Home >Web Front-end >JS Tutorial >jQuery+canvas implements simple oblique throwing and color dynamic transformation effects_jquery

jQuery+canvas implements simple oblique throwing and color dynamic transformation effects_jquery

WBOYOriginal: 2016-05-16 15:17:181682browse

The example in this article describes how jQuery+canvas can achieve simple oblique throwing and color dynamic transformation effects. 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 PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
  <title>canvas简单斜抛</title>
  <script src="jquery-1.7.1.min.js" type="text/javascript"></script>
  <script type="text/javascript" >
    var canvasHeight = 0;
    var canvasWidth = 0;
    var g = 9.8;
    function Cast(context, castSettings) {
      Cast.createColor = function () {
        var r = Math.round(Math.random() * 256),
          g = Math.round(Math.random() * 256),
          b = Math.round(Math.random() * 256);
        return "rgb("+r+","+g+","+b+")";
      }
      var _self = this;
      // x, y, radian, r, v
      $.extend(_self, castSettings);
      _self.radian = _self.radian / 180 * Math.PI;
      _self.vo = _self.v;
      _self.vxo = Math.cos(_self.radian) * _self.vo;
      _self.vyo = Math.sin(_self.radian) * _self.vo;
      console.log("vyo:"+_self.vyo+":vxo:"+_self.vxo+":"+_self.radian);
      _self.prevTime = new Date().getTime();
      _self.xo = _self.x;
      _self.yo = _self.y;
      _self.cast = function () {
        if (_self.x > canvasWidth - _self.r || _self.y > _self.yo) {
          return;
        }
        var time = (new Date().getTime() - _self.prevTime) / 1000;
        var x = _self.vxo * time;
        var y = _self.vyo * time - 1 / 2 * g * time * time;
        console.log(time+":"+_self.yo+":"+_self.xo+":"+y);
        context.beginPath();
        context.fillStyle = Cast.createColor();
        context.arc(x + _self.xo, _self.yo- y , _self.r, 0, 2 * Math.PI);
        context.fill();
        context.closePath();
        _self.x = x + _self.xo;
        _self.y = _self.yo - y;
        setTimeout(function () {
          _self.cast();
        }, 30);
      }
      _self.cast();
    }
    $(document).ready(function () {
      var canvas = $("#canvas");
      var context = canvas.get(0).getContext('2d');
      canvasHeight = canvas.height();
      canvasWidth = canvas.width();
      new Cast(context, { x: 0, y: 400, v: 70, r: 5, radian: 20 });
      new Cast(context, { x: 0, y: 400, v: 70, r: 5, radian: 30 });
      new Cast(context, { x: 0, y: 400, v: 70, r: 5, radian: 40 });
      new Cast(context, { x: 0, y: 400, v: 70, r: 5, radian: 50 });
      new Cast(context, { x: 0, y: 400, v: 70, r: 5, radian: 60 });
      new Cast(context, { x: 0, y: 400, v: 70, r: 5, radian: 70 });
    });
  </script>
  <style type="text/css" >
    h2 { color:Gray; line-height:50px; }
    #canvas { background:#DDDDDD;}
  </style>
</head>
<body>
 <center>
 <h3>canvas实现斜抛效果</h3>
 <hr />
 <canvas id="canvas" width="500" height="500"></canvas>
 <hr />
 </center>
</body>
</html>

Readers who are interested in more jQuery-related content can check out the special topics on 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 jQuery 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 JavaScript counting the number of occurrences of each character in a string_javascript skillsNext article：Complete example of JavaScript counting the number of occurrences of each character in a string_javascript skills

See more

jQuery+canvas implements simple oblique throwing and color dynamic transformation effects_jquery

Related articles