http://bugs.winehq.org/show_bug.cgi?id=9665
--- Comment #22 from Stefan Dösinger stefandoesinger@gmx.at 2007-10-29 12:32:42 --- The default is some sort of autodetection. It tells the app that D3D is available. If the game uses D3D, it uses OpenGL surfaces. Otherwise, it sticks to GDI surfaces. If you set it to "gdi", it says D3D is NOT available, and returns an error if the app tries to use it.