BMesh: improve rip tool /w mon-manifold verts

Can now rip from multiple fans (mixed single faces or larger regions)

Also add BM_vert_is_manifold_region which only checks if a vert has disconnected fans.

1 files changed, 99 insertions, 0 deletions

diff --git a/source/blender/bmesh/intern/bmesh_queries.c b/source/blender/bmesh/intern/bmesh_queries.c
index 031fc68e66f..63e36178e0f 100644
--- a/source/blender/bmesh/intern/bmesh_queries.c
+++ b/source/blender/bmesh/intern/bmesh_queries.c
@@ -917,6 +917,105 @@ bool BM_vert_is_manifold(const BMVert *v)
 	return (loop_num == loop_num_region);
 }
 
+#define LOOP_VISIT _FLAG_WALK
+#define EDGE_VISIT _FLAG_WALK
+
+static int bm_loop_region_count__recursive(BMEdge *e, BMVert *v)
+{
+	BMLoop *l_iter, *l_first;
+	int count = 0;
+
+	BLI_assert(!BM_ELEM_API_FLAG_TEST(e, EDGE_VISIT));
+	BM_ELEM_API_FLAG_ENABLE(e, EDGE_VISIT);
+
+	l_iter = l_first = e->l;
+	do {
+		if (l_iter->v == v) {
+			BMEdge *e_other = l_iter->prev->e;
+			if (!BM_ELEM_API_FLAG_TEST(l_iter, LOOP_VISIT)) {
+				BM_ELEM_API_FLAG_ENABLE(l_iter, LOOP_VISIT);
+				count += 1;
+			}
+			if (!BM_ELEM_API_FLAG_TEST(e_other, EDGE_VISIT)) {
+				count += bm_loop_region_count__recursive(e_other, v);
+			}
+		}
+		else if (l_iter->next->v == v) {
+			BMEdge *e_other = l_iter->next->e;
+			if (!BM_ELEM_API_FLAG_TEST(l_iter->next, LOOP_VISIT)) {
+				BM_ELEM_API_FLAG_ENABLE(l_iter->next, LOOP_VISIT);
+				count += 1;
+			}
+			if (!BM_ELEM_API_FLAG_TEST(e_other, EDGE_VISIT)) {
+				count += bm_loop_region_count__recursive(e_other, v);
+			}
+		}
+		else {
+			BLI_assert(0);
+		}
+	} while ((l_iter = l_iter->radial_next) != l_first);
+
+	return count;
+}
+
+static int bm_loop_region_count__clear(BMLoop *l)
+{
+	int count = 0;
+	BMEdge *e_iter, *e_first;
+
+	/* clear flags */
+	e_iter = e_first = l->e;
+	do {
+		BM_ELEM_API_FLAG_DISABLE(e_iter, EDGE_VISIT);
+		if (e_iter->l) {
+			BMLoop *l_iter, *l_first;
+			l_iter = l_first = e_iter->l;
+			do {
+				if (l_iter->v == l->v) {
+					BM_ELEM_API_FLAG_DISABLE(l_iter, LOOP_VISIT);
+					count += 1;
+				}
+			} while ((l_iter = l_iter->radial_next) != l_first);
+		}
+	} while ((e_iter = BM_DISK_EDGE_NEXT(e_iter, l->v)) != e_first);
+
+	return count;
+}
+
+/**
+ * The number of loops connected to this loop (not including disconnected regions).
+ */
+int BM_loop_region_loops_count_ex(BMLoop *l, int *r_loop_total)
+{
+	const int count       = bm_loop_region_count__recursive(l->e, l->v);
+	const int count_total = bm_loop_region_count__clear(l);
+	if (r_loop_total) {
+		*r_loop_total = count_total;
+	}
+	return count;
+}
+
+#undef LOOP_VISIT
+#undef EDGE_VISIT
+
+int BM_loop_region_loops_count(BMLoop *l)
+{
+	return BM_loop_region_loops_count_ex(l, NULL);
+}
+
+/**
+ * A version of #BM_vert_is_manifold
+ * which only checks if we're connected to multiple isolated regions.
+ */
+bool BM_vert_is_manifold_region(const BMVert *v)
+{
+	BMLoop *l_first = BM_vert_find_first_loop((BMVert *)v);
+	int count, count_total;
+
+	count = BM_loop_region_loops_count_ex(l_first, &count_total);
+	return (count == count_total);
+}
+
 /**
  * Check if the edge is convex or concave
  * (depends on face winding)