let x2, y2, x2speed, y2speed;

​

​

function setup() {

  createCanvas(400, 400);

  x1 = width / 2;

  y1 = height / 2;

  x1speed = 1;

  y1speed = 0.3;

​

  x2 = width / 2;

  y2 = height / 2;

  x2speed = 1.4;

  y2speed = -1.3;

​

}

​

function draw() {

  background(220);

  move();

  display();

​

}

​

function display() {

  ellipse(x1, y1, 50, 50);

  ellipse(x2, y2, 50, 50);

​

}

​

function move() {

  x1 += x1speed;

  y1 += y1speed;

​

  x2 += x2speed;

  y2 += y2speed;

​

  x1speed = bounce(x1, 0, width, x1speed);

  y1speed = bounce(y1, 0, height, y1speed);

​

  x2speed = bounce(x2, 0, width, x2speed);

  y2speed = bounce(y2, 0, height, y2speed);

​

​

}

​

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

  if (pos < low || pos > high) {

    speed *= -1;

    return speed;

  } else return speed;

}