bmesh py api: expose BM_face_calc_tangent_*

D1988 by @wisaac, with own edits and improvements.

This improves on existing tangent calculation functions too.

- BM_face_calc_tangent_auto: Chooses method based on number of sides, used by manipulator (not exposed to Python).
- BM_face_calc_tangent_edge: from longest edge.
- BM_face_calc_tangent_edge_pair: from longest edge-pair (most useful with quads).
- BM_face_calc_tangent_edge_diagonal: edge farthest from any vertex.
- BM_face_calc_tangent_vert_diagonal: vert farthest from any vertex.

Also optimize BM_vert_tri_calc_tangent_edge* functions to avoid sqrt.

1 files changed, 2 insertions, 2 deletions

diff --git a/source/blender/editors/transform/transform_orientations.c b/source/blender/editors/transform/transform_orientations.c
index 59d2485c964..90a4aa3614d 100644
--- a/source/blender/editors/transform/transform_orientations.c
+++ b/source/blender/editors/transform/transform_orientations.c
@@ -636,7 +636,7 @@ int getTransformOrientation_ex(const bContext *C, float normal[3], float plane[3
 
 					BM_ITER_MESH (efa, &iter, em->bm, BM_FACES_OF_MESH) {
 						if (BM_elem_flag_test(efa, BM_ELEM_SELECT)) {
-							BM_face_calc_plane(efa, vec);
+							BM_face_calc_tangent_auto(efa, vec);
 							add_v3_v3(normal, efa->no);
 							add_v3_v3(plane, vec);
 						}
@@ -690,7 +690,7 @@ int getTransformOrientation_ex(const bContext *C, float normal[3], float plane[3
 							sub_v3_v3v3(plane, v_pair[0]->co, v_pair[1]->co);
 						}
 						else {
-							BM_vert_tri_calc_plane(v_tri, plane);
+							BM_vert_tri_calc_tangent_edge(v_tri, plane);
 						}
 					}
 					else {