​

function setup() {

  createCanvas(400, 400);

  ball1 = {

    x: width / 2,

    y: height / 2,

    xspeed: 1,

    yspeed: 1.7

  }

​

  ball2 = {

    x: width / 2,

    y: height / 2,

    xspeed: 1.3,

    yspeed: -1.7

  }

}

​

function draw() {

  background(220);

  move();

  display();

​

}

​

function display() {

  ellipse(ball1.x, ball1.y, 50, 50);

  ellipse(ball2.x, ball2.y, 50, 50);

​

}

​

function move() {

  ball1.x += ball1.xspeed;

  ball2.y += ball2.yspeed;

​

  ball1.xspeed = bounce(ball1.x, 0, width, ball1.xspeed);

  ball1.yspeed = bounce(ball1.y, 0, height, ball1.yspeed);

​

  ball2.xspeed = bounce(ball2.x, 0, width, ball2.xspeed);

  ball2.yspeed = bounce(ball2.y, 0, height, ball2.yspeed);

​

​

}

​

function bounce(pos, low, high, speed) {

  if (pos < low || pos > high) {

    speed *= -1;

    return speed;

  } else return speed;

}