[csharp][unity] simple swipe controller

SwipeManagerImproved.cs

/* 
  In the original source, there are two unnecessary magnitude calculations, calculated
  each frame. This isn't the most performant choice as to calculate magnitude one must divide
  by the sqrRoot of the sum of each component squared, so
  this may improve performance, however slight. 
  
  Also removed was a redundant calculation where the original author determined 
  delta x and y, once for checking if a swipe happened and once more to determine the sign.
  
  Essentially, all these removed operations, were calculating the same thing, so all the redundant
  calculations were removed and replcaed by:
  
    Vector3 positionDelta = (Vector3) t.position - startPosition;
    
  which then yields delta x and delta y via positionDelta.x and positionDelta.y respectively.

  There are some other improvements made to this script not shown in this example as they do not pertain
  directly to the improvement of the original source code.
   
  Original source: https://dl.dropboxusercontent.com/u/97948256/SwipeDetctor.cs 
*/


using UnityEngine;

public class InputController : MonoBehaviour {
    [SerializeField] private float minimumSwipeDistanceY;
    [SerializeField] private float minimumSwipeDistanceX;

    private Touch t = default(Touch);
    private Vector3 startPosition = Vector3.zero;

    private void Update () {
        if (Input.touches.Length > 0) {

        t = Input.touches[0];

        switch (t.phase) {
            case TouchPhase.Began:
                startPosition = t.position;
                return;
            case TouchPhase.Ended:
                Vector3 positionDelta = (Vector3) t.position - startPosition;
                if (Mathf.Abs(positionDelta.y) > minimumSwipeDistanceY) {
                    if (positionDelta.y > 0) {
                        Debug.Log("UP SWIPE!!!");
                    } else {
                        Debug.Log("DOWN SWIPE!!!");
                    }
                }
                if (Mathf.Abs(positionDelta.x) > minimumSwipeDistanceX) {
                    if (positionDelta.x > 0) {
                        Debug.Log("SWIPE RIGHT");
                    } else {
                        Debug.Log("SWIPE LEFT");
                    }
                }
                return;
            default:
                return;
            }
        }
    }
}