RectTransformUtility.RectangleContainsScreenPoint performance

Hi,

As odd as it sounds I'm having an issue with the performance of RectTransformUtility.RectangleContainsScreenPoint. I don't imagine its a crazy complex bit of functionality but from the CS reference I can only get as far as RectTransformUtility.PointInRectangle. Any chance of getting hold of the source code or an implementation I can maybe optimize for my needs?

 

this is what Ive come up with but not sure if its a 100% match

Code (CSharp):

1. static bool RectangleContainsScreenPoint(RectTransform rt, Vector3 pos, Camera cam)
2. {
3.     var ray = cam.ScreenPointToRay(pos);
4.     var plane = new Plane(rt.forward, rt.position);
5.     if (plane.Raycast(ray, out var hit))
6.     {
7.         var hitPoint = ray.origin + ray.direction * hit;
8.         var u = rt.InverseTransformPoint(hitPoint);
9.         var rect = rt.rect;
10.         return u.x > rect.xMin && u.x < rect.xMax &&
11.                u.y > rect.yMin && u.y < rect.yMax;
12.     }
13.     return false;
14. }