possiblem, this has to guess when the size is too big so as to re-
well.
If this isnt done, then the number of faces is used to allocate the
initial array to at least avoid many small allocs.
added BLI_array_reserve() to reserve elements and avoid reallocing many
small arrays when the loop starts.
- made editbmesh_calc_modifiers() ensure tessfaces, this has the advantage that if the tessfaces are already created they wont get re-made as was happening before.
- Pass MFace, MTface and OrigIndex arrays via userData to compareDrawParams callback
rather than looking up for this layers for each face
- This allowed to avoid massing DM to compare callback which seems like a bad-level pass
- Fixed crashes on some video cards when assigning different materials to different
faces in edit mode. Both of intel and nvidia cards in my laptop were affected by
this error
