彩色圆圈放大特效背景Js美化代码

你的网站仅仅只是一个二次元或风景图片做背景看腻了或许认为动态的更好看，不妨看看这个背景特效随机生成一个彩色圈圈再放大的特效多好看~

代码如下：

<div id="bubble"><canvas style="display: block; position: fixed; top: 0px; left: 0px; z-index: -1;" width="1920" height="28"></canvas></div>

class BGBubble{constructor(i){this.defaultOpts={id:"",num:100,start_probability:.1,radius_min:1,radius_max:2,radius_add_min:.3,radius_add_max:.5,opacity_min:.3,opacity_max:.5,opacity_prev_min:.003,opacity_prev_max:.005,light_min:40,light_max:70,is_same_color:!1,background:"#f5f5f5"},"[object Object]"==Object.prototype.toString.call(i)?this.userOpts={...this.defaultOpts,...i}:this.userOpts={...this.defaultOpts,id:i},this.color=this.random(0,360),this.bubbleNum=[],this.requestAnimationFrame=window.requestAnimationFrame||window.mozRequestAnimationFrame||window.webkitRequestAnimationFrame||window.msRequestAnimationFrame,this.cancelAnimationFrame=window.cancelAnimationFrame||window.mozCancelAnimationFrame}random(i,t){return Math.random()*(t-i)+i}initBubble(i,t){const a=window.innerWidth,s=window.innerHeight,n=this.userOpts,e=this.random(n.light_min,n.light_max);this.bubble={x:this.random(0,a),y:this.random(0,s),radius:this.random(n.radius_min,n.radius_max),radiusChange:this.random(n.radius_add_min,n.radius_add_max),opacity:this.random(n.opacity_min,n.opacity_max),opacityChange:this.random(n.opacity_prev_min,n.opacity_prev_max),light:e,color:`hsl(${t?i:this.random(0,360)},100%,${e}%)`}}bubbling(i,t,a){!this.bubble&&this.initBubble(t,a);const s=this.bubble;i.fillStyle=s.color,i.globalAlpha=s.opacity,i.beginPath(),i.arc(s.x,s.y,s.radius,0,2*Math.PI,!0),i.closePath(),i.fill(),i.globalAlpha=1,s.opacity-=s.opacityChange,s.radius+=s.radiusChange,s.opacity<=0&&this.initBubble(t,a)}createCanvas(){this.canvas=document.createElement("canvas"),this.ctx=this.canvas.getContext("2d"),this.canvas.style.display="block",this.canvas.width=window.innerWidth,this.canvas.height=window.innerHeight,this.canvas.style.position="fixed",this.canvas.style.top="0",this.canvas.style.left="0",this.canvas.style.zIndex="-1",document.getElementById(this.userOpts.id).appendChild(this.canvas),window.onresize=(()=>{this.canvas.width=window.innerWidth,this.canvas.height=window.innerHeight})}start(){const i=window.innerWidth,t=window.innerHeight;this.color+=.1,this.ctx.fillStyle=this.defaultOpts.background,this.ctx.fillRect(0,0,i,t),this.bubbleNum.length<this.userOpts.num&&Math.random()<this.userOpts.start_probability&&this.bubbleNum.push(new BGBubble),this.bubbleNum.forEach(i=>i.bubbling(this.ctx,this.color,this.userOpts.is_same_color));const a=this.requestAnimationFrame;this.myReq=a(()=>this.start())}destory(){(0,this.cancelAnimationFrame)(this.myReq),window.onresize=null}}const bubbleDemo=new BGBubble("bubble");bubbleDemo.createCanvas(),bubbleDemo.start();

使用教程：将第一个代码放置Html底部代码-第二个代码放置js代码即可