複数のボール跳ね返り3D

/**
 * Copyright _wonder ( http://wonderfl.net/user/_wonder )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/jQqB
 */

// forked from _wonder's 跳ね返り3D
// forked from _wonder's ボールを動かす3D
// forked from _wonder's 遠ざかるボール
// forked from _wonder's base
package {
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.events.KeyboardEvent;
    import flash.ui.Keyboard;
    
    public class MultiBound extends Sprite {
        private var balls:Array;
        private var numBalls:Number = 100;
        private var fl:Number = 250;
        private var vpX:Number = stage.stageWidth / 2;
        private var vpY:Number = stage.stageHeight / 2;
        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 MultiBound() {
            balls = new Array();
            for( var i:uint = 0; i < numBalls; i++ ){
                var ball:Ball3D = new Ball3D( 5 );
                balls.push( ball );
                ball.vx = Math.random() * 10 - 5;
                ball.vy = Math.random() * 10 - 5;
                ball.vz = Math.random() * 10 - 5;
                addChild( ball );
            }

            addEventListener(Event.ENTER_FRAME, onEnterFrame);
        }
        
        private function onEnterFrame(e:Event):void {
            for( var i:uint = 0; i < numBalls; i++ ){
                var ball:Ball3D = balls[i];
                move( ball );
            }
            sortZ();
        }

        private function move(ball:Ball3D):void {
            var radius:Number = ball.radius;
            
            ball.xpos += ball.vx;
            ball.ypos += ball.vy;
            ball.zpos += ball.vz;
            
            if( ball.xpos + radius > right ){
                ball.xpos = right - radius;
                ball.vx *= -1;
            } else if ( ball.xpos - radius < left ){
                ball.xpos = left + radius;
                ball.vx *= -1;
            }
            
            if( ball.ypos + radius > bottom ){
                ball.ypos = bottom - radius;
                ball.vy *= -1;
            } else if ( ball.ypos - radius < top ){
                ball.ypos = top + radius;
                ball.vy *= -1;
            }
            
            if( ball.zpos + radius > front ){
                ball.zpos = front - radius;
                ball.vz *= -1;
            } else if ( ball.zpos - radius < back ){
                ball.zpos = back + radius;
                ball.vz *= -1;
            }
            
            if( ball.zpos > -fl ){
                var scale:Number = fl / ( fl + ball.zpos );
                ball.scaleX = ball.scaleY = scale;
                ball.x = vpX + ball.xpos * scale;
                ball.y = vpX + ball.ypos * scale;
                ball.visible = true;
            } else {
                ball.visible = false;
            }
        }
        
        private function sortZ():void {
            balls.sortOn( "zpos", Array.DESCENDING | Array.NUMERIC );
            for( var i:uint = 0; i < numBalls; i++ ){
                var ball:Ball3D = balls[i];
                setChildIndex( ball, i );
            }
        }
    }
}

import flash.display.Sprite;

class Ball3D extends Sprite {
    public var radius:Number;
    public var color:uint;
    public var xpos:Number = 0;
    public var ypos:Number = 0;
    public var zpos:Number = 0;
    public var vx:Number = 0;
    public var vy:Number = 0;
    public var vz:Number = 0;
    public var mass:Number = 1;
    
    public function Ball3D(radius:Number=40, color:uint=0Xff0000){
        this.radius = radius;
        this.color = color;
        init();
    }
    
    public function init():void {
        graphics.lineStyle( 0 );
        graphics.beginFill(color);
        graphics.drawCircle(0, 0, radius);
        graphics.endFill();
    }
}