Add fireworks effects (from anime.js) to a reveal.js slideshow

fireworks.js

// Source https://codepen.io/juliangarnier/pen/gmOwJX
// (C) Julian Garnier
// Adapted by Lilian Besson (Naereen) https://github.com/Naereen
// to add a fireworks effect on a reveal.js slideshows

var canvasEl = document.querySelector('.fireworks');
var ctx = canvasEl.getContext('2d');
var numberOfParticules = 40;
var pointerX = 0;
var pointerY = 0;
var tap = ('ontouchstart' in window || navigator.msMaxTouchPoints) ? 'touchstart' : 'mousedown';
var colors = ['#FF1461', '#18FF92', '#5A87FF', '#FBF38C'];

function setCanvasSize() {
  canvasEl.width = window.innerWidth * 2;
  canvasEl.height = window.innerHeight * 2;
  canvasEl.style.width = window.innerWidth + 'px';
  canvasEl.style.height = window.innerHeight + 'px';
  canvasEl.getContext('2d').scale(2, 2);
}

function updateCoords(e) {
  pointerX = e.clientX || e.touches[0].clientX;
  pointerY = e.clientY || e.touches[0].clientY;
}

function setParticuleDirection(p) {
  var angle = anime.random(0, 360) * Math.PI / 180;
  var value = anime.random(50, 180);
  var radius = [-1, 1][anime.random(0, 1)] * value;
  return {
    x: p.x + radius * Math.cos(angle),
    y: p.y + radius * Math.sin(angle)
  }
}

function createParticule(x,y) {
  var p = {};
  p.x = x;
  p.y = y;
  p.color = colors[anime.random(0, colors.length - 1)];
  p.radius = anime.random(16, 32);
  p.endPos = setParticuleDirection(p);
  p.draw = function() {
    ctx.beginPath();
    ctx.arc(p.x, p.y, p.radius, 0, 2 * Math.PI, true);
    ctx.fillStyle = p.color;
    ctx.fill();
  }
  return p;
}

function createCircle(x,y) {
  var p = {};
  p.x = x;
  p.y = y;
  p.color = '#FFF';
  p.radius = 0.1;
  p.alpha = .5;
  p.lineWidth = 6;
  p.draw = function() {
    ctx.globalAlpha = p.alpha;
    ctx.beginPath();
    ctx.arc(p.x, p.y, p.radius, 0, 2 * Math.PI, true);
    ctx.lineWidth = p.lineWidth;
    ctx.strokeStyle = p.color;
    ctx.stroke();
    ctx.globalAlpha = 1;
  }
  return p;
}

function renderParticule(anim) {
  for (var i = 0; i < anim.animatables.length; i++) {
    anim.animatables[i].target.draw();
  }
}

function animateParticules(x, y) {
  var circle = createCircle(x, y);
  var particules = [];
  for (var i = 0; i < numberOfParticules; i++) {
    particules.push(createParticule(x, y));
  }
  anime.timeline().add({
    targets: particules,
    x: function(p) { return p.endPos.x; },
    y: function(p) { return p.endPos.y; },
    radius: 0.1,
    duration: anime.random(1200, 1800),
    easing: 'easeOutExpo',
    update: renderParticule
  })
    .add({
    targets: circle,
    radius: anime.random(120, 460),
    lineWidth: 0,
    alpha: {
      value: 0,
      easing: 'linear',
      duration: anime.random(600, 800),  
    },
    duration: anime.random(1200, 1800),
    easing: 'easeOutExpo',
    update: renderParticule,
    offset: 0
  });
}

var render = anime({
  duration: Infinity,
  update: function() {
    ctx.clearRect(0, 0, canvasEl.width, canvasEl.height);
  }
});

var isEnabled = true;

// document.querySelector( '.reveal .slides' ).addEventListener(tap, function(e) {
document.addEventListener(tap, function(e) {
  if (isEnabled && !Reveal.isOverview()) {
    render.play();
    updateCoords(e);
    animateParticules(pointerX, pointerY);
  }
}, false);

// From https://stackoverflow.com/a/442474/
function getOffset( el ) {
    var _x = 0;
    var _y = 0;
    while( el && !isNaN( el.offsetLeft ) && !isNaN( el.offsetTop ) ) {
        _x += el.offsetLeft - el.scrollLeft;
        _y += el.offsetTop - el.scrollTop;
        el = el.offsetParent;
    }
    return { top: _y, left: _x };
    // return (_y, _x);
}

// Add the fireworks effect to all slide change
function handleReady() {

    Reveal.addEventListener( 'slidechanged', function( event ) {
        // event.previousSlide, event.currentSlide, event.indexh, event.indexv
        if (!Reveal.isOverview()) {
            render.play();
            var offsets = getOffset( document.querySelector( 'aside.controls' ) );
            // console.log("offsets = ", offsets);
            animateParticules(offsets.left - 60, offsets.top - 20);
        }
    } );

	Reveal.addEventListener( 'overviewshown', function() { isEnabled = false; } );
	Reveal.addEventListener( 'overviewhidden', function() { isEnabled = true; } );
}

if (Reveal.isReady()) {
  handleReady();
} else {
  Reveal.addEventListener('ready', () => handleReady());
}

var centerX = window.innerWidth / 2;
var centerY = window.innerHeight / 2;

setCanvasSize();
window.addEventListener('resize', setCanvasSize, false);

slide.html

<!doctype html>
<html>
	<head>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
		<meta name="author" content="Lilian Besson (@Naereen)">

		<title>fireworks.js for reveal.js demo</title>

		<link type="text/css" rel="stylesheet" href="css/reveal.css">
		<link type="text/css" rel="stylesheet" href="css/theme/moon.css" id="theme">

		<!-- Theme used for syntax highlighting of code -->
		<link type="text/css" rel="stylesheet" href="lib/css/zenburn.css">

		<!-- Printing and PDF exports -->
		<script type="text/javascript">
			var link = document.createElement( "link" );
			link.rel = "stylesheet";
			link.type = "text/css";
			link.href = window.location.search.match( /print-pdf/gi ) ? "css/print/pdf.css" : "css/print/paper.css";
			document.getElementsByTagName( "head" )[0].appendChild( link );
		</script>
	</head>
	<body>
		<div class="reveal">
			<div class="slides">
				<section>
<h1>reveal.js slideshow</h1>
With fireworks effect.
				</section>
				<section>
Each click event trigger a nice fireworks effect.
				</section>
				<section>
But what is really awesome is the fireworks triggered by every slide change!.
				</section>
				<canvas class="fireworks"></canvas>		
			</div>
		</div>

		<script type="text/javascript" src="lib/js/head.min.js"></script>
		<script type="text/javascript" src="js/reveal.js"></script>

		<script type="text/javascript">
			// More info about config & dependencies:
			// - https://github.com/hakimel/reveal.js#configuration
			// - https://github.com/hakimel/reveal.js#dependencies
			Reveal.initialize({
				dependencies: [
					{ src: 'plugin/markdown/marked.js' },
					{ src: 'plugin/markdown/markdown.js' },
					{ src: 'plugin/highlight/highlight.js', async: true, callback: function() { hljs.initHighlightingOnLoad(); } },
					{ src: 'plugin/anime-js/anime.min.js' },
					{ src: 'plugin/anime-js/fireworks.js' },
                ]
            });
		</script>
	</body>
</html>

Demo: