package
{
	import flash.display.*;
	import flash.events.*;
	import flash.filters.*;
	import flash.geom.*;
	import flash.utils.*;
	
	import org.papervision3d.cameras.*;
	import org.papervision3d.view.*;
	import org.papervision3d.materials.*;
	import org.papervision3d.objects.*;
	import org.papervision3d.objects.primitives.*
	
	import caurina.transitions.Tweener;
	
	[SWF(width = "720", height = "480", frameRate = "30", backgroundColor = "#001122")]
	
	public class Main extends BasicView 
	{	
		// const vars
		static private const SNOW_PLACE_RANGE :int = 1500;
		static private const SNOW_MAX_DEPTH   :int = 64;
		static private const FOCUS_POSITION   :int = 2000;
		
		// 3d vars
		private var list   :Array = [];
		private var blurs  :Array = [];
		
		[Embed(source = "snow.png")] private var BitmapSnow:Class;
		
		/**
		 * Constructor
		 */
		public function Main()
		{
			stage.quality = StageQuality.LOW;
			
			//camera
			camera.focus = 500;
			camera.zoom  = 2;
			camera.x     = 0;
			camera.y     = -1000;
			camera.z     = 0;
			
			// create blur field material
			for (var i:int = 0; i < SNOW_MAX_DEPTH; i++)
			{
				// create circle graphics
				var snow:Sprite = new Sprite();
				snow.addChild(new BitmapSnow());
				
				// ぼかしの適用値
				var blurFilter:BlurFilter = new BlurFilter(i, i, 3);
				
				// 明度の適用値
				var b:Number = (SNOW_MAX_DEPTH - i) / SNOW_MAX_DEPTH;
				var blightnessArr:Array =
				[
					1 - 0.2 * b, 0, 0, 0, 0,
					0, 1 - 0.1 * b, 0, 0, 0,
					0, 0, 1, 0, 0,
					0, 0, 0, 0.5 + 0.5 * b, 0
				];
				var blightnessFilter:ColorMatrixFilter = new ColorMatrixFilter(blightnessArr);
				
				// add Fileter
				snow.filters = [blightnessFilter , blurFilter];
				
				// copy bitmapdata
				var bitmapData:BitmapData = new BitmapData(100, 100, true, 0x00000000);
				bitmapData.draw(snow);
				
				// create material from bitmapdata
				var mat:BitmapMaterial = new BitmapMaterial(bitmapData);
				
				// save
				blurs.push(mat);
			}
			
			// partcle create interval
			var timer:Timer = new Timer(10);
			timer.addEventListener(TimerEvent.TIMER, timerHandler);
			timer.start();
			
			// arrange blur
			addEventListener(Event.ENTER_FRAME, enterFrameHandler);
			
			// render
			startRendering(); 
		}
		
		/**
		 * partcle create interval
		 * @param	e
		 */
		private function timerHandler(e:TimerEvent):void 
		{
			// crarete 3d plane
			var o:Plane = new Plane(blurs[SNOW_MAX_DEPTH - 1], 100, 100, 1, 1);
			
			// 3d plane position
			o.x = SNOW_PLACE_RANGE * Math.random() - SNOW_PLACE_RANGE / 2;
			o.y = 4000;
			o.z = SNOW_PLACE_RANGE * Math.random() - SNOW_PLACE_RANGE / 2;
			o.rotationX = -90;
			
			// 3d plane motion
			Tweener.addTween(o , 
			{
				y                : -1000,
				time             : 5,
				transition       : "easeInSine",
				onCompleteParams : [o],
				onComplete       : onCompleteHandler
			});
			
			// save and display
			scene.addChild(o);
			list.push(o);
		}
		
		/**
		 * 3d plane remove handler
		 * @param	snow
		 */
		private function onCompleteHandler(p:Plane):void
		{
			var len:uint = list.length;
			for (var i:int; i < len; i++ )
			{
				if (list[i] == p)
				{
					list.splice(i, 1);
					break;
				}
			}
			scene.removeChild(p);
		}
		
		/**
		 * 被写界深度表現のチェック
		 * @param	event
		 */
		private function enterFrameHandler(event:Event):void
		{
			// マウスのインタラクティブ
			camera.x += ((mouseX / stage.stageWidth * 500)- 250 - camera.x) * .1;
			camera.z += ((mouseY / stage.stageHeight * 750)- camera.z) * .1;
			
			// 被写界深度フィルターの適用
			var len:uint = list.length;
			for (var i:int = 0; i < len; i++)
			{
				if(list[i] == null) continue;
				
				var o:DisplayObject3D = list[i] as DisplayObject3D;
				
				// 距離の算出
				var f:Number = calcPointDistanceFromCamera(o) - FOCUS_POSITION;
				var deg:Number = (f ^ (f >> 31)) - (f >> 31); // Math.abs(f)と同等
				
				// ぼかしの適用値
				var blurVal:int = Math.min(SNOW_MAX_DEPTH - 1, deg * .01 << 1 ); //ココの調整が絶妙
				
				// ぼかしマテリアルを入れ替え
				o.material = blurs[blurVal];
			}
		}
		
		/**
		 * カメラからの距離を算出します
		 * @param	obj 計測したいオブジェクト
		 * @return	カメラからの距離(3D空間内のpx値)
		 */
		private function calcPointDistanceFromCamera(obj:DisplayObject3D):Number
		{
			var vecX:Number = obj.x - camera.x;
			var vecY:Number = obj.y - camera.y;
			var vecZ:Number = obj.z - camera.z;
			return Math.sqrt((vecX * vecX) + (vecY * vecY) + (vecZ * vecZ));
		}

	}
}