public IAltoTween OnUpdate(AltoTweenCallback onUpdate)
 {
     _onUpdate   = onUpdate;
     _passedTime = 0;
     Update(0);
     return(this);
 }
        /// <summary>
        ///   トゥイーンを登録する。obj は途中で止めたくなった時の対象指定用なので
        ///   その用途が無ければ null を渡してもよい
        /// </summary>
        public void Go(
            object obj, float from, float to, float duration,
            AltoEasingFunc easingFunc,
            AltoTweenCallback onUpdate
            )
        {
            var tween = new AltoTween(from, to, duration, easingFunc, onUpdate);

            tween.Init();
            AddTween(obj, tween);
        }
 public AltoTween(
     float from = 0f, float to = 0f, float duration = 0f,
     AltoEasingFunc easingFunc    = null,
     AltoTweenCallback onUpdate   = null,
     AltoTweenCallback onComplete = null
     )
 {
     _from       = from;
     _to         = to;
     _duration   = duration;
     _easingFunc = easingFunc;
     _onUpdate   = onUpdate;
     _onComplete = onComplete;
 }
 public IAltoTween OnComplete(AltoTweenCallback onComplete)
 {
     _onComplete = onComplete;
     return(this);
 }