Until now I used a Win32 application under Windows95. (CVF6.6B). Now I have changed the system to Windows 2000.
There appeared to be an important difference in redrawing the window when an activated menu is removed from the screen. In W95 only the part used by the menu was repainted, but in W2000 the whole window is repainted.
As well an executable made under W95 as a newly compiled and linked executable under W2000 produces the same problem.
How can I anticipate this complete redraw of the window when using a menu?
My program is an W32 application using OpenGL to draw the user window area.