Cleanup: remove redundant doxygen \file argument
[blender.git] / source / blender / bmesh / operators / bmo_inset.c
index 29522b6..a0b9185 100644 (file)
@@ -1,6 +1,4 @@
 /*
- * ***** BEGIN GPL LICENSE BLOCK *****
- *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version 2
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- *
- * Contributor(s): Campbell Barton
- *
- * ***** END GPL LICENSE BLOCK *****
  */
 
-/** \file blender/bmesh/operators/bmo_inset.c
- *  \ingroup bmesh
+/** \file \ingroup bmesh
  *
  * Inset face regions.
  * Inset individual faces.
- *
  */
 
 #include "MEM_guardedalloc.h"
@@ -39,6 +31,9 @@
 
 #include "intern/bmesh_operators_private.h" /* own include */
 
+/* Merge loop-data that diverges, see: T41445 */
+#define USE_LOOP_CUSTOMDATA_MERGE
+
 #define ELE_NEW                1
 
 
@@ -90,8 +85,9 @@ static void bm_interp_face_store(InterpFace *iface, BMesh *bm, BMFace *f, MemAre
                CustomData_bmesh_copy_data(&bm->vdata, &bm->vdata, l_iter->v->head.data, &blocks_v[i]);
 
                /* use later for index lookups */
-               BM_elem_index_set(l_iter, i); /* set_ok */
-       } while (i++, (l_iter = l_iter->next) != l_first);
+               BM_elem_index_set(l_iter, i); /* set_dirty */
+       } while ((void)i++, (l_iter = l_iter->next) != l_first);
+       bm->elem_index_dirty |= BM_LOOP;
 }
 static void bm_interp_face_free(InterpFace *iface, BMesh *bm)
 {
@@ -105,6 +101,153 @@ static void bm_interp_face_free(InterpFace *iface, BMesh *bm)
        }
 }
 
