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.
Some stateblock parameters have to be compiled into the GL pixel
shader code, like lines for pixelformat fixups. This leads to problems
when applications switch those settings, requiring a recompilation of
the shader. This patch enables wined3d to have multiple GL shaders for
a D3D shader(pixel shaders only so far) to handle this more
efficiently.
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.
It isn't related to the shader backend any longer. The nvts_enable in
the ffp code isn't quite right as well, it should be moved away once
there is a dedicated nvts fragment pipeline replacement
Calling shader_select() from inside depth_blt() isn't necessarily
safe. shader_select() assumes CompileShader() has been called for the
current shaders, but that depends on STATE_VSHADER / STATE_PIXELSHADER
being applied. That isn't always true when depth_blt() gets called,
with the result that sometimes GLSL programs could be created with no
shader objects attached.
The previous logic assumed that if NVTS or ATIFS are available they
will be used. This happens to be true for NVTS, but ATIFS is only used
if neither ARBFP nor GLSL are supported. This breaks fixed function
fragment processing on ATI r300 and newer cards
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.
Generating the shader ID and parts of the shader prolog and epilog was
done by the common vertexshader.c / pixelshader.c, which is ugly.
This patch doesn't get rid of all the uglyness, somewhen we'll still
have to sort out the relationship of [arb|glsl]_generate_shader and
[arb|glsl]_generate_declarations.
Henri Verbeet