Starburst

  float cx,cy;
  int[] screenBuf;
  PImage[] frames;
  
  int cycleLength = 48;
  
  void setup()
  {
    size(500,500);
    loadPixels();
  
    cx = width/2;
    cy = height/2;
    frames = new PImage[cycleLength];
    frameRate(24);
  }
  
  void draw() 
  {
    if (frameCount <= cycleLength) {
      // Do slow computation, and save frame
      float t = frameCount*TWO_PI/cycleLength;
      int n = 0;
      for (int y = 0; y < height; ++y) {
        for (int x = 0; x < width; ++x) {
          float d = log(dist(x,y,cx,cy));
          float a = atan2(y-cy, x-cx);
          float r = sin(d*8+a) * sin(a*3);
          float g = sin(d*8+a-HALF_PI-t ) * sin(a*5);
          float b = sin(d*8+a+HALF_PI+t ) * sin(a*7);
          r = r*128+128;
          g = g*128+128;
          b = b*128+128;
    
          pixels[n] = color(r,g,b);
          n++;
        }
      }
      updatePixels();
      frames[frameCount % cycleLength] = get();
    }
    else {
      // Play back saved frame
      image(frames[frameCount % cycleLength],0,0);
    }  
  }