TouchPad.cs



public class TouchPad: MonoBehaviour {
	
	public float touchRectX;
	public float touchRectY;
	public float touchRectW;
	public float touchRectH;
	

	private Rect touchArea;
	private bool touching;
	private int touchId = -1;
	
	void Update() {
		
		int count = Input.touchCount;
	
		if ( count == 0 ) {
			touching = false;
			touchId = -1;
		} else {
			for(int i = 0;i < count; i++) {
				Touch touch = Input.GetTouch(i);
				
				if (touchArea.Contains(touch.position)
					&& (touchId == -1 || touchId != touch.fingerId)) {
	
					touchId = touch.fingerId;
					
				}
		
				if ( touchId == touch.fingerId ) {
					
					if ( touch.phase == TouchPhase.Ended 
						|| touch.phase == TouchPhase.Canceled ) {
						
						touching = false;				
						touchId = -1;		
					} else {
						touching = true;
					}
				}			
			}
		}
	}
	
	public bool GetTouch() {
		return touching;
	}

}

touchRectX,touchRectY,touchRectW,touchRectHは0から1までのfloat型で指定する。
画面左下が(0,0)となる。