http://bugs.winehq.org/show_bug.cgi?id=7644
--- Comment #24 from Douglas E. Warner silfreed-winehq@silfreed.net 2007-10-30 13:48:43 --- (In reply to comment #23)
Yes, however the OpenGL limits screw this up on your card. The card supports vertex shaders via GL_ARB_vertex_program just fine. The problem is that the lowest general way to implement pixel shaders is GL_ARB_fragment_program, which equals Shader Model 2.0 aka DirectX 9 shaders. This is not supported on your card.
There is an option though via an ATI specific extension called GL_ATI_fragment_shader. Unfortunately this would require a an additional complete shader backend, which isn't only ATI specific, but also specific to this very special type of cards. And since we don't even know if ati_fragment_shader works on the dri driver nobody wrote one yet. Patches are welcome ;-)
Okay; it must be implemented in the driver for windows because HL2 works just fine there and doesn't experience any of these artifacts.
I should mention that I'm using the free radeon driver right now; perhaps I should test with the fglrx driver and see if that is any better.