Merge branch 'master' into tmp-usd-alab-v2-T100452tmp-usd-alab-v2-T100452

29 files changed, 342 insertions, 400 deletions

diff --git a/source/blender/bmesh/CMakeLists.txt b/source/blender/bmesh/CMakeLists.txt
index 0d1eeab8eec..0efa5f73ae4 100644
--- a/source/blender/bmesh/CMakeLists.txt
+++ b/source/blender/bmesh/CMakeLists.txt
@@ -111,7 +111,7 @@ set(SRC
   intern/bmesh_query.c
   intern/bmesh_query.h
   intern/bmesh_query_inline.h
-  intern/bmesh_query_uv.c
+  intern/bmesh_query_uv.cc
   intern/bmesh_query_uv.h
   intern/bmesh_structure.c
   intern/bmesh_structure.h
diff --git a/source/blender/bmesh/bmesh.h b/source/blender/bmesh/bmesh.h
index 2833105e5a4..3956db0288a 100644
--- a/source/blender/bmesh/bmesh.h
+++ b/source/blender/bmesh/bmesh.h
@@ -148,7 +148,7 @@
  *
  * These conventions should be used throughout the bmesh module.
  *
- * - `bmesh_kernel_*()` - Low level API, for primitive functions that others are built ontop of.
+ * - `bmesh_kernel_*()` - Low level API, for primitive functions that others are built on top of.
  * - `bmesh_***()` - Low level API function.
  * - `bm_***()` -     'static' functions, not a part of the API at all,
  *   but use prefix since they operate on BMesh data.
diff --git a/source/blender/bmesh/intern/bmesh_construct.c b/source/blender/bmesh/intern/bmesh_construct.c
index 0ee5545527b..3ee9fa7aee4 100644
--- a/source/blender/bmesh/intern/bmesh_construct.c
+++ b/source/blender/bmesh/intern/bmesh_construct.c
@@ -21,8 +21,6 @@
 #include "bmesh.h"
 #include "intern/bmesh_private.h"
 
-#define SELECT 1
-
 bool BM_verts_from_edges(BMVert **vert_arr, BMEdge **edge_arr, const int len)
 {
   int i, i_prev = len - 1;
@@ -507,42 +505,34 @@ void BM_mesh_copy_init_customdata_from_mesh_array(BMesh *bm_dst,
     allocsize = &bm_mesh_allocsize_default;
   }
 
-  char cd_flag = 0;
-
   for (int i = 0; i < me_src_array_len; i++) {
     const Mesh *me_src = me_src_array[i];
     if (i == 0) {
       CustomData_copy_mesh_to_bmesh(
-          &me_src->vdata, &bm_dst->vdata, CD_MASK_BMESH.vmask, CD_CALLOC, 0);
+          &me_src->vdata, &bm_dst->vdata, CD_MASK_BMESH.vmask, CD_SET_DEFAULT, 0);
       CustomData_copy_mesh_to_bmesh(
-          &me_src->edata, &bm_dst->edata, CD_MASK_BMESH.emask, CD_CALLOC, 0);
+          &me_src->edata, &bm_dst->edata, CD_MASK_BMESH.emask, CD_SET_DEFAULT, 0);
       CustomData_copy_mesh_to_bmesh(
-          &me_src->ldata, &bm_dst->ldata, CD_MASK_BMESH.lmask, CD_CALLOC, 0);
+          &me_src->ldata, &bm_dst->ldata, CD_MASK_BMESH.lmask, CD_SET_DEFAULT, 0);
       CustomData_copy_mesh_to_bmesh(
-          &me_src->pdata, &bm_dst->pdata, CD_MASK_BMESH.pmask, CD_CALLOC, 0);
+          &me_src->pdata, &bm_dst->pdata, CD_MASK_BMESH.pmask, CD_SET_DEFAULT, 0);
     }
     else {
       CustomData_merge_mesh_to_bmesh(
-          &me_src->vdata, &bm_dst->vdata, CD_MASK_BMESH.vmask, CD_CALLOC, 0);
+          &me_src->vdata, &bm_dst->vdata, CD_MASK_BMESH.vmask, CD_SET_DEFAULT, 0);
       CustomData_merge_mesh_to_bmesh(
-          &me_src->edata, &bm_dst->edata, CD_MASK_BMESH.emask, CD_CALLOC, 0);
+          &me_src->edata, &bm_dst->edata, CD_MASK_BMESH.emask, CD_SET_DEFAULT, 0);
       CustomData_merge_mesh_to_bmesh(
-          &me_src->ldata, &bm_dst->ldata, CD_MASK_BMESH.lmask, CD_CALLOC, 0);
+          &me_src->ldata, &bm_dst->ldata, CD_MASK_BMESH.lmask, CD_SET_DEFAULT, 0);
       CustomData_merge_mesh_to_bmesh(
-          &me_src->pdata, &bm_dst->pdata, CD_MASK_BMESH.pmask, CD_CALLOC, 0);
+          &me_src->pdata, &bm_dst->pdata, CD_MASK_BMESH.pmask, CD_SET_DEFAULT, 0);
     }
-
-    cd_flag |= me_src->cd_flag;
   }
 
-  cd_flag |= BM_mesh_cd_flag_from_bmesh(bm_dst);
-
   CustomData_bmesh_init_pool(&bm_dst->vdata, allocsize->totvert, BM_VERT);
   CustomData_bmesh_init_pool(&bm_dst->edata, allocsize->totedge, BM_EDGE);
   CustomData_bmesh_init_pool(&bm_dst->ldata, allocsize->totloop, BM_LOOP);
   CustomData_bmesh_init_pool(&bm_dst->pdata, allocsize->totface, BM_FACE);
-
-  BM_mesh_cd_flag_apply(bm_dst, cd_flag);
 }
 
 void BM_mesh_copy_init_customdata_from_mesh(BMesh *bm_dst,
@@ -558,10 +548,10 @@ void BM_mesh_copy_init_customdata(BMesh *bm_dst, BMesh *bm_src, const BMAllocTem
     allocsize = &bm_mesh_allocsize_default;
   }
 
-  CustomData_copy(&bm_src->vdata, &bm_dst->vdata, CD_MASK_BMESH.vmask, CD_CALLOC, 0);
-  CustomData_copy(&bm_src->edata, &bm_dst->edata, CD_MASK_BMESH.emask, CD_CALLOC, 0);
-  CustomData_copy(&bm_src->ldata, &bm_dst->ldata, CD_MASK_BMESH.lmask, CD_CALLOC, 0);
-  CustomData_copy(&bm_src->pdata, &bm_dst->pdata, CD_MASK_BMESH.pmask, CD_CALLOC, 0);
+  CustomData_copy(&bm_src->vdata, &bm_dst->vdata, CD_MASK_BMESH.vmask, CD_SET_DEFAULT, 0);
+  CustomData_copy(&bm_src->edata, &bm_dst->edata, CD_MASK_BMESH.emask, CD_SET_DEFAULT, 0);
+  CustomData_copy(&bm_src->ldata, &bm_dst->ldata, CD_MASK_BMESH.lmask, CD_SET_DEFAULT, 0);
+  CustomData_copy(&bm_src->pdata, &bm_dst->pdata, CD_MASK_BMESH.pmask, CD_SET_DEFAULT, 0);
 
   CustomData_bmesh_init_pool(&bm_dst->vdata, allocsize->totvert, BM_VERT);
   CustomData_bmesh_init_pool(&bm_dst->edata, allocsize->totedge, BM_EDGE);
@@ -596,7 +586,7 @@ void BM_mesh_copy_init_customdata_all_layers(BMesh *bm_dst,
 
     for (int l = 0; l < src->totlayer; l++) {
       CustomData_add_layer_named(
-          dst, src->layers[l].type, CD_CALLOC, NULL, 0, src->layers[l].name);
+          dst, src->layers[l].type, CD_SET_DEFAULT, NULL, 0, src->layers[l].name);
     }
     CustomData_bmesh_init_pool(dst, size, htypes[i]);
   }
@@ -720,35 +710,21 @@ BMesh *BM_mesh_copy(BMesh *bm_old)
   return bm_new;
 }
 
-char BM_vert_flag_from_mflag(const char mflag)
-{
-  return ((mflag & SELECT) ? BM_ELEM_SELECT : 0);
-}
 char BM_edge_flag_from_mflag(const short mflag)
 {
-  return (((mflag & SELECT) ? BM_ELEM_SELECT : 0) | ((mflag & ME_SEAM) ? BM_ELEM_SEAM : 0) |
-          ((mflag & ME_EDGEDRAW) ? BM_ELEM_DRAW : 0) |
+  return (((mflag & ME_SEAM) ? BM_ELEM_SEAM : 0) | ((mflag & ME_EDGEDRAW) ? BM_ELEM_DRAW : 0) |
           ((mflag & ME_SHARP) == 0 ? BM_ELEM_SMOOTH : 0));
 }
 char BM_face_flag_from_mflag(const char mflag)
 {
-  return (((mflag & ME_FACE_SEL) ? BM_ELEM_SELECT : 0) |
-          ((mflag & ME_SMOOTH) ? BM_ELEM_SMOOTH : 0));
-}
-
-char BM_vert_flag_to_mflag(BMVert *v)
-{
-  const char hflag = v->head.hflag;
-
-  return (((hflag & BM_ELEM_SELECT) ? SELECT : 0));
+  return ((mflag & ME_SMOOTH) ? BM_ELEM_SMOOTH : 0);
 }
 
 short BM_edge_flag_to_mflag(BMEdge *e)
 {
   const char hflag = e->head.hflag;
 
-  return (((hflag & BM_ELEM_SELECT) ? SELECT : 0) | ((hflag & BM_ELEM_SEAM) ? ME_SEAM : 0) |
-          ((hflag & BM_ELEM_DRAW) ? ME_EDGEDRAW : 0) |
+  return (((hflag & BM_ELEM_SEAM) ? ME_SEAM : 0) | ((hflag & BM_ELEM_DRAW) ? ME_EDGEDRAW : 0) |
           ((hflag & BM_ELEM_SMOOTH) == 0 ? ME_SHARP : 0) |
           (BM_edge_is_wire(e) ? ME_LOOSEEDGE : 0) | /* not typical */
           ME_EDGERENDER);
@@ -757,6 +733,5 @@ char BM_face_flag_to_mflag(BMFace *f)
 {
   const char hflag = f->head.hflag;
 
-  return (((hflag & BM_ELEM_SELECT) ? ME_FACE_SEL : 0) |
-          ((hflag & BM_ELEM_SMOOTH) ? ME_SMOOTH : 0));
+  return ((hflag & BM_ELEM_SMOOTH) ? ME_SMOOTH : 0);
 }
diff --git a/source/blender/bmesh/intern/bmesh_construct.h b/source/blender/bmesh/intern/bmesh_construct.h
index 1851cf58d4e..225e15c90e9 100644
--- a/source/blender/bmesh/intern/bmesh_construct.h
+++ b/source/blender/bmesh/intern/bmesh_construct.h
@@ -169,8 +169,5 @@ BMesh *BM_mesh_copy(BMesh *bm_old);
 char BM_face_flag_from_mflag(char mflag);
 char BM_edge_flag_from_mflag(short mflag);
 /* ME -> BM */
-char BM_vert_flag_from_mflag(char mflag);
 char BM_face_flag_to_mflag(BMFace *f);
 short BM_edge_flag_to_mflag(BMEdge *e);
-/* BM -> ME */
-char BM_vert_flag_to_mflag(BMVert *v);
diff --git a/source/blender/bmesh/intern/bmesh_core.c b/source/blender/bmesh/intern/bmesh_core.c
index 4d84d558cd7..5fbbd087d7e 100644
--- a/source/blender/bmesh/intern/bmesh_core.c
+++ b/source/blender/bmesh/intern/bmesh_core.c
@@ -95,7 +95,7 @@ BMVert *BM_vert_create(BMesh *bm,
       /* handles 'v->no' too */
       BM_elem_attrs_copy(bm, bm, v_example, v);
 