+#ifdef USE_LOOP_CUSTOMDATA_MERGE
+/**
+ * This function merges loop customdata (UV's)
+ * where interpolating the values across the face causes values to diverge.
+ */
+static void bm_loop_customdata_merge(
+        BMesh *bm,
+        BMEdge *e_connect,
+        BMLoop *l_a_outer, BMLoop *l_b_outer,
+        BMLoop *l_a_inner, BMLoop *l_b_inner)
+{
+       /**
+        * Check for diverged values at the vert shared by
+        * \a l_a_inner & \a l_b_inner.
+        *
+        * <pre>
+        *  -----------------------+
+        *           l_a_outer--> /|<--l_b_outer
+        *                       / |
+        *      (face a)        /  |
+        *                     / <--e_connect
+        *                    /    |
+        * e_a  l_a_inner--> / <--l_b_inner
+        * -----------------+      |
+        *                 /|      |
+        * l_a/b_inner_inset| (face b)
+        *               /  |      |
+        *              /   |e_b   |
+        *  (inset face(s)) |      |
+        *            /     |      |
+        * </pre>
+        */
+
+       const bool is_flip = (l_a_inner->next == l_a_outer);
+       BMLoop *l_a_inner_inset, *l_b_inner_inset;
+       BMEdge *e_a, *e_b;
+       int layer_n;
+
+       /* paranoid sanity checks */
+       BLI_assert(l_a_outer->v == l_b_outer->v);
+       BLI_assert(l_a_inner->v == l_b_inner->v);
+
+       BLI_assert(l_b_inner->f != l_a_inner->f);
+
+       BLI_assert(l_a_outer->f == l_a_inner->f);
+       BLI_assert(l_b_outer->f == l_b_inner->f);
+
+       (void) e_connect;
+       BLI_assert(BM_edge_in_face(e_connect, l_a_inner->f));
+       BLI_assert(BM_edge_in_face(e_connect, l_b_inner->f));
+
+       if (is_flip) {
+               e_a = l_a_inner->prev->e;
+               e_b = l_b_inner->e;
+       }
+       else {
+               e_a = l_a_inner->e;
+               e_b = l_b_inner->prev->e;
+       }
+
+       l_a_inner_inset = BM_edge_other_loop(e_a, l_a_inner);
+       l_b_inner_inset = BM_edge_other_loop(e_b, l_b_inner);
+       BLI_assert(l_a_inner_inset->v == l_b_inner_inset->v);
+
+       /* check if there is no chance of diversion */
+       if (l_a_inner_inset->f == l_b_inner_inset->f) {
+               return;
+       }
+
+       for (layer_n = 0; layer_n < bm->ldata.totlayer; layer_n++) {
+               const int type = bm->ldata.layers[layer_n].type;
+               const int offset = bm->ldata.layers[layer_n].offset;
+               if (!CustomData_layer_has_math(&bm->ldata, layer_n))
+                       continue;
+
+               /* check we begin with merged data */
+               if ((CustomData_data_equals(
+                        type,
+                        BM_ELEM_CD_GET_VOID_P(l_a_outer, offset),
+                        BM_ELEM_CD_GET_VOID_P(l_b_outer, offset))  == true)
+
+                   /* epsilon for comparing UV's is too big, gives noticable problems */
+#if 0
+                   &&
+                   /* check if the data ends up diverged */
+                   (CustomData_data_equals(
+                        type,
+                        BM_ELEM_CD_GET_VOID_P(l_a_inner, offset),
+                        BM_ELEM_CD_GET_VOID_P(l_b_inner, offset)) == false)
+#endif
+                   )
+               {
+                       /* no need to allocate a temp block:
+                        * a = (a + b);
+                        * a *= 0.5f;
+                        * b = a;
+                        */
+                       const void *data_src;
+
+                       CustomData_data_mix_value(
+                               type,
+                               BM_ELEM_CD_GET_VOID_P(l_a_inner_inset, offset),
+                               BM_ELEM_CD_GET_VOID_P(l_b_inner_inset, offset),
+                               CDT_MIX_MIX, 0.5f);
+                       CustomData_data_copy_value(
+                               type,
+                               BM_ELEM_CD_GET_VOID_P(l_a_inner_inset, offset),
+                               BM_ELEM_CD_GET_VOID_P(l_b_inner_inset, offset));
+
+                       /* use this as a reference (could be 'l_b_inner_inset' too) */
+                       data_src = BM_ELEM_CD_GET_VOID_P(l_a_inner_inset, offset);
+
+                       /* check if the 2 faces share an edge */
+                       if (is_flip ?
+                           (l_b_inner_inset->e == l_a_inner_inset->prev->e) :
+                           (l_a_inner_inset->e == l_b_inner_inset->prev->e))
+                       {
+                               /* simple case, we have all loops already */
+                       }
+                       else {
+                               /* compare with (l_a_inner / l_b_inner) and assign the blended value if they match */
+                               BMIter iter;
+                               BMLoop *l_iter;
+                               const void *data_cmp_a = BM_ELEM_CD_GET_VOID_P(l_b_inner, offset);
+                               const void *data_cmp_b = BM_ELEM_CD_GET_VOID_P(l_a_inner, offset);
+                               BM_ITER_ELEM (l_iter, &iter, l_a_inner_inset->v, BM_LOOPS_OF_VERT) {
+                                       if (BM_elem_flag_test(l_iter->f, BM_ELEM_TAG)) {
+                                               if (!ELEM(l_iter, l_a_inner, l_b_inner, l_a_inner_inset, l_b_inner_inset)) {
+                                                       void *data_dst = BM_ELEM_CD_GET_VOID_P(l_iter, offset);
+
+                                                       if (CustomData_data_equals(type, data_dst, data_cmp_a) ||
+                                                           CustomData_data_equals(type, data_dst, data_cmp_b))
+                                                       {
+                                                               CustomData_data_copy_value(type, data_src, data_dst);
+                                                       }
+                                               }
+                                       }
+                               }
+                       }
+
+                       CustomData_data_copy_value(type, data_src, BM_ELEM_CD_GET_VOID_P(l_b_inner, offset));
+                       CustomData_data_copy_value(type, data_src, BM_ELEM_CD_GET_VOID_P(l_a_inner, offset));
+               }
+       }
+}
+#endif  /* USE_LOOP_CUSTOMDATA_MERGE */
+
 
