momObj.prototype.draw=function()

{

this.x=lerpDistance(mx,this.x,0.99);//运动速度

this.y=lerpDistance(my,this.y,0.99);

    var deltaY=my-this.y;//角度差

    var deltaX=mx-this.x;

    var beta = Math.atan2(deltaY,deltaX);

    this.angel=lerpAngle(beta,this.angel,-0.6);

ctx1.save();//表示仅限于适用大鱼

ctx1.translate(this.x,this.y);//移动原点

ctx1.rotate(this.angel);

    ctx1.drawImage(this.bigEye,-this.bigEye.width*0.5,-this.bigEye.height*0.5);

    ctx1.drawImage(this.bigBody,-this.bigBody.width*0.5,-this.bigBody.height*0.5);

    ctx1.drawImage(this.bigTail,-this.bigTail.width*0.5+30,-this.bigTail.height*0.5);

    ctx1.restore();

}