/**
 * Copyright nemu90kWw ( http://wonderfl.net/user/nemu90kWw )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/cj1y
 */

// forked from nemu90kWw's BitmapData直描きにすれば残像付きでも超軽いよ
// forked from nemu90kWw's 画像をトリミングしてみた（中心点未調整）
// forked from keno42's ちょっと変えたけどそんなに速くならなかった
// forked from keno42's forked from: forked from: 速度比較したら一個前の方法が速かったっぽい
// forked from keno42's forked from: 速度比較したら一個前の方法が速かったっぽい
// forked from keno42's 速度比較したら一個前の方法が速かったっぽい
// forked from bkzen's forked from: 色と透明度もいれてみた。こんなのどうだろバージョン
// forked from bkzen's 色と透明度もいれてみた。速度向上したらいいなばーじょん
// forked from keno42's 角度計算修正、色と透明度もいれてみた。重ね順ソートが重い。
// forked from bkzen's forked from: BitmapDataで配列に格納すると高速化するよ(角度修正)
// forked from clockmaker's BitmapDataで配列に格納すると高速化するよ
// forked from clockmaker's 3D Flow Simulation with Field of Blur
// forked from clockmaker's 3D Flow Simulation
// forked from clockmaker's Interactive Liquid 10000
// forked from clockmaker's Liquid110000 By Vector
// forked from munegon's forked from: forked from: forked from: forked from: Liquid10000
// forked from Saqoosha's forked from: forked from: forked from: Liquid10000
// forked from nutsu's forked from: forked from: Liquid10000
// forked from nutsu's forked from: Liquid10000
// forked from zin0086's Liquid10000
package
{
	// いっぱいあるように見えるよ！！
	// 画面クリックでフルスクリーンになります。
	import flash.display.*;
	
	[SWF(width="465", height="465", backgroundColor="0x0", frameRate="90")]
	public class Root extends Sprite
	{
		function Root()
		{
			stage.quality = StageQuality.LOW;
			addChild(new Main());
		}
	}
}

import flash.display.*;
import flash.geom.*;
import flash.events.*;
import flash.filters.*;

const ROT_STEPS:int = 128;
const ALPHA_STEPS:int = 20;
var rotArr:Vector.<DisplayImage> = new Vector.<DisplayImage>(ROT_STEPS * ALPHA_STEPS, true);
var stageWidth:int, stageHeight:int;

class Main extends Sprite
{
	private const NUM_PARTICLE:int = 1000;
	private const NUM_BUFFER:int = 8;
	
	private var buffers:Vector.<BitmapData> = new Vector.<BitmapData>(NUM_BUFFER, true);
	private var buffer_index:int;
	private var screen:Bitmap = new Bitmap(new BitmapData(465, 465, false, 0));
	
	private var particleList:Array = [];
	
	private var forceMap:BitmapData;
	private var seed:Number;
	private var offset:Array;
	
	function Main()
	{
		var i:int, j:int, k:int;
		
		// 矢印をプレレンダリング
		var dummy:Sprite = new Sprite();
		var dummyBg:Sprite = new Sprite();
		var dummyHolder:Sprite = new Sprite();
		dummy.graphics.beginFill(0xFFFFFF, 1);
		dummy.graphics.lineStyle(1, 0x003399, 1);
		dummy.graphics.drawPath(Vector.<int>([1,2,2,2,2,2,2,2]), Vector.<Number>([-9,-7,-3,-7,-3,-11,9,-4,-3,3,-3,-1,-9,-1,-9,-7]));
		dummyBg.graphics.beginFill(0x0, 1);
		dummyBg.graphics.lineStyle(1, 0x0, 1);
		dummyBg.graphics.drawPath(Vector.<int>([1,2,2,2,2,2,2,2]), Vector.<Number>([-9,-7,-3,-7,-3,-11,9,-4,-3,3,-3,-1,-9,-1,-9,-7]));
		dummyHolder.addChild(dummyBg);
		dummyHolder.addChild(dummy);
		
		var temp:BitmapData;
		var rect:Rectangle;
		var matrix:Matrix = new Matrix();
		
		j = ALPHA_STEPS;
		while(j--)
		{
			i = ROT_STEPS;
			k = j * ROT_STEPS;
			dummy.alpha = j / (ALPHA_STEPS-1);
			dummy.filters = dummyBg.filters = [new BlurFilter(4.0*(1.0 - j / (ALPHA_STEPS-1)),4.0*(1.0 - j / (ALPHA_STEPS-1)),3)];
			while (i--)
			{
				matrix.identity();
				matrix.rotate( ( 360 / ROT_STEPS * i )* Math.PI / 180);
				matrix.translate(11, 11);
				temp = new BitmapData(22, 22, true, 0x0);
				temp.draw(dummyHolder, matrix);
				rotArr[i+k] = new DisplayImage(temp, 11, 11);
			}
		}
		
