Windowed OpenGL & Windows 98


I have a strange problem when running my app in windowed mode under Windows 98: The OpenGL always draws its entire rectangle, even if my window is overlapped by another one. The bug happens after working some time with my computer, it’s not from the beginning. I don’t have this problem with Windows XP. Any tips?


Which OpenGL implementation is rendering?
If it’s Microsoft’s GDI generic, that’s an MS bug then, search their knowledge base for known bugs.
If it’s any other vendor, this might be a driver error. Update the graphics drivers.
If it’s only happening in your application, check if you have initialized the window style correctly to contain WS_CLIPCHILDREN and WS_CLIPSIBLINGS.
Check if explicitly requesting a PIXELFORMATDESCRIPTOR which has the PFD_SWAP_COPY flag set helps.