BMesh: shrink/fatten faces-normals in face mode

nice for solid-modeling, gives better results for partial selections.

4 files changed, 43 insertions, 4 deletions

diff --git a/source/blender/bmesh/intern/bmesh_polygon.c b/source/blender/bmesh/intern/bmesh_polygon.c
index a8e1acd9c71..a5a7bc5189e 100644
--- a/source/blender/bmesh/intern/bmesh_polygon.c
+++ b/source/blender/bmesh/intern/bmesh_polygon.c
@@ -422,6 +422,43 @@ void BM_edge_normals_update(BMEdge *e)
 	BM_vert_normal_update(e->v2);
 }
 
+bool BM_vert_normal_update_ex(BMVert *v, const char hflag, float r_no[3])
+{
+	/* TODO, we can normalize each edge only once, then compare with previous edge */
+
+	BMIter liter;
+	BMLoop *l;
+	int len = 0;
+
+	zero_v3(r_no);
+
+	BM_ITER_ELEM (l, &liter, v, BM_LOOPS_OF_VERT) {
+		if (BM_elem_flag_test(l->f, hflag)) {
+			float vec1[3], vec2[3], fac;
+
+			/* Same calculation used in BM_mesh_normals_update */
+			sub_v3_v3v3(vec1, l->v->co, l->prev->v->co);
+			sub_v3_v3v3(vec2, l->next->v->co, l->v->co);
+			normalize_v3(vec1);
+			normalize_v3(vec2);
+
+			fac = saacos(-dot_v3v3(vec1, vec2));
+
+			madd_v3_v3fl(r_no, l->f->no, fac);
+
+			len++;
+		}
+	}
+
+	if (len) {
+		normalize_v3(r_no);
+		return true;
+	}
+	else {
+		return false;
+	}
+}
+
 /**
  * update a vert normal (but not the faces incident on it)
  */
@@ -431,12 +468,13 @@ void BM_vert_normal_update(BMVert *v)
 
 	BMIter liter;
 	BMLoop *l;
-	float vec1[3], vec2[3], fac;
 	int len = 0;
 
 	zero_v3(v->no);
 
 	BM_ITER_ELEM (l, &liter, v, BM_LOOPS_OF_VERT) {
+		float vec1[3], vec2[3], fac;
+
 		/* Same calculation used in BM_mesh_normals_update */
 		sub_v3_v3v3(vec1, l->v->co, l->prev->v->co);
 		sub_v3_v3v3(vec2, l->next->v->co, l->v->co);
diff --git a/source/blender/bmesh/intern/bmesh_polygon.h b/source/blender/bmesh/intern/bmesh_polygon.h
index 91e649edb16..d62c81c4052 100644
--- a/source/blender/bmesh/intern/bmesh_polygon.h
+++ b/source/blender/bmesh/intern/bmesh_polygon.h
@@ -49,6 +49,7 @@ void  BM_face_normal_update(BMFace *f) ATTR_NONNULL();
 
 void  BM_edge_normals_update(BMEdge *e) ATTR_NONNULL();
 
+bool BM_vert_normal_update_ex(BMVert *v, const char hflag, float r_no[3]);
 void  BM_vert_normal_update(BMVert *v) ATTR_NONNULL();
 void  BM_vert_normal_update_all(BMVert *v) ATTR_NONNULL();
 
diff --git a/source/blender/bmesh/intern/bmesh_queries.c b/source/blender/bmesh/intern/bmesh_queries.c
index ca40cf9e6c8..0792e956e5b 100644
--- a/source/blender/bmesh/intern/bmesh_queries.c
+++ b/source/blender/bmesh/intern/bmesh_queries.c
@@ -1373,7 +1373,7 @@ float BM_vert_calc_shell_factor(BMVert *v)
 }
 /* alternate version of #BM_vert_calc_shell_factor which only
  * uses 'hflag' faces, but falls back to all if none found. */
-float BM_vert_calc_shell_factor_ex(BMVert *v, const char hflag)
+float BM_vert_calc_shell_factor_ex(BMVert *v, const float no[3], const char hflag)
 {
 	BMIter iter;
 	BMLoop *l;
@@ -1384,7 +1384,7 @@ float BM_vert_calc_shell_factor_ex(BMVert *v, const char hflag)
 	BM_ITER_ELEM (l, &iter, v, BM_LOOPS_OF_VERT) {
 		if (BM_elem_flag_test(l->f, hflag)) {  /* <-- main difference to BM_vert_calc_shell_factor! */
 			const float face_angle = BM_loop_calc_face_angle(l);
-			accum_shell += shell_v3v3_normalized_to_dist(v->no, l->f->no) * face_angle;
+			accum_shell += shell_v3v3_normalized_to_dist(no, l->f->no) * face_angle;
 			accum_angle += face_angle;
 			tot_sel++;
 		}
diff --git a/source/blender/bmesh/intern/bmesh_queries.h b/source/blender/bmesh/intern/bmesh_queries.h
index c8578a8b093..b5b423ed58f 100644
--- a/source/blender/bmesh/intern/bmesh_queries.h
+++ b/source/blender/bmesh/intern/bmesh_queries.h
@@ -97,7 +97,7 @@ void    BM_edge_calc_face_tangent(const BMEdge *e, const BMLoop *e_loop, float r
 
 float   BM_vert_calc_edge_angle(BMVert *v) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
 float   BM_vert_calc_shell_factor(BMVert *v) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
-float   BM_vert_calc_shell_factor_ex(BMVert *v, const char hflag) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
+float   BM_vert_calc_shell_factor_ex(BMVert *v, const float no[3], const char hflag) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
 float   BM_vert_calc_mean_tagged_edge_length(BMVert *v) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
 
 BMLoop *BM_face_find_shortest_loop(BMFace *f) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();