/**
 * Moving Fractal Triangle Effect
 * by David Oxley.
 * 
 * Uses bitwise XOR to generate the fractal triangle pattern 
 * XOR copies and shifts pixels for scrolling effect
 */
 
// This will contain the pixels used to calculate the scrolling triangle effect
int[][] fire;

// Flame colors
color[] palette;
float angle;

void setup(){
  size(640, 480, P2D);

  frameRate(100);

  colorMode(HSB);

  fire = new int[width][height];
  palette = new color[255];

  // Generate the palette
  for(int x = 0; x < palette.length; x++) {
    //Hue goes from 0 to 85: red to yellow
    //Saturation is always the maximum: 255
    //Lightness is 0..255 for x=0..128, and 255 for x=128..255
    palette[x] = color(x/3, 255, constrain(x*3, 0, 255));
  }

}

void draw() {
  angle = angle + 0.05;

  // Rotating wireframe cube
  /*
  pg.beginDraw();
  pg.translate(width >> 1, height >> 1);
  pg.rotateX(sin(angle/2));
  pg.rotateY(cos(angle/2));
  pg.background(0);
  pg.stroke(128);
  pg.scale(25);
  pg.noFill();
  pg.box(4);
  pg.endDraw();
  */

  // Randomize the bottom row of the fire buffer
  /*
  for(int x = 0; x < width; x++)
  {
    fire[x][height-1] = int(random(0,190)) ;
  }
  */

  loadPixels();

  //fire[320+20+int(10*sin(angle/3))][height-2] = 100;
  //fire[320][height-2] = 120;
  fire[600+int(30*sin(angle/3)*cos(angle/5))][height-65+int(60*sin(angle/2)*cos(angle/4))] = 100;

  int counter = 0;
  for (int y = 1; y < height-2; y++) {
    for(int x = 0; x < width; x++) {
      if (x > 2 && y > 2 && x < width-2 && y < height-2) {
        //fire[x-1][y-1] = fire[x][y-1] ^= fire[x][y]; 
        fire[x-1][y-1] = fire[x][y]^fire[x][y-1]; 
        
        //fire[x-2][y-1] = fire[x-1][y] ^= fire[x][y]; 
        
        
        //fire[x+1][y-1] ^= fire[x][y]; 
        //fire[x-1][y-1] = fire[x][y-1];
      }

      pixels[counter] = palette[fire[x][y]];
      counter++;
    }
  }
  updatePixels();
}