-      /* exception: don't copy the original shapekey index */
+      /* Exception: don't copy the original shape-key index. */
       keyi = CustomData_bmesh_get(&bm->vdata, v->head.data, CD_SHAPE_KEYINDEX);
       if (keyi) {
         *keyi = ORIGINDEX_NONE;
diff --git a/source/blender/bmesh/intern/bmesh_delete.c b/source/blender/bmesh/intern/bmesh_delete.c
index e2436e53099..8ec7dc410d0 100644
--- a/source/blender/bmesh/intern/bmesh_delete.c
+++ b/source/blender/bmesh/intern/bmesh_delete.c
@@ -86,7 +86,6 @@ void BMO_mesh_delete_oflag_tagged(BMesh *bm, const short oflag, const char htype
 void BMO_mesh_delete_oflag_context(BMesh *bm, const short oflag, const int type)
 {
   BMEdge *e;
-  BMFace *f;
 
   BMIter eiter;
   BMIter fiter;
@@ -128,6 +127,7 @@ void BMO_mesh_delete_oflag_context(BMesh *bm, const short oflag, const int type)
     case DEL_FACES:
     case DEL_FACES_KEEP_BOUNDARY: {
       /* go through and mark all edges and all verts of all faces for delete */
+      BMFace *f;
       BM_ITER_MESH (f, &fiter, bm, BM_FACES_OF_MESH) {
         if (BMO_face_flag_test(bm, f, oflag)) {
           BMLoop *l_first = BM_FACE_FIRST_LOOP(f);
@@ -257,8 +257,6 @@ void BM_mesh_delete_hflag_tagged(BMesh *bm, const char hflag, const char htype)
 
 void BM_mesh_delete_hflag_context(BMesh *bm, const char hflag, const int type)
 {
-  BMEdge *e;
-  BMFace *f;
 
   BMIter eiter;
   BMIter fiter;
@@ -271,6 +269,7 @@ void BM_mesh_delete_hflag_context(BMesh *bm, const char hflag, const int type)
     }
     case DEL_EDGES: {
       /* flush down to vert */
+      BMEdge *e;
       BM_ITER_MESH (e, &eiter, bm, BM_EDGES_OF_MESH) {
         if (BM_elem_flag_test(e, hflag)) {
           BM_elem_flag_enable(e->v1, hflag);
@@ -299,6 +298,8 @@ void BM_mesh_delete_hflag_context(BMesh *bm, const char hflag, const int type)
     }
     case DEL_FACES: {
       /* go through and mark all edges and all verts of all faces for delete */
+      BMFace *f;
+      BMEdge *e;
       BM_ITER_MESH (f, &fiter, bm, BM_FACES_OF_MESH) {
         if (BM_elem_flag_test(f, hflag)) {
           BMLoop *l_first = BM_FACE_FIRST_LOOP(f);
diff --git a/source/blender/bmesh/intern/bmesh_interp.c b/source/blender/bmesh/intern/bmesh_interp.c
index 0c3db31dd1f..b7028dee5e1 100644
--- a/source/blender/bmesh/intern/bmesh_interp.c
+++ b/source/blender/bmesh/intern/bmesh_interp.c
@@ -846,7 +846,7 @@ void BM_data_layer_add(BMesh *bm, CustomData *data, int type)
   /* the pool is now owned by olddata and must not be shared */
   data->pool = NULL;
 
-  CustomData_add_layer(data, type, CD_DEFAULT, NULL, 0);
+  CustomData_add_layer(data, type, CD_SET_DEFAULT, NULL, 0);
 
   update_data_blocks(bm, &olddata, data);
   if (olddata.layers) {
@@ -864,7 +864,7 @@ void BM_data_layer_add_named(BMesh *bm, CustomData *data, int type, const char *
   /* the pool is now owned by olddata and must not be shared */
   data->pool = NULL;
 
-  CustomData_add_layer_named(data, type, CD_DEFAULT, NULL, 0, name);
+  CustomData_add_layer_named(data, type, CD_SET_DEFAULT, NULL, 0, name);
 
   update_data_blocks(bm, &olddata, data);
   if (olddata.layers) {
diff --git a/source/blender/bmesh/intern/bmesh_log.c b/source/blender/bmesh/intern/bmesh_log.c
index 64e6c63e9f0..04ad80214c2 100644
--- a/source/blender/bmesh/intern/bmesh_log.c
+++ b/source/blender/bmesh/intern/bmesh_log.c
@@ -288,7 +288,8 @@ static void bm_log_verts_restore(BMesh *bm, BMLog *log, GHash *verts)
 static void bm_log_faces_restore(BMesh *bm, BMLog *log, GHash *faces)
 {
   GHashIterator gh_iter;
-  const int cd_face_sets = CustomData_get_offset(&bm->pdata, CD_SCULPT_FACE_SETS);
+  const int cd_face_sets = CustomData_get_offset_named(
+      &bm->pdata, CD_PROP_INT32, ".sculpt_face_set");
 
   GHASH_ITER (gh_iter, faces) {
     void *key = BLI_ghashIterator_getKey(&gh_iter);
diff --git a/source/blender/bmesh/intern/bmesh_log.h b/source/blender/bmesh/intern/bmesh_log.h
index 5daa5dd9a68..75ff54c7d46 100644
--- a/source/blender/bmesh/intern/bmesh_log.h
+++ b/source/blender/bmesh/intern/bmesh_log.h
@@ -22,7 +22,7 @@ BMLog *BM_log_create(BMesh *bm);
 /**
  * Allocate and initialize a new #BMLog using existing #BMLogEntries
  *
- * The 'entry' should be the last entry in the BMLog. Its prev pointer
+ * The 'entry' should be the last entry in the #BMLog. Its `prev` pointer
  * will be followed back to find the first entry.
  *
  * The unused IDs field of the log will be initialized by taking all
diff --git a/source/blender/bmesh/intern/bmesh_marking.c b/source/blender/bmesh/intern/bmesh_marking.c
index f348cd58085..a1c2815ab2f 100644
--- a/source/blender/bmesh/intern/bmesh_marking.c
+++ b/source/blender/bmesh/intern/bmesh_marking.c
@@ -1020,7 +1020,7 @@ static BMEditSelection *bm_select_history_create(BMHeader *ele)
   return ese;
 }
 
-/* --- macro wrapped funcs --- */
+/* --- Macro wrapped functions. --- */
 
 bool _bm_select_history_check(BMesh *bm, const BMHeader *ele)
 {
@@ -1075,7 +1075,7 @@ void _bm_select_history_store_after(BMesh *bm, BMEditSelection *ese_ref, BMHeade
     BM_select_history_store_after_notest(bm, ese_ref, (BMElem *)ele);
   }
 }
-/* --- end macro wrapped funcs --- */
+/* --- End macro wrapped functions --- */
 
 void BM_select_history_clear(BMesh *bm)
 {
diff --git a/source/blender/bmesh/intern/bmesh_mesh_convert.cc b/source/blender/bmesh/intern/bmesh_mesh_convert.cc
index b9c004b5392..a97c7d1ea20 100644
--- a/source/blender/bmesh/intern/bmesh_mesh_convert.cc
+++ b/source/blender/bmesh/intern/bmesh_mesh_convert.cc
@@ -110,85 +110,6 @@ using blender::MutableSpan;
 using blender::Span;
 using blender::StringRef;
 
-void BM_mesh_cd_flag_ensure(BMesh *bm, Mesh *mesh, const char cd_flag)
-{
-  const char cd_flag_all = BM_mesh_cd_flag_from_bmesh(bm) | cd_flag;
-  BM_mesh_cd_flag_apply(bm, cd_flag_all);
-  if (mesh) {
-    mesh->cd_flag = cd_flag_all;
-  }
-}
-
-void BM_mesh_cd_flag_apply(BMesh *bm, const char cd_flag)
-{
-  /* CustomData_bmesh_init_pool() must run first */
-  BLI_assert(bm->vdata.totlayer == 0 || bm->vdata.pool != nullptr);
-  BLI_assert(bm->edata.totlayer == 0 || bm->edata.pool != nullptr);
-  BLI_assert(bm->pdata.totlayer == 0 || bm->pdata.pool != nullptr);
-
-  if (cd_flag & ME_CDFLAG_VERT_BWEIGHT) {
-    if (!CustomData_has_layer(&bm->vdata, CD_BWEIGHT)) {
-      BM_data_layer_add(bm, &bm->vdata, CD_BWEIGHT);
-    }
-  }
-  else {
-    if (CustomData_has_layer(&bm->vdata, CD_BWEIGHT)) {
-      BM_data_layer_free(bm, &bm->vdata, CD_BWEIGHT);
-    }
-  }
-
-  if (cd_flag & ME_CDFLAG_VERT_CREASE) {
-    if (!CustomData_has_layer(&bm->vdata, CD_CREASE)) {
-      BM_data_layer_add(bm, &bm->vdata, CD_CREASE);
-    }
-  }
-  else {
-    if (CustomData_has_layer(&bm->vdata, CD_CREASE)) {
-      BM_data_layer_free(bm, &bm->vdata, CD_CREASE);
-    }
-  }
-
-  if (cd_flag & ME_CDFLAG_EDGE_BWEIGHT) {
-    if (!CustomData_has_layer(&bm->edata, CD_BWEIGHT)) {
-      BM_data_layer_add(bm, &bm->edata, CD_BWEIGHT);
-    }
-  }
-  else {
-    if (CustomData_has_layer(&bm->edata, CD_BWEIGHT)) {
-      BM_data_layer_free(bm, &bm->edata, CD_BWEIGHT);
-    }
-  }
-
-  if (cd_flag & ME_CDFLAG_EDGE_CREASE) {
-    if (!CustomData_has_layer(&bm->edata, CD_CREASE)) {
-      BM_data_layer_add(bm, &bm->edata, CD_CREASE);
-    }
-  }
-  else {
-    if (CustomData_has_layer(&bm->edata, CD_CREASE)) {
-      BM_data_layer_free(bm, &bm->edata, CD_CREASE);
-    }
-  }
-}
-
-char BM_mesh_cd_flag_from_bmesh(BMesh *bm)
-{
-  char cd_flag = 0;
-  if (CustomData_has_layer(&bm->vdata, CD_BWEIGHT)) {
-    cd_flag |= ME_CDFLAG_VERT_BWEIGHT;
-  }
-  if (CustomData_has_layer(&bm->vdata, CD_CREASE)) {
-    cd_flag |= ME_CDFLAG_VERT_CREASE;
-  }
-  if (CustomData_has_layer(&bm->edata, CD_BWEIGHT)) {
-    cd_flag |= ME_CDFLAG_EDGE_BWEIGHT;
-  }
-  if (CustomData_has_layer(&bm->edata, CD_CREASE)) {
-    cd_flag |= ME_CDFLAG_EDGE_CREASE;
-  }
-  return cd_flag;
-}
-
 /* Static function for alloc (duplicate in modifiers_bmesh.c) */
 static BMFace *bm_face_create_from_mpoly(BMesh &bm,
                                          Span<MLoop> loops,
@@ -217,10 +138,10 @@ void BM_mesh_bm_from_me(BMesh *bm, const Mesh *me, const struct BMeshFromMeshPar
 
   if (!me || !me->totvert) {
     if (me && is_new) { /* No verts? still copy custom-data layout. */
-      CustomData_copy_mesh_to_bmesh(&me->vdata, &bm->vdata, mask.vmask, CD_DEFAULT, 0);
-      CustomData_copy_mesh_to_bmesh(&me->edata, &bm->edata, mask.emask, CD_DEFAULT, 0);
-      CustomData_copy_mesh_to_bmesh(&me->ldata, &bm->ldata, mask.lmask, CD_DEFAULT, 0);
-      CustomData_copy_mesh_to_bmesh(&me->pdata, &bm->pdata, mask.pmask, CD_DEFAULT, 0);
+      CustomData_copy_mesh_to_bmesh(&me->vdata, &bm->vdata, mask.vmask, CD_CONSTRUCT, 0);
+      CustomData_copy_mesh_to_bmesh(&me->edata, &bm->edata, mask.emask, CD_CONSTRUCT, 0);
+      CustomData_copy_mesh_to_bmesh(&me->ldata, &bm->ldata, mask.lmask, CD_CONSTRUCT, 0);
+      CustomData_copy_mesh_to_bmesh(&me->pdata, &bm->pdata, mask.pmask, CD_CONSTRUCT, 0);
 
