JavaScript Canvas实现三角形粒子动态效果

<!DOCTYPE html>
<html lang="en">

<head>
 <meta charset="UTF-8">
 <meta name="viewport" content="width=device-width, initial-scale=1.0">
 <title>粒子</title>
 <style>
  * {
   margin: 0;
   padding: 0;
  }

  body {
   overflow: hidden;
  }
 </style>
 <script>
  //随机数获取 3 10 *7+3
  function random(min, max) {
   return Math.random() * (max - min) + min;

  }
  //亮色系
  // colors = ['#7cb5ec', '#434348', '#90ed7d', '#f7a35c', '#8085e9', '#f15c80', '#e4d354', '#8085e8', '#8d4653', '#91e8e1'];
  //暗色系
  colors = ['#c23531', '#2f4554', '#61a0a8', '#d48265', '#91c7ae', '#749f83', '#ca8622', '#bda29a', '#6e7074', '#546570', '#c4ccd3']
  //获取窗口宽高
  var width = window.innerWidth;
  var height = window.innerHeight;
  function Bubble() {
   this.r = random(5, 100);
   this.x1 = random(this.r, this.r * 2);
   this.y1 = random(this.r, this.r * 2);
   this.x2 = random(this.r, this.r * 2);
   this.y2 = random(this.r, this.r * 2);
   this.x3 = random(this.r, this.r * 2);
   this.y3 = random(this.r, this.r * 2);
   //随机获取colors数组里的颜色
   this.color = colors[Math.floor(random(0, colors.length))];
   //偏移步长
   this.xr = random(-5, 5);
   this.yr = random(-5, 5);
  }
  Bubble.prototype = {
   //绘制
   draw: function (context) {
    //开始路径
    context.beginPath();
    context.moveTo(this.x1, this.y1);
    context.lineTo(this.x2, this.y2);
    context.lineTo(this.x3, this.y3);
    context.lineTo(this.x1, this.y1);
    context.fillStyle = this.color;
    context.fill();
   },
   //移动
   move: function (context) {
    this.x1 += this.xr;
    this.y1 += this.yr;
    this.x2 += this.xr;
    this.y2 += this.yr;
    this.x3 += this.xr;
    this.y3 += this.yr;
    //边缘检测
    (this.x1 > width || this.x1 < 0) ? this.xr = -this.xr : null;
    (this.y1 > height || this.y1 < 0) ? this.yr = -this.yr : null;
    (this.x2 > width || this.x2 < 0) ? this.xr = -this.xr : null;
    (this.y2 > height || this.y2 < 0) ? this.yr = -this.yr : null;
    (this.x3 > width || this.x3 < 0) ? this.xr = -this.xr : null;
    (this.y3 > height || this.y3 < 0) ? this.yr = -this.yr : null;
    this.draw(context);
   }
  }

  window.onload = function () {
   //获取画布dom
   var canvas = document.querySelector('canvas');
   //设置canvas的宽高
   canvas.width = width;
   canvas.height = height;
   //获取画布上下文对象
   var context = canvas.getContext('2d');
   //数组存储bubble
   var arr = [];
   //生成粒子
   var total = 100;
   //生成例子
   for (var i = 0; i < total; i++) {
    var bubble = new Bubble();
    bubble.draw(context);
    arr.push(bubble);
   }
   var id = setInterval(function () {
    //清除
    context.clearRect(0, 0, width, height);
    //开始移动
    for (var i = 0; i < arr.length; i++) {
     arr[i].move(context);
    }
   }, 1000 / 60)
   //点击次数
   var count = 0;
   canvas.onclick = function () {
    if (count++ % 2 == 0) {
     //停止
     clearInterval(id);
    } else {
     //运行
     id = setInterval(function () {
      //清除
      context.clearRect(0, 0, width, height);
      //开始移动
      for (var i = 0; i < arr.length; i++) {
       arr[i].move(context);
      }
     }, 1000 / 60)
    }
   }
  }
 </script>
</head>

<body>
 <canvas title="点击停止，再次点击活动"></canvas>
</body>

</html>