Flex/orbit1 - Sample is best!

開発環境	Apache Flex SDK 4.13.0
	FlashDevelop 4.7.1.1
実行環境	Microsoft Windows 8.1 (64bit)
プロジェクトの種類	ActionScript 3/AS3 Project
プロジェクト名	orbit1

http://www.maroon.dti.ne.jp/lance/flash/orbit1.html

Main.as

package
{
	import flash.display.Graphics;
	import flash.display.Sprite;
	import flash.events.Event;
 
	public class Main extends Sprite 
	{
		private const r:Number = 200; // 半径
		private var a:Number = 0; // 角度
		private var canvas:Sprite;
 
		public function Main() 
		{
			if (stage) init();
			else addEventListener(Event.ADDED_TO_STAGE, init);
		}
 
		private function init(e:Event = null):void 
		{
			removeEventListener(Event.ADDED_TO_STAGE, init);
			// entry point
 
			canvas = new Sprite;
			addChild(canvas);
			canvas.x = 400;
			canvas.y = 300;
 
			addEventListener(Event.ENTER_FRAME, onEnterFrame);
		}
 
		private function onEnterFrame(e:Event):void 
		{
			var x:Number = r * Math.cos(a * Math.PI / 180);
			var y:Number = r * Math.sin(a * Math.PI / 180);
			a += 2;
 
			// 円軌道
			var g:Graphics = canvas.graphics;
			g.clear();
			g.lineStyle(1, 0x000000);
			g.drawCircle(0, 0, r);
			g.beginFill(0xff0000);
			g.drawCircle(0, 0, 10);
			g.drawCircle(x, -y, 5);
			g.endFill();
		}
 
	}
 
}