jQ HTML5图片旋转代码

http://www.codefans.net/jscss/code/4812.shtml
https://github.com/cropzoom/cropzoom
http://d.lanrentuku.com/down/js/qita-1199/

< html >
 < head >
  < mata  charset = "utf-8" >
  < title > title >

  < link  rel = "stylesheet"  href = "style.css" >
 head >

 < body >
  < canvas  id = "canvas"  width = "400"  height = "400" >
    < p > :(  抱歉~   您的浏览器貌似不支持HTML5的标签"canvas"的说，试试更换成
Chrome,FireFox,IE9... p >

  canvas >

  < script  src = "arrow.js" > script >

  < script  src = "utils.js" > script >

  < script >
  window.onload=function(){
    var canvas=document.getElementById("canvas"),
    context=canvas.getContext('2d'),
    mouse=utils.captureMouse(canvas),
    arrow=new Arrow();

    arrow.x=canvas.width/2;
    arrow.y=canvas.height/2;

    if (!window.requestAnimationFrame) {
      window.requestAnimationFrame = (window.webkitRequestAnimationFrame ||
                                      window.mozRequestAnimationFrame ||
                                      window.oRequestAnimationFrame ||
                                      window.msRequestAnimationFrame ||
                                      function (callback) {
                                        return window.setTimeout(callback, 1000/60);
                                      });
    }
    (function drawFrame(){
    window.requestAnimationFrame(drawFrame,canvas);
    context.clearRect(0,0,canvas.width,canvas.height);

    var dx=mouse.x-arrow.x;
    var dy=mouse.y-arrow.y;

    arrow.rotation=Math.atan2(dy,dx);
    arrow.draw(context);
    }());

  };
  script >

 body >

html >