No colorstate conversions allowed here, though technically we could use
the alternate color state for the source most of the time, as the mask's
colorstate is only relevant for luminance.
This adds a GdkColorStates that encodes 2 of the default GdkColorStates
and wether their values are premultiplied or not.
Neither do the shaders do anything with this information yet, nor do the
shaders do anything with it yet, this is just the plumbing.
Make the generator generate calls for the correct glBindAttribLocation()
calls.
Usually this was done correctly, but we can't rely on it. So do it
explicitly.
A variation is a #define/specialization constant that every shader can
use to specialize itself as it sees fit.
This commit adds the infrastrcture, future commits will add
implementations.
This shader can take over from the ubershader. And it can be used
instead of launching the ubershader when no offscreens are necessary.
Also includes an optimization that uses the colorize shader when
appropriate.
