path: root/examples/web/shaders/shaders_julia_set.c

/*******************************************************************************************
*
*   raylib [shaders] example - julia sets
*
*   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).
*
*   This example has been created using raylib 2.5 (www.raylib.com)
*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
*
*   Example contributed by eggmund (@eggmund) and reviewed by Ramon Santamaria (@raysan5)
*
*   Copyright (c) 2019 eggmund (@eggmund) and Ramon Santamaria (@raysan5)
*
********************************************************************************************/

#include "raylib.h"

#if defined(PLATFORM_WEB)
    #include <emscripten/emscripten.h>
#endif

#if defined(PLATFORM_DESKTOP)
    #define GLSL_VERSION            330
#else   // PLATFORM_RPI, PLATFORM_ANDROID, PLATFORM_WEB
    #define GLSL_VERSION            100
#endif

// A few good julia sets
const float POINTS_OF_INTEREST[6][2] =
{
    { -0.348827, 0.607167 },
    { -0.786268, 0.169728 },
    { -0.8, 0.156 },
    { 0.285, 0.0 },
    { -0.835, -0.2321 },
    { -0.70176, -0.3842 },
};

//----------------------------------------------------------------------------------
// Global Variables Definition
//----------------------------------------------------------------------------------
const int screenWidth = 800;
const int screenHeight = 450;

// NOTE: Textures MUST be loaded after Window initialization (OpenGL context is required)

RenderTexture2D target = { 0 };
Shader shader = { 0 };

float c[2] = { 0.0f, 0.0f };
float offset[2] = { 0.0f, 0.0f };

int cLoc = 0;
int zoomLoc = 0;
int offsetLoc = 0;

float zoom = 1.0f;
Vector2 offsetSpeed = { 0.0f, 0.0f };

int incrementSpeed = 0;     // Multiplier of speed to change c value
bool showControls = true;   // Show controls
static bool pause = false;         // Pause animation

//----------------------------------------------------------------------------------
// Module Functions Declaration
//----------------------------------------------------------------------------------
void UpdateDrawFrame(void);     // Update and Draw one frame

//----------------------------------------------------------------------------------
// 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 = LoadShader(0, TextFormat("resources/shaders/glsl%i/julia_set.fs", GLSL_VERSION));

    // c constant to use in z^2 + c
    c[0] = POINTS_OF_INTEREST[0][0];
    c[1] = POINTS_OF_INTEREST[0][1];

    // Offset and zoom to draw the julia set at. (centered on screen and default size)
    offset[0] = -(float)screenWidth/2;
    offset[1] = -(float)screenHeight/2;

    // 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
    cLoc = GetShaderLocation(shader, "c");
    zoomLoc = GetShaderLocation(shader, "zoom");
    offsetLoc = GetShaderLocation(shader, "offset");

    // Tell the shader what the screen dimensions, zoom, offset and c are
    float screenDims[2] = { (float)screenWidth, (float)screenHeight };
    SetShaderValue(shader, GetShaderLocation(shader, "screenDims"), screenDims, UNIFORM_VEC2);

    SetShaderValue(shader, cLoc, c, UNIFORM_VEC2);
    SetShaderValue(shader, zoomLoc, &zoom, UNIFORM_FLOAT);
    SetShaderValue(shader, offsetLoc, offset, UNIFORM_VEC2);

    // Create a RenderTexture2D to be used for render to texture
    target = LoadRenderTexture(screenWidth, screenHeight);

#if defined(PLATFORM_WEB)
    emscripten_set_main_loop(UpdateDrawFrame, 60, 1);
#else
    SetTargetFPS(60);               // Set our game to run at 60 frames-per-second
    //--------------------------------------------------------------------------------------

    // Main game loop
    while (!WindowShouldClose())    // Detect window close button or ESC key
    {
        UpdateDrawFrame();
    }
#endif

