/*******************************************************************************************
*
* raylib [shaders] example - Render julia sets using a shader.
*
* 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)
*
* Author: eggmund (https://github.com/eggmund)
*
********************************************************************************************/
#include "raylib.h"
#include <string.h> // For memcpy
// Speed when using auto
const float AUTO_SPEED = 0.0005;
// 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},
};
int main()
{
// Initialization
//--------------------------------------------------------------------------------------
int screenWidth = 1280;
int screenHeight = 720;
InitWindow(screenWidth, screenHeight, "raylib [shaders] example - julia set renderer");
// If julia set is rendered for this frame.
bool rendered = false;
bool showControls = true;
// Multiplier of speed to change c value. Set to 3 to start off with.
int incrementSpeed = 3;
// Offset and zoom to draw the julia set at. (centered on screen and 1.6 times smaller)
float offset[2] = { -(float)screenWidth/2, -(float)screenHeight/2 };
float zoom = 1.6;
// c constant to use in z^2 + c
float c[2];
// Copy a point of interest into the c variable. 4 bytes per float (32 bits).
memcpy(c, &POINTS_OF_INTEREST[0], 8);
// Load julia set shader
// NOTE: Defining 0 (NULL) for vertex shader forces usage of internal default vertex shader
Shader shader = LoadShader(0, "resources/shaders/glsl330/julia_shader.fs");
// Get variable (uniform) location on the shader to connect with the program
// NOTE: If uniform variable could not be found in the shader, function returns -1
// The location of c will be stored since we will need to change this whenever c changes
int cLoc = GetShaderLocation(shader, "c");
// 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, GetShaderLocation(shader, "zoom"), &zoom, UNIFORM_FLOAT);
SetShaderValue(shader, GetShaderLocation(shader, "offset"), offset, UNIFORM_VEC2);
SetShaderValue(shader, cLoc, c, UNIFORM_VEC2);
// Create a RenderTexture2D to be used for render to texture
RenderTexture2D target = LoadRenderTexture(screenWidth, screenHeight);
SetTargetFPS(60); // Set the window to run at 60 frames-per-second
//--------------------------------------------------------------------------------------
// Main game loop
while (!WindowShouldClose()) // Detect window close button or ESC key
{
// Update
//----------------------------------------------------------------------------------
// Get input
//----------------------------------------------------------------------------------
// Press 0 - 4 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))
{
memcpy(c, &POINTS_OF_INTEREST[0], 8);
}
else if (IsKeyPressed(KEY_TWO))
{
memcpy(c, &POINTS_OF_INTEREST[1], 8);
}
else if (IsKeyPressed(KEY_THREE))
{
memcpy(c, &POINTS_OF_INTEREST[2], 8);
}
else if (IsKeyPressed(KEY_FOUR))
{
memcpy(c, &POINTS_OF_INTEREST[3], 8);
}
else if (IsKeyPressed(KEY_FIVE))
{
memcpy(c, &POINTS_OF_INTEREST[4], 8);
}
else if (IsKeyPressed(KEY_SIX))
{
memcpy(c, &POINTS_OF_INTEREST[5], 8);
}
SetShaderValue(shader, cLoc, c, UNIFORM_VEC2);
rendered = false; // c value has changed, so render the set again.
}
// Press "r" to stop changing c
if (IsKeyPressed(KEY_R))
{
incrementSpeed = 0;
}
// Toggle whether or not to show controls
if (IsKeyPressed(KEY_H))
{
showControls = !showControls;
}
// Scroll to change c increment speed.
int mouseMv = GetMouseWheelMove(); // Get the amount the mouse has moved this frame
if (mouseMv != 0)
{
if (IsKeyDown(KEY_LEFT_SHIFT))
{
incrementSpeed += mouseMv * 10;
}
else
{
incrementSpeed += mouseMv;
}
rendered = false;
}
if (incrementSpeed != 0)
{
float amount = GetFrameTime() * incrementSpeed * AUTO_SPEED;
c[0] += amount;
c[1] += amount;
// Update the c value in the shader.
SetShaderValue(shader, cLoc, c, UNIFORM_VEC2);
rendered = false;
}
//----------------------------------------------------------------------------------
// Draw
//----------------------------------------------------------------------------------
BeginDrawing();
ClearBackground(BLACK); // Clear the screen of the previous frame.
// If the c value has changed, redraw the julia set using the shader, onto the render texture.
if (!rendered)
{
BeginTextureMode(target); // Enable drawing to texture
ClearBackground(BLACK); // Clear the last frame drawn on the texture.
// Draw a rectangle in shader mode. This acts as a canvas for the shader to draw on.
BeginShaderMode(shader);
DrawRectangle(0, 0, screenWidth, screenHeight, BLACK);
EndShaderMode();
EndTextureMode();
rendered = true; // The set is now rendered, so do not compute it again until it next changes.
}
// Draw the saved texture (rendered julia set).
DrawTextureRec(target.texture, (Rectangle){ 0, 0, target.texture.width, target.texture.height }, (Vector2){ 0, 0 }, WHITE);
// Print information.
DrawText( FormatText("cx: %f\ncy: %f\nspeed: %d", c[0], c[1], incrementSpeed), 10, 10, 20, RAYWHITE );
if (showControls)
{
DrawText("Press keys 1 - 6 to change point of interest.", 10, screenHeight - 88, 20, RAYWHITE);
DrawText("Use the scroll wheel to auto increment the c value. Hold shift while scrolling to increase speed by 10.", 10, screenHeight - 66, 20, RAYWHITE);
DrawText("Press 'r' to reset speed.", 10, screenHeight - 44, 20, RAYWHITE);
DrawText("Press 'h' to hide these controls.", 10, screenHeight - 22, 20, RAYWHITE);
}
EndDrawing();
//----------------------------------------------------------------------------------
}
// De-Initialization
//--------------------------------------------------------------------------------------
UnloadShader(shader); // Unload shader
UnloadRenderTexture(target); // Unload render texture
CloseWindow(); // Close window and OpenGL context
//--------------------------------------------------------------------------------------
return 0;
}