 /* -------------------------------------------------------------------- */
 /* Inset Individual */
@@ -124,7 +267,7 @@ static void bmo_face_inset_individual(
 
        BMLoop *l_iter, *l_first;
        BMLoop *l_other;
-       unsigned int i;
+       uint i;
        float e_length_prev;
 
        l_first = BM_FACE_FIRST_LOOP(f);
@@ -142,7 +285,7 @@ static void bmo_face_inset_individual(
 
                /* unrelated to splitting, but calc here */
                BM_edge_calc_face_tangent(l_iter->e, l_iter, edge_nors[i]);
-       } while (i++, ((l_iter = l_iter->next) != l_first));
+       } while ((void)i++, ((l_iter = l_iter->next) != l_first));
 
 
        /* build rim faces */
@@ -162,7 +305,7 @@ static void bmo_face_inset_individual(
                                                      l_iter->next->v,
                                                      l_iter->v,
                                                      f, BM_CREATE_NOP);
-               BMO_elem_flag_enable(bm, f_new_outer, ELE_NEW);
+               BMO_face_flag_enable(bm, f_new_outer, ELE_NEW);
 
                /* copy loop data */
                l_other = l_iter->radial_next;
@@ -173,7 +316,7 @@ static void bmo_face_inset_individual(
                        BM_elem_attrs_copy(bm, bm, l_iter->next, l_other);
                        BM_elem_attrs_copy(bm, bm, l_iter, l_other->next);
                }
-       } while (i++, ((l_iter = l_iter->next) != l_first));
+       } while ((void)i++, ((l_iter = l_iter->next) != l_first));
 
        /* hold interpolation values */
        if (use_interpolate) {
@@ -201,7 +344,7 @@ static void bmo_face_inset_individual(
                copy_v3_v3(v_new_co, l_iter->v->co);
 
                if (use_even_offset) {
-                       mul_v3_fl(tvec, shell_angle_to_dist(angle_normalized_v3v3(eno_prev,  eno_next) / 2.0f));
+                       mul_v3_fl(tvec, shell_v3v3_mid_normalized_to_dist(eno_prev,  eno_next));
                }
 
                /* Modify vertices and their normals */
@@ -225,19 +368,21 @@ static void bmo_face_inset_individual(
 
 
                copy_v3_v3(coords[i], v_new_co);
-       } while (i++, ((l_iter = l_iter->next) != l_first));
+       } while ((void)i++, ((l_iter = l_iter->next) != l_first));
 
        /* update the coords */
        l_iter = l_first;
        i = 0;
        do {
                copy_v3_v3(l_iter->v->co, coords[i]);
-       } while (i++, ((l_iter = l_iter->next) != l_first));
+       } while ((void)i++, ((l_iter = l_iter->next) != l_first));
 
 
        if (use_interpolate) {
-               BM_face_interp_from_face_ex(bm, iface->f, iface->f, true,
-                                           iface->blocks_l, iface->blocks_v, iface->cos_2d, iface->axis_mat);
+               BM_face_interp_from_face_ex(
+                       bm, iface->f, iface->f, true,
+                       (const void **)iface->blocks_l, (const void **)iface->blocks_v,
+                       iface->cos_2d, iface->axis_mat);
 
