improved BM_face_copy_shared to copy from more possible connected loops and add filter function (not used yet).

source/blender/bmesh/bmesh_class.h

@@ -254,6 +254,8 @@ enum {
 struct BPy_BMGeneric;
 extern void bpy_bm_generic_invalidate(struct BPy_BMGeneric *self);
 
+typedef bool (*BMElemFilterFunc)(BMElem *, void *user_data);
+
 /* defines */
 #define BM_ELEM_CD_GET_VOID_P(ele, offset) \
 	(assert(offset != -1), (void *)((char *)(ele)->head.data + (offset)))

source/blender/bmesh/intern/bmesh_construct.c

@@ -127,32 +127,60 @@ BMFace *BM_face_create_quad_tri_v(BMesh *bm, BMVert **verts, int len, const BMFa
 
 /**
  * \brief copies face loop data from shared adjacent faces.
+ *
+ * \param filter_fn  A function that filters the source loops before copying (don't always want to copy all)
+ *
  * \note when a matching edge is found, both loops of that edge are copied
  * this is done since the face may not be completely surrounded by faces,
- * this way: a quad with 2 connected quads on either side will still get all 4 loops updated */
-void BM_face_copy_shared(BMesh *bm, BMFace *f)
+ * this way: a quad with 2 connected quads on either side will still get all 4 loops updated
+ */
+void BM_face_copy_shared(BMesh *bm, BMFace *f,
+                         BMElemFilterFunc filter_fn, void *user_data)
 {
 	BMLoop *l_first;
 	BMLoop *l_iter;
 
+#ifdef DEBUG
+	l_iter = l_first = BM_FACE_FIRST_LOOP(f);
+	do {
+		BLI_assert(BM_ELEM_API_FLAG_TEST(l_iter, _FLAG_OVERLAP) == 0);
+	} while ((l_iter = l_iter->next) != l_first);
+#endif
+
 	l_iter = l_first = BM_FACE_FIRST_LOOP(f);
 	do {
 		BMLoop *l_other = l_iter->radial_next;
 
 		if (l_other && l_other != l_iter) {
+			BMLoop *l_src[2];
+			BMLoop *l_dst[2] = {l_iter, l_iter->next};
+			unsigned int j;
+
 			if (l_other->v == l_iter->v) {
-				bm_loop_attrs_copy(bm, bm, l_other, l_iter);
-				bm_loop_attrs_copy(bm, bm, l_other->next, l_iter->next);
+				l_src[0] = l_other;
+				l_src[1] = l_other->next;
 			}
 			else {
-				bm_loop_attrs_copy(bm, bm, l_other->next, l_iter);
-				bm_loop_attrs_copy(bm, bm, l_other, l_iter->next);
+				l_src[0] = l_other->next;
+				l_src[1] = l_other;
 			}
-			/* since we copy both loops of the shared edge, step over the next loop here */
-			if ((l_iter = l_iter->next) == l_first) {
-				break;
+
+			for (j = 0; j < 2; j++) {
+				BLI_assert(l_dst[j]->v == l_src[j]->v);
+				if (BM_ELEM_API_FLAG_TEST(l_dst[j], _FLAG_OVERLAP) == 0) {
+					if ((filter_fn == NULL) || filter_fn((BMElem *)l_src[j], user_data)) {
+						bm_loop_attrs_copy(bm, bm, l_src[j], l_dst[j]);
+						BM_ELEM_API_FLAG_ENABLE(l_dst[j], _FLAG_OVERLAP);
 					}
 				}
+			}
+		}
+	} while ((l_iter = l_iter->next) != l_first);
+
+
+	l_iter = l_first = BM_FACE_FIRST_LOOP(f);
+	do {
+		BM_ELEM_API_FLAG_DISABLE(l_iter, _FLAG_OVERLAP);
 	} while ((l_iter = l_iter->next) != l_first);
 }
 

source/blender/bmesh/intern/bmesh_construct.h

@@ -36,7 +36,8 @@ BMFace *BM_face_create_quad_tri_v(BMesh *bm,
 BMFace *BM_face_create_quad_tri(BMesh *bm, BMVert *v1, BMVert *v2, BMVert *v3, BMVert *v4,
                                 const BMFace *example, const bool no_double);
 
-void BM_face_copy_shared(BMesh *bm, BMFace *f);
+void BM_face_copy_shared(BMesh *bm, BMFace *f,
+                         BMElemFilterFunc filter_fn, void *user_data);
 
 BMFace *BM_face_create_ngon(BMesh *bm, BMVert *v1, BMVert *v2, BMEdge **edges, const int len, const int create_flag);
 BMFace *BM_face_create_ngon_verts(BMesh *bm, BMVert **vert_arr, const int len, const int create_flag,

source/blender/bmesh/intern/bmesh_queries.h

@@ -27,8 +27,6 @@
  *  \ingroup bmesh
  */
 
-typedef bool (*BMElemFilterFunc)(BMElem *, void *user_data);
-
 bool    BM_vert_in_face(BMFace *f, BMVert *v);
 int     BM_verts_in_face_count(BMFace *f, BMVert **varr, int len);
 bool    BM_verts_in_face(BMFace *f, BMVert **varr, int len);

source/blender/bmesh/operators/bmo_hull.c

@@ -136,7 +136,7 @@ static void hull_output_triangles(BMesh *bm, GHash *hull_triangles)
 
 				/* Create new hull face */
 				f = BM_face_create_quad_tri_v(bm, t->v, 3, example, true);
-				BM_face_copy_shared(bm, f);
+				BM_face_copy_shared(bm, f, NULL, NULL);
 			}
 			/* Mark face for 'geom.out' slot and select */
 			BMO_elem_flag_enable(bm, f, HULL_FLAG_OUTPUT_GEOM);

source/blender/bmesh/operators/bmo_inset.c

@@ -796,7 +796,7 @@ void bmo_inset_region_exec(BMesh *bm, BMOperator *op)
 #if 0
 		/* don't use this because face boundaries have no adjacent loops and won't be filled in.
 		 * instead copy from the opposite side with the code below */
-		BM_face_copy_shared(bm, f);
+		BM_face_copy_shared(bm, f, NULL, NULL);
 #else
 		{
 			/* 2 inner loops on the edge between the new face and the original */