let v; // variable

let vspeed; // speed variable

let xspeed;

let yspeed;

​

​

function setup() {

  createCanvas(400, 400);

  x = 0;

  y = 0;

  xspeed = 3;

  yspeed = 5;

}

​

function draw() {

  drawBackground();

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

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

  moveBall();

  drawBall();

}

​

function drawBackground() {

  background(220);

}

​

function drawBall() {

  ellipse(x, y, 20, 20);

}

​

function moveBall() {

  x += xspeed;

  y += yspeed;

}

​

function bounce(pos, mini, maxi, vspeed) {

  if (pos > maxi || pos < mini) {

    vspeed *= -1;

  }

  return vspeed

}

​