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.

7 files changed, 28 insertions, 18 deletions

diff --git a/source/blender/editors/include/ED_mesh.h b/source/blender/editors/include/ED_mesh.h
index b76c35c7d7a..0e2be5eb568 100644
--- a/source/blender/editors/include/ED_mesh.h
+++ b/source/blender/editors/include/ED_mesh.h
@@ -36,6 +36,7 @@ struct BMFace;
 struct BMLoop;
 struct BMVert;
 struct BMesh;
+struct BMeshNormalsUpdate_Params;
 struct Base;
 struct Depsgraph;
 struct ID;
@@ -76,6 +77,8 @@ struct BMFace *EDBM_verts_mirror_get_face(struct BMEditMesh *em, struct BMFace *
 void EDBM_verts_mirror_cache_clear(struct BMEditMesh *em, struct BMVert *v);
 void EDBM_verts_mirror_cache_end(struct BMEditMesh *em);
 
+void EDBM_mesh_normals_update_ex(struct BMEditMesh *em,
+                                 const struct BMeshNormalsUpdate_Params *params);
 void EDBM_mesh_normals_update(struct BMEditMesh *em);
 void EDBM_mesh_clear(struct BMEditMesh *em);
 
diff --git a/source/blender/editors/mesh/editmesh_utils.c b/source/blender/editors/mesh/editmesh_utils.c
index c8f8f12ba90..071ca818120 100644
--- a/source/blender/editors/mesh/editmesh_utils.c
+++ b/source/blender/editors/mesh/editmesh_utils.c
@@ -1405,9 +1405,17 @@ bool EDBM_mesh_reveal(BMEditMesh *em, bool select)
 /** \name Update API
  * \{ */
 
+void EDBM_mesh_normals_update_ex(BMEditMesh *em, const struct BMeshNormalsUpdate_Params *params)
+{
+  BM_mesh_normals_update_ex(em->bm, params);
+}
+
 void EDBM_mesh_normals_update(BMEditMesh *em)
 {
-  BM_mesh_normals_update(em->bm);
+  EDBM_mesh_normals_update_ex(em,
+                              &(const struct BMeshNormalsUpdate_Params){
+                                  .face_normals = true,
+                              });
 }
 
 void EDBM_stats_update(BMEditMesh *em)
@@ -1449,12 +1457,18 @@ void EDBM_update(Mesh *mesh, const struct EDBMUpdate_Params *params)
   DEG_id_tag_update(&mesh->id, ID_RECALC_GEOMETRY);
   WM_main_add_notifier(NC_GEOM | ND_DATA, &mesh->id);
 
-  if (params->calc_normals) {
-    EDBM_mesh_normals_update(em);
+  if (params->calc_normals && params->calc_looptri) {
+    /* Calculating both has some performance gains. */
+    BKE_editmesh_looptri_and_normals_calc(em);
   }
+  else {
+    if (params->calc_normals) {
+      EDBM_mesh_normals_update(em);
+    }
 
-  if (params->calc_looptri) {
-    BKE_editmesh_looptri_calc(em);
+    if (params->calc_looptri) {
+      BKE_editmesh_looptri_calc(em);
+    }
   }
 
   if (params->is_destructive) {
diff --git a/source/blender/editors/object/object_edit.c b/source/blender/editors/object/object_edit.c
index 5be572baec5..c8923bb55c1 100644
--- a/source/blender/editors/object/object_edit.c
+++ b/source/blender/editors/object/object_edit.c
@@ -794,9 +794,7 @@ bool ED_object_editmode_enter_ex(Main *bmain, Scene *scene, Object *ob, int flag
 
     BMEditMesh *em = BKE_editmesh_from_object(ob);
     if (LIKELY(em)) {
-      /* order doesn't matter */
-      EDBM_mesh_normals_update(em);
-      BKE_editmesh_looptri_calc(em);
+      BKE_editmesh_looptri_and_normals_calc(em);
     }
 
     WM_main_add_notifier(NC_SCENE | ND_MODE | NS_EDITMODE_MESH, NULL);
diff --git a/source/blender/editors/object/object_hook.c b/source/blender/editors/object/object_hook.c
index d56ee17a73f..7122fd09892 100644
--- a/source/blender/editors/object/object_hook.c
+++ b/source/blender/editors/object/object_hook.c
@@ -350,8 +350,7 @@ static bool object_hook_index_array(Main *bmain,
 
       em = me->edit_mesh;
 
-      EDBM_mesh_normals_update(em);
-      BKE_editmesh_looptri_calc(em);
+      BKE_editmesh_looptri_and_normals_calc(em);
 
       /* check selected vertices first */
       if (return_editmesh_indexar(em, r_tot, r_indexar, r_cent) == 0) {
diff --git a/source/blender/editors/object/object_relations.c b/source/blender/editors/object/object_relations.c
index f3433833b5f..cdf12bcb5df 100644
--- a/source/blender/editors/object/object_relations.c
+++ b/source/blender/editors/object/object_relations.c
@@ -153,8 +153,7 @@ static int vertex_parent_set_exec(bContext *C, wmOperator *op)
 
     em = me->edit_mesh;
 
-    EDBM_mesh_normals_update(em);
-    BKE_editmesh_looptri_calc(em);
+    BKE_editmesh_looptri_and_normals_calc(em);
 
     /* Make sure the evaluated mesh is updated.
      *
diff --git a/source/blender/editors/transform/transform_convert_mesh.c b/source/blender/editors/transform/transform_convert_mesh.c
index 422370cb13b..4c674136b6a 100644
--- a/source/blender/editors/transform/transform_convert_mesh.c
+++ b/source/blender/editors/transform/transform_convert_mesh.c
@@ -1842,13 +1842,11 @@ void recalcData_mesh(TransInfo *t)
      * It's impractical to calculate this ahead of time.
      * Further, the down side of using partial updates when their not needed is negligible. */
     if (em->bm->totvert == em->bm->totvertsel) {
-      EDBM_mesh_normals_update(em);
-      BKE_editmesh_looptri_calc(em);
+      BKE_editmesh_looptri_and_normals_calc(em);
     }
     else {
       BMPartialUpdate *partial_update_cache = tc_mesh_ensure_partial_update(t, tc);
-      BM_mesh_normals_update_with_partial(em->bm, partial_update_cache);
-      BKE_editmesh_looptri_calc_with_partial(em, partial_update_cache);
+      BKE_editmesh_looptri_and_normals_calc_with_partial(em, partial_update_cache);
     }
   }
 }
diff --git a/source/blender/editors/transform/transform_convert_mesh_skin.c b/source/blender/editors/transform/transform_convert_mesh_skin.c
index 7c61da31f72..69b44998980 100644
--- a/source/blender/editors/transform/transform_convert_mesh_skin.c
+++ b/source/blender/editors/transform/transform_convert_mesh_skin.c
@@ -300,8 +300,7 @@ void recalcData_mesh_skin(TransInfo *t)
   FOREACH_TRANS_DATA_CONTAINER (t, tc) {
     DEG_id_tag_update(tc->obedit->data, ID_RECALC_GEOMETRY);
     BMEditMesh *em = BKE_editmesh_from_object(tc->obedit);
-    EDBM_mesh_normals_update(em);
-    BKE_editmesh_looptri_calc(em);
+    BKE_editmesh_looptri_and_normals_calc(em);
   }
 }
 /** \} */