canofworms

int num=50, frames=120;
long rs;
float theta;

void setup() {
  size(750, 500);
  blendMode(DIFFERENCE);
  rs =(long) random(10000);
  //strokeCap(SQUARE);
  rectMode(CENTER);
}

void draw() {
  randomSeed(rs);
  background(0);
  for (int i=0; i<num; i++) {
    float x = width/2;
    float y = height/2;
    pushMatrix();
    translate(x,y);
    int speed=int(random(1,4));
    int dir=random(1)>.5?1:-1;
    rotate(theta*dir*speed);
    float w = random(width*.2, width*1.2);
    float h = w;
    float start = random(TWO_PI);
    float end = start + random(PI/4, PI/2);
    stroke(255);
    strokeWeight(random(20,100));
    noFill();
    arc(0, 0, w, h, start, end);
    popMatrix();
  }
  theta += TWO_PI/frames;
  //if (frameCount<=frames) saveFrame("image-###.gif");
}