A continuation of #116901. This one doesn't have a performance impact
in my testing. It also adds a bit more code compared to main so it isn't
really obviously "better" like the previous refactors. However it does
get us closer to removing the "extractors" callback iteration loop
(`edit_data` is the only other enabled by default), and I'd argue that
the final code is easier to iterate on in the future since it's more
self-contained.
I made an effort to avoid storing restart indices in the index buffers.
Though this requires a bit more calculation on the CPU (particularly
because the hidden gaps in the IBO need to be compressed out), it
reduces overall CPU->GPU traffic and removes the need to strip the
restart indices on Metal.
Pull Request: https://projects.blender.org/blender/blender/pulls/122084
07eac30070