[AIR] Accelerometerから、回転角度に変換

AccelerometerConvertToRotation_Sample.as

/**
 * copyright (c) 2012 www.romatica.com
 * @auther itoz
 * 2012.2.17 17:31:03
 */
package 
{
    import flash.events.AccelerometerEvent;
    import flash.sensors.Accelerometer;
    import flash.events.Event;
    import flash.display.Sprite;

    /**
     * [Air] Accelerometerから、回転角度に変換.
     *
     * 【サンプル動画 】
     * @see http://www.youtube.com/watch?v=IkPVwSv6rjE
     *     
     */
    public class AccelerometerConvertToRotation_Sample extends Sprite
    {
        private var circle : Sprite;
        private var rollingX : Number = 0;
        private var rollingY : Number = 0;
        private const FACTOR : Number = 0.5;

        public function AccelerometerConvertToRotation_Sample()
        {
            addEventListener(Event.ADDED_TO_STAGE, onAdded);
        }

        private function onAdded(event : Event) : void
        {
            removeEventListener(Event.ADDED_TO_STAGE, onAdded);
            setCircle();
            setAccelerometer();
        }

        /**
         * 円を生成
         */
        private function setCircle() : void
        {
            circle = addChild(new Sprite()) as Sprite;
            circle.graphics.beginFill(0x00cc00);
            circle.graphics.drawCircle(0, 0, 64);
            circle.graphics.beginFill(0x0000cc);
            circle.graphics.drawCircle(50, 0, 10);
            circle.graphics.endFill();
            circle.x = stage.stageWidth / 2;
            circle.y = stage.stageHeight / 2;
        }

        /**
         * Accelerometerを生成
         */
        private function setAccelerometer() : Boolean
        {
            var accelerometer : Accelerometer;
            if (Accelerometer.isSupported) {
                accelerometer = new Accelerometer();
                if (!accelerometer.muted) {
                    accelerometer.setRequestedUpdateInterval(1000 / 30);
                    accelerometer.addEventListener(AccelerometerEvent.UPDATE, accelerometerUpdate);
                    return true;
                }
            }
            return false;
        }

        /**
         * Accelerometer アップデート
         */
        private function accelerometerUpdate(event : AccelerometerEvent) : void
        {
            // ----------------------------------
            // Accelerometerの傾きを 角度に変換
            // ----------------------------------
            rollingX = (event.accelerationX * FACTOR) + (rollingX * (1 - FACTOR));
            rollingY = (event.accelerationY * FACTOR) + (rollingY * (1 - FACTOR));
            var rad : Number = Math.atan2(rollingY, -rollingX);
            var angle : Number = rad * 180 / Math.PI;

            //----------------------------------
            //  円を回転
            //----------------------------------
            if (circle != null) circle.rotation = angle;
        }
    }
}