This is the Nth attemt to make clipping work with GLSL shaders. The patch now
uses the GLSL quirk table to handle cards that need a custom varying for
gl_ClipPos, and the code is adapted to the changed state table and shader
backend system.
This extension is a subset of GL_NV_half_float that defines support
for the stream format(same constant), but doesn't define texture
formats or immediate mode entrypoints.
GL_ARB_shader_texture is supported on dx9 ATI cards(and probably dx10
ones too). For Nvidia cards I included a fallback to normal texld.
GL_EXT_gpu_shader4 supports similar texture*Grad GLSL functions, just
with an EXT prefix instead of ARB. For dx9 NV cards we'd have to use
GL_NV_fragment_program2, which supports a texldd equivalent on those
cards.
Nvidia doesn't offer it on geforce 7 and earlier cards, but some games need
it. This is surprising because the extension was made specifically for
compatibility purposes for older cards.
Some drivers apparently need private constants, or don't have an efficient
immval packing. For example, MacOS seems to need 1 float for each different
relative addressing offset. fglrx has the same issue, although it is more
efficient in general
Previously this worked on most drivers because the 16 + 4 reserved int and
bool constants kept the problem hidden. Now that we are more aggressive with
uniforms we have to keep free room for some drivers.
This allows better defining of driver desc fixups without adding extra if
lines for each card.
For starters, there's a fixup for the advertised GLSL constants in ATI cards.
fglrx advertises 512 GLSL uniforms instead of the supported 1024(means 128
instead of 256 vec4's). This bug was confirmed by ATI.
This moves the GLSL and ARB specific reserved constants out of directx.c into
the get_caps methods of the shader backends. That way the number of reserved
constants remains in the backend.
GL_LIMITS({v/p}shader_constantsF) now contains the real number of constants as
advertised by GL instead of some mixture of GL info and backend implementation
specifics. This makes it easier for backends to decide how many constants to
use.
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.
Louis Lenders