Should also fix [#30266], [#29451], and partly [#30316].
Here are the changes made by this commit:
* It adds a "dirty" flag to DerivedMesh struct (for now, only DM_DIRTY_TESS_CDLAYERS, but more might be added as needed).
* It adds a new func, DM_update_tessface_data, which assumes tessfaces themselves are valid, but updates tessellated customdata from their poly/loop counter parts.
* At end of modstack, when valid tessellated faces are present in finaldm , but the cdlayers dirty flag is set, call that function (instead of recomputing the whole tessellation).
* Edits to the codes concerned (UVProject, DynamicPaint, and Subsurf modifiers).
* Also add to subsurf dm generation code the creation of a CD_POLYINDEX layer (mandatory for DM_update_tessface_data to work well, and imho all tessellated dm should have one).
Note: some pieces of old code are just #if 0’ed, will clean them later.
this is no big improvement but at least its not a regression.
using the new operator for the bevel modifier can be enabled again be uncommenting a define.
This idea is borrowed from the multires modifier, which already
checked if the object was in sculpt mode and, if so, created the
PBVH. That check is now moved higher up the chain into
mesh_build_data(), so that it occurs for CDDerivedMesh too.
This also replaces an assert in cdDM_getPBVH for tesselated mesh faces
with a call to create them if missing.
* 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
rather then recalc polygon normals - solidify is simple enough to just flip the normals of the copied faces, the rim faces normals are already re-calculated so copy them.
Don't really know why, but appears we need to recalc normals when this option is ON.
Also small perf improvement (avoid to compute twice each face normals).
* better type safety for BM_elem_flag_* and BM_elem_index_* functions.
* add BMElem type to be used where BMFace/Edge/Vert/Loop can be interchanged.
* fix bug in select manifold, found when making functions more strict.
* change BMO_elem_flag_* defines to inline functions.
* BMO_slot_map_insert() is too big for an inline function - un-inline it.
* remove redundant casts.
* remove 'select' and 'hide' from BMLoop
* remove BMesh.update
* add BMesh.normal_update(skip_hidden=False)
* add BMElemSet.index_update(), eg: bm.verts.index_update()
bmesh api
* BM_mesh_normals_update() now takes skip_hidden as an argument
(previously this was default behavior), however this isnt good when
using BMesh modifiers, where you want all normals to be recalculated.
* add bm_iter_itype_htype_map[], to get the iter type from a BMesh
iterator.
Seems that after converting tessfaces into faces normals should be re-calculated.
At least that's what happening in some other modifiers and what makes boolean
work fine with smooth normals.
- use SMOOTH flag for edges (removed sharp flag and inverted), gives us an extra flag slot available.
- rename BM_edge_is_nonmanifold --> BM_edge_is_manifold and invert result, BM_vert_is_nonmanifold too.
`_set` suffix was used in two ways (confusing)
* to set a flag to be enabled.
* to set a value passed as an argument.
now use enable/disable rather then set/clear for functions which change flags.
also remove BME_weld.c, the file didnt contain much code and the current extrude works well
* add DM_to_bmesh_ex, DM_to_bmesh for converting a derived mesh to a BMesh (rather than a BMEditMesh)
* have a generic variable for allocsize: bm_mesh_allocsize_default, rather than copying the values about.
* Exploded faces that were meant to be hidden were still created with invalid vertices (0,0,0,0).
* In normal cases this went unnoticed, but for example edge split modifier crashed when it encountered these faces.
These changes are to make the bmesh api more consistent and easier to learn, grouping similar functions which is convenient for autocomplete.
This uses similar convention to RNA.
* use face/loop/edge/vert as a prefix for functions.
* use 'elem' as a prefix too for functions that can take any type with a BMHeader.
* changed from camel case to underscore separated (like RNA).
