How can I determine if a RECT area inside of my window is covered by other windows (occluded). I mean, if the user can see this RECT area or not?
I could not find the right answer to this question. In fact, I should define a function with a signature like this
bool isWindowPartVisible(HWND handle, RECT rect)
Inside this function, I am allowed to use only the Windows API function.
Source: Windows Questions