Rewrite all shaders to use 2 predefined samplers called GSK_TEXTURE0 and
GSK_TEXTURE1 instead of wrapper functions.
On GL and Vulkan compat mode, these map directly to samplers.
On Vulkan proper, they map to 2 indices into the texture array, like
before.
From now on, the old nvidia GPUs - ie the 3xx drivers - should start
working again.
Fixes: #6564Fixes: #6574Fixes: #6654
This by itself is just more work refcounting all those images, but
there's actually a goal here, that will become visible in future
commits.
But this is split out for correctness and benchmarking purposes (the
overhead from refcounting seems to be negligible on my computer).
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.
This shader converts between two color states, by using the
same functions that we use on the cpu. The conversion to perform
is passed as part of the variation.
As premultiplication is part of color states on the shader, we also
encode the premultiplication in the shader.
And because opacity is a useful optimization, we also allow setting
opacity.
For now, the only possible color states are srgb and srgb-linear.
