flash on 2010-11-12

/**
 * Copyright yama3 ( http://wonderfl.net/user/yama3 )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/3cMl
 */

package {
    import flash.display.Bitmap;
    import flash.display.BitmapData;
    import flash.display.Sprite;
    import flash.display.StageAlign;
    import flash.display.StageScaleMode;
    import flash.events.Event;
    import flash.geom.ColorTransform;
    import flash.geom.Point;
    import flash.geom.Rectangle;
    import net.hires.debug.Stats;
    
    [SWF(frameRate='60', backgroundColor='0x0')]
    
    public class FlashTest extends Sprite {
        private var _bmp:Bitmap;
        private var _bmd:BitmapData;
        private var _bmdRect:Rectangle;
        private var _colorTransform:ColorTransform = new ColorTransform(0.0, 0.5, 0.9, 1.0);
        private var _nodeArray:Array = [];
        private var _first:Node;
        private var _maxNum:int = 30000;
        
        public function FlashTest() {
            this.stage.align = StageAlign.TOP_LEFT;
            this.stage.scaleMode = StageScaleMode.NO_SCALE;
            addEventListener(Event.ADDED_TO_STAGE, init);            
        }
        
        private function init(evt:Event):void {
            removeEventListener(Event.ADDED_TO_STAGE, init);
            var old:Node;
            
            _bmd = new BitmapData(465, 465, false, 0x000000);
            _bmp = new Bitmap(_bmd);
            addChild(_bmp);
            this._bmdRect = new Rectangle(0, 0, 465, 465);
            
            for(var i:int=0; i<this._maxNum; i++){
                var n:Node = new Node();
                n.pos_x = Math.random() * 465;
                n.pos_y = Math.random() * 465;
                this._nodeArray.push(n);
                if(_first == null) {
                    old = _first = n;
                } else {
                    old.next = n;
                    old = n;
                }
            }
            addChild(new Stats());
            addEventListener(Event.ENTER_FRAME, onEnter);
        }
        
        private function onEnter(evt:Event):void
        {
            var gravPoint_x:Number = mouseX;
            var gravPoint_y:Number = mouseY;
            var n:Node = _first;
            this._bmd.lock();
            do
            {
                var diff_x:Number = gravPoint_x - n.pos_x;
                var diff_y:Number = gravPoint_y - n.pos_y;
                var acc:Number = 50 / (diff_x * diff_x + diff_y * diff_y);
                var acc_x:Number = acc * diff_x;
                var acc_y:Number = acc * diff_y;
                n.v_x += acc_x;
                n.v_y += acc_y;
                n.pos_x += n.v_x;
                n.pos_y += n.v_y;
                n.v_x *= 0.96;
                n.v_y *= 0.96;
                
                if(n.pos_x > 465)
                n.pos_x = 0;
                else if(n.pos_x < 0)
                n.pos_x = 465;
                if(n.pos_y > 465)
                n.pos_y = 0;
                else if(n.pos_y < 0)
                n.pos_y = 465;
                
                this._bmd.setPixel(n.pos_x, n.pos_y, 0xffffff);
            }
            while(n = n.next);
            this._bmd.colorTransform(this._bmdRect, this._colorTransform);
            this._bmd.unlock();
        }
    }
}

import flash.geom.Point;

class Node
{
    public var v_x:Number = 0;
    public var v_y:Number = 0;
    public var pos_x:Number = 0;
    public var pos_y:Number = 0;
    public var next:Node;
}