Shape key interpolation was never implemented. Nowadays it's
probably better to implement similar features in different ways
rather than extending this system. Also some layer mapping
generation was unused. The motivation for this is easing some
cleanups to make this modifier less directly reliant on CustomData.
Pull Request: https://projects.blender.org/blender/blender/pulls/142131
This commit moves the freestyle edge and face mark tags to become
generic attributes, similar to other changes over the past years. The
attributes are called "freestyle_edge" and "freestyle_face", and they're
now propagated like regular boolean attributes.
Compatibility wise, forward and backward blend file compatibility are
maintained (for forward compatibility this is implemented a bit
differently than in the past because of the ongoing `AttributeStorage`
transition). In the Python API, `use_freestyle_mark` has been removed;
the attribute API should be used instead (just like bevel weights).
The BMesh (`freestyle`) accessors are removed too.
The conversions benefit from the fact that bit-wise, the old structs are
the same as `bool`, so we can convert to the old and new formats without
reallocating arrays.
Pull Request: https://projects.blender.org/blender/blender/pulls/141996
