BMesh: support face-normal calculation in normal & looptri functions

Support calculating face normals when tessellating. When this is done
before updating vertex normals it gives ~20% performance improvement.

Now vertex normal calculation only needs to perform a single pass on the
mesh vertices when called after tessellation.

Extended versions of normal & looptri update functions have been added:

- BM_mesh_calc_tessellation_ex
- BM_mesh_normals_update_ex

Most callers don't need to be aware of this detail by using:

- BKE_editmesh_looptri_and_normals_calc
- BKE_editmesh_looptri_and_normals_calc_with_partial

- EDBM_update also takes advantage of this,
  where calling EDBM_update with calc_looptri & calc_normals
  enabled uses the faster normal updating logic.

1 files changed, 10 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_editmesh.h b/source/blender/blenkernel/BKE_editmesh.h
index 3a1eedfd807..075a9bc0eac 100644
--- a/source/blender/blenkernel/BKE_editmesh.h
+++ b/source/blender/blenkernel/BKE_editmesh.h
@@ -34,6 +34,7 @@ extern "C" {
 struct BMLoop;
 struct BMesh;
 struct BMPartialUpdate;
+struct BMeshCalcTessellation_Params;
 struct BoundBox;
 struct Depsgraph;
 struct Mesh;
@@ -85,8 +86,17 @@ typedef struct BMEditMesh {
 } BMEditMesh;
 
 /* editmesh.c */
+void BKE_editmesh_looptri_calc_ex(BMEditMesh *em,
+                                  const struct BMeshCalcTessellation_Params *params);
 void BKE_editmesh_looptri_calc(BMEditMesh *em);
+void BKE_editmesh_looptri_calc_with_partial_ex(BMEditMesh *em,
+                                               struct BMPartialUpdate *bmpinfo,
+                                               const struct BMeshCalcTessellation_Params *params);
 void BKE_editmesh_looptri_calc_with_partial(BMEditMesh *em, struct BMPartialUpdate *bmpinfo);
+void BKE_editmesh_looptri_and_normals_calc_with_partial(BMEditMesh *em,
+                                                        struct BMPartialUpdate *bmpinfo);
+
+void BKE_editmesh_looptri_and_normals_calc(BMEditMesh *em);
 
 BMEditMesh *BKE_editmesh_create(BMesh *bm, const bool do_tessellate);
 BMEditMesh *BKE_editmesh_copy(BMEditMesh *em);