This adds code for handling fixed function fragment processing with the
GL_ATI_fragment_shader extension. This is a sort-of programmable
interface for fragment processing at the level of shader model 1.4 in
d3d. This code is of use on r200, r250 and r280 cards(radeon 8500 to
9200) which do not support GL_ARB_fragment_program, but support pixel
shader 1.4 on Windows. This code is somewhat a counterpart to the
existing fragment processing code using GL_NV_register_combiners and
GL_NV_texture_shader.
The whole control structures in directx.c get terribly confusing with
the various codepaths for texturing and different shader
implementations. It is also hard to reflect the shader model
decisions this way too. This patch moves the shader specific parts of
the caps code into the shader backend where we can set our caps
dependent of the shader model decisions and without complex caps flag
checks.
It is legal to pass Usage=0 to CheckDeviceFormat and in both this case
and in the case a format isn't available UsageCaps would be 0 and a
format would be reported available.
We assume it has the same capabilities as VOLUMETEXTURE. MSDN is very
vague on this topic. Intel/Nvidia/ATI drivers seem to offer nearly the
same caps on both, so do that too.
Add a new property of the shader backend which indicates whether the
shader backend is able to dirtify single constants rather than
dirtifying vshader and pshader constants as a whole. Depending on this
a different Set*ConstantF implementation is used which marks constants
dirty. The ARB shader backend uses this and marks constants clean
after uploading.
As some Mesa developers pointed out, the GL_ARB_vertex_program grammar
does not allow an immediate value as source argument in ARL. Most
compilers accept it, but since it is not the purpose of the test
program to test for this replace it with a proper constant.
Often the Linux / MacOS graphics driver version is of no use for
finding a proper driver version to report to the D3D app. So this
patch adds some infrastructure for easy hardcoding of card specific
driver versions to report to the application. This helps applications
which make assumptions based on the driver version, like bug
workarounds.
Stefan Dösinger