonja (@JordSant) * ********************************************************************************************/ #include "raylib.h" #include #if defined(PLATFORM_DESKTOP) #define GLSL_VERSION 330 #else // PLATFORM_ANDROID, PLATFORM_WEB #define GLSL_VERSION 100 #endif // A few good interesting places const float pointsOfInterest[6][3] = { { -1.76826775f, -0.00422996283f, 28435.9238f }, { 0.322004497f, -0.0357099883f, 56499.7266f }, { -0.748880744f, -0.0562955774f, 9237.59082f }, { -1.78385007f, -0.0156200649f, 14599.5283f }, { -0.0985441282f, -0.924688697f, 26259.8535f }, { 0.317785531f, -0.0322612226f, 29297.9258f }, }; const int screenWidth = 800; const int screenHeight = 450; const float zoomSpeed = 1.01f; const float offsetSpeedMul = 2.0f; const float startingZoom = 0.6f; const float startingOffset[2] = { -0.5f, 0.0f }; //------------------------------------------------------------------------------------ // Program main entry point //------------------------------------------------------------------------------------ int main(void) { // Initialization //-------------------------------------------------------------------------------------- InitWindow(screenWidth, screenHeight, "raylib [shaders] example - mandelbrot set"); // Load mandelbrot set shader // NOTE: Defining 0 (NULL) for vertex shader forces usage of internal default vertex shader Shader shader = LoadShader(0, TextFormat("resources/shaders/glsl%i/mandelbrot_set.fs", GLSL_VERSION)); // Create a RenderTexture2D to be used for render to texture RenderTexture2D target = LoadRenderTexture(GetScreenWidth(), GetScreenHeight()); // Offset and zoom to draw the mandelbrot set at. (centered on screen and default size) float offset[2] = { startingOffset[0], startingOffset[1] }; float zoom = startingZoom; // Depending on the zoom the mximum number of iterations must be adapted to get more detail as we zzoom in // The solution is not perfect, so a control has been added to increase/decrease the number of iterations with UP/DOWN keys int maxIterations = 333; float maxIterationsMultiplier = 166.5f; // Get variable (uniform) locations on the shader to connect with the program // NOTE: If uniform variable could not be found in the shader, function returns -1 int zoomLoc = GetShaderLocation(shader, "zoom"); int offsetLoc = GetShaderLocation(shader, "offset"); int maxIterationsLoc = GetShaderLocation(shader, "maxIterations"); // Upload the shader uniform values! SetShaderValue(shader, zoomLoc, &zoom, SHADER_UNIFORM_FLOAT); SetShaderValue(shader, offsetLoc, offset, SHADER_UNIFORM_VEC2); SetShaderValue(shader, maxIterationsLoc, &maxIterations, SHADER_UNIFORM_INT); bool showControls = true; // Show controls SetTargetFPS(60); // Set our game to run at 60 frames-per-second //-------------------------------------------------------------------------------------- // Main game loop while (!WindowShouldClose()) // Detect window close button or ESC key { // Update //---------------------------------------------------------------------------------- bool updateShader = false; // Press [1 - 6] to reset c to a point of interest if (IsKeyPressed(KEY_ONE) || IsKeyPressed(KEY_TWO) || IsKeyPressed(KEY_THREE) || IsKeyPressed(KEY_FOUR) || IsKeyPressed(KEY_FIVE) || IsKeyPressed(KEY_SIX)) { int interestIndex = 0; if (IsKeyPressed(KEY_ONE)) interestIndex = 0; else if (IsKeyPressed(KEY_TWO)) interestIndex = 1; else if (IsKeyPressed(KEY_THREE)) interestIndex = 2; else if (IsKeyPressed(KEY_FOUR)) interestIndex = 3; else if (IsKeyPressed(KEY_FIVE)) interestIndex = 4; else if (IsKeyPressed(KEY_SIX)) interestIndex = 5; offset[0] = pointsOfInterest[interestIndex][0]; offset[1] = pointsOfInterest[interestIndex][1]; zoom = pointsOfInterest[interestIndex][2]; updateShader = true; } // If "R" is pressed, reset zoom and offset if (IsKeyPressed(KEY_R)) { offset[0] = startingOffset[0]; offset[1] = startingOffset[1]; zoom = startingZoom; updateShader = true; } if (IsKeyPressed(KEY_F1)) showControls = !showControls; // Toggle whether or not to show controls // Change number of max iterations with UP and DOWN keys // WARNING: Increasing the number of max iterations greatly impacts performance if (IsKeyPressed(KEY_UP)) { maxIterationsMultiplier *= 1.4f; updateShader = true; } else if (IsKeyPressed(KEY_DOWN)) { maxIterationsMultiplier /= 1.4f; updateShader = true; } // If either left or right button is pressed, zoom in/out if (IsMouseButtonDown(MOUSE_BUTTON_LEFT) || IsMouseButtonDown(MOUSE_BUTTON_RIGHT)) { // Change zoom. If Mouse left -> zoom in. Mouse right -> zoom out zoom *= IsMouseButtonDown(MOUSE_BUTTON_LEFT)? zoomSpeed : (1.0f/zoomSpeed); const Vector2 mousePos = GetMousePosition(); Vector2 offsetVelocity; // Find the velocity at which to change the camera. Take the distance of the mouse // From the center of the screen as the direction, and adjust magnitude based on the current zoom offsetVelocity.x = (mousePos.x/(float)screenWidth - 0.5f)*offsetSpeedMul/zoom; offsetVelocity.y = (mousePos.y/(float)screenHeight - 0.5f)*offsetSpeedMul/zoom; // Apply move velocity to camera offset[0] += GetFrameTime()*offsetVelocity.x; offset[1] += GetFrameTime()*offsetVelocity.y; updateShader = true; } // In case a parameter has been changed, update the shader values if (updateShader) { // As we zoom in, increase the number of max iterations to get more detail // Aproximate formula, but it works-ish maxIterations = (int)(sqrtf(2.0f*sqrtf(fabsf(1.0f - sqrtf(37.5f*zoom))))*maxIterationsMultiplier); // Update the shader uniform values! SetShaderValue(shader, zoomLoc, &zoom, SHADER_UNIFORM_FLOAT); SetShaderValue(shader, offsetLoc, offset, SHADER_UNIFORM_VEC2); SetShaderValue(shader, maxIterationsLoc, &maxIterations, SHADER_UNIFORM_INT); } //---------------------------------------------------------------------------------- // Draw //---------------------------------------------------------------------------------- // Using a render texture to draw Mandelbrot set BeginTextureMode(target); // Enable drawing to texture ClearBackground(BLACK); // Clear the render texture // Draw a rectangle in shader mode to be used as shader canvas // NOTE: Rectangle uses font white character texture coordinates, // So shader can not be applied here directly because input vertexTexCoord // Do not represent full screen coordinates (space where want to apply shader) DrawRectangle(0, 0, GetScreenWidth(), GetScreenHeight(), BLACK); EndTextureMode(); BeginDrawing(); ClearBackground(BLACK); // Clear screen background // Draw the saved texture and rendered mandelbrot set with shader // NOTE: We do not invert texture on Y, already considered inside shader BeginShaderMode(shader); // WARNING: If FLAG_WINDOW_HIGHDPI is enabled, HighDPI monitor scaling should be considered // When rendering the RenderTexture2D to fit in the HighDPI scaled Window DrawTextureEx(target.texture, (Vector2){ 0.0f, 0.0f }, 0.0f, 1.0f, WHITE); EndShaderMode(); if (showControls) { DrawText("Press Mouse buttons right/left to zoom in/out and move", 10, 15, 10, RAYWHITE); DrawText("Press F1 to toggle these controls", 10, 30, 10, RAYWHITE); DrawText("Press [1 - 6] to change point of interest", 10, 45, 10, RAYWHITE); DrawText("Press UP | DOWN to change number of iterations", 10, 60, 10, RAYWHITE); DrawText("Press R to recenter the camera", 10, 75, 10, RAYWHITE); } EndDrawing(); //---------------------------------------------------------------------------------- } // De-Initialization //-------------------------------------------------------------------------------------- UnloadShader(shader); // Unload shader UnloadRenderTexture(target); // Unload render texture CloseWindow(); // Close window and OpenGL context //-------------------------------------------------------------------------------------- return 0; }