       CustomData_bmesh_init_pool(&bm->vdata, me->totvert, BM_VERT);
       CustomData_bmesh_init_pool(&bm->edata, me->totedge, BM_EDGE);
@@ -236,16 +157,16 @@ void BM_mesh_bm_from_me(BMesh *bm, const Mesh *me, const struct BMeshFromMeshPar
   }
 
   if (is_new) {
-    CustomData_copy_mesh_to_bmesh(&me->vdata, &bm->vdata, mask.vmask, CD_CALLOC, 0);
-    CustomData_copy_mesh_to_bmesh(&me->edata, &bm->edata, mask.emask, CD_CALLOC, 0);
-    CustomData_copy_mesh_to_bmesh(&me->ldata, &bm->ldata, mask.lmask, CD_CALLOC, 0);
-    CustomData_copy_mesh_to_bmesh(&me->pdata, &bm->pdata, mask.pmask, CD_CALLOC, 0);
+    CustomData_copy_mesh_to_bmesh(&me->vdata, &bm->vdata, mask.vmask, CD_SET_DEFAULT, 0);
+    CustomData_copy_mesh_to_bmesh(&me->edata, &bm->edata, mask.emask, CD_SET_DEFAULT, 0);
+    CustomData_copy_mesh_to_bmesh(&me->ldata, &bm->ldata, mask.lmask, CD_SET_DEFAULT, 0);
+    CustomData_copy_mesh_to_bmesh(&me->pdata, &bm->pdata, mask.pmask, CD_SET_DEFAULT, 0);
   }
   else {
-    CustomData_bmesh_merge(&me->vdata, &bm->vdata, mask.vmask, CD_CALLOC, bm, BM_VERT);
-    CustomData_bmesh_merge(&me->edata, &bm->edata, mask.emask, CD_CALLOC, bm, BM_EDGE);
-    CustomData_bmesh_merge(&me->ldata, &bm->ldata, mask.lmask, CD_CALLOC, bm, BM_LOOP);
-    CustomData_bmesh_merge(&me->pdata, &bm->pdata, mask.pmask, CD_CALLOC, bm, BM_FACE);
+    CustomData_bmesh_merge(&me->vdata, &bm->vdata, mask.vmask, CD_SET_DEFAULT, bm, BM_VERT);
+    CustomData_bmesh_merge(&me->edata, &bm->edata, mask.emask, CD_SET_DEFAULT, bm, BM_EDGE);
+    CustomData_bmesh_merge(&me->ldata, &bm->ldata, mask.lmask, CD_SET_DEFAULT, bm, BM_LOOP);
+    CustomData_bmesh_merge(&me->pdata, &bm->pdata, mask.pmask, CD_SET_DEFAULT, bm, BM_FACE);
   }
 
   /* -------------------------------------------------------------------- */
@@ -338,47 +259,41 @@ void BM_mesh_bm_from_me(BMesh *bm, const Mesh *me, const struct BMeshFromMeshPar
     CustomData_bmesh_init_pool(&bm->ldata, me->totloop, BM_LOOP);
     CustomData_bmesh_init_pool(&bm->pdata, me->totpoly, BM_FACE);
   }
-  BM_mesh_cd_flag_apply(bm, me->cd_flag | (is_new ? 0 : BM_mesh_cd_flag_from_bmesh(bm)));
 
   /* Only copy these values over if the source mesh is flagged to be using them.
    * Even if `bm` has these layers, they may have been added from another mesh, when `!is_new`. */
-  const int cd_vert_bweight_offset = (me->cd_flag & ME_CDFLAG_VERT_BWEIGHT) ?
-                                         CustomData_get_offset(&bm->vdata, CD_BWEIGHT) :
-                                         -1;
-  const int cd_edge_bweight_offset = (me->cd_flag & ME_CDFLAG_EDGE_BWEIGHT) ?
-                                         CustomData_get_offset(&bm->edata, CD_BWEIGHT) :
-                                         -1;
-  const int cd_edge_crease_offset = (me->cd_flag & ME_CDFLAG_EDGE_CREASE) ?
-                                        CustomData_get_offset(&bm->edata, CD_CREASE) :
-                                        -1;
   const int cd_shape_key_offset = tot_shape_keys ? CustomData_get_offset(&bm->vdata, CD_SHAPEKEY) :
                                                    -1;
   const int cd_shape_keyindex_offset = is_new && (tot_shape_keys || params->add_key_index) ?
                                            CustomData_get_offset(&bm->vdata, CD_SHAPE_KEYINDEX) :
                                            -1;
 
+  const bool *select_vert = (const bool *)CustomData_get_layer_named(
+      &me->vdata, CD_PROP_BOOL, ".select_vert");
+  const bool *select_edge = (const bool *)CustomData_get_layer_named(
+      &me->edata, CD_PROP_BOOL, ".select_edge");
+  const bool *select_poly = (const bool *)CustomData_get_layer_named(
+      &me->pdata, CD_PROP_BOOL, ".select_poly");
   const bool *hide_vert = (const bool *)CustomData_get_layer_named(
       &me->vdata, CD_PROP_BOOL, ".hide_vert");
   const bool *hide_edge = (const bool *)CustomData_get_layer_named(
       &me->edata, CD_PROP_BOOL, ".hide_edge");
   const bool *hide_poly = (const bool *)CustomData_get_layer_named(
       &me->pdata, CD_PROP_BOOL, ".hide_poly");
+  const int *material_indices = (const int *)CustomData_get_layer_named(
+      &me->pdata, CD_PROP_INT32, "material_index");
 
-  Span<MVert> mvert{me->mvert, me->totvert};
+  Span<MVert> mvert = me->verts();
   Array<BMVert *> vtable(me->totvert);
   for (const int i : mvert.index_range()) {
     BMVert *v = vtable[i] = BM_vert_create(
         bm, keyco ? keyco[i] : mvert[i].co, nullptr, BM_CREATE_SKIP_CD);
     BM_elem_index_set(v, i); /* set_ok */
 
-    /* Transfer flag. */
-    v->head.hflag = BM_vert_flag_from_mflag(mvert[i].flag & ~SELECT);
     if (hide_vert && hide_vert[i]) {
       BM_elem_flag_enable(v, BM_ELEM_HIDDEN);
     }
-
-    /* This is necessary for selection counts to work properly. */
-    if (mvert[i].flag & SELECT) {
+    if (select_vert && select_vert[i]) {
       BM_vert_select_set(bm, v, true);
     }
 
@@ -389,10 +304,6 @@ void BM_mesh_bm_from_me(BMesh *bm, const Mesh *me, const struct BMeshFromMeshPar
     /* Copy Custom Data */
     CustomData_to_bmesh_block(&me->vdata, &bm->vdata, i, &v->head.data, true);
 
-    if (cd_vert_bweight_offset != -1) {
-      BM_ELEM_CD_SET_FLOAT(v, cd_vert_bweight_offset, (float)mvert[i].bweight / 255.0f);
-    }
-
     /* Set shape key original index. */
     if (cd_shape_keyindex_offset != -1) {
       BM_ELEM_CD_SET_INT(v, cd_shape_keyindex_offset, i);
@@ -410,7 +321,7 @@ void BM_mesh_bm_from_me(BMesh *bm, const Mesh *me, const struct BMeshFromMeshPar
     bm->elem_index_dirty &= ~BM_VERT; /* Added in order, clear dirty flag. */
   }
 
-  Span<MEdge> medge{me->medge, me->totedge};
+  const Span<MEdge> medge = me->edges();
   Array<BMEdge *> etable(me->totedge);
   for (const int i : medge.index_range()) {
     BMEdge *e = etable[i] = BM_edge_create(
@@ -418,32 +329,23 @@ void BM_mesh_bm_from_me(BMesh *bm, const Mesh *me, const struct BMeshFromMeshPar
     BM_elem_index_set(e, i); /* set_ok */
 
     /* Transfer flags. */
-    e->head.hflag = BM_edge_flag_from_mflag(medge[i].flag & ~SELECT);
+    e->head.hflag = BM_edge_flag_from_mflag(medge[i].flag);
     if (hide_edge && hide_edge[i]) {
       BM_elem_flag_enable(e, BM_ELEM_HIDDEN);
     }
-
-    /* This is necessary for selection counts to work properly. */
-    if (medge[i].flag & SELECT) {
+    if (select_edge && select_edge[i]) {
       BM_edge_select_set(bm, e, true);
     }
 
     /* Copy Custom Data */
     CustomData_to_bmesh_block(&me->edata, &bm->edata, i, &e->head.data, true);
-
-    if (cd_edge_bweight_offset != -1) {
-      BM_ELEM_CD_SET_FLOAT(e, cd_edge_bweight_offset, (float)medge[i].bweight / 255.0f);
-    }
-    if (cd_edge_crease_offset != -1) {
-      BM_ELEM_CD_SET_FLOAT(e, cd_edge_crease_offset, (float)medge[i].crease / 255.0f);
-    }
   }
   if (is_new) {
     bm->elem_index_dirty &= ~BM_EDGE; /* Added in order, clear dirty flag. */
   }
 
-  Span<MPoly> mpoly{me->mpoly, me->totpoly};
-  Span<MLoop> mloop{me->mloop, me->totloop};
+  const Span<MPoly> mpoly = me->polys();
+  const Span<MLoop> mloop = me->loops();
 
   /* Only needed for selection. */
 
@@ -474,17 +376,15 @@ void BM_mesh_bm_from_me(BMesh *bm, const Mesh *me, const struct BMeshFromMeshPar
     BM_elem_index_set(f, bm->totface - 1); /* set_ok */
 
     /* Transfer flag. */
-    f->head.hflag = BM_face_flag_from_mflag(mpoly[i].flag & ~ME_FACE_SEL);
+    f->head.hflag = BM_face_flag_from_mflag(mpoly[i].flag);
     if (hide_poly && hide_poly[i]) {
       BM_elem_flag_enable(f, BM_ELEM_HIDDEN);
     }
-
-    /* This is necessary for selection counts to work properly. */
-    if (mpoly[i].flag & ME_FACE_SEL) {
+    if (select_poly && select_poly[i]) {
       BM_face_select_set(bm, f, true);
     }
 
-    f->mat_nr = mpoly[i].mat_nr;
+    f->mat_nr = material_indices == nullptr ? 0 : material_indices[i];
     if (i == me->act_face) {
       bm->act_face = f;
     }
@@ -703,7 +603,7 @@ static int bm_to_mesh_shape_layer_index_from_kb(BMesh *bm, KeyBlock *currkey)
  */
 static void bm_to_mesh_shape(BMesh *bm,
                              Key *key,
-                             MVert *mvert,
+                             MutableSpan<MVert> mvert,
                              const bool active_shapekey_to_mvert)
 {
   KeyBlock *actkey = static_cast<KeyBlock *>(BLI_findlink(&key->block, bm->shapenr - 1));
@@ -923,28 +823,35 @@ BLI_INLINE void bmesh_quick_edgedraw_flag(MEdge *med, BMEdge *e)
   }
 }
 
