package {
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.display.StageScaleMode;
    import flash.display.StageAlign;
    import flash.geom.Rectangle;
    import flash.events.MouseEvent;
    import flash.ui.Mouse;
    import flash.ui.MouseCursor;
 
    public class MultiAngleBounce extends Sprite {
        private var ball:Ball;
        private var lines:Array;
        private var numLines:uint=5;
        private var gravity:Number=0.3;
        private var bounce:Number=-0.6;
 
        public function MultiAngleBounce() {
            init();
        }
 
        private function init():void {
            stage.scaleMode=StageScaleMode.NO_SCALE;
            stage.align=StageAlign.TOP_LEFT;
            ball=new Ball(20);
            addChild(ball);
            ball.x=100;
            ball.y=50;
            // 创建 5 个 line 影片 
            lines = new Array();
            for (var i:uint = 0; i < numLines; i++) {
                var line:Sprite = new Sprite();
                line.graphics.lineStyle(1);
                line.graphics.moveTo(-50, 0);
                line.graphics.lineTo(50, 0);
                addChild(line);
                lines.push(line);
            }
 
            // 放置并旋转 
            lines[0].x=100;
            lines[0].y=100;
            lines[0].rotation=30;
            lines[1].x=100;
            lines[1].y=230;
            lines[1].rotation=45;
            lines[2].x=250;
            lines[2].y=180;
            lines[2].rotation=-30;
            lines[3].x=150;
            lines[3].y=330;
            lines[3].rotation=10;
            lines[4].x=230;
            lines[4].y=250;
            lines[4].rotation=-30;
            addEventListener(Event.ENTER_FRAME, onEnterFrame);
 
            ball.addEventListener(MouseEvent.MOUSE_DOWN,MouseDownHandler);
            ball.addEventListener(MouseEvent.MOUSE_OVER,MouseOverHandler);
            stage.addEventListener(MouseEvent.MOUSE_UP,MouseUpHandler);
        }
 
 
        function MouseOverHandler(e:MouseEvent):void {
            Mouse.cursor=MouseCursor.HAND;
        }
 
        function MouseDownHandler(e:MouseEvent):void {
            Mouse.cursor=MouseCursor.HAND;
            var bounds:Rectangle = new Rectangle(ball.width,ball.height,stage.stageWidth-2*ball.width,stage.stageHeight-2*ball.height);
            ball.startDrag(true,bounds);
            removeEventListener(Event.ENTER_FRAME, onEnterFrame);
        }
 
        function MouseUpHandler(e:MouseEvent):void {
            ball.stopDrag();
            ball.vx=0;
            ball.vy=0;
            Mouse.cursor=MouseCursor.AUTO;
            addEventListener(Event.ENTER_FRAME, onEnterFrame);
        }
 
        private function onEnterFrame(event:Event):void {
            // normal motion code 
            ball.vy+=gravity;
            ball.x+=ball.vx;
            ball.y+=ball.vy;
            // 舞台四周的反弹 
            if (ball.x+ball.radius>stage.stageWidth) {
                ball.x=stage.stageWidth-ball.radius;
                ball.vx*=bounce;
            } else if (ball.x - ball.radius < 0) {
                ball.x=ball.radius;
                ball.vx*=bounce;
            }
            if (ball.y+ball.radius>stage.stageHeight) {
                ball.y=stage.stageHeight-ball.radius;
                ball.vy*=bounce;
            } else if (ball.y - ball.radius < 0) {
                ball.y=ball.radius;
                ball.vy*=bounce;
            }
            // 检查每条线 
            for (var i:uint = 0; i < numLines; i++) {
                checkLine(lines[i]);
            }
        }
        private function checkLine(line:Sprite):void {
            // 获得 line 的边界 
            var bounds:Rectangle=line.getBounds(this);
            if (ball.x>bounds.left&&ball.x<bounds.right) {
                // 获取角度与正余弦值 
                var angle:Number=line.rotation*Math.PI/180;
                var cos:Number=Math.cos(angle);
                var sin:Number=Math.sin(angle);
                // 获取 ball 与 line 的相对位置 
                var x1:Number=ball.x-line.x;
                var y1:Number=ball.y-line.y;
                // 旋转坐标 
                var y2:Number=cos*y1-sin*x1;
                // 旋转速度向量 
                var vy1:Number=cos*ball.vy-sin*ball.vx;
                // 实现反弹 
                if (y2>- ball.height/2&&y2<vy1) {
                    // 旋转坐标 
                    var x2:Number=cos*x1+sin*y1;
                    // 旋转速度向量 
                    var vx1:Number=cos*ball.vx+sin*ball.vy;
                    y2=- ball.height/2;
                    vy1*=bounce;
                    // 将一切旋转回去 
                    x1=cos*x2-sin*y2;
 
                    y1=cos*y2+sin*x2;
                    ball.vx=cos*vx1-sin*vy1;
                    ball.vy=cos*vy1+sin*vx1;
                    ball.x=line.x+x1;
                    ball.y=line.y+y1;
                }
            }
        }
    }
}