Support calculating face normals when tessellating. When this is done
before updating vertex normals it gives ~20% performance improvement.
Now vertex normal calculation only needs to perform a single pass on the
mesh vertices when called after tessellation.
Extended versions of normal & looptri update functions have been added:
- BM_mesh_calc_tessellation_ex
- BM_mesh_normals_update_ex
Most callers don't need to be aware of this detail by using:
- BKE_editmesh_looptri_and_normals_calc
- BKE_editmesh_looptri_and_normals_calc_with_partial
- EDBM_update also takes advantage of this,
where calling EDBM_update with calc_looptri & calc_normals
enabled uses the faster normal updating logic.
8a1860bd9a