-template<typename GetFn>
-static void write_elem_flag_to_attribute(blender::bke::MutableAttributeAccessor &attributes,
-                                         const StringRef attribute_name,
-                                         const eAttrDomain domain,
-                                         const bool do_write,
-                                         const GetFn &get_fn)
+template<typename T, typename GetFn>
+static void write_fn_to_attribute(blender::bke::MutableAttributeAccessor attributes,
+                                  const StringRef attribute_name,
+                                  const eAttrDomain domain,
+                                  const GetFn &get_fn)
 {
   using namespace blender;
-  if (do_write) {
-    bke::SpanAttributeWriter<bool> attribute = attributes.lookup_or_add_for_write_only_span<bool>(
-        attribute_name, domain);
-    threading::parallel_for(attribute.span.index_range(), 4096, [&](IndexRange range) {
-      for (const int i : range) {
-        attribute.span[i] = get_fn(i);
-      }
-    });
-    attribute.finish();
-  }
-  else {
-    /* To avoid overhead, remove the hide attribute if possible. */
-    attributes.remove(attribute_name);
-  }
+  bke::SpanAttributeWriter<T> attribute = attributes.lookup_or_add_for_write_only_span<T>(
+      attribute_name, domain);
+  threading::parallel_for(attribute.span.index_range(), 4096, [&](IndexRange range) {
+    for (const int i : range) {
+      attribute.span[i] = get_fn(i);
+    }
+  });
+  attribute.finish();
+}
+
+static void assert_bmesh_has_no_mesh_only_attributes(const BMesh &bm)
+{
+  (void)bm; /* Unused in the release builds. */
+
+  /* The "hide" attributes are stored as flags on #BMesh. */
+  BLI_assert(CustomData_get_layer_named(&bm.vdata, CD_PROP_BOOL, ".hide_vert") == nullptr);
+  BLI_assert(CustomData_get_layer_named(&bm.edata, CD_PROP_BOOL, ".hide_edge") == nullptr);
+  BLI_assert(CustomData_get_layer_named(&bm.pdata, CD_PROP_BOOL, ".hide_poly") == nullptr);
+  /* The "selection" attributes are stored as flags on #BMesh. */
+  BLI_assert(CustomData_get_layer_named(&bm.vdata, CD_PROP_BOOL, ".select_vert") == nullptr);
+  BLI_assert(CustomData_get_layer_named(&bm.edata, CD_PROP_BOOL, ".select_edge") == nullptr);
+  BLI_assert(CustomData_get_layer_named(&bm.pdata, CD_PROP_BOOL, ".select_poly") == nullptr);
 }
 
 static void convert_bmesh_hide_flags_to_mesh_attributes(BMesh &bm,
@@ -955,43 +862,71 @@ static void convert_bmesh_hide_flags_to_mesh_attributes(BMesh &bm,
 {
   using namespace blender;
   /* The "hide" attributes are stored as flags on #BMesh. */
-  BLI_assert(CustomData_get_layer_named(&bm.vdata, CD_PROP_BOOL, ".hide_vert") == nullptr);
-  BLI_assert(CustomData_get_layer_named(&bm.edata, CD_PROP_BOOL, ".hide_edge") == nullptr);
-  BLI_assert(CustomData_get_layer_named(&bm.pdata, CD_PROP_BOOL, ".hide_poly") == nullptr);
+  assert_bmesh_has_no_mesh_only_attributes(bm);
 
   if (!(need_hide_vert || need_hide_edge || need_hide_poly)) {
     return;
   }
 
-  bke::MutableAttributeAccessor attributes = bke::mesh_attributes_for_write(mesh);
+  bke::MutableAttributeAccessor attributes = mesh.attributes_for_write();
   BM_mesh_elem_table_ensure(&bm, BM_VERT | BM_EDGE | BM_FACE);
 
-  write_elem_flag_to_attribute(
-      attributes, ".hide_vert", ATTR_DOMAIN_POINT, need_hide_vert, [&](const int i) {
-        return BM_elem_flag_test(BM_vert_at_index(&bm, i), BM_ELEM_HIDDEN);
-      });
-  write_elem_flag_to_attribute(
-      attributes, ".hide_edge", ATTR_DOMAIN_EDGE, need_hide_edge, [&](const int i) {
-        return BM_elem_flag_test(BM_edge_at_index(&bm, i), BM_ELEM_HIDDEN);
-      });
-  write_elem_flag_to_attribute(
-      attributes, ".hide_poly", ATTR_DOMAIN_FACE, need_hide_poly, [&](const int i) {
-        return BM_elem_flag_test(BM_face_at_index(&bm, i), BM_ELEM_HIDDEN);
-      });
+  if (need_hide_vert) {
+    write_fn_to_attribute<bool>(attributes, ".hide_vert", ATTR_DOMAIN_POINT, [&](const int i) {
+      return BM_elem_flag_test(BM_vert_at_index(&bm, i), BM_ELEM_HIDDEN);
+    });
+  }
+  if (need_hide_edge) {
+    write_fn_to_attribute<bool>(attributes, ".hide_edge", ATTR_DOMAIN_EDGE, [&](const int i) {
+      return BM_elem_flag_test(BM_edge_at_index(&bm, i), BM_ELEM_HIDDEN);
+    });
+  }
+  if (need_hide_poly) {
+    write_fn_to_attribute<bool>(attributes, ".hide_poly", ATTR_DOMAIN_FACE, [&](const int i) {
+      return BM_elem_flag_test(BM_face_at_index(&bm, i), BM_ELEM_HIDDEN);
+    });
+  }
+}
+
+static void convert_bmesh_selection_flags_to_mesh_attributes(BMesh &bm,
+                                                             const bool need_select_vert,
+                                                             const bool need_select_edge,
+                                                             const bool need_select_poly,
+                                                             Mesh &mesh)
+{
+  using namespace blender;
+  if (!(need_select_vert || need_select_edge || need_select_poly)) {
+    return;
+  }
+
+  bke::MutableAttributeAccessor attributes = mesh.attributes_for_write();
+  BM_mesh_elem_table_ensure(&bm, BM_VERT | BM_EDGE | BM_FACE);
+
+  if (need_select_vert) {
+    write_fn_to_attribute<bool>(attributes, ".select_vert", ATTR_DOMAIN_POINT, [&](const int i) {
+      return BM_elem_flag_test(BM_vert_at_index(&bm, i), BM_ELEM_SELECT);
+    });
+  }
+  if (need_select_edge) {
+    write_fn_to_attribute<bool>(attributes, ".select_edge", ATTR_DOMAIN_EDGE, [&](const int i) {
+      return BM_elem_flag_test(BM_edge_at_index(&bm, i), BM_ELEM_SELECT);
+    });
+  }
+  if (need_select_poly) {
+    write_fn_to_attribute<bool>(attributes, ".select_poly", ATTR_DOMAIN_FACE, [&](const int i) {
+      return BM_elem_flag_test(BM_face_at_index(&bm, i), BM_ELEM_SELECT);
+    });
+  }
 }
 
 void BM_mesh_bm_to_me(Main *bmain, BMesh *bm, Mesh *me, const struct BMeshToMeshParams *params)
 {
-  MEdge *med;
   BMVert *v, *eve;
   BMEdge *e;
   BMFace *f;
   BMIter iter;
   int i, j;
 
-  const int cd_vert_bweight_offset = CustomData_get_offset(&bm->vdata, CD_BWEIGHT);
-  const int cd_edge_bweight_offset = CustomData_get_offset(&bm->edata, CD_BWEIGHT);
-  const int cd_edge_crease_offset = CustomData_get_offset(&bm->edata, CD_CREASE);
   const int cd_shape_keyindex_offset = CustomData_get_offset(&bm->vdata, CD_SHAPE_KEYINDEX);
 
   const int ototvert = me->totvert;
@@ -1016,91 +951,76 @@ void BM_mesh_bm_to_me(Main *bmain, BMesh *bm, Mesh *me, const struct BMeshToMesh
   {
     CustomData_MeshMasks mask = CD_MASK_MESH;
     CustomData_MeshMasks_update(&mask, &params->cd_mask_extra);
-    CustomData_copy_mesh_to_bmesh(&bm->vdata, &me->vdata, mask.vmask, CD_CALLOC, me->totvert);
-    CustomData_copy_mesh_to_bmesh(&bm->edata, &me->edata, mask.emask, CD_CALLOC, me->totedge);
-    CustomData_copy_mesh_to_bmesh(&bm->ldata, &me->ldata, mask.lmask, CD_CALLOC, me->totloop);
-    CustomData_copy_mesh_to_bmesh(&bm->pdata, &me->pdata, mask.pmask, CD_CALLOC, me->totpoly);
+    CustomData_copy_mesh_to_bmesh(&bm->vdata, &me->vdata, mask.vmask, CD_SET_DEFAULT, me->totvert);
+    CustomData_copy_mesh_to_bmesh(&bm->edata, &me->edata, mask.emask, CD_SET_DEFAULT, me->totedge);
+    CustomData_copy_mesh_to_bmesh(&bm->ldata, &me->ldata, mask.lmask, CD_SET_DEFAULT, me->totloop);
+    CustomData_copy_mesh_to_bmesh(&bm->pdata, &me->pdata, mask.pmask, CD_SET_DEFAULT, me->totpoly);
   }
 
-  MVert *mvert = bm->totvert ? (MVert *)MEM_callocN(sizeof(MVert) * bm->totvert, "bm_to_me.vert") :
-                               nullptr;
-  MEdge *medge = bm->totedge ? (MEdge *)MEM_callocN(sizeof(MEdge) * bm->totedge, "bm_to_me.edge") :
-                               nullptr;
-  MLoop *mloop = bm->totloop ? (MLoop *)MEM_callocN(sizeof(MLoop) * bm->totloop, "bm_to_me.loop") :
-                               nullptr;
-  MPoly *mpoly = bm->totface ? (MPoly *)MEM_callocN(sizeof(MPoly) * bm->totface, "bm_to_me.poly") :
-                               nullptr;
-
-  CustomData_add_layer(&me->vdata, CD_MVERT, CD_ASSIGN, mvert, me->totvert);
-  CustomData_add_layer(&me->edata, CD_MEDGE, CD_ASSIGN, medge, me->totedge);
-  CustomData_add_layer(&me->ldata, CD_MLOOP, CD_ASSIGN, mloop, me->totloop);
-  CustomData_add_layer(&me->pdata, CD_MPOLY, CD_ASSIGN, mpoly, me->totpoly);
-
+  CustomData_add_layer(&me->vdata, CD_MVERT, CD_SET_DEFAULT, nullptr, me->totvert);
+  CustomData_add_layer(&me->edata, CD_MEDGE, CD_SET_DEFAULT, nullptr, me->totedge);
+  CustomData_add_layer(&me->ldata, CD_MLOOP, CD_SET_DEFAULT, nullptr, me->totloop);
+  CustomData_add_layer(&me->pdata, CD_MPOLY, CD_SET_DEFAULT, nullptr, me->totpoly);
+  MutableSpan<MVert> mvert = me->verts_for_write();
+  MutableSpan<MEdge> medge = me->edges_for_write();
+  MutableSpan<MPoly> mpoly = me->polys_for_write();
+  MutableSpan<MLoop> mloop = me->loops_for_write();
+
+  bool need_select_vert = false;
+  bool need_select_edge = false;
+  bool need_select_poly = false;
   bool need_hide_vert = false;
   bool need_hide_edge = false;
   bool need_hide_poly = false;
+  bool need_material_index = false;
 
   /* Clear normals on the mesh completely, since the original vertex and polygon count might be
    * different than the BMesh's. */
   BKE_mesh_clear_derived_normals(me);
 
-  me->cd_flag = BM_mesh_cd_flag_from_bmesh(bm);
-
-  /* This is called again, 'dotess' arg is used there. */
-  BKE_mesh_update_customdata_pointers(me, false);
-
   i = 0;
   BM_ITER_MESH (v, &iter, bm, BM_VERTS_OF_MESH) {
-    copy_v3_v3(mvert->co, v->co);
+    copy_v3_v3(mvert[i].co, v->co);
 
-    mvert->flag = BM_vert_flag_to_mflag(v);
     if (BM_elem_flag_test(v, BM_ELEM_HIDDEN)) {
       need_hide_vert = true;
     }
+    if (BM_elem_flag_test(v, BM_ELEM_SELECT)) {
+      need_select_vert = true;
+    }
 
     BM_elem_index_set(v, i); /* set_inline */
 
     /* Copy over custom-data. */
     CustomData_from_bmesh_block(&bm->vdata, &me->vdata, v->head.data, i);
 
-    if (cd_vert_bweight_offset != -1) {
-      mvert->bweight = BM_ELEM_CD_GET_FLOAT_AS_UCHAR(v, cd_vert_bweight_offset);
-    }
-
     i++;
-    mvert++;
 
     BM_CHECK_ELEMENT(v);
   }
   bm->elem_index_dirty &= ~BM_VERT;
 
-  med = medge;
   i = 0;
   BM_ITER_MESH (e, &iter, bm, BM_EDGES_OF_MESH) {
-    med->v1 = BM_elem_index_get(e->v1);
-    med->v2 = BM_elem_index_get(e->v2);
+    medge[i].v1 = BM_elem_index_get(e->v1);
+    medge[i].v2 = BM_elem_index_get(e->v2);
 
-    med->flag = BM_edge_flag_to_mflag(e);
+    medge[i].flag = BM_edge_flag_to_mflag(e);
     if (BM_elem_flag_test(e, BM_ELEM_HIDDEN)) {
       need_hide_edge = true;
     }
+    if (BM_elem_flag_test(e, BM_ELEM_SELECT)) {
+      need_select_edge = true;
+    }
 
