bmesh api function: BM_edge_face_tangent()

 was used by inset but make into an api function since scripts can use this too.

3 files changed, 28 insertions, 12 deletions

diff --git a/source/blender/bmesh/intern/bmesh_queries.c b/source/blender/bmesh/intern/bmesh_queries.c
index 5efdd547ba9..b021fb4c320 100644
--- a/source/blender/bmesh/intern/bmesh_queries.c
+++ b/source/blender/bmesh/intern/bmesh_queries.c
@@ -813,6 +813,31 @@ float BM_edge_face_angle(BMEdge *e)
 }
 
 /**
+ * \brief BMESH EDGE/FACE TANGENT
+ *
+ * Calculate the tangent at this loop corner or fallback to the face normal on straignt lines.
+ * This vector always points inward into the face.
+ *
+ * \brief BM_edge_face_tangent
+ * \param e
+ * \param e_loop The loop to calculate the tangent at,
+ * used to get the face and winding direction.
+ */
+
+void BM_edge_face_tangent(BMEdge *e, BMLoop *e_loop, float r_tangent[3])
+{
+	float tvec[3];
+	BMVert *v1, *v2;
+	BM_edge_ordered_verts_ex(e, &v1, &v2, e_loop);
+
+	sub_v3_v3v3(tvec, v1->co, v2->co); /* use for temp storage */
+	/* note, we could average the tangents of both loops,
+	 * for non flat ngons it will give a better direction */
+	cross_v3_v3v3(r_tangent, tvec, e_loop->f->no);
+	normalize_v3(r_tangent);
+}
+
+/**
  * \brief BMESH VERT/EDGE ANGLE
  *
  * Calculates the angle a verts 2 edges.
diff --git a/source/blender/bmesh/intern/bmesh_queries.h b/source/blender/bmesh/intern/bmesh_queries.h
index 567d60eeac6..280fe843b1c 100644
--- a/source/blender/bmesh/intern/bmesh_queries.h
+++ b/source/blender/bmesh/intern/bmesh_queries.h
@@ -62,6 +62,8 @@ void    BM_loop_face_normal(BMLoop *l, float r_normal[3]);
 void    BM_loop_face_tangent(BMLoop *l, float r_tangent[3]);
 
 float   BM_edge_face_angle(BMEdge *e);
+void    BM_edge_face_tangent(BMEdge *e, BMLoop *e_loop, float r_tangent[3]);
+
 float   BM_vert_edge_angle(BMVert *v);
 
 BMEdge *BM_edge_exists(BMVert *v1, BMVert *v2);
diff --git a/source/blender/bmesh/operators/bmo_inset.c b/source/blender/bmesh/operators/bmo_inset.c
index 3bfacb29197..1c823e7590c 100644
--- a/source/blender/bmesh/operators/bmo_inset.c
+++ b/source/blender/bmesh/operators/bmo_inset.c
@@ -42,17 +42,6 @@ typedef struct SplitEdgeInfo {
 	BMLoop *l;
 } SplitEdgeInfo;
 
-static void edge_loop_tangent(BMEdge *e, BMLoop *e_loop, float r_no[3])
-{
-	float tvec[3];
-	BMVert *v1, *v2;
-	BM_edge_ordered_verts_ex(e, &v1, &v2, e_loop);
-
-	sub_v3_v3v3(tvec, v1->co, v2->co); /* use for temp storage */
-	cross_v3_v3v3(r_no, tvec, e_loop->f->no);
-	normalize_v3(r_no);
-}
-
 /**
  * return the tag loop where there is...
  * - only 1 tagged face attached to this edge.
@@ -188,7 +177,7 @@ void bmo_inset_exec(BMesh *bm, BMOperator *op)
 
 		/* calc edge-split info */
 		es->e_new = es->l->e;
-		edge_loop_tangent(es->e_new, es->l, es->no);
+		BM_edge_face_tangent(es->e_new, es->l, es->no);
 
 		if (es->e_new == es->e_old) { /* happens on boundary edges */
 			/* take care here, we're creating this double edge which _must_ have its verts replaced later on */