void setup() {
  size(600, 600);
  background(120);
  smooth();
}


void draw() {
  float eSize = random(50);
  strokeWeight(random(5));  
  stroke(random(255));
  fill(random(255));
  ellipse(mouseX, mouseY, eSize, eSize);
}

void keyPressed(){
 // save frame
  if(keyPressed) {
    if (key == 's' || key == 'S') {
      saveFrame("image-####.png");
    }
  }
}