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 这篇文章主要介绍了Canvas波浪花环的示例代码,文中通过示例代码介绍的非常详细,对大家的学习或者工作具有一定的参考学习价值,需要的朋友们下面随着小编来一起学习学习吧 JS中的Canvas动画 几天没写博客了,今天又忙到很晚,教大家做一个波浪花环吧 效果图如上所示: 老规矩先把代码给大家,新建一个html文档(新建一个txt文本文档,把后缀名改为“ .html ”),以记事本打开,把复制好的代码粘贴进去,“ 保存 ”,退出,双击或右键选择浏览器打开。 祝大家前端学习愉快,在今后的日子中与君共勉 <!DOCTYPE html><html lang="en">
 <head>
 <meta charset="UTF-8">
 <title>Document</title>
 <style>
 body {
 background: #111;
 padding:0;
 margin:0;
 overflow:hidden;
 }
 </style>
 </head>
 <body>
 <div></div>
 </body>
 <script>
 (function(){
 'use strict';
 let wrapper, canvas, ctx, width, height,
 Tau=Math.PI*2, PI180=Math.PI/180,
 systems=[];
 /* PlanetarySystem */let PlanetarySystem = function(id='pSys'){
 Object.defineProperty(this, 'id',               { value:id, writable:true} );
 Object.defineProperty(this, 'x',                { value:0, writable:true });
 Object.defineProperty(this, 'y',                { value:0, writable:true });
 Object.defineProperty(this, 'allBodies',        { value:[], writable:true });
 Object.defineProperty(this, 'allBodiesLookup',  { value:{}, writable:true });    // fast id lookup for children
 Object.defineProperty(this, 'numBodies',        { value:0, writable:true });
 }
 PlanetarySystem.prototype.addBody = function(vo) {
 vo.parentSystem = this;
 vo.parentBody = vo.parentBody === null ? this : this.allBodiesLookup[vo.parentBody];
 let body = new PlanetaryBody(vo);
 body.update();
 this.allBodies.push(body);
 this.allBodiesLookup[vo.id] = body;
 this.numBodies += 1;
 }
 PlanetarySystem.prototype.setSpeedFactor = function(value){
 let body;
 for(let i=0; i<this.numBodies; i++){
 body = this.allBodies[i];
 body.setSpeedFactor(value);
 }
 }
 PlanetarySystem.prototype.update = function(){
 let body;
 for(let i=0; i<this.numBodies; i++){
 body = this.allBodies[i];
 body.update();
 }
 }
 /* PlanetaryBody */
 let PlanetaryBody = function(vo){
 Object.defineProperty(this, 'id',     { value:vo.id, writable:true} );
 Object.defineProperty(this, 'diameter',    { value:vo.diameter, writable:true });
 Object.defineProperty(this, 'colour',    { value:vo.colour, writable:true });
 Object.defineProperty(this, 'x',     { value:0, writable:true });
 Object.defineProperty(this, 'y',     { value:0, writable:true });
 Object.defineProperty(this, 'vx',     { value:0, writable:true });
 Object.defineProperty(this, 'vy',     { value:0, writable:true });
 Object.defineProperty(this, 'degrees',    { value:vo.degrees, writable:true });
 Object.defineProperty(this, 'speedBase',   { value:vo.speed, writable:true });
 Object.defineProperty(this, 'speed',    { value:vo.speed , writable:true });
 Object.defineProperty(this, 'orbitalRadius',  { value:vo.orbitalRadius, writable:true });
 Object.defineProperty(this, 'parentSystem',   { value:vo.parentSystem, writable:true });
 Object.defineProperty(this, 'parentBody',   { value:vo.parentBody, writable:true });
 return this;}
 PlanetaryBody.prototype.update = function(){
 let angle = this.degrees * PI180;
 this.degrees += this.speed;
 this.vx = this.orbitalRadius * Math.cos(angle);
 this.vy = this.orbitalRadius * Math.sin(angle);
 // update position
 if(this.parentBody != null){
 this.x = this.vx + this.parentBody.x;
 this.y = this.vy + this.parentBody.y;
 }
 }
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