     BM_elem_index_set(e, i); /* set_inline */
 
     /* Copy over custom-data. */
     CustomData_from_bmesh_block(&bm->edata, &me->edata, e->head.data, i);
 
-    bmesh_quick_edgedraw_flag(med, e);
-
-    if (cd_edge_crease_offset != -1) {
-      med->crease = BM_ELEM_CD_GET_FLOAT_AS_UCHAR(e, cd_edge_crease_offset);
-    }
-    if (cd_edge_bweight_offset != -1) {
-      med->bweight = BM_ELEM_CD_GET_FLOAT_AS_UCHAR(e, cd_edge_bweight_offset);
-    }
+    bmesh_quick_edgedraw_flag(&medge[i], e);
 
     i++;
-    med++;
     BM_CHECK_ELEMENT(e);
   }
   bm->elem_index_dirty &= ~BM_EDGE;
@@ -1109,24 +1029,28 @@ void BM_mesh_bm_to_me(Main *bmain, BMesh *bm, Mesh *me, const struct BMeshToMesh
   j = 0;
   BM_ITER_MESH (f, &iter, bm, BM_FACES_OF_MESH) {
     BMLoop *l_iter, *l_first;
-    mpoly->loopstart = j;
-    mpoly->totloop = f->len;
-    mpoly->mat_nr = f->mat_nr;
-    mpoly->flag = BM_face_flag_to_mflag(f);
+    mpoly[i].loopstart = j;
+    mpoly[i].totloop = f->len;
+    if (f->mat_nr != 0) {
+      need_material_index = true;
+    }
+    mpoly[i].flag = BM_face_flag_to_mflag(f);
     if (BM_elem_flag_test(f, BM_ELEM_HIDDEN)) {
       need_hide_poly = true;
     }
+    if (BM_elem_flag_test(f, BM_ELEM_SELECT)) {
+      need_select_poly = true;
+    }
 
     l_iter = l_first = BM_FACE_FIRST_LOOP(f);
     do {
-      mloop->e = BM_elem_index_get(l_iter->e);
-      mloop->v = BM_elem_index_get(l_iter->v);
+      mloop[j].e = BM_elem_index_get(l_iter->e);
+      mloop[j].v = BM_elem_index_get(l_iter->v);
 
       /* Copy over custom-data. */
       CustomData_from_bmesh_block(&bm->ldata, &me->ldata, l_iter->head.data, j);
 
       j++;
-      mloop++;
       BM_CHECK_ELEMENT(l_iter);
       BM_CHECK_ELEMENT(l_iter->e);
       BM_CHECK_ELEMENT(l_iter->v);
@@ -1140,10 +1064,17 @@ void BM_mesh_bm_to_me(Main *bmain, BMesh *bm, Mesh *me, const struct BMeshToMesh
     CustomData_from_bmesh_block(&bm->pdata, &me->pdata, f->head.data, i);
 
     i++;
-    mpoly++;
     BM_CHECK_ELEMENT(f);
   }
 
+  if (need_material_index) {
+    BM_mesh_elem_table_ensure(bm, BM_FACE);
+    write_fn_to_attribute<int>(
+        me->attributes_for_write(), "material_index", ATTR_DOMAIN_FACE, [&](const int i) {
+          return static_cast<int>(BM_face_at_index(bm, i)->mat_nr);
+        });
+  }
+
   /* Patch hook indices and vertex parents. */
   if (params->calc_object_remap && (ototvert > 0)) {
     BLI_assert(bmain != nullptr);
@@ -1210,8 +1141,8 @@ void BM_mesh_bm_to_me(Main *bmain, BMesh *bm, Mesh *me, const struct BMeshToMesh
 
   convert_bmesh_hide_flags_to_mesh_attributes(
       *bm, need_hide_vert, need_hide_edge, need_hide_poly, *me);
-
-  BKE_mesh_update_customdata_pointers(me, false);
+  convert_bmesh_selection_flags_to_mesh_attributes(
+      *bm, need_select_vert, need_select_edge, need_select_poly, *me);
 
   {
     me->totselect = BLI_listbase_count(&(bm->selected));
@@ -1238,7 +1169,7 @@ void BM_mesh_bm_to_me(Main *bmain, BMesh *bm, Mesh *me, const struct BMeshToMesh
   }
 
   if (me->key) {
-    bm_to_mesh_shape(bm, me->key, me->mvert, params->active_shapekey_to_mvert);
+    bm_to_mesh_shape(bm, me->key, mvert, params->active_shapekey_to_mvert);
   }
 
   /* Run this even when shape keys aren't used since it may be used for hooks or vertex parents. */
@@ -1259,8 +1190,12 @@ void BM_mesh_bm_to_me(Main *bmain, BMesh *bm, Mesh *me, const struct BMeshToMesh
   BKE_mesh_runtime_clear_geometry(me);
 }
 
+/* NOTE: The function is called from multiple threads with the same input BMesh and different
+ * mesh objects. */
 void BM_mesh_bm_to_me_for_eval(BMesh *bm, Mesh *me, const CustomData_MeshMasks *cd_mask_extra)
 {
+  using namespace blender;
+
   /* Must be an empty mesh. */
   BLI_assert(me->totvert == 0);
   BLI_assert(cd_mask_extra == nullptr || (cd_mask_extra->vmask & CD_MASK_SHAPEKEY) == 0);
@@ -1271,10 +1206,10 @@ void BM_mesh_bm_to_me_for_eval(BMesh *bm, Mesh *me, const CustomData_MeshMasks *
   me->totloop = bm->totloop;
   me->totpoly = bm->totface;
 
-  CustomData_add_layer(&me->vdata, CD_MVERT, CD_CALLOC, nullptr, bm->totvert);
-  CustomData_add_layer(&me->edata, CD_MEDGE, CD_CALLOC, nullptr, bm->totedge);
-  CustomData_add_layer(&me->ldata, CD_MLOOP, CD_CALLOC, nullptr, bm->totloop);
-  CustomData_add_layer(&me->pdata, CD_MPOLY, CD_CALLOC, nullptr, bm->totface);
+  CustomData_add_layer(&me->vdata, CD_MVERT, CD_SET_DEFAULT, nullptr, bm->totvert);
+  CustomData_add_layer(&me->edata, CD_MEDGE, CD_SET_DEFAULT, nullptr, bm->totedge);
+  CustomData_add_layer(&me->ldata, CD_MLOOP, CD_SET_DEFAULT, nullptr, bm->totloop);
+  CustomData_add_layer(&me->pdata, CD_MPOLY, CD_SET_DEFAULT, nullptr, bm->totface);
 
   /* Don't process shape-keys, we only feed them through the modifier stack as needed,
    * e.g. for applying modifiers or the like. */
@@ -1283,37 +1218,32 @@ void BM_mesh_bm_to_me_for_eval(BMesh *bm, Mesh *me, const CustomData_MeshMasks *
     CustomData_MeshMasks_update(&mask, cd_mask_extra);
   }
   mask.vmask &= ~CD_MASK_SHAPEKEY;
-  CustomData_merge(&bm->vdata, &me->vdata, mask.vmask, CD_CALLOC, me->totvert);
-  CustomData_merge(&bm->edata, &me->edata, mask.emask, CD_CALLOC, me->totedge);
-  CustomData_merge(&bm->ldata, &me->ldata, mask.lmask, CD_CALLOC, me->totloop);
-  CustomData_merge(&bm->pdata, &me->pdata, mask.pmask, CD_CALLOC, me->totpoly);
-
-  BKE_mesh_update_customdata_pointers(me, false);
+  CustomData_merge(&bm->vdata, &me->vdata, mask.vmask, CD_SET_DEFAULT, me->totvert);
+  CustomData_merge(&bm->edata, &me->edata, mask.emask, CD_SET_DEFAULT, me->totedge);
+  CustomData_merge(&bm->ldata, &me->ldata, mask.lmask, CD_SET_DEFAULT, me->totloop);
+  CustomData_merge(&bm->pdata, &me->pdata, mask.pmask, CD_SET_DEFAULT, me->totpoly);
 
   BMIter iter;
   BMVert *eve;
   BMEdge *eed;
   BMFace *efa;
-  MVert *mvert = me->mvert;
-  MEdge *medge = me->medge;
-  MLoop *mloop = me->mloop;
-  MPoly *mpoly = me->mpoly;
+  MutableSpan<MVert> mvert = me->verts_for_write();
+  MutableSpan<MEdge> medge = me->edges_for_write();
+  MutableSpan<MPoly> mpoly = me->polys_for_write();
+  MutableSpan<MLoop> loops = me->loops_for_write();
+  MLoop *mloop = loops.data();
   unsigned int i, j;
 
-  const int cd_vert_bweight_offset = CustomData_get_offset(&bm->vdata, CD_BWEIGHT);
-  const int cd_edge_bweight_offset = CustomData_get_offset(&bm->edata, CD_BWEIGHT);
-  const int cd_edge_crease_offset = CustomData_get_offset(&bm->edata, CD_CREASE);
-
-  bool need_hide_vert = false;
-  bool need_hide_edge = false;
-  bool need_hide_poly = false;
-
   /* Clear normals on the mesh completely, since the original vertex and polygon count might be
    * different than the BMesh's. */
   BKE_mesh_clear_derived_normals(me);
 
   me->runtime.deformed_only = true;
 
+  bke::MutableAttributeAccessor mesh_attributes = me->attributes_for_write();
+
+  bke::SpanAttributeWriter<bool> hide_vert_attribute;
+  bke::SpanAttributeWriter<bool> select_vert_attribute;
   BM_ITER_MESH_INDEX (eve, &iter, bm, BM_VERTS_OF_MESH, i) {
     MVert *mv = &mvert[i];
 
@@ -1321,23 +1251,27 @@ void BM_mesh_bm_to_me_for_eval(BMesh *bm, Mesh *me, const CustomData_MeshMasks *
 
     BM_elem_index_set(eve, i); /* set_inline */
 
-    mv->flag = BM_vert_flag_to_mflag(eve);
     if (BM_elem_flag_test(eve, BM_ELEM_HIDDEN)) {
-      need_hide_vert = true;
-    }
-
-    if (cd_vert_bweight_offset != -1) {
-      mv->bweight = BM_ELEM_CD_GET_FLOAT_AS_UCHAR(eve, cd_vert_bweight_offset);
+      if (!hide_vert_attribute) {
+        hide_vert_attribute = mesh_attributes.lookup_or_add_for_write_span<bool>(
+            ".hide_vert", ATTR_DOMAIN_POINT);
+      }
+      hide_vert_attribute.span[i] = true;
     }
-
-    if (cd_vert_bweight_offset != -1) {
-      mv->bweight = BM_ELEM_CD_GET_FLOAT_AS_UCHAR(eve, cd_vert_bweight_offset);
+    if (BM_elem_flag_test(eve, BM_ELEM_SELECT)) {
+      if (!select_vert_attribute) {
+        select_vert_attribute = mesh_attributes.lookup_or_add_for_write_span<bool>(
+            ".select_vert", ATTR_DOMAIN_POINT);
+      }
+      select_vert_attribute.span[i] = true;
     }
 
     CustomData_from_bmesh_block(&bm->vdata, &me->vdata, eve->head.data, i);
   }
   bm->elem_index_dirty &= ~BM_VERT;
 
+  bke::SpanAttributeWriter<bool> hide_edge_attribute;
+  bke::SpanAttributeWriter<bool> select_edge_attribute;
   BM_ITER_MESH_INDEX (eed, &iter, bm, BM_EDGES_OF_MESH, i) {
     MEdge *med = &medge[i];
 
@@ -1348,7 +1282,18 @@ void BM_mesh_bm_to_me_for_eval(BMesh *bm, Mesh *me, const CustomData_MeshMasks *
 
     med->flag = BM_edge_flag_to_mflag(eed);
     if (BM_elem_flag_test(eed, BM_ELEM_HIDDEN)) {
-      need_hide_edge = true;
+      if (!hide_edge_attribute) {
+        hide_edge_attribute = mesh_attributes.lookup_or_add_for_write_span<bool>(".hide_edge",
+                                                                                 ATTR_DOMAIN_EDGE);
+      }
+      hide_edge_attribute.span[i] = true;
+    }
+    if (BM_elem_flag_test(eed, BM_ELEM_SELECT)) {
+      if (!select_edge_attribute) {
+        select_edge_attribute = mesh_attributes.lookup_or_add_for_write_span<bool>(
+            ".select_edge", ATTR_DOMAIN_EDGE);
+      }
+      select_edge_attribute.span[i] = true;
     }
 
