Right now we assume that the extension is there but this isn't always
the case. The next patch in this series will add a
non-WGL_ARB_pixel_format codepath to help VirtualBox and others.
The idea here is that we should lookup format information in struct
GlPixelFormatDesc, while StaticPixelFormatDesc and GlPixelFormatDescTemplate
will only be used to build the table.
Other than being a bit nicer than passing function pointers all over the
place, this helps dxgi/d3d10. While the swapchain itself is created in dxgi,
its surfaces are constructed in d3d10core, which makes it impractical for dxgi
to pass the appropriate function pointers.
This prevents fallout from the GL_EXT_fog_coord emulation. glEnable
and glDisable calls other than those that change GL_FOG are not
hooked. The glEnableWINE and glDisableWINE functions can be used to
add other hooks too if ever needed.
This confuses applications like Steam, which hook d3d9 and opengl
functions. It sees that the application uses opengl32, but it doesn't
realize that d3d9 is wrapped to opengl. Thus it starts messing around
with wined3d's wgl context. It usually tries to draw geometry with the
context, but cannot deal with some of the obscure extensions we have
activated.
Based on a patch by Stefan Dösinger. This is more flexible, and allows
the shader backend implementation to be simpler, since it doesn't have
to know about specific formats. The next patch makes use of this.
Note that minMipLookup and magLookup aren't particularly safe to use,
they're global arrays initialized from IWineD3DImpl_FillGLCaps(). The same
goes for the other global dynamic lookup tables.
GL_ATI_envmap_bumpmap provides two things: Signed V8U8 pixel formats,
and bump mapping. The extension is only supported on fglrx, and this
driver also supports GL_ARB_fragment_program. Thus the bump mapping
code is never used on any driver out there. Furthermore, if it is
used, it tends to crash the driver
The signed pixel format is used, as it can be used by pixel shaders or
the ARBfp replacement. However, the format is broken in fglrx, and
negative values are clamped to 0.0. This results in test
failures. WineD3D has an alternative codepath using scale+bias to
enable V8U8 using a standard signed RGB which works correctly on
fglrx.
Henri Verbeet