SPRING PARTICLES

Main
メインクラス.

by kazy 23 Jun 2009

• Related works: 2
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/**
 * Copyright kazy ( http://wonderfl.net/user/kazy )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/oNX4
 */

package {
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.geom.Point;
	/**
	 * Main
 	 * メインクラス.
	 */
	public class Main extends Sprite
	{
		private var particles:Array;
		private var numParticles:uint = 100;
		private var minDist:Number = 100;
		private var springAmount:Number = .001;
		/**
		 * コンストラクタ.
		 */
		public function Main()
		{
			init();
		}
		/**
		 * 初期設定.
		 */
		private function init():void
		{
			particles = new Array();
			//numParticlesの数だけボール生成
			for(var i:uint = 0; i < numParticles; i++)
			{
				var particle:Ball = new Ball(2);
				particle.x = Math.random() * stage.stageWidth;
				particle.y = Math.random() * stage.stageHeight;
				particle.vx = Math.random() * 6 - 3;
				particle.vy = Math.random() * 6 - 3;
				addChild(particle);
				particles.push(particle);
			}
			//ENTER_FRAMEをリスナー登録
			addEventListener(Event.ENTER_FRAME, onEnterFrame);
		}
		/**
		 * onEnterFrame.
		 */
		private function onEnterFrame(event:Event):void
		{		
			for(var i:uint = 0; i < numParticles; i++)
			{
				var particle:Ball = particles[i];
				//加速
				particle.x += particle.vx;
				particle.y += particle.vy;
				//ステージを出たら、反対側から入る
				if(particle.x > stage.stageWidth)
				{
					particle.x = 0;
				}
				else if(particle.x < 0)
				{
					particle.x = stage.stageWidth;
				}
				if(particle.y > stage.stageHeight)
				{
					particle.y = 0;
				}
				else if(particle.y < 0)
				{
					particle.y = stage.stageHeight;
				}
			}
			  
			for(i=0; i < numParticles - 1; i++)
			{
				var partA:Ball = particles[i];
				for(var j:uint = i + 1; j < numParticles; j++)
				{
					var partB:Ball = particles[j];
					//バネの動き
					spring(partA, partB);
				}
			}
		}
		/**
		 * ボール間スプリング.
		 * @param partA ボールA
		 * @param partB ボールB
		 */
		private function spring(partA:Ball, partB:Ball):void
		{
			//各座標の距離
			var dx:Number = partB.x - partA.x;
			var dy:Number = partB.y - partA.y;
			//直線距離
			var dist:Number = Math.sqrt(dx * dx + dy * dy);
			if(dist < minDist)
			{
				//スプリング加速
				var ax:Number = dx * springAmount;
				var ay:Number = dy * springAmount;
				//各ボールの加速度へ設定
				partA.vx += ax;
				partA.vy += ay;
				partB.vx -= ax;
				partB.vy -= ay;
			}
		}
	}
}
/**
 * Ball
 * ボール生成クラス.
 */
class Ball extends flash.display.Sprite {
	public var radius:Number;
	private var color:uint;
	public var vx:Number = 0;
	public var vy:Number = 0;
	public var mass:Number = 1;
	/**
	 * コンストラクタ.
	 */
	public function Ball(radius:Number=40, color:uint=0x990033) {
		this.radius = radius;
		this.color = color;
		init();
	}
	/**
	 * 初期化.
	 */
	public function init():void {
		graphics.beginFill(color);
		graphics.drawCircle(0, 0, radius);
		graphics.endFill();
	}
}