Mesh: Avoid unnecessary normal calculation and dirty tags

This is mostly a cleanup to avoid hardcoding the eager calculation of
normals it isn't necessary, by reducing calls to `BKE_mesh_calc_normals`
and by removing calls to `BKE_mesh_normals_tag_dirty` when the mesh
is newly created and already has dirty normals anyway. This reduces
boilerplate code and makes the "dirty by default" state more clear.
Any regressions from this commit should be easy to fix, though the
lazy calculation is solid enough that none are expected.

19 files changed, 7 insertions, 51 deletions

diff --git a/source/blender/modifiers/intern/MOD_array.c b/source/blender/modifiers/intern/MOD_array.c
index 758858c8b1d..c44a4e0b438 100644
--- a/source/blender/modifiers/intern/MOD_array.c
+++ b/source/blender/modifiers/intern/MOD_array.c
@@ -789,13 +789,6 @@ static Mesh *arrayModifier_doArray(ArrayModifierData *amd,
     MEM_freeN(full_doubles_map);
   }
 
-  /* In case org dm has dirty normals, or we made some merging, mark normals as dirty in new mesh!
-   * TODO: we may need to set other dirty flags as well?
-   */
-  if (use_recalc_normals) {
-    BKE_mesh_normals_tag_dirty(result);
-  }
-
   if (vgroup_start_cap_remap) {
     MEM_freeN(vgroup_start_cap_remap);
   }
diff --git a/source/blender/modifiers/intern/MOD_bevel.c b/source/blender/modifiers/intern/MOD_bevel.c
index b6cceade4e2..a7364af10a3 100644
--- a/source/blender/modifiers/intern/MOD_bevel.c
+++ b/source/blender/modifiers/intern/MOD_bevel.c
@@ -229,8 +229,6 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *
 
   BM_mesh_free(bm);
 
-  BKE_mesh_normals_tag_dirty(result);
-
   return result;
 }
 
diff --git a/source/blender/modifiers/intern/MOD_boolean.cc b/source/blender/modifiers/intern/MOD_boolean.cc
index 915428f99da..d47f2a130e3 100644
--- a/source/blender/modifiers/intern/MOD_boolean.cc
+++ b/source/blender/modifiers/intern/MOD_boolean.cc
@@ -501,7 +501,6 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *
         result = BKE_mesh_from_bmesh_for_eval_nomain(bm, nullptr, mesh);
 
         BM_mesh_free(bm);
-        BKE_mesh_normals_tag_dirty(result);
       }
 
       if (result == nullptr) {
@@ -536,7 +535,6 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *
 
           result = BKE_mesh_from_bmesh_for_eval_nomain(bm, nullptr, mesh);
           BM_mesh_free(bm);
-          BKE_mesh_normals_tag_dirty(result);
         }
       }
     }
diff --git a/source/blender/modifiers/intern/MOD_build.c b/source/blender/modifiers/intern/MOD_build.c
index 61959d242d8..687ff04cedf 100644
--- a/source/blender/modifiers/intern/MOD_build.c
+++ b/source/blender/modifiers/intern/MOD_build.c
@@ -263,8 +263,6 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, struct
   MEM_freeN(edgeMap);
   MEM_freeN(faceMap);
 
-  BKE_