Method which overrides a base class's virtual methods are expetced to
be marked with `override`. This also gives better idea to the developers
about what is going on.
This does two things:
* Introduce new `materialize_compressed` methods. Those are used
when the dst array should not have any gaps.
* Add materialize methods in various classes where they were missing
(and therefore caused overhead, because slower fallbacks had to be used).
In a test file from T96282, this commit reduces the runtime of the
delete geometry node from 82 ms to 23 ms, a 3.6x improvement.
Writing to vertex groups in other cases should be faster too.
The largest improvement comes from not writing a new weight
of zero if the vertex is not in the group. This mirrors the behavior
of custom data interpolation in `layerInterp_mdeformvert`.
Other improvements come from using `set_all` for writing
output attributes and implementing that method for vertex groups.
I also implemented `materialize` methods. Though I didn't obverse
an improvement from this, I think it's best to remove virtual method
call overhead where it's simple to do so.
The test file for the delete geometry node needs to be updated.
These methods could be parallelized too, but better to do that later.
Differential Revision: https://developer.blender.org/D14420
