The bug is related to 31581 and the main cause is the small offset that
BM_loop_interp_from_face introduces before calculating barycentric
weights. Solved by only calculating displacement layer.
- memset(..., -1) is used incorrectly even though it worked: MOD_solidify.c - thanks Halley from IRC for noticing this. use fill_vn_i() instead.
- quiet warnings in editmesh_slide.c
- cleanup comments in bmesh and some other minor comment additions.
- Edge rotate would leave verts selected, this would give problems because those selections would leave edges that would try to rotate when run again. now de-select old verts on edge rotate.
- Rotating into hidden verts gave odd results, now make sure hidden state is ok.
- BMO_slot_buffer_hflag_disable / BMO_slot_buffer_hflag_enable now have flushing for the hide flag too.
Knifetool accumulates a bunch of proposed cuts and when the user
confirms, it makes them all. The old code did this by using scanfill
to triangulate the cutting edges in their faces, and then merging
triangles where possible. This sometimes ended up with strange
lost faces, and also made it so that when holes were cut, the
surrounding face ended up totally triangulated. But 29908 was
an example of a lost face.
This new code directly finds chains of cutting edges that go from
one side of a face to the other and using BM_edge_split_n to make
the cuts. Holes are handled by finding two good places where
the hole can be connected to the containing face (using two
because I think some other code in bmesh assumes that there are
no edges that appear twice in a face).
The old code is still there with #if SCANFILL_CUTS, so can easily revert
if this proves to be a bad idea.
Also, a small fix to previously added BM_split_n (forgot to
copy face attributes to new face).
Now create the rotate edge in advance and copy its customdata (before joining the faces).
This commit also fixes an annoyance where tryangulating faces could create duplicate edges.
On a user level, edge rotate now works better with multiple edges selected, it wont make zero area faces or rotate edges into existing ones.
With a single edge selected - rotate is less strict and will allow ugly resulting faces but still checks on duplicate edges.
API:
* BM_edge_rotate now takes a flag, to optionally...
** check for existing edge
** splice edge (rotate and merge)
** check for degenerate resulting faces (overlapping geometry, zero area)
** beauty - only rotate to a better fit.
... this allows it to still be used as a low level API function since all checks can be skipped.
* BM_edge_rotate() now works a bit different, it find the new edge rotation before joining the faces - exposed by BM_edge_rotate_calc().
* Added api call bmesh_radial_faceloop_find_vert() - Radial Find a Vertex Loop in Face
* improve check to see if edge rotate can be done,
was checking if both edges verts have an edge count of 2, which is really a meaningless test since the verts can have stray edges connected and the result wont work right.
instead check if the next verts in both faces share a vertex.
* add utility function BM_face_other_vert_loop() which gets the next loop in a face.
* add convenience function BM_edge_face_pair() which returns 2 faces for edges that have exactly 2 face users. (saves ugly e->l->radial_next ... in code) and is more readable.
* made bmesh_structure.h function names more consistant.
* remove unused code in bmesh_structure.c
* removed 'Edge Flip' operator (missing from bmesh but looked into trunk feature and dont think its worth keeping).
* tagged some BMESH_TODO's
now collapse the vertex into the edges.
also disable removing the vertrex when it could not be collapsed (old code), found it could would connected faces which isn't acceptable - now return fail in that case.
