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Use npm Packages

We can make npm packages available for you to use in your JavaScript. We use webpack to prepare them and make them available to import. We'll also process your JavaScript with Babel.

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HTML Settings

Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

              <canvas id="canvas"></canvas>
              // here we are defining some global variables that we need access to in our whole program

let randomSize = () => {
  return Math.random() * (50 - 5) + 5;

let randomColor = () => {
 return '#'+Math.floor(Math.random()*16777215).toString(16);

// if you want to draw lots of circles you'll use this function
let drawCircle = (circle) => {
  ctx.fillStyle = circle.color; // set the color
  ctx.beginPath(); // telling canvas we're about to define a path.
  ctx.arc(circle.x, circle.y, circle.radius, 0, Math.PI*2, true); // x&y coordinates, the size, ..?, pi*2 for radius, true? defines we are drawing a cirlce. You can draw all sorts of curves with .arc
  ctx.fill(); // fill defines it's colored in, instead of just an outline or something like that.

// if you want to draw lots of rectangles you'll use this function
let drawRect = (rectangle) => {
  ctx.fillStyle = rectangle.color; // set the color
  ctx.fillRect(rectangle.x, rectangle.y, rectangle.width, rectangle.height);
}; // pass in x,y, width & height to fill in a rectangle with color

let c; // the canvas element on the page
let ctx; // the canvas context that we draw on
let ball = {
  color: '#FFF',
  x: 100,
  y: 100,
  radius: randomSize(),
  speedX: 10,
  speedY: 4
let background = {
  color: '#000',
  x: 0,
  y: 0
const fps = 60;

// this is boilerplate code that everyone uses to makes sure we're rending our code when the browser is ready which is supposed to help it run smoothly and efficiently
window.requestAnimFrame = (function(){
  return  window.requestAnimationFrame       ||
          window.webkitRequestAnimationFrame ||
          window.mozRequestAnimationFrame    ||
          function( callback ){
            window.setTimeout(callback, 1000 / fps);

// window.onload means once the browser is done loading and ready to start doing things, it's very common on every web project that runs javascript at all
window.onload = ()  => {
  c = document.getElementById('canvas');
  c.width = window.innerWidth;
  c.height = window.innerHeight;
  ctx = c.getContext('2d');
  background.width = c.width;
  background.height = c.height;
  animationLoop(); // run our animationLoop function

let animationLoop = () => {
  requestAnimFrame(animationLoop); // we run that boilerplate code which tells this to run 60 times a second
  render(); // run our function that defines all the drawing that's done every frame.

let render = () => {
  // all of your render code goes here
  ball.x += ball.speedX;
  ball.y += ball.speedY;
  if (ball.x >= c.width || ball.x <= 0) {
    ball.speedX = -ball.speedX;
    ball.color = randomColor();
    ball.radius = randomSize();
  if (ball.y >= c.height || ball.y <= 0) {
    ball.speedY = -ball.speedY;
    ball.color = randomColor();
    ball.radius = randomSize();
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