If a format is not supported natively by opengl, a shader may be able
to convert it. Up to now, CheckDeviceFormat had magic knowldge which
GL extensions lead to which supported format. This patch adds
functions that allow CheckDeviceFormat to ask the actual
implementation for its capabilities.
This is an ATI specific format designed for compressed normal maps,
and quite a few games check for its existence. While it is an
ATI-specific "extension" in d3d9, it is a core part of
D3D10(DXGI_FORMAT_BC5), and supported on Geforce 8 cards.
This patch enables texture filtering for textures using the A4R4G4B4
format, I can see no reason why it shouldn't be filtered (especially
considering X4R4G4B4 has it).
This creates an nvts version of this function, and removes the nvts
code from the original one. The nvts version is used by the nvts
pipeline implementation, the original one by the nvrc-only, atifs and
ffp one.
For each pixel format we store a flag in the table whether it supports
post pixelshader blending. Before applying blending or during a
context switch we verify that blending is turned off for the
format. In case of R32F this gave a 5-6x performance boost (without
filtering and software conversion).
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.
OpenGL drivers do not support some low precision internal formats
like GL_RGB5 for fbo color targets. Direct3D application depend on them,
so provide a fallback format for render targets if the requested format
itself is not supported.