How to check if touch I made is over a specific gameobject?

I was looking to draw a line on the screen.I only want to draw on the specific area of the screen .So how can I set if I could draw only on specific area. Drawing area(which is also UI) which is at the centre. That is when Drawing the lines with touch I want only to draw on the centre area avoiding the two sides.

Code (CSharp):

1.  if (!EventSystem.current.IsPointerOverGameObject(Input.GetTouch(0).fingerId))
2. {
3.  
4. // if touch is only on the central part then draw.
5.  
6.   }
7.  

 

I would instead add a script to the central drawing area game object which implements the IPointClickHandler interface - this would intercept clicks/taps made on that object. You can then pass that information to a more general input controller class to decide what to do with it.

Code (CSharp):

1. using UnityEngine.EventSystems;
2.  
3. public class DrawingArea : Monobehavior, IPointerClickHandler
4. {
5.     public void OnPointerClick(PointerEventData pointerEventData)
6.     {
7.         Debug.Log("Clicked on the drawing area!");
8.     }
9. }