var q = 100;

var w= 100;

​

function setup() {

  createCanvas(400,400);

  background(0);

}

​

function draw() {

  fill(255);

  ellipse (x,10,20,20);

  x=x+1;

  //One element that changes over time, independently of the mouse.

  fill(255);

  noStroke();

  ellipse(mouseX,mouseY,10,10);

  //One element controlled by the mouse.

  q = random(0, width);

  w = random(0, height);

  noStroke();

  fill(144);

  ellipse(q, w, 10, 10);

  //One element that is different every time you run the sketch.

}

​