The color correction cannot be done behind the back of the individual
instruction handlers because it might conflict with the instruction's
color modifications and the D3D provided writemask.
Most callers work on a stateblock rather than a device, and the main fields
we check (vertexShader and pixelShader) are part of the stateblock as well.
This is a first step towards cleaning up the fog mess. The fog
parameter is added to the pixelshader compile args structure. That way
multiple pshaders are compiled for different fog settings, and the
pixel shader can remove the fog line if fog is not enabled. That way
we don't need special fog start and end settings, and this allows us
to implement EXP and EXP2 fog in the future too.
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.
This was suggested by Ivan quite a while ago, and we need it to better
handle conflicting texture format corrections and similar stateblock
value changes which until now required a recompilation of the entire
shader
A number of considerations contribute to this:
1) The shader backend knows best which shader(s) it needs. GLSL needs
both, arb only one
2) The shader backend may pass some parameters to the compilation
code(e.g. which pixel format fixup to use)
3) The structures used in (2) are different in vs and ps, so a
baseshader::Compile won't work
4) The structures in (2) are wined3d-private structures, so
having a public method in the vtable won't work(its a bad idea
anyway).
SM3.0 requires 10 4 component float varyings for passing stuff between
vertex and pixel shaders. GF7 and earlier report 8 generic varyings +
gl_Color and gl_SecondaryColor in GLSL. This patch allows us to use
gl_Color and gl_SecondaryColor to get 2 extra varyings, which some
games, like C&C3 with highest gfx settings, require.
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.
Stefan Dösinger