                /* build rim faces */
                l_iter = l_first;
@@ -388,15 +533,15 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
        const bool use_outset          = BMO_slot_bool_get(op->slots_in, "use_outset");
        const bool use_boundary        = BMO_slot_bool_get(op->slots_in, "use_boundary") && (use_outset == false);
        const bool use_even_offset     = BMO_slot_bool_get(op->slots_in, "use_even_offset");
-       const bool use_even_boundry    = use_even_offset; /* could make own option */
+       const bool use_even_boundary   = use_even_offset; /* could make own option */
        const bool use_relative_offset = BMO_slot_bool_get(op->slots_in, "use_relative_offset");
        const bool use_edge_rail       = BMO_slot_bool_get(op->slots_in, "use_edge_rail");
        const bool use_interpolate     = BMO_slot_bool_get(op->slots_in, "use_interpolate");
        const float thickness          = BMO_slot_float_get(op->slots_in, "thickness");
        const float depth              = BMO_slot_float_get(op->slots_in, "depth");
-
-       /* store vert coords in normals, needed for 'use_edge_rail' */
-#define USE_VERTNORMAL_HACK
+#ifdef USE_LOOP_CUSTOMDATA_MERGE
+       const bool has_math_ldata      = (use_interpolate && CustomData_has_math(&bm->ldata));
+#endif
 
        int edge_info_len = 0;
 
@@ -410,10 +555,15 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
        int          iface_array_len;
        MemArena *interp_arena = NULL;
 
+       /* BMVert original location storage */
+       const bool use_vert_coords_orig = use_edge_rail;
+       MemArena *vert_coords_orig = NULL;
+       GHash *vert_coords = NULL;
+
        BMVert *v;
        BMEdge *e;
        BMFace *f;
-       int i, j, k;
+       int i, k;
 
        if (use_interpolate) {
                interp_arena = BLI_memarena_new(BLI_MEMARENA_STD_BUFSIZE, __func__);
@@ -429,6 +579,7 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
        else {
                BM_mesh_elem_hflag_enable_all(bm, BM_FACE, BM_ELEM_TAG, false);
                BMO_slot_buffer_hflag_disable(bm, op->slots_in, "faces", BM_FACE, BM_ELEM_TAG, false);
+               BMO_slot_buffer_hflag_disable(bm, op->slots_in, "faces_exclude", BM_FACE, BM_ELEM_TAG, false);
        }
 
        /* first count all inset edges we will split */
@@ -456,11 +607,6 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
 
                        BM_elem_index_set(e, -1); /* set_dirty! */
                }
-
-#ifdef USE_VERTNORMAL_HACK
-                       copy_v3_v3(e->v1->no, e->v1->co);
-                       copy_v3_v3(e->v2->no, e->v2->co);
-#endif
        }
        bm->elem_index_dirty |= BM_EDGE;
 
@@ -479,6 +625,26 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
                }
        }
 
+
+       if (use_vert_coords_orig) {
+               vert_coords_orig = BLI_memarena_new(BLI_MEMARENA_STD_BUFSIZE, __func__);
+               vert_coords = BLI_ghash_ptr_new(__func__);
+       }
+
+       /* util macros */
+#define VERT_ORIG_STORE(_v)  { \
+               float *_co = BLI_memarena_alloc(vert_coords_orig, sizeof(float[3])); \
+               copy_v3_v3(_co, (_v)->co); \
+               BLI_ghash_insert(vert_coords, _v, _co); \
+       } (void)0
+#define VERT_ORIG_GET(_v)  \
+       (const float *)BLI_ghash_lookup_default(vert_coords, (_v), (_v)->co)
+       /* memory for the coords isn't given back to the arena,
+        * acceptable in this case since it runs a fixed number of times. */
+#define VERT_ORIG_REMOVE(_v)  \
+       BLI_ghash_remove(vert_coords, (_v), NULL, NULL)
+
+
        for (i = 0, es = edge_info; i < edge_info_len; i++, es++) {
                if ((es->l = bm_edge_is_mixed_face_tag(es->e_old->l))) {
                        /* do nothing */
@@ -487,9 +653,10 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
                        es->l = es->e_old->l; /* must be a boundary */
                }
 
