package {
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.display.StageAlign;
    import flash.display.StageScaleMode;
     
    public class Bounce3D extends Sprite {
        private var ball:Ball;
        private var xpos:Number=0;
        private var ypos:Number=0;
        private var zpos:Number=0;
        private var vx:Number=Math.random()*12-6;
        private var vy:Number=Math.random()*12-6;
        private var vz:Number=Math.random()*12-6;
        private var fl:Number=250;
         
        //消失点
        private var vpX:Number=stage.stageWidth/2;
        private var vpY:Number=stage.stageHeight/2;
         
        //相对于消失点的六个边界面(上，下，左，右，前，后)
        private var top:Number=-100;
        private var bottom:Number=100;
        private var left:Number=-100;
        private var right:Number=100;
        private var front:Number=100;
        private var back:Number=-100;
         
        public function Bounce3D() {
            init();
        }
        private function init():void {
            stage.align = StageAlign.TOP_LEFT;  
            stage.scaleMode = StageScaleMode.NO_SCALE;
            ball=new Ball(15);
            addChild(ball);
            addEventListener(Event.ENTER_FRAME, EnterFrameHandler);
        }
        private function EnterFrameHandler(event:Event):void {
            vpX =stage.stageWidth/2;
            vpY =stage.stageHeight/2; 
             
            xpos+=vx;
            ypos+=vy;
            zpos+=vz;
            var radius:Number=ball.radius;
            //左右边界
            if (xpos+radius>right) {
                xpos=right-radius;
                vx*=-1;
            } else if (xpos - radius < left) {
                xpos=left+radius;
                vx*=-1;
            }
            //上下边界
            if (ypos+radius>bottom) {                
                ypos=bottom-radius;
                vy*=-1;
            } else if (ypos - radius < top) {
                ypos=top+radius;
                vy*=-1;
            }
            //前后边界
            if (zpos+radius>front) {
                zpos=front-radius;
                vz*=-1;
            } else if (zpos - radius < back) {
                zpos=back+radius;
                vz*=-1;
            }
             
            //换算成平面二维坐标及缩放比率
            if (zpos>- fl) {
                var scale:Number = fl / (fl + zpos);
                ball.scaleX=ball.scaleY=scale;
                ball.x=vpX+xpos*scale;
                ball.y=vpY+ypos*scale;
                ball.visible=true;
            } else {
                ball.visible=false;
            }
             
            //辅助线
            graphics.clear();
            graphics.lineStyle(1,0xccccff);
            graphics.moveTo(0,stage.stageHeight/2);
            graphics.lineTo(stage.stageWidth,stage.stageHeight/2);
            graphics.lineTo(stage.stageWidth-15,stage.stageHeight/2-8);
            graphics.moveTo(stage.stageWidth,stage.stageHeight/2);
            graphics.lineTo(stage.stageWidth-15,stage.stageHeight/2+8);
             
            graphics.moveTo(0,stage.stageHeight);
            graphics.lineTo(stage.stageWidth,0);
            graphics.lineTo(stage.stageWidth-15,2);
            graphics.moveTo(stage.stageWidth,0);
            graphics.lineTo(stage.stageWidth-6,13);
             
            graphics.moveTo(stage.stageWidth/2,0);
            graphics.lineTo(stage.stageWidth/2,stage.stageHeight);
            graphics.lineTo(stage.stageWidth/2-8,stage.stageHeight-15);
            graphics.moveTo(stage.stageWidth/2,stage.stageHeight);
            graphics.lineTo(stage.stageWidth/2+8,stage.stageHeight-15);
            graphics.lineStyle(1,0xffccff);
            graphics.moveTo(vpX,vpY);
            graphics.lineTo(ball.x,ball.y);
        }
    }
}