3d多物体点旋转

package com.ddd
{
    import flash.display.Sprite;
    import flash.display.StageScaleMode;
    import flash.events.Event;

    /**
     * 3d多物体点旋转
     * @author Administrator
     *
     */
    public class RotateY extends Sprite
    {
        private var balls:Array=[];
        private var num:int=10;

        private var vpX:Number=stage.stageWidth / 2;
        private var vpY:Number=stage.stageHeight / 2;

        private var fl:Number=250;

        public function RotateY()
        {
            super();
            stage.scaleMode=StageScaleMode.NO_SCALE;
            init();
        }

        private function init():void
        {
            for (var i:int=0; i < num; i++)
            {
                var ball:Ball=new Ball;
                this.addChild(ball);

                ball.xpos=Math.random() * 200 - 100;
                ball.ypos=Math.random() * 200 - 100;
                ball.zpos=Math.random() * 200 - 100;

                balls.push(ball);
            }

            this.addEventListener(Event.ENTER_FRAME, onEnterFrame)
        }

        private function onEnterFrame(e:Event):void
        {
            //注意这里,这是朝着鼠标坐标方向的运动方式
            var angleY:Number=(mouseX - vpX) * .001;
            var angleX:Number=(mouseY - vpY) * .001;

            for (var i:int=0; i < num; i++)
            {
                var ball:Ball=balls[i];
                rotateY(ball, angleY);
                rotateX(ball, angleX);
                dopetive(ball);
            }

            sortZ();
        }

        private function rotateY(ball:Ball, _angle:Number):void
        {
            var xp:Number=Math.cos(_angle) * ball.xpos - Math.sin(_angle) * ball.zpos;
            var zp:Number=Math.cos(_angle) * ball.zpos + Math.sin(_angle) * ball.xpos;

            ball.xpos=xp;
            ball.zpos=zp;
        }

        private function rotateX(ball:Ball, _angle:Number):void
        {
            var yp:Number=Math.cos(_angle) * ball.ypos - Math.sin(_angle) * ball.zpos;
            var zp:Number=Math.cos(_angle) * ball.zpos + Math.sin(_angle) * ball.ypos

            ball.ypos=yp;
            ball.zpos=zp;
        }

        private function dopetive(ball:Ball):void
        {
            if (ball.zpos > -fl)
            {
                var scale:Number=fl / (fl + ball.zpos);
                ball.scaleX=ball.scaleY=scale;

                ball.x=vpX + ball.xpos * scale;
                ball.y=vpY + ball.ypos * scale;

                ball.visible=true;
            }
            else
            {
                ball.visible=false;
            }
        }

        private function sortZ():void
        {
            balls.sortOn("zpos", Array.DESCENDING | Array.NUMERIC);

            for (var i:int=0; i < num; i++)
            {
                var ball:Ball=balls[i];
                this.setChildIndex(ball, i)
            }

        }

    }
}