-
                /* run the separate arg */
-               bmesh_edge_separate(bm, es->e_old, es->l, false);
+               if (!BM_edge_is_boundary(es->e_old)) {
+                       bmesh_kernel_edge_separate(bm, es->e_old, es->l, false);
+               }
 
                /* calc edge-split info */
                es->e_new = es->l->e;
@@ -551,7 +718,7 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
         * here but don't do this since we will be splitting them off (iterating stuff you modify is bad juju)
         * instead loop over edges then their verts */
        for (i = 0, es = edge_info; i < edge_info_len; i++, es++) {
-               for (j = 0; j < 2; j++) {
+               for (int j = 0; j < 2; j++) {
                        v = (j == 0) ? es->e_new->v1 : es->e_new->v2;
 
                        /* end confusing part - just pretend this is a typical loop on verts */
@@ -567,14 +734,14 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
                                /* disable touching twice, this _will_ happen if the flags not disabled */
                                BM_elem_flag_disable(v, BM_ELEM_TAG);
 
-                               bmesh_vert_separate(bm, v, &vout, &r_vout_len, false);
+                               bmesh_kernel_vert_separate(bm, v, &vout, &r_vout_len, false);
                                v = NULL; /* don't use again */
 
                                /* in some cases the edge doesn't split off */
                                if (r_vout_len == 1) {
-#ifdef USE_VERTNORMAL_HACK
-                                       copy_v3_v3(vout[0]->no, vout[0]->co);
-#endif
+                                       if (use_vert_coords_orig) {
+                                               VERT_ORIG_STORE(vout[0]);
+                                       }
                                        MEM_freeN(vout);
                                        continue;
                                }
@@ -586,9 +753,9 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
                                        int vert_edge_tag_tot = 0;
                                        int vecpair[2];
 
-#ifdef USE_VERTNORMAL_HACK
-                                       copy_v3_v3(v_split->no, v_split->co);
-#endif
+                                       if (use_vert_coords_orig) {
+                                               VERT_ORIG_STORE(v_split);
+                                       }
 
                                        /* find adjacent */
                                        BM_ITER_ELEM (e, &iter, v_split, BM_EDGES_OF_VERT) {
@@ -647,11 +814,12 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
 
                                                                        /* note that we can't use 'l_other_a->v' directly since it
                                                                         * may be inset and give a feedback loop. */
-#ifdef USE_VERTNORMAL_HACK
-                                                                       co_other = l_other_a->v->no;
-#else
-                                                                       co_other = l_other_a->v->co;
-#endif
+                                                                       if (use_vert_coords_orig) {
+                                                                               co_other = VERT_ORIG_GET(l_other_a->v);
+                                                                       }
+                                                                       else {
+                                                                               co_other = l_other_a->v->co;
+                                                                       }
 
                                                                        sub_v3_v3v3(tvec, co_other, v_split->co);
                                                                        is_mid = false;
@@ -680,14 +848,16 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
                                                        /* scale by edge angle */
                                                        if (use_even_offset) {
                                                                if (is_mid) {
-                                                                       mul_v3_fl(tvec, shell_angle_to_dist(angle_normalized_v3v3(e_info_a->no,
-                                                                                                                                 e_info_b->no) / 2.0f));
+                                                                       mul_v3_fl(tvec, shell_v3v3_mid_normalized_to_dist(e_info_a->no,
+                                                                                                                         e_info_b->no));
                                                                }
                                                                else {
-                                                                       mul_v3_fl(tvec, shell_angle_to_dist(max_ff(angle_normalized_v3v3(tvec,
-                                                                                                                                        e_info_a->no),
-                                                                                                                  angle_normalized_v3v3(tvec,
-                                                                                                                                        e_info_b->no))));
+                                                                       /* use the largest angle */
+                                                                       mul_v3_fl(tvec,
+                                                                                 shell_v3v3_normalized_to_dist(tvec,
+                                                                                                               len_squared_v3v3(tvec, e_info_a->no) >
+                                                                                                               len_squared_v3v3(tvec, e_info_b->no) ?
+                                                                                                                   e_info_a->no : e_info_b->no));
                                                                }
                                                        }
 
