canvas中来做元素的旋转移动

 一张 图片，在canvas中 怎么 做 旋转 同时移动，直接上demo先。用chrome才看的到哦亲

-----------------------------我是可爱的源码分割线------------------------------------

    var width = 600;
    var height = 300;
    var imgs = [];

    var X = 74, Y = 74;
    var X1=452,Y1=74;
    var rotation=0;
    var rotation1=0

    var regx = 74;
    var regy = 42;
    var iwidth = 148;
    var iheight = 84;
    
    var canvas = document.getElementById('myCanvas');
    var ctx = canvas.getContext('2d');

    var img = new Image();
    img.onload = function(){            
        imgs.push(this);                
        imgs.push(this);        
    };
    img.src = 'buy.png';
    
    function loop(){
        ctx.clearRect(0, 0, width, height);
        for(var i = 0; i < imgs.length; i++){
            if (i==0){              
                var img = imgs[i];
                ctx.save();
                rotation += 6;
                if( X != 0 || Y != 0 ) ctx.translate( X , Y );
                if( rotation % 360 != 0) ctx.rotate( rotation%360 * (Math.PI / 180) );            
                if( regx != 0 || regy != 0 ) ctx.translate( -regx, -regy ); 
                
                X += 6;                    
                if (X>=452){
                   X -= 6;    
                }
                ctx.drawImage( img , 0, 0 , iwidth,iheight, 0 , 0 , iwidth, iheight);
                ctx.restore();
            }
            if (i==1){
                var img1=imgs[i];
                ctx.save();
                rotation1 -=15;
                
                if( X1 != 0 || Y1 != 0 ) ctx.translate( X1 , Y1 );
                if( rotation1 % 360 != 0) ctx.rotate( rotation1%360 * (Math.PI / 180) );            
                if( regx != 0 || regy != 0 ) ctx.translate( -regx, -regy ); 

                X1 -= 6;    
                if (X1<=74){
                  X1 += 6;
                }
                
                ctx.drawImage( img1 , 0, 0,iwidth , iheight,0,0 , iwidth, iheight);
                ctx.restore();
            }
        };
    }

    window.setTimeout(function(){    
        setInterval(loop, 1000 / 24);
    },500);/**/