This patch gathers all values to be loaded to shader uniforms into a new
struct gl_shader_config along with texture target and filter
information. Struct gl_shader becomes opaque outside of gl-shaders.c.
Everything that used or open-coded these are converted.
The aim is to make gl-renderer.c easier to read. Previously, uniform
values were loaded up in various places, texture units were set up in
one place, textures were bound into units in different places. Stuff was
all over the place.
Now, shader requirements and associated uniform data is stored in a
single struct. The data is loaded into a shader program in one function
only.
That makes it easy for things like maybe_censor_override() to replace
the whole config rather than poke only the shader requirements. This may
not look like much right now, but when color management adds more
uniforms and even hardcoded color need to go through the proper color
pipeline, doing things the old way would become intractable.
Similar simplification can be seen in draw_view(), where the RGBA->RGBX
override becomes more contained. There is no longer a need to "pre-load"
the shader used by triangle fan debug. Triangle fan debug no longer
needs to play tricks with saving and restoring the current shader.
The real benefit of this change will probably come when almost all
shader operations need to take color spaces into account. That means
filling in gl_shader_config parts based on a color transformation.
This is based on an idea Sebastian already used in his Weston color
management work.
Co-authored-by: Sebastian Wick <sebastian@sebastianwick.net>
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>