@@ -699,7 +869,7 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
                                                else if (vert_edge_tag_tot == 1) { /* 1 edge user - boundary vert, not so common */
                                                        const float *e_no_a = edge_info[vecpair[0]].no;
 
-                                                       if (use_even_boundry) {
+                                                       if (use_even_boundary) {
 
                                                                /* This case where only one edge attached to v_split
                                                                 * is used - ei - the face to inset is on a boundary.
@@ -758,7 +928,7 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
                                                                normalize_v3(tvec);
 
                                                                if (use_even_offset) {
-                                                                       mul_v3_fl(tvec, shell_angle_to_dist(angle_normalized_v3v3(e_no_a, tvec)));
+                                                                       mul_v3_fl(tvec, shell_v3v3_normalized_to_dist(e_no_a, tvec));
                                                                }
                                                        }
                                                        else {
@@ -798,7 +968,11 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
                                                                v_glue = v_split;
                                                        }
                                                        else {
-                                                               BM_vert_splice(bm, v_split, v_glue);
+                                                               if (BM_vert_splice(bm, v_glue, v_split)) {
+                                                                       if (use_vert_coords_orig) {
+                                                                               VERT_ORIG_REMOVE(v_split);
+                                                                       }
+                                                               }
                                                        }
                                                }
                                        }
@@ -810,12 +984,19 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
                }
        }
 
+       if (use_vert_coords_orig) {
+               BLI_memarena_free(vert_coords_orig);
+               BLI_ghash_free(vert_coords, NULL, NULL);
+       }
+
        if (use_interpolate) {
                for (i = 0; i < iface_array_len; i++) {
                        if (iface_array[i]) {
                                InterpFace *iface = iface_array[i];
-                               BM_face_interp_from_face_ex(bm, iface->f, iface->f, true,
-                                                           iface->blocks_l, iface->blocks_v, iface->cos_2d, iface->axis_mat);
+                               BM_face_interp_from_face_ex(
+                                       bm, iface->f, iface->f, true,
+                                       (const void **)iface->blocks_l, (const void **)iface->blocks_v,
+                                       iface->cos_2d, iface->axis_mat);
                        }
                }
        }
@@ -823,6 +1004,7 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
        /* create faces */
        for (i = 0, es = edge_info; i < edge_info_len; i++, es++) {
                BMVert *varr[4] = {NULL};
+               int j;
                /* get the verts in the correct order */
                BM_edge_ordered_verts_ex(es->e_new, &varr[1], &varr[0], es->l);
 #if 0
@@ -855,7 +1037,7 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
                /* no need to check doubles, we KNOW there won't be any */
                /* yes - reverse face is correct in this case */
                f = BM_face_create_verts(bm, varr, j, es->l->f, BM_CREATE_NOP, true);
-               BMO_elem_flag_enable(bm, f, ELE_NEW);
+               BMO_face_flag_enable(bm, f, ELE_NEW);
 
                /* copy for loop data, otherwise UV's and vcols are no good.
                 * tiny speedup here we could be more clever and copy from known adjacent data
@@ -881,17 +1063,68 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
                        BM_elem_attrs_copy(bm, bm, l_a_other, l_a);
                        BM_elem_attrs_copy(bm, bm, l_b_other, l_b);
 
+                       BLI_assert(l_a->f != l_a_other->f);
+                       BLI_assert(l_b->f != l_b_other->f);
+
                        /* step around to the opposite side of the quad - warning, this may have no other edges! */
                        l_a = l_a->next->next;
                        l_b = l_a->next;
 
