processing for animated gif

gistfile1.java

void setup() {
  size(500, 500);
  smooth(8);
  noStroke();
}

float t, tt, ht, x, y;
int N = 11;
float l = 24;
float sp = l*1.5;

void di(float q) {
  float qq = (4*q) % 1;
  pushMatrix();
  rotate(floor(4*q)*HALF_PI);
  rect(-l/2, -l/2, l/3, l*(1-2/3.0*qq));
  rect(-l/2, -l/2, l/3+l*2/3.0*qq, l/3);
  popMatrix();
}

void draw() {
  t = frameCount/80.0;

  background(250);
  pushMatrix();
  translate(width/2, height/2);
  rotate(QUARTER_PI);
  for (int i=-N; i<=N; i++) {
    for (int j=-N; j<=N; j++) {
      if ((i+j)%2 == 0)
        fill(64);
      else
        fill(32);
      x = (i+.5)*sp; 
      y = (j+.5)*sp;
      pushMatrix();
      translate(x, y);
      tt = t + 10 - atan2(x, y)/TWO_PI - 0.0012*dist(x, y, 0, 0);
      tt %= 1;
      di(tt);
      popMatrix();
    }
  }
  popMatrix();

  /*saveFrame("f##.png");
   if(frameCount==80)
   exit(); */
}