    // De-Initialization
    //--------------------------------------------------------------------------------------
    UnloadShader(shader);           // Unload shader
    UnloadRenderTexture(target);    // Unload render texture

    CloseWindow();                  // Close window and OpenGL context
    //--------------------------------------------------------------------------------------

    return 0;
}

//----------------------------------------------------------------------------------
// Module Functions Definition
//----------------------------------------------------------------------------------
void UpdateDrawFrame(void)
{
    // 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] = POINTS_OF_INTEREST[0][0], c[1] = POINTS_OF_INTEREST[0][1];
        else if (IsKeyPressed(KEY_TWO)) c[0] = POINTS_OF_INTEREST[1][0], c[1] = POINTS_OF_INTEREST[1][1];
        else if (IsKeyPressed(KEY_THREE)) c[0] = POINTS_OF_INTEREST[2][0], c[1] = POINTS_OF_INTEREST[2][1];
        else if (IsKeyPressed(KEY_FOUR)) c[0] = POINTS_OF_INTEREST[3][0], c[1] = POINTS_OF_INTEREST[3][1];
        else if (IsKeyPressed(KEY_FIVE)) c[0] = POINTS_OF_INTEREST[4][0], c[1] = POINTS_OF_INTEREST[4][1];
        else if (IsKeyPressed(KEY_SIX)) c[0] = POINTS_OF_INTEREST[5][0], c[1] = POINTS_OF_INTEREST[5][1];

        SetShaderValue(shader, cLoc, c, UNIFORM_VEC2);
    }

    if (IsKeyPressed(KEY_SPACE)) pause = !pause;                 // Pause animation (c change)
    if (IsKeyPressed(KEY_F1)) showControls = !showControls;  // Toggle whether or not to show controls

    if (!pause)
    {
        if (IsKeyPressed(KEY_RIGHT)) incrementSpeed++;
        else if (IsKeyPressed(KEY_LEFT)) incrementSpeed--;

        // TODO: The idea is to zoom and move around with mouse
        // Probably offset movement should be proportional to zoom level
        if (IsMouseButtonDown(MOUSE_LEFT_BUTTON) || IsMouseButtonDown(MOUSE_RIGHT_BUTTON))
        {
            if (IsMouseButtonDown(MOUSE_LEFT_BUTTON)) zoom += zoom*0.003f;
            if (IsMouseButtonDown(MOUSE_RIGHT_BUTTON)) zoom -= zoom*0.003f;

            Vector2 mousePos = GetMousePosition();

            offsetSpeed.x = mousePos.x -(float)screenWidth/2;
            offsetSpeed.y = mousePos.y -(float)screenHeight/2;

            // Slowly move camera to targetOffset
            offset[0] += GetFrameTime()*offsetSpeed.x*0.8f;
            offset[1] += GetFrameTime()*offsetSpeed.y*0.8f;
        }
        else offsetSpeed = (Vector2){ 0.0f, 0.0f };

        SetShaderValue(shader, zoomLoc, &zoom, UNIFORM_FLOAT);
        SetShaderValue(shader, offsetLoc, offset, UNIFORM_VEC2);

        // Increment c value with time
        float amount = GetFrameTime()*incrementSpeed*0.0005f;
        c[0] += amount;
        c[1] += amount;

        SetShaderValue(shader, cLoc, c, UNIFORM_VEC2);
    }
    //----------------------------------------------------------------------------------

    // Draw
    //----------------------------------------------------------------------------------
    BeginDrawing();

        ClearBackground(BLACK);         // Clear the screen of the previous frame.

        // 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();

        // Draw the saved texture and rendered julia set with shader
        // NOTE: We do not invert texture on Y, already considered inside shader
        BeginShaderMode(shader);
            DrawTexture(target.texture, 0, 0, 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 pause movement animation", 10, 75, 10, RAYWHITE);
        }

    EndDrawing();
    //----------------------------------------------------------------------------------
}