     /* Handle this differently to editmode switching,
@@ -1359,18 +1304,14 @@ void BM_mesh_bm_to_me_for_eval(BMesh *bm, Mesh *me, const CustomData_MeshMasks *
       }
     }
 
-    if (cd_edge_crease_offset != -1) {
-      med->crease = BM_ELEM_CD_GET_FLOAT_AS_UCHAR(eed, cd_edge_crease_offset);
-    }
-    if (cd_edge_bweight_offset != -1) {
-      med->bweight = BM_ELEM_CD_GET_FLOAT_AS_UCHAR(eed, cd_edge_bweight_offset);
-    }
-
     CustomData_from_bmesh_block(&bm->edata, &me->edata, eed->head.data, i);
   }
   bm->elem_index_dirty &= ~BM_EDGE;
 
   j = 0;
+  bke::SpanAttributeWriter<int> material_index_attribute;
+  bke::SpanAttributeWriter<bool> hide_poly_attribute;
+  bke::SpanAttributeWriter<bool> select_poly_attribute;
   BM_ITER_MESH_INDEX (efa, &iter, bm, BM_FACES_OF_MESH, i) {
     BMLoop *l_iter;
     BMLoop *l_first;
@@ -1381,11 +1322,28 @@ void BM_mesh_bm_to_me_for_eval(BMesh *bm, Mesh *me, const CustomData_MeshMasks *
     mp->totloop = efa->len;
     mp->flag = BM_face_flag_to_mflag(efa);
     if (BM_elem_flag_test(efa, BM_ELEM_HIDDEN)) {
-      need_hide_poly = true;
+      if (!hide_poly_attribute) {
+        hide_poly_attribute = mesh_attributes.lookup_or_add_for_write_span<bool>(".hide_poly",
+                                                                                 ATTR_DOMAIN_FACE);
+      }
+      hide_poly_attribute.span[i] = true;
+    }
+    if (BM_elem_flag_test(efa, BM_ELEM_SELECT)) {
+      if (!select_poly_attribute) {
+        select_poly_attribute = mesh_attributes.lookup_or_add_for_write_span<bool>(
+            ".select_poly", ATTR_DOMAIN_FACE);
+      }
+      select_poly_attribute.span[i] = true;
     }
 
     mp->loopstart = j;
-    mp->mat_nr = efa->mat_nr;
+    if (efa->mat_nr != 0) {
+      if (!material_index_attribute) {
+        material_index_attribute = mesh_attributes.lookup_or_add_for_write_span<int>(
+            "material_index", ATTR_DOMAIN_FACE);
+      }
+      material_index_attribute.span[i] = efa->mat_nr;
+    }
 
     l_iter = l_first = BM_FACE_FIRST_LOOP(efa);
     do {
@@ -1403,8 +1361,13 @@ void BM_mesh_bm_to_me_for_eval(BMesh *bm, Mesh *me, const CustomData_MeshMasks *
   }
   bm->elem_index_dirty &= ~(BM_FACE | BM_LOOP);
 
-  convert_bmesh_hide_flags_to_mesh_attributes(
-      *bm, need_hide_vert, need_hide_edge, need_hide_poly, *me);
+  assert_bmesh_has_no_mesh_only_attributes(*bm);
 
-  me->cd_flag = BM_mesh_cd_flag_from_bmesh(bm);
+  material_index_attribute.finish();
+  hide_vert_attribute.finish();
+  hide_edge_attribute.finish();
+  hide_poly_attribute.finish();
+  select_vert_attribute.finish();
+  select_edge_attribute.finish();
+  select_poly_attribute.finish();
 }
diff --git a/source/blender/bmesh/intern/bmesh_mesh_convert.h b/source/blender/bmesh/intern/bmesh_mesh_convert.h
index e2871dc04d3..3f8e9e3dfef 100644
--- a/source/blender/bmesh/intern/bmesh_mesh_convert.h
+++ b/source/blender/bmesh/intern/bmesh_mesh_convert.h
@@ -13,10 +13,6 @@ struct CustomData_MeshMasks;
 struct Main;
 struct Mesh;
 
-void BM_mesh_cd_flag_ensure(BMesh *bm, struct Mesh *mesh, char cd_flag);
-void BM_mesh_cd_flag_apply(BMesh *bm, char cd_flag);
-char BM_mesh_cd_flag_from_bmesh(BMesh *bm);
-
 struct BMeshFromMeshParams {
   bool calc_face_normal;
   bool calc_vert_normal;
@@ -61,8 +57,8 @@ struct BMeshToMeshParams {
   bool active_shapekey_to_mvert;
   struct CustomData_MeshMasks cd_mask_extra;
 };
+
 /**
- *
  * \param bmain: May be NULL in case \a calc_object_remap parameter option is not set.
  */
 void BM_mesh_bm_to_me(struct Main *bmain,
diff --git a/source/blender/bmesh/intern/bmesh_query.h b/source/blender/bmesh/intern/bmesh_query.h
index 85eadd3076a..9d690395d72 100644
--- a/source/blender/bmesh/intern/bmesh_query.h
+++ b/source/blender/bmesh/intern/bmesh_query.h
@@ -138,7 +138,6 @@ BMLoop *BM_face_other_vert_loop(BMFace *f, BMVert *v_prev, BMVert *v) ATTR_WARN_
  *     +----------+ <-- This loop defines the face and vertex..
  *                l
  * </pre>
- *
  */
 BMLoop *BM_loop_other_vert_loop_by_edge(BMLoop *l, BMEdge *e) ATTR_WARN_UNUSED_RESULT
     ATTR_NONNULL();
diff --git a/source/blender/bmesh/intern/bmesh_query_uv.c b/source/blender/bmesh/intern/bmesh_query_uv.cc
index 1225543cd06..5a725407c6b 100644
--- a/source/blender/bmesh/intern/bmesh_query_uv.c
+++ b/source/blender/bmesh/intern/bmesh_query_uv.cc
@@ -6,9 +6,10 @@
 
 #include "MEM_guardedalloc.h"
 
-#include "BLI_alloca.h"
+#include "BLI_array.hh"
 #include "BLI_linklist.h"
 #include "BLI_math.h"
+#include "BLI_math_vec_types.hh"
 #include "BLI_utildefines_stack.h"
 
 #include "BKE_customdata.h"
@@ -80,7 +81,7 @@ void BM_face_uv_calc_center_median(const BMFace *f, const int cd_loop_uv_offset,
   zero_v2(r_cent);
   l_iter = l_first = BM_FACE_FIRST_LOOP(f);
   do {
-    const MLoopUV *luv = BM_ELEM_CD_GET_VOID_P(l_iter, cd_loop_uv_offset);
+    const MLoopUV *luv = (const MLoopUV *)BM_ELEM_CD_GET_VOID_P(l_iter, cd_loop_uv_offset);
     add_v2_v2(r_cent, luv->uv);
   } while ((l_iter = l_iter->next) != l_first);
 
@@ -89,16 +90,16 @@ void BM_face_uv_calc_center_median(const BMFace *f, const int cd_loop_uv_offset,
 
 float BM_face_uv_calc_cross(const BMFace *f, const int cd_loop_uv_offset)
 {
-  float(*uvs)[2] = BLI_array_alloca(uvs, f->len);
+  blender::Array<blender::float2, BM_DEFAULT_NGON_STACK_SIZE> uvs(f->len);
   const BMLoop *l_iter;
   const BMLoop *l_first;
   int i = 0;
   l_iter = l_first = BM_FACE_FIRST_LOOP(f);
   do {
-    const MLoopUV *luv = BM_ELEM_CD_GET_VOID_P(l_iter, cd_loop_uv_offset);
-    copy_v2_v2(uvs[i++], luv->uv);
+    const MLoopUV *luv = (const MLoopUV *)BM_ELEM_CD_GET_VOID_P(l_iter, cd_loop_uv_offset);
+    uvs[i++] = luv->uv;
   } while ((l_iter = l_iter->next) != l_first);
-  return cross_poly_v2(uvs, f->len);
+  return cross_poly_v2(reinterpret_cast<const float(*)[2]>(uvs.data()), f->len);
 }
 
 void BM_face_uv_minmax(const BMFace *f, float min[2], float max[2], const int cd_loop_uv_offset)
@@ -107,7 +108,7 @@ void BM_face_uv_minmax(const BMFace *f, float min[2], float max[2], const int cd
   const BMLoop *l_first;
   l_iter = l_first = BM_FACE_FIRST_LOOP(f);
   do {
-    const MLoopUV *luv = BM_ELEM_CD_GET_VOID_P(l_iter, cd_loop_uv_offset);
+    const MLoopUV *luv = (const MLoopUV *)BM_ELEM_CD_GET_VOID_P(l_iter, cd_loop_uv_offset);
     minmax_v2v2_v2(min, max, luv->uv);
   } while ((l_iter = l_iter->next) != l_first);
 }
@@ -118,7 +119,7 @@ void BM_face_uv_transform(BMFace *f, const float matrix[2][2], const int cd_loop
   BMLoop *l_first;
   l_iter = l_first = BM_FACE_FIRST_LOOP(f);
   do {
-    MLoopUV *luv = BM_ELEM_CD_GET_VOID_P(l_iter, cd_loop_uv_offset);
+    MLoopUV *luv = (MLoopUV *)BM_ELEM_CD_GET_VOID_P(l_iter, cd_loop_uv_offset);
     mul_m2_v2(matrix, luv->uv);
   } while ((l_iter = l_iter->next) != l_first);
 }
@@ -126,12 +127,12 @@ void BM_face_uv_transform(BMFace *f, const float matrix[2][2], const int cd_loop
 bool BM_loop_uv_share_edge_check(BMLoop *l_a, BMLoop *l_b, const int cd_loop_uv_offset)
 {
   BLI_assert(l_a->e == l_b->e);
-  MLoopUV *luv_a_curr = BM_ELEM_CD_GET_VOID_P(l_a, cd_loop_uv_offset);
-  MLoopUV *luv_a_next = BM_ELEM_CD_GET_VOID_P(l_a->next, cd_loop_uv_offset);
-  MLoopUV *luv_b_curr = BM_ELEM_CD_GET_VOID_P(l_b, cd_loop_uv_offset);
-  MLoopUV *luv_b_next = BM_ELEM_CD_GET_VOID_P(l_b->next, cd_loop_uv_offset);
+  MLoopUV *luv_a_curr = (MLoopUV *)BM_ELEM_CD_GET_VOID_P(l_a, cd_loop_uv_offset);
+  MLoopUV *luv_a_next = (MLoopUV *)BM_ELEM_CD_GET_VOID_P(l_a->next, cd_loop_uv_offset);
+  MLoopUV *luv_b_curr = (MLoopUV *)BM_ELEM_CD_GET_VOID_P(l_b, cd_loop_uv_offset);
+  MLoopUV *luv_b_next = (MLoopUV *)BM_ELEM_CD_GET_VOID_P(l_b->next, cd_loop_uv_offset);
   if (l_a->v != l_b->v) {
-    SWAP(MLoopUV *, luv_b_curr, luv_b_next);
+    std::swap(luv_b_curr, luv_b_next);
   }
   return (equals_v2v2(luv_a_curr->uv, luv_b_curr->uv) &&
           equals_v2v2(luv_a_next->uv, luv_b_next->uv));
@@ -140,8 +141,8 @@ bool BM_loop_uv_share_edge_check(BMLoop *l_a, BMLoop *l_b, const int cd_loop_uv_
 bool BM_loop_uv_share_vert_check(BMLoop *l_a, BMLoop *l_b, const int cd_loop_uv_offset)
 {
   BLI_assert(l_a->v == l_b->v);
-  const MLoopUV *luv_a = BM_ELEM_CD_GET_VOID_P(l_a, cd_loop_uv_offset);
-  const MLoopUV *luv_b = BM_ELEM_CD_GET_VOID_P(l_b, cd_loop_uv_offset);
+  const MLoopUV *luv_a = (const MLoopUV *)BM_ELEM_CD_GET_VOID_P(l_a, cd_loop_uv_offset);
+  const MLoopUV *luv_b = (const MLoopUV *)BM_ELEM_CD_GET_VOID_P(l_b, cd_loop_uv_offset);
   if (!equals_v2v2(luv_a->uv, luv_b->uv)) {
     return false;
   }
@@ -160,8 +161,10 @@ bool BM_edge_uv_share_vert_check(BMEdge *e, BMLoop *l_a, BMLoop *l_b, const int
   const BMLoop *l_other_b = BM_loop_other_vert_loop_by_edge(l_b, e);
 