		// ループ処理
		addEventListener(Event.ENTER_FRAME, loop);
		
		addEventListener(MouseEvent.CLICK, stageClick);
		init(465, 465);
	}
	
	private function init(width:int, height:int):void
	{
		stageWidth = width;
		stageHeight = height;
		
		var i:int;
		
		// フォースマップの初期化をおこないます
		forceMap = new BitmapData(width >> 2, height >> 2, false, 0x000000);
		seed = Math.floor( Math.random() * 0xFFFF );
		offset = [new Point(), new Point()];
		
		// バッファを生成します
		for (i = 0; i < NUM_BUFFER; i++) {
			buffers[i] = new BitmapData(width, height, false, 0);
		}
		
		// パーティクルを生成します
		for (i = 0; i < NUM_PARTICLE; i++) {
			particleList[i] = new Arrow(Math.random() * width, Math.random() * height);
		}
		
		screen.bitmapData = buffers[0];
		buffer_index = 0;
		
		addChild(screen);
	}
	
	private function loop(e:Event):void
	{
		var len:int = particleList.length;
		var arrow:Arrow;
		var buffer:BitmapData = screen.bitmapData = buffers[buffer_index];
		
		offset[0].x += 0.6;
		offset[1].y += 0.3;
		forceMap.perlinNoise(forceMap.width >> 1, forceMap.height >> 1, 2, seed, false, true, 6, false, offset);
		
		buffer.lock();
		buffer.colorTransform(buffer.rect, new ColorTransform(1, 1, 1, 1, -6, -12, -12, 0));
		
		particleList.sortOn("speed", Array.NUMERIC);
		
		for (var i:int = 0; i < len; i++)
		{
			arrow = particleList[i];
			arrow.step(forceMap.getPixel(arrow.x >> 2, arrow.y >> 2));
			buffer.copyPixels(arrow.img.bmp, arrow.img.bmp.rect, new Point(arrow.x-arrow.img.cx, arrow.y-arrow.img.cy));
		}
		
		buffer.unlock();
		buffer_index++;
		if(buffer_index >= NUM_BUFFER) {buffer_index = 0;}
	}
	
	private function stageClick(e:MouseEvent):void
	{
		switch(stage.displayState) {
		case StageDisplayState.NORMAL:
			stage.fullScreenSourceRect = new Rectangle(0, 0, 640, 480);
			init(640, 480);
			stage.displayState = StageDisplayState.FULL_SCREEN;
			return;
		case StageDisplayState.FULL_SCREEN:
		default:
			init(465, 465);
			stage.displayState = StageDisplayState.NORMAL;
			return;
		}
	}
}

class DisplayImage
{
	public var bmp:BitmapData;
	public var rect:Rectangle;
	public var cx:int, cy:int;
	
	function DisplayImage(bmp:BitmapData, cx:int, cy:int)
	{
		this.bmp = bmp;
		this.rect = bmp.rect;
		this.cx = cx;
		this.cy = cy;
		trimming();
	}
	
	private function trimming():void
	{
		var rect:Rectangle = bmp.getColorBoundsRect(0xFF000000, 0x00000000);
		var temp:BitmapData = new BitmapData(rect.width, rect.height, true, 0x00000000);
		cx -= rect.x;
		cy -= rect.y;
		temp.copyPixels(bmp, rect, new Point(0, 0));
		bmp = temp;
	}
}

class Arrow
{
	public var img:DisplayImage;
	public var x:int, y:int;
	public var vx:Number = 0, vy:Number = 0, ax:Number = 0, ay:Number = 0;
	public var rot:int = 0, speed:int = 0;
	private const MULTIPLY:Number = 64 / Math.PI;
	
	function Arrow(x:int, y:int) {
		this.x = x;
		this.y = y;
	}
	
	public function step(col:uint):void
	{
		ax += ( (col      & 0xff) - 0x80 ) * .0005;
		ay += ( (col >> 8 & 0xff) - 0x80 ) * .0005;
		vx += ax;
		vy += ay;
		x += vx;
		y += vy;
		
		rot = (128 + Math.atan2( vy, vx )* MULTIPLY) & 127;
		speed = Math.min(ALPHA_STEPS-1, (vx*vx + vy*vy));
		img = rotArr[rot + ROT_STEPS * speed];
		
		ax *= .96;
		ay *= .96;
		vx *= .92;
		vy *= .92;
		
		( x > stageWidth ) ? x = 0 : ( x < 0 ) ? x = stageWidth : 0;
		( y > stageHeight ) ? y = 0 : ( y < 0 ) ? y = stageHeight : 0;
	}
}