raylib/examples/shaders/shaders_julia_set.c
2019-05-15 12:53:13 +02:00

183 lines
8.0 KiB
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"
// 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
//--------------------------------------------------------------------------------------
const int screenWidth = 800;
const int screenHeight = 450;
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, "resources/shaders/glsl330/julia_shader.fs");
// c constant to use in z^2 + c
float c[2] = { POINTS_OF_INTEREST[0][0], POINTS_OF_INTEREST[0][1] };
// 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 targetOffset[2] = { offset[0], offset[1] };
float zoom = 1.6f;
// 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");
// 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
RenderTexture2D target = LoadRenderTexture(screenWidth, screenHeight);
int incrementSpeed = 3; // Multiplier of speed to change c value
bool showControls = true; // Show controls
bool pause = false; // Pause animation
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
//----------------------------------------------------------------------------------
// 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_P)) pause = !pause; // Pause animation (c change)
if (IsKeyPressed(KEY_F1)) showControls = !showControls; // Toggle whether or not to show controls
if (!pause)
{
if (IsKeyDown(KEY_RIGHT)) incrementSpeed++;
else if (IsKeyDown(KEY_LEFT)) incrementSpeed--;
// Use mouse button to change offset
if (IsMouseButtonDown(MOUSE_LEFT_BUTTON))
{
if (IsKeyDown(KEY_LEFT_SHIFT)) zoom -= 0.002f;
else zoom += 0.002f;
// TODO: Logic is not correct, the idea is getting zoom focus to pointed area
Vector2 mousePos = GetMousePosition();
targetOffset[0] = mousePos.x -(float)screenWidth;
targetOffset[1] = mousePos.y -(float)screenHeight;
}
// Slowly move camera to targetOffset
offset[0] += GetFrameTime()*2.0f*(targetOffset[0] - offset[0]);
offset[1] += GetFrameTime()*2.0f*(targetOffset[1] - offset[1]);
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
// NOTE: This acts as a canvas for the shader to draw on
BeginShaderMode(shader);
DrawRectangle(0, 0, GetScreenWidth(), GetScreenHeight(), BLACK);
EndShaderMode();
EndTextureMode();
// Draw the saved texture (rendered julia set)
DrawTextureRec(target.texture, (Rectangle){ 0, 0, target.texture.width, -target.texture.height }, (Vector2){ 0.0f, 0.0f }, WHITE);
// Draw information
//DrawText( FormatText("cx: %f\ncy: %f\nspeed: %d", c[0], c[1], incrementSpeed), 10, 10, 10, RAYWHITE);
if (showControls)
{
DrawText("Press keys [1 - 6] to change point of interest", 10, GetScreenHeight() - 60, 10, RAYWHITE);
DrawText("Press KEY_LEFT | KEY_RIGHT to change speed", 10, GetScreenHeight() - 45, 10, RAYWHITE);
DrawText("Press KEY_P to pause movement animation", 10, GetScreenHeight() - 30, 10, RAYWHITE);
DrawText("Press KEY_F1 to toggle these controls", 10, GetScreenHeight() - 15, 10, RAYWHITE);
}
EndDrawing();
//----------------------------------------------------------------------------------
}
// De-Initialization
//--------------------------------------------------------------------------------------
UnloadShader(shader); // Unload shader
UnloadRenderTexture(target); // Unload render texture
CloseWindow(); // Close window and OpenGL context
//--------------------------------------------------------------------------------------
return 0;
}