UniRx + MessagePipe で、マウス操作をメッセージ化する

public class MouseEventManager : MonoBehaviour {

    [Inject] private IPublisher<MouseEvent> mouse { get; set; }

    [Inject] private IPublisher<DragEvent> drag { get; set; }

    private IObservable<MouseEvent> mouseDown { get; set; }
    private IObservable<MouseEvent> mouseUp { get; set; }
    private IObservable<MouseEvent> mouseDrag { get; set; }

    private Camera mainCamera;
    private IDisposable dragDisposable;

    private void Start () {

        mainCamera = Camera.main;

        // Stream の作成
        mouseDown = this.UpdateAsObservable ()
            .Where (_ => Input.GetMouseButtonDown (0))
            .Select (_ => { return GetMouseEvent (); });

        mouseUp = this.UpdateAsObservable ()
            .Where (_ => Input.GetMouseButtonUp (0))
            .Select (_ => { return GetMouseEvent (); });

        // ドラッグ中マウス座標をストリームし続ける
        mouseDrag = this.UpdateAsObservable ()
            .SkipUntil (mouseDown)
            .TakeUntil (mouseUp)
            .Repeat ()
            .Select (_ => { return GetMouseEvent (); });

        // SubScribe
        mouseDown.Subscribe (_ => {
            mouse.Publish (GetMouseEvent ());
        }).AddTo (this);

        dragDisposable = mouseDrag.Subscribe (d => {
            drag.Publish (new DragEvent {
                position = d.position, time = d.time
            });
        });

    }
    private MouseEvent GetMouseEvent () {
        var p = new Vector3 (
            Input.mousePosition.x,
            Input.mousePosition.y,
            12
        );

        return new MouseEvent {
            position = mainCamera.ScreenToWorldPoint (p), time = Time.time
        };
    }

    private void OnDestroy () {
        dragDisposable?.Dispose ();
    }
}

public class MouseEvent : IMouseEvent {
    public Vector3 position { get; set; }
    public float time { get; set; }
}

// MonoBehavior に取り付けて LifetimeScope へ登録するだけでマウスドラッグ先にくっつく
public class Player : MonoBehaviour {

    [Inject] private ISubscriber<DragEvent> drag { get; set; }

    void Start () {
        drag.Subscribe (d => {
            this.transform.position = d.position;
        });
    }

}