Home > Article > Web Front-end > A complete example of a hundred flowers blooming effect produced by JavaScript+html5 canvas_javascript skills

A complete example of a hundred flowers blooming effect produced by JavaScript+html5 canvas_javascript skills

WBOYOriginal: 2016-05-16 15:17:541438browse

The example in this article describes the blooming effect produced by JavaScript+html5 canvas. Share it with everyone for your reference, the details are as follows:

The screenshot of the running effect is as follows:

The specific code is as follows:

<!DOCTYPE html>
<html>
 <head>
  <title>demo</title>
  <style type="text/css">
   body {
    margin:0; padding:0; 
   }
   #canvas {
    border:5px solid gray; box-shadow:0 0 15px 15px #494949 inset;
    margin-top:50px; margin-left:200px;
   }
  </style>
 </head>
 <body >
  <canvas id="canvas" width="1000px" height="500px"></canvas>
  <script type="text/javascript">
   var dyl = {};
   dyl.canvas = document.getElementById("canvas");
   dyl.ctx = dyl.canvas.getContext("2d");
   dyl.runTime = 0;
   dyl.colorList = "01234567890ABCDEFabcdef".split("");
   dyl.colorListLength = dyl.colorList.length;
   dyl.arcList = null;
   /**
   * 得到16进制随机颜色值
   */
   dyl.getColor = function() {
    var color = "#";
    for(var i=0; i<6; i++) {
     color += dyl.colorList[Math.floor(Math.random()*dyl.colorListLength)];
    }
    return color;
   };
   /**
   * 一个随机角度，随机初始速度的斜抛对象
   */
   var Arc = function(i) {
    // 设置自有属性
    this.v = Math.round(Math.random()*100)+50;
    this.angle = Math.round(Math.random()*145) + 45;
    this.startTime = +new Date();
    this._angle = this.angle/180*Math.PI;
    this.v_x = this.v*Math.cos(this._angle);
    this.v_y_start = this.v*Math.sin(this._angle);
    this.color = dyl.getColor();
    this.x = 500;
    this.g = 250;
    this.y = 490;
    this.index = i;
    var _self = this;
    this.run = function() {
     var endTime = +new Date();
     var timeSpan = (endTime - _self.startTime)/1000;
     var v_y_now = _self.v_y_start - 1/2*_self.g*Math.pow(timeSpan, 2);
     _self.x = _self.x +_self.v_x * timeSpan;
     _self.y = _self.y - (_self.v_y_start * timeSpan - 1/2*_self.g*Math.pow(timeSpan, 2));
     return this;
    };
    return this;
   };
   /**
   * 全局绘制图像
   */
   dyl.draw = function() {
    var arcList = dyl.arcList;
    var ctx = dyl.ctx;
    dyl.runTime++;
    for(var i=0, length=arcList.length; i<length; i++) {
     var arc = arcList[i];
     if(!arc) {
      continue;
     }
     arc.run();
     ctx.save();
     ctx.beginPath();
     ctx.fillStyle = arc.color;
     ctx.arc(arc.x, arc.y, 2, 0, Math.PI*2);
     ctx.fill();
     ctx.closePath();
     ctx.restore();
    }
    console.log(dyl.runTime);
    if(dyl.runTime >= 25) {
     setTimeout(dyl.init, 1050);
    } else {
     setTimeout(dyl.draw, 20);
    }
   };
   /**
   * 初始化整个事件
   */
   dyl.init = function() {
    dyl.ctx.clearRect(0, 0, 1000, 500);
    dyl.arcList = [];
    dyl.runTime = 0;
    for(var i=0; i<100; i++) {
     dyl.arcList.push(new Arc(i));
    }
    dyl.draw();
   };
   dyl.init();
  </script>
 </body>
</html>

Readers who are interested in more content related to js special effects can check out the special topics of this site: "Summary of jQuery animation and special effects usage" and "Summary of common classic special effects of jQuery"

I hope this article will be helpful to everyone in JavaScript programming.

Statement：

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Previous article：Complete example of brilliant circle effect based on canvas_javascript skillsNext article：Complete example of brilliant circle effect based on canvas_javascript skills

See more

A complete example of a hundred flowers blooming effect produced by JavaScript+html5 canvas_javascript skills

Related articles