/*******************************************************************************************
*
* raylib [shaders] example - Julia sets
*
* 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 2.5, last time updated with raylib 4.0
*
* Example contributed by Josh Colclough (@joshcol9232) and reviewed by Ramon Santamaria (@raysan5)
*
* 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) 2019-2025 Josh Colclough (@joshcol9232) and Ramon Santamaria (@raysan5)
*
********************************************************************************************/
#include "raylib.h"
#if defined(PLATFORM_DESKTOP)
#define GLSL_VERSION 330
#else // PLATFORM_ANDROID, PLATFORM_WEB
#define GLSL_VERSION 100
#endif
// A few good julia sets
const float pointsOfInterest[6][2] =
{
{ -0.348827f, 0.607167f },
{ -0.786268f, 0.169728f },
{ -0.8f, 0.156f },
{ 0.285f, 0.0f },
{ -0.835f, -0.2321f },
{ -0.70176f, -0.3842f },
};
const int screenWidth = 800;
const int screenHeight = 450;
const float zoomSpeed = 1.01f;
const float offsetSpeedMul = 2.0f;
const float startingZoom = 0.75f;
//------------------------------------------------------------------------------------
// Program main entry point
//------------------------------------------------------------------------------------
int main(void)
{
// Initialization
//--------------------------------------------------------------------------------------
InitWindow(screenWidth, screenHeight, "raylib [shaders] example - julia sets");
// Load julia 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/julia_set.fs", GLSL_VERSION));
// Create a RenderTexture2D to be used for render to texture
RenderTexture2D target = LoadRenderTexture(GetScreenWidth(), GetScreenHeight());
// c constant to use in z^2 + c
float c[2] = { pointsOfInterest[0][0], pointsOfInterest[0][1] };
// Offset and zoom to draw the julia set at. (centered on screen and default size)
float offset[2] = { 0.0f, 0.0f };
float zoom = startingZoom;
// 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 cLoc = GetShaderLocation(shader, "c");
int zoomLoc = GetShaderLocation(shader, "zoom");
int offsetLoc = GetShaderLocation(shader, "offset");
// Upload the shader uniform values!
SetShaderValue(shader, cLoc, c, SHADER_UNIFORM_VEC2);
SetShaderValue(shader, zoomLoc, &zoom, SHADER_UNIFORM_FLOAT);
SetShaderValue(shader, offsetLoc, offset, SHADER_UNIFORM_VEC2);
int incrementSpeed = 0; // Multiplier of speed to change c value
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
//----------------------------------------------------------------------------------
// 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))
{
if (IsKeyPressed(KEY_ONE)) c[0] = pointsOfInterest[0][0], c[1] = pointsOfInterest[0][1];
else if (IsKeyPressed(KEY_TWO)) c[0] = pointsOfInterest[1][0], c[1] = pointsOfInterest[1][1];
else if (IsKeyPressed(KEY_THREE)) c[0] = pointsOfInterest[2][0], c[1] = pointsOfInterest[2][1];
else if (IsKeyPressed(KEY_FOUR)) c[0] = pointsOfInterest[3][0], c[1] = pointsOfInterest[3][1];
else if (IsKeyPressed(KEY_FIVE)) c[0] = pointsOfInterest[4][0], c[1] = pointsOfInterest[4][1];
else if (IsKeyPressed(KEY_SIX)) c[0] = pointsOfInterest[5][0], c[1] = pointsOfInterest[5][1];
SetShaderValue(shader, cLoc, c, SHADER_UNIFORM_VEC2);
}
// If "R" is pressed, reset zoom and offset.
if (IsKeyPressed(KEY_R))
{
zoom = startingZoom;
offset[0] = 0.0f;
offset[1] = 0.0f;
SetShaderValue(shader, zoomLoc, &zoom, SHADER_UNIFORM_FLOAT);
SetShaderValue(shader, offsetLoc, offset, SHADER_UNIFORM_VEC2);
}
if (IsKeyPressed(KEY_SPACE)) incrementSpeed = 0; // Pause animation (c change)
if (IsKeyPressed(KEY_F1)) showControls = !showControls; // Toggle whether or not to show controls
if (IsKeyPressed(KEY_RIGHT)) incrementSpeed++;
else if (IsKeyPressed(KEY_LEFT)) incrementSpeed--;
// 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;
// Update the shader uniform values!
SetShaderValue(shader, zoomLoc, &zoom, SHADER_UNIFORM_FLOAT);
SetShaderValue(shader, offsetLoc, offset, SHADER_UNIFORM_VEC2);
}
// Increment c value with time
const float dc = GetFrameTime()*(float)incrementSpeed*0.0005f;
c[0] += dc;
c[1] += dc;
SetShaderValue(shader, cLoc, c, SHADER_UNIFORM_VEC2);
//----------------------------------------------------------------------------------
// Draw
//----------------------------------------------------------------------------------
// Using a render texture to draw Julia 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 julia 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 KEY_F1 to toggle these controls", 10, 30, 10, RAYWHITE);
DrawText("Press KEYS [1 - 6] to change point of interest", 10, 45, 10, RAYWHITE);
DrawText("Press KEY_LEFT | KEY_RIGHT to change speed", 10, 60, 10, RAYWHITE);
DrawText("Press KEY_SPACE to stop movement animation", 10, 75, 10, RAYWHITE);
DrawText("Press KEY_R to recenter the camera", 10, 90, 10, RAYWHITE);
}
EndDrawing();
//----------------------------------------------------------------------------------
}
// De-Initialization
//--------------------------------------------------------------------------------------
UnloadShader(shader); // Unload shader
UnloadRenderTexture(target); // Unload render texture
CloseWindow(); // Close window and OpenGL context
//--------------------------------------------------------------------------------------
return 0;
}