   {
-    const MLoopUV *luv_other_a = BM_ELEM_CD_GET_VOID_P(l_other_a, cd_loop_uv_offset);
-    const MLoopUV *luv_other_b = BM_ELEM_CD_GET_VOID_P(l_other_b, cd_loop_uv_offset);
+    const MLoopUV *luv_other_a = (const MLoopUV *)BM_ELEM_CD_GET_VOID_P(l_other_a,
+                                                                        cd_loop_uv_offset);
+    const MLoopUV *luv_other_b = (const MLoopUV *)BM_ELEM_CD_GET_VOID_P(l_other_b,
+                                                                        cd_loop_uv_offset);
     if (!equals_v2v2(luv_other_a->uv, luv_other_b->uv)) {
       return false;
     }
@@ -172,7 +175,7 @@ bool BM_edge_uv_share_vert_check(BMEdge *e, BMLoop *l_a, BMLoop *l_b, const int
 
 bool BM_face_uv_point_inside_test(const BMFace *f, const float co[2], const int cd_loop_uv_offset)
 {
-  float(*projverts)[2] = BLI_array_alloca(projverts, f->len);
+  blender::Array<blender::float2, BM_DEFAULT_NGON_STACK_SIZE> projverts(f->len);
 
   BMLoop *l_iter;
   int i;
@@ -180,8 +183,9 @@ bool BM_face_uv_point_inside_test(const BMFace *f, const float co[2], const int
   BLI_assert(BM_face_is_normal_valid(f));
 
   for (i = 0, l_iter = BM_FACE_FIRST_LOOP(f); i < f->len; i++, l_iter = l_iter->next) {
-    copy_v2_v2(projverts[i], BM_ELEM_CD_GET_VOID_P(l_iter, cd_loop_uv_offset));
+    projverts[i] = ((const MLoopUV *)BM_ELEM_CD_GET_VOID_P(l_iter, cd_loop_uv_offset))->uv;
   }
 
-  return isect_point_poly_v2(co, projverts, f->len, false);
+  return isect_point_poly_v2(
+      co, reinterpret_cast<const float(*)[2]>(projverts.data()), f->len, false);
 }
diff --git a/source/blender/bmesh/intern/bmesh_structure.c b/source/blender/bmesh/intern/bmesh_structure.c
index 6baaeb43f1a..7d340f02f2e 100644
--- a/source/blender/bmesh/intern/bmesh_structure.c
+++ b/source/blender/bmesh/intern/bmesh_structure.c
@@ -182,9 +182,8 @@ void bmesh_disk_edge_remove(BMEdge *e, BMVert *v)
 
 BMEdge *bmesh_disk_edge_exists(const BMVert *v1, const BMVert *v2)
 {
-  BMEdge *e_iter, *e_first;
-
   if (v1->e) {
+    BMEdge *e_iter, *e_first;
     e_first = e_iter = v1->e;
 
     do {
diff --git a/source/blender/bmesh/operators/bmo_connect.c b/source/blender/bmesh/operators/bmo_connect.c
index 42de425103e..59a12db9241 100644
--- a/source/blender/bmesh/operators/bmo_connect.c
+++ b/source/blender/bmesh/operators/bmo_connect.c
@@ -18,7 +18,7 @@
 #define VERT_INPUT 1
 
 #define EDGE_OUT 1
-/* Edge spans 2 VERT_INPUT's, its a nop,
+/* Edge spans 2 VERT_INPUT's, its a NOP,
  * but include in "edges.out" */
 #define EDGE_OUT_ADJ 2
 
diff --git a/source/blender/bmesh/operators/bmo_connect_nonplanar.c b/source/blender/bmesh/operators/bmo_connect_nonplanar.c
index ac88ffb9065..8112844fc8a 100644
--- a/source/blender/bmesh/operators/bmo_connect_nonplanar.c
+++ b/source/blender/bmesh/operators/bmo_connect_nonplanar.c
@@ -24,7 +24,7 @@
 static float bm_face_subset_calc_planar(BMLoop *l_first, BMLoop *l_last, const float no[3])
 {
   float axis_mat[3][3];
-  float z_prev, z_curr;
+  float z_prev;
   float delta_z = 0.0f;
 
   /* Newell's Method */
@@ -35,7 +35,7 @@ static float bm_face_subset_calc_planar(BMLoop *l_first, BMLoop *l_last, const f
 
   z_prev = dot_m3_v3_row_z(axis_mat, l_last->v->co);
   do {
-    z_curr = dot_m3_v3_row_z(axis_mat, l_iter->v->co);
+    const float z_curr = dot_m3_v3_row_z(axis_mat, l_iter->v->co);
     delta_z += fabsf(z_curr - z_prev);
     z_prev = z_curr;
   } while ((l_iter = l_iter->next) != l_term);
diff --git a/source/blender/bmesh/operators/bmo_create.c b/source/blender/bmesh/operators/bmo_create.c
index a809fe6ee3d..9dba48a8961 100644
--- a/source/blender/bmesh/operators/bmo_create.c
+++ b/source/blender/bmesh/operators/bmo_create.c
@@ -77,7 +77,6 @@ void bmo_contextual_create_exec(BMesh *bm, BMOperator *op)
    * |        .
    * |        .
    * +........+ <-- starts out free standing.
-   *
    */
 
   /* Here we check for consistency and create 2 edges */
diff --git a/source/blender/bmesh/operators/bmo_join_triangles.c b/source/blender/bmesh/operators/bmo_join_triangles.c
index 1339efb3057..ab74aa2e1bb 100644
--- a/source/blender/bmesh/operators/bmo_join_triangles.c
+++ b/source/blender/bmesh/operators/bmo_join_triangles.c
@@ -22,7 +22,9 @@
 
 #include "intern/bmesh_operators_private.h" /* own include */
 
-/* assumes edges are validated before reaching this poin */
+/**
+ * \note Assumes edges are validated before reaching this point.
+ */
 static float quad_calc_error(const float v1[3],
                              const float v2[3],
                              const float v3[3],
diff --git a/source/blender/bmesh/operators/bmo_poke.c b/source/blender/bmesh/operators/bmo_poke.c
index 7ff3b9b072c..6622dbf7575 100644
--- a/source/blender/bmesh/operators/bmo_poke.c
+++ b/source/blender/bmesh/operators/bmo_poke.c
@@ -52,8 +52,7 @@ void bmo_poke_exec(BMesh *bm, BMOperator *op)
   }
 
   BMO_ITER (f, &oiter, op->slots_in, "faces", BM_FACE) {
-    BMFace *f_new;
-    float f_center[3], f_center_mean[3];
+    float f_center[3];
     BMVert *v_center = NULL;
     BMLoop *l_iter, *l_first;
     /* only interpolate the central loop from the face once,
@@ -69,15 +68,6 @@ void bmo_poke_exec(BMesh *bm, BMOperator *op)
     v_center = BM_vert_create(bm, f_center, NULL, BM_CREATE_NOP);
     BMO_vert_flag_enable(bm, v_center, ELE_NEW);
 
-    if (cd_loop_mdisp_offset != -1) {
-      if (center_mode == BMOP_POKE_MEDIAN) {
-        copy_v3_v3(f_center_mean, f_center);
-      }
-      else {
-        BM_face_calc_center_median(f, f_center_mean);
-      }
-    }
-
     /* handled by BM_loop_interp_from_face */
     // BM_vert_interp_from_face(bm, v_center, f);
 
@@ -92,8 +82,7 @@ void bmo_poke_exec(BMesh *bm, BMOperator *op)
     l_iter = l_first = BM_FACE_FIRST_LOOP(f);
     do {
       BMLoop *l_new;
-
-      f_new = BM_face_create_quad_tri(
+      BMFace *f_new = BM_face_create_quad_tri(
           bm, l_iter->v, l_iter->next->v, v_center, NULL, f, BM_CREATE_NOP);
       l_new = BM_FACE_FIRST_LOOP(f_new);
 
diff --git a/source/blender/bmesh/operators/bmo_removedoubles.c b/source/blender/bmesh/operators/bmo_removedoubles.c
index e3275555b86..99ca49f3d4f 100644
--- a/source/blender/bmesh/operators/bmo_removedoubles.c
+++ b/source/blender/bmesh/operators/bmo_removedoubles.c
@@ -657,10 +657,10 @@ static void bmesh_find_doubles_common(BMesh *bm,
     for (int i = 0; i < verts_len; i++) {
       BMVert *v_check = verts[i];
       if (duplicates[i] == -1) {
-        /* nop (others can use as target) */
+        /* NOP (others can use as target). */
       }
       else if (duplicates[i] == i) {
-        /* keep (others can use as target) */
+        /* Keep (others can use as target). */
       }
       else {
         BMVert *v_other = verts[duplicates[i]];
diff --git a/source/blender/bmesh/operators/bmo_subdivide.c b/source/blender/bmesh/operators/bmo_subdivide.c
index d6c64809e13..6b2df40549d 100644
--- a/source/blender/bmesh/operators/bmo_subdivide.c
+++ b/source/blender/bmesh/operators/bmo_subdivide.c
@@ -86,7 +86,7 @@ typedef struct SubDPattern {
  *   split the edge only?
  */
 
-/* flags for all elements share a common bitfield space */
+/** Flags for all elements share a common bit-field space. */
 #define SUBD_SPLIT 1
 
 #define EDGE_PERCENT 2
@@ -966,7 +966,7 @@ void bmo_subdivide_edges_exec(BMesh *bm, BMOperator *op)
     patterns[5] = NULL;
   }
 
-  /* add a temporary shapekey layer to store displacements on current geometry */
+  /* Add a temporary shape-key layer to store displacements on current geometry. */
   BM_data_layer_add(bm, &bm->vdata, CD_SHAPEKEY);
 
   bmo_subd_init_shape_info(bm, &params);
diff --git a/source/blender/bmesh/operators/bmo_subdivide_edgering.c b/source/blender/bmesh/operators/bmo_subdivide_edgering.c
index 3d2f5947539..6f41da7bb43 100644
--- a/source/blender/bmesh/operators/bmo_subdivide_edgering.c
+++ b/source/blender/bmesh/operators/bmo_subdivide_edgering.c
@@ -42,7 +42,8 @@
 #define FACE_IN_STACK (1 << 2)
 
 /* -------------------------------------------------------------------- */
-/* Specialized Utility Funcs */
+/** \name Specialized Utility Functions
+ * \{ */
 
 #ifndef NDEBUG
 static uint bm_verts_tag_count(BMesh *bm)
@@ -183,9 +184,13 @@ finally:
   return has_overlap;
 }
 
+/** \} */
+
 /* -------------------------------------------------------------------- */
-/* Edge Loop Pairs */
-/* key (ordered loop pointers) */
+/** \name Edge Loop Pairs
+ *
+ * key (ordered loop pointers).
+ * \{ */
 static GSet *bm_edgering_pair_calc(BMesh *bm, ListBase *eloops_rim)
 {
   /**
@@ -258,8 +263,11 @@ static GSet *bm_edgering_pair_calc(BMesh *bm, ListBase *eloops_rim)
   return eloop_pair_gs;
 }
 
+/** \} */
+
 /* -------------------------------------------------------------------- */
-/* Subdivide an edge 'n' times and return an open edgeloop */
+/** \name Subdivide an edge 'n' times and return an open edgeloop
+ * \{ */
 
 static void bm_edge_subdiv_as_loop(
     BMesh *bm, ListBase *eloops, BMEdge *e, BMVert *v_a, const int cuts)
@@ -290,8 +298,11 @@ static void bm_edge_subdiv_as_loop(
   BLI_addtail(eloops, eloop);
 }
 
