[Bug 12557] System Shock 2 Demo: Starting game results in black screen

http://bugs.winehq.org/show_bug.cgi?id=12557

--- Comment #57 from Roderick Colenbrander   2008-05-04 09:54:13 ---
The main limitation for older ddraw / d3d apps is the poor LockRect /
UnlockRect performance. These calls on Windows give you direct access to e.g.
the framebuffer (they can give you a direct pointer to the video memory).
OpenGL doesn't provide this and we need to read the data from the framebuffer
on a LockRect operation and need to write the result back to screen during an
UnlockRect operation. On systems with PBOs performance is a lot better because
they give you asynchronous reads / writes which results in that you don't have
to wait before you can continue with other tasks.