代码：
<!DOCTYPE html>
<html class=''>
<head>
<meta charset='UTF-8'>
<meta name="robots" content="noindex">
<style>
body {
background: #111;
}
canvas {
background: #111;
border: 1px solid #171717;
display: block;
left: 50%;
margin: -51px 0 0 -201px;
position: absolute;
top: 50%;
}
</style>
</head>
<body>
<script>
/*=================*/
/* Light Loader
/*=================*/
var lightLoader = function(c, cw, ch){
var _this = this;
this.c = c;
this.ctx = c.getContext('2d');
this.cw = cw;
this.ch = ch;
this.loaded = 0;
this.loaderSpeed = .6;
this.loaderHeight = 10;
this.loaderWidth = 310;
this.loader = {
x: (this.cw/2) - (this.loaderWidth/2),
y: (this.ch/2) - (this.loaderHeight/2)
};
this.particles = [];
this.particleLift = 180;
this.hueStart = 0
this.hueEnd = 120;
this.hue = 0;
this.gravity = .15;
this.particleRate = 4;
/*=================*/
/* Initialize
/*=================*/
this.init = function(){
this.loop();
};
/*===================*/
/* Utility Functions
/*===================*/
this.rand = function(rMi, rMa){return ~~((Math.random()*(rMa-rMi+1))+rMi);};
this.hitTest = function(x1, y1, w1, h1, x2, y2, w2, h2){return !(x1 + w1 < x2 || x2 + w2 < x1 || y1 + h1 < y2 || y2 + h2 < y1);};
/*====================*/
/* Update Loader
/*====================*/
this.updateLoader = function(){
if(this.loaded < 100){
this.loaded += this.loaderSpeed;
} else {
this.loaded = 0;
}
};
/*======================*/
/* Render Loader
/*======================*/
this.renderLoader = function(){
this.ctx.fillStyle = '#000';
this.ctx.fillRect(this.loader.x, this.loader.y, this.loaderWidth, this.loaderHeight);
thisthis.hue = this.hueStart + (this.loaded/100)*(this.hueEnd - this.hueStart);
var newWidth = (this.loaded/100)*this.loaderWidth;
this.ctx.fillStyle = 'hsla('+this.hue+', 100%, 40%, 1)';
this.ctx.fillRect(this.loader.x, this.loader.y, newWidth, this.loaderHeight);
this.ctx.fillStyle = '#222';
this.ctx.fillRect(this.loader.x, this.loader.y, newWidth, this.loaderHeight/2);
};
/*======================*/
/* Particles
/*======================*/
this.Particle = function(){
this.x = _this.loader.x + ((_this.loaded/100)*_this.loaderWidth) - _this.rand(0, 1);
this.y = _this.ch/2 + _this.rand(0,_this.loaderHeight)-_this.loaderHeight/2;
this.vx = (_this.rand(0,4)-2)/100;
this.vy = (_this.rand(0,_this.particleLift)-_this.particleLift*2)/100;
this.width = _this.rand(1,4)/2;
this.height = _this.rand(1,4)/2;
this.hue = _this.hue;
};
this.Particle.prototype.update = function(i){
this.vx += (_this.rand(0,6)-3)/100;
this.vy += _this.gravity;
this.x += this.vx;
this.y += this.vy;
if(this.y > _this.ch){
_this.particles.splice(i, 1);
}
};
this.Particle.prototype.render = function(){
_this.ctx.fillStyle = 'hsla('+this.hue+', 100%, '+_this.rand(50,70)+'%, '+_this.rand(20,100)/100+')';
_this.ctx.fillRect(this.x, this.y, this.width, this.height);
};
this.createParticles = function(){
var i = this.particleRate;
while(i--){
this.particles.push(new this.Particle());
};
};
this.updateParticles = function(){
var i = this.particles.length;
while(i--){
var p = this.particles[i];
p.update(i);
};
};
this.renderParticles = function(){
var i = this.particles.length;
while(i--){
var p = this.particles[i];
p.render();
};
};
/*======================*/
/* Clear Canvas
/*======================*/
this.clearCanvas = function(){
this.ctx.globalCompositeOperation = 'source-over';
this.ctx.clearRect(0,0,this.cw,this.ch);
this.ctx.globalCompositeOperation = 'lighter';
};
/*====================*/
/* Animation Loop
/*====================*/
this.loop = function(){
var loopIt = function(){
requestAnimationFrame(loopIt, _this.c);
_this.clearCanvas();
_this.createParticles();
_this.updateLoader();
_this.updateParticles();
_this.renderLoader();
_this.renderParticles();
};
loopIt();
};
};
/*=======================*/
/* Check Canvas Support
/*=======================*/
var isCanvasSupported = function(){
var elem = document.createElement('canvas');
return !!(elem.getContext && elem.getContext('2d'));
};
/*===============================*/
/* Setup requestAnimationFrame
/*===============================*/
var setupRAF = function(){
var lastTime = 0;
var vendors = ['ms', 'moz', 'webkit', 'o'];
for(var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x){
windowwindow.requestAnimationFrame = window[vendors[x]+'RequestAnimationFrame'];
windowwindow.cancelAnimationFrame = window[vendors[x]+'CancelAnimationFrame'] || window[vendors[x]+'CancelRequestAnimationFrame'];
};
if(!window.requestAnimationFrame){
window.requestAnimationFrame = function(callback, element){
var currTime = new Date().getTime();
var timeToCall = Math.max(0, 16 - (currTime - lastTime));
var id = window.setTimeout(function() { callback(currTime + timeToCall); }, timeToCall);
lastTime = currTime + timeToCall;
return id;
};
};
if (!window.cancelAnimationFrame){
window.cancelAnimationFrame = function(id){
clearTimeout(id);
};
};
};
/*================================*/
/* Define Canvas and Initialize
/*================================*/
if(isCanvasSupported){
var c = document.createElement('canvas');
c.width = 400;
c.height = 100;
var ccw = c.width;
var cch = c.height;
document.body.appendChild(c);
var cl = new lightLoader(c, cw, ch);
setupRAF();
cl.init();
}
</script>
<div style="position:absolute; bottom: 0;width:100%">
<div class="footer-banner" style="width:728px;margin:30px auto"></div>
</div>
</body>
</html>