// Daniel Shiffman

// http://natureofcode.com

​

// Example 1-1: Bouncing Ball, no vectors

let x = 100;

let y = 100;

let xspeed = 2.5;

let yspeed = 2;

​

function setup() {

  createCanvas(640, 360);

}

​

function draw() {

  background(51);

​

  // Add the current speed to the position.

  x = x + xspeed;

  y = y + yspeed;

​

  if ((x > width) || (x < 0)) {

    xspeed = xspeed * -1;

  }

  if ((y > height) || (y < 0)) {

    yspeed = yspeed * -1;

  }

​

  // Display circle at x position

  stroke(0);

  strokeWeight(2);

  fill(127);

  ellipse(x, y, 48, 48);

}