本文实例讲述了jQuery+canvas实现的球体平抛及颜色动态变换效果。分享给大家供大家参考,具体如下:
运行效果截图如下:

具体代码如下:
<!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平抛</title><script src="jquery-1.7.1.min.js" type="text/javascript"></script><script type="text/javascript" >var canvasHeight = 300;var canvasWidth = 300;var g = 9.8;//x, y, vo, rfunction HorizenCast(context, settings) {var _self = this;$.extend(_self, settings);_self.xo = _self.x;_self.yo = _self.y;HorizenCast.createColor = function () {var r = Math.round(Math.random() * 256),g = Math.round(Math.random() * 256),b = Math.round(Math.random() * 256);return "rgb("+r+","+g+","+b+")";}_self.cast = function () {if (_self.x > canvasWidth - _self.r || _self.y > canvasHeight - _self.r) {return;}var time = (new Date().getTime() - _self.prevTime) / 1000,x = _self.xo +_self.vo * time,y = _self.yo + 1 / 2 * g * time * time;context.beginPath();context.fillStyle = HorizenCast.createColor();context.arc(_self.x, _self.y, _self.r, 0, 2 * Math.PI);context.fill();context.closePath();_self.x = x;_self.y = y;setTimeout(function () {_self.cast();}, 30);}_self.prevTime = new Date().getTime();_self.cast();}$(document).ready(function () {var canvas = document.getElementById("canvas");var context = canvas.getContext("2d");new HorizenCast(context, { x: 0, y: 0, vo: 100, r: 5 });new HorizenCast(context, { x: 0, y: 0, vo: 90, r: 5 });new HorizenCast(context, { x: 0, y: 0, vo: 80, r: 5 });new HorizenCast(context, { x: 0, y: 0, vo: 70, r: 5 });new HorizenCast(context, { x: 0, y: 0, vo: 60, r: 5 });new HorizenCast(context, { x: 0, y: 0, vo: 50, r: 5 });new HorizenCast(context, { x: 0, y: 0, vo: 40, r: 5 });new HorizenCast(context, { x: 0, y: 0, vo: 30, r: 5 });new HorizenCast(context, { x: 0, y: 0, vo: 20, r: 5 });new HorizenCast(context, { x: 0, y: 0, vo: 10, r: 5 });new HorizenCast(context, { x: 0, y: 0, vo: 5, r: 5 });});</script><style type="text/css" >h2 { color:Gray; line-height:50px; }#canvas { background:#DDDDDD;}</style></head><body> <center> <h3>canvas实现平抛效果</h3> <hr /> <canvas id="canvas" width="300" height="300"></canvas> <hr /> </center></body></html>更多关于jQuery相关内容感兴趣的读者可查看本站专题:《jQuery动画与特效用法总结》及《jQuery常见经典特效汇总》
希望本文所述对大家jQuery程序设计有所帮助。