+/** \} */
+
 /* -------------------------------------------------------------------- */
-/* LoopPair Cache (struct and util funcs) */
+/** \name Loop Pair Cache (struct and utilities functions)
+ * \{ */
 
 /**
  * Use for finding spline handle direction from surrounding faces.
@@ -510,8 +521,11 @@ static void bm_edgering_pair_store_free(LoopPairStore *lpair, const int interp_m
   MEM_freeN(lpair);
 }
 
+/** \} */
+
 /* -------------------------------------------------------------------- */
-/* Interpolation Function */
+/** \name Interpolation Function
+ * \{ */
 
 static void bm_edgering_pair_interpolate(BMesh *bm,
                                          LoopPairStore *lpair,
@@ -1216,3 +1230,5 @@ cleanup:
     BMO_slot_buffer_from_enabled_flag(bm, op, op->slots_out, "faces.out", BM_FACE, FACE_OUT);
   }
 }
+
+/** \} */
diff --git a/source/blender/bmesh/operators/bmo_utils.c b/source/blender/bmesh/operators/bmo_utils.c
index 309ef2cf21e..d88f3112a71 100644
--- a/source/blender/bmesh/operators/bmo_utils.c
+++ b/source/blender/bmesh/operators/bmo_utils.c
@@ -470,7 +470,7 @@ void bmo_rotate_uvs_exec(BMesh *bm, BMOperator *op)
         BMLoop *lf;           /* current face loops */
         MLoopUV *f_luv;       /* first face loop uv */
         float p_uv[2];        /* previous uvs */
-        float t_uv[2];        /* tmp uvs */
+        float t_uv[2];        /* temp uvs */
 
         int n = 0;
         BM_ITER_ELEM (lf, &l_iter, fs, BM_LOOPS_OF_FACE) {
@@ -603,7 +603,7 @@ void bmo_rotate_colors_exec(BMesh *bm, BMOperator *op)
 
   const size_t size = cd_loop_color_type == CD_PROP_COLOR ? sizeof(MPropCol) : sizeof(MLoopCol);
   void *p_col;                /* previous color */
-  void *t_col = alloca(size); /* tmp color */
+  void *t_col = alloca(size); /* Temp color. */
 
   BMO_ITER (fs, &fs_iter, op->slots_in, "faces", BM_FACE) {
     if (use_ccw == false) { /* same loops direction */
diff --git a/source/blender/bmesh/tools/bmesh_bevel.c b/source/blender/bmesh/tools/bmesh_bevel.c
index aa2c93f7c5a..b08051341be 100644
--- a/source/blender/bmesh/tools/bmesh_bevel.c
+++ b/source/blender/bmesh/tools/bmesh_bevel.c
@@ -4799,7 +4799,7 @@ static float projected_boundary_area(BevVert *bv, BMFace *f)
   find_face_internal_boundverts(bv, f, unsnapped);
   do {
     float *co = v->nv.v->co;
-    if (v == unsnapped[0] || v == unsnapped[1] || v == unsnapped[2]) {
+    if (ELEM(v, unsnapped[0], unsnapped[1], unsnapped[2])) {
       mul_v2_m3v3(proj_co[i], axis_mat, co);
     }
     else {
@@ -4922,7 +4922,7 @@ static void build_center_ngon(BevelParams *bp, BMesh *bm, BevVert *bv, int mat_n
     BLI_array_append(vv, mesh_vert(vm, i, ns2, ns2)->v);
     if (frep) {
       BLI_array_append(vf, frep);
-      if (v == frep_unsnapped[0] || v == frep_unsnapped[1] || v == frep_unsnapped[2]) {
+      if (ELEM(v, frep_unsnapped[0], frep_unsnapped[1], frep_unsnapped[2])) {
         BLI_array_append(ve, NULL);
       }
       else {
@@ -5299,7 +5299,7 @@ static void snap_edges_for_vmesh_vert(int i,
     int previ = (i + n_bndv - 1) % n_bndv;
     /* Make jj and kk be the j and k indices for this corner. */
     int jj = corner < 2 ? j : j + 1;
-    int kk = (corner == 0 || corner == 3) ? k : k + 1;
+    int kk = ELEM(corner, 0, 3) ? k : k + 1;
     if (jj < ns2 && kk < ns2) {
       ; /* No snap. */
     }
@@ -5765,7 +5765,7 @@ static BMFace *bevel_build_poly(BevelParams *bp, BMesh *bm, BevVert *bv)
     BLI_array_append(bmverts, bndv->nv.v);
     if (repface) {
       BLI_array_append(bmfaces, repface);
-      if (bndv == unsnapped[0] || bndv == unsnapped[1] || bndv == unsnapped[2]) {
+      if (ELEM(bndv, unsnapped[0], unsnapped[1], unsnapped[2])) {
         BLI_array_append(bmedges, NULL);
       }
       else {
@@ -7083,7 +7083,7 @@ static void bevel_build_edge_polygons(BMesh *bm, BevelParams *bp, BMEdge *bme)
     }
   }
 
-  /* Fix UVs along end edge joints. A nop unless other side built already. */
+  /* Fix UVs along end edge joints. A NOP unless other side built already. */
   /* TODO: If some seam, may want to do selective merge. */
   if (!bv1->any_seam && bv1->vmesh->mesh_kind == M_NONE) {
     bev_merge_end_uvs(bm, bv1, e1);
diff --git a/source/blender/bmesh/tools/bmesh_path_region_uv.c b/source/blender/bmesh/tools/bmesh_path_region_uv.c
index 5c70f7fa5ec..56090ed9916 100644
--- a/source/blender/bmesh/tools/bmesh_path_region_uv.c
+++ b/source/blender/bmesh/tools/bmesh_path_region_uv.c
@@ -109,9 +109,10 @@ static bool bm_loop_region_test_chain(BMLoop *l, int *const depths[2], const int
 static LinkNode *mesh_calc_path_region_elem(BMesh *bm,
                                             BMElem *ele_src,
                                             BMElem *ele_dst,
-                                            const uint cd_loop_uv_offset,
+                                            const int cd_loop_uv_offset,
                                             const char path_htype)
 {
+  BLI_assert(cd_loop_uv_offset >= 0);
   int ele_loops_len[2];
   BMLoop **ele_loops[2];
 
@@ -397,7 +398,7 @@ static LinkNode *mesh_calc_path_region_elem(BMesh *bm,
 LinkNode *BM_mesh_calc_path_uv_region_vert(BMesh *bm,
                                            BMElem *ele_src,
                                            BMElem *ele_dst,
-                                           const uint cd_loop_uv_offset,
+                                           const int cd_loop_uv_offset,
                                            bool (*filter_fn)(BMLoop *, void *user_data),
                                            void *user_data)
 {
@@ -426,7 +427,7 @@ LinkNode *BM_mesh_calc_path_uv_region_vert(BMesh *bm,
 LinkNode *BM_mesh_calc_path_uv_region_edge(BMesh *bm,
                                            BMElem *ele_src,
                                            BMElem *ele_dst,
-                                           const uint cd_loop_uv_offset,
+                                           const int cd_loop_uv_offset,
                                            bool (*filter_fn)(BMLoop *, void *user_data),
                                            void *user_data)
 {
@@ -455,7 +456,7 @@ LinkNode *BM_mesh_calc_path_uv_region_edge(BMesh *bm,
 LinkNode *BM_mesh_calc_path_uv_region_face(BMesh *bm,
                                            BMElem *ele_src,
                                            BMElem *ele_dst,
-                                           const uint cd_loop_uv_offset,
+                                           const int cd_loop_uv_offset,
                                            bool (*filter_fn)(BMFace *, void *user_data),
                                            void *user_data)
 {
diff --git a/source/blender/bmesh/tools/bmesh_path_region_uv.h b/source/blender/bmesh/tools/bmesh_path_region_uv.h
index fa1b2bfcf9b..f399395e051 100644
--- a/source/blender/bmesh/tools/bmesh_path_region_uv.h
+++ b/source/blender/bmesh/tools/bmesh_path_region_uv.h
@@ -9,7 +9,7 @@
 struct LinkNode *BM_mesh_calc_path_uv_region_vert(BMesh *bm,
                                                   BMElem *ele_src,
                                                   BMElem *ele_dst,
-                                                  uint cd_loop_uv_offset,
+                                                  int cd_loop_uv_offset,
                                                   bool (*filter_fn)(BMLoop *, void *user_data),
                                                   void *user_data) ATTR_WARN_UNUSED_RESULT
     ATTR_NONNULL(1, 2, 3);
@@ -17,7 +17,7 @@ struct LinkNode *BM_mesh_calc_path_uv_region_vert(BMesh *bm,
 struct LinkNode *BM_mesh_calc_path_uv_region_edge(BMesh *bm,
                                                   BMElem *ele_src,
                                                   BMElem *ele_dst,
-                                                  uint cd_loop_uv_offset,
+                                                  int cd_loop_uv_offset,
                                                   bool (*filter_fn)(BMLoop *, void *user_data),
                                                   void *user_data) ATTR_WARN_UNUSED_RESULT
     ATTR_NONNULL(1, 2, 3);
@@ -25,7 +25,7 @@ struct LinkNode *BM_mesh_calc_path_uv_region_edge(BMesh *bm,
 struct LinkNode *BM_mesh_calc_path_uv_region_face(BMesh *bm,
                                                   BMElem *ele_src,
                                                   BMElem *ele_dst,
-                                                  uint cd_loop_uv_offset,
+                                                  int cd_loop_uv_offset,
                                                   bool (*filter_fn)(BMFace *, void *user_data),
                                                   void *user_data) ATTR_WARN_UNUSED_RESULT
     ATTR_NONNULL(1, 2, 3);
diff --git a/source/blender/bmesh/tools/bmesh_path_uv.c b/source/blender/bmesh/tools/bmesh_path_uv.c
index 3d736cdc3b8..6531677fce6 100644
--- a/source/blender/bmesh/tools/bmesh_path_uv.c
+++ b/source/blender/bmesh/tools/bmesh_path_uv.c
@@ -65,7 +65,7 @@ static void verttag_add_adjacent_uv(HeapSimple *heap,
                                     const struct BMCalcPathUVParams *params)
 {
   BLI_assert(params->aspect_y != 0.0f);
-  const uint cd_loop_uv_offset = params->cd_loop_uv_offset;
+  const int cd_loop_uv_offset = params->cd_loop_uv_offset;
   const int l_a_index = BM_elem_index_get(l_a);
   const MLoopUV *luv_a = BM_ELEM_CD_GET_VOID_P(l_a, cd_loop_uv_offset);
   const float uv_a[2] = {luv_a->uv[0], luv_a->uv[1] / params->aspect_y};
@@ -225,7 +225,7 @@ static void edgetag_add_adjacent_uv(HeapSimple *heap,
                                     const struct BMCalcPathUVParams *params)
 {
   BLI_assert(params->aspect_y != 0.0f);
-  const uint cd_loop_uv_offset = params->cd_loop_uv_offset;
+  const int cd_loop_uv_offset = params->cd_loop_uv_offset;
   BMLoop *l_a_verts[2] = {l_a, l_a->next};
   const int l_a_index = BM_elem_index_get(l_a);
 
@@ -462,7 +462,7 @@ static void facetag_add_adjacent_uv(HeapSimple *heap,
                                     const float aspect_v2[2],
                                     const struct BMCalcPathUVParams *params)
 {
-  const uint cd_loop_uv_offset = params->cd_loop_uv_offset;
+  const int cd_loop_uv_offset = params->cd_loop_uv_offset;
   const int f_a_index = BM_elem_index_get(f_a);
 
   /* Loop over faces of face, but do so by first looping over loops. */
diff --git a/source/blender/bmesh/tools/bmesh_path_uv.h b/source/blender/bmesh/tools/bmesh_path_uv.h
index d7b5faa70e5..ebfedba70bb 100644
--- a/source/blender/bmesh/tools/bmesh_path_uv.h
+++ b/source/blender/bmesh/tools/bmesh_path_uv.h
@@ -9,7 +9,7 @@
 struct BMCalcPathUVParams {
   uint use_topology_distance : 1;
   uint use_step_face : 1;
-  uint cd_loop_uv_offset;
+  int cd_loop_uv_offset;
   float aspect_y;
 };