Slightly reduces the number of unique vertex shaders but doesn't do much
for the pipeline count, as the fragment shader has a tex flag. Still
worth doing for the simplification.
Instead of just the vertex type.
This will allow things like the vertex decoder supplying defaults, in
order to reduce the number of unique vertex shaders at the cost of
slightly larger vertex data.
This doesn't actually do that yet though, it's just a refactor that can
be done separately.
Part of #16567
Will resolve a future issue in the multisampling PR, where the
GPU_USE_FRAMEBUFFER_FETCH flag changes at runtime if you switch between no AA and MSAA.
Just figured I'd get it in separately for safety.
In #16104, we drastically reduced the number of shader variants for
games that use flexible lighting setups. I looked at a few games and it
seems that a lot of games have the same shaders with fog on/off, while
fog is super cheap to compute. So let's just always do it, reducing
vertex shader variants further (though the amount of pipelines will probably
remain the same, since we still specialize the fragment shader).
Might also be worth adding a dynamic bool for the fragment shader, but
if so, doing it separately.
This drastically reduces the shader compile stutter that happens when a lot of new
light setups are created, like on the first punch in Tekken 6.
There's more stuff that might benefit from being made dynamic like this.
These branches are very cheap on modern GPUs since they're branching on
a uniform variable, so no divergence.
Only tested on Vulkan. I think we'll need to keep the old path too for
gpus like Mali-450...