+                       /**
+                        * Loops vars from newly created face (face_a/b)
+                        * <pre>
+                        *              l_a->e & l_b->prev->e
+                        * +------------------------------------+
+                        * |\ l_a                          l_b /|
+                        * | \ l_a->prev->e            l_b->e / |
+                        * |  \ l_a->prev          l_b->next /  |
+                        * |   +----------------------------+   |
+                        * |   |l_a_other    ^     l_b_other|   |
+                        * |   |        l_b->next->e &...   |   |
+                        * |   |        l_a->prev->prev->e  |   |
+                        * |   |        (inset face)        |   |
+                        * |   +----------------------------+   |
+                        * |  /                              \  |
+                        * | /                                \ |
+                        * |/                                  \|
+                        * +------------------------------------+
+                        * </pre>
+                        */
+
                        /* swap a<->b intentionally */
                        if (use_interpolate) {
                                InterpFace *iface = iface_array[BM_elem_index_get(es->l->f)];
                                const int i_a = BM_elem_index_get(l_a_other);
                                const int i_b = BM_elem_index_get(l_b_other);
+                               CustomData_bmesh_free_block_data(&bm->ldata, l_b->head.data);
+                               CustomData_bmesh_free_block_data(&bm->ldata, l_a->head.data);
                                CustomData_bmesh_copy_data(&bm->ldata, &bm->ldata, iface->blocks_l[i_a], &l_b->head.data);
                                CustomData_bmesh_copy_data(&bm->ldata, &bm->ldata, iface->blocks_l[i_b], &l_a->head.data);
+
+#ifdef USE_LOOP_CUSTOMDATA_MERGE
+                               if (has_math_ldata) {
+                                       BMEdge *e_connect;
+
+                                       /* connecting edge 'a' */
+                                       e_connect = l_a->prev->e;
+                                       if (BM_edge_is_manifold(e_connect)) {
+                                               bm_loop_customdata_merge(
+                                                       bm, e_connect,
+                                                       l_a,       BM_edge_other_loop(e_connect, l_a),
+                                                       l_a->prev, BM_edge_other_loop(e_connect, l_a->prev));
+                                       }
+
+                                       /* connecting edge 'b' */
+                                       e_connect = l_b->e;
+                                       if (BM_edge_is_manifold(e_connect)) {
+                                               /* swap arg order to maintain winding */
+                                               bm_loop_customdata_merge(
+                                                       bm, e_connect,
+                                                       l_b,       BM_edge_other_loop(e_connect, l_b),
+                                                       l_b->next, BM_edge_other_loop(e_connect, l_b->next));
+                                       }
+                               }
+#endif  /* USE_LOOP_CUSTOMDATA_MERGE */
                        }
                        else {
                                BM_elem_attrs_copy(bm, bm, l_a_other, l_b);
@@ -927,7 +1160,7 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
                        zero_v3(es->e_new->v2->no);
                }
                for (i = 0, es = edge_info; i < edge_info_len; i++, es++) {
-                       float *no = es->l->f->no;
+                       const float *no = es->l->f->no;
                        add_v3_v3(es->e_new->v1->no, no);
                        add_v3_v3(es->e_new->v2->no, no);
                }
@@ -962,7 +1195,7 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
                        if (BM_elem_flag_test(v, BM_ELEM_TAG)) {
                                const float fac = (depth *
                                                   (use_relative_offset ? bm_edge_info_average_length(v, edge_info) : 1.0f) *
-                                                  (use_even_boundry    ? BM_vert_calc_shell_factor(v) : 1.0f));
+                                                  (use_even_boundary   ? BM_vert_calc_shell_factor(v) : 1.0f));
                                madd_v3_v3v3fl(varr_co[i], v->co, v->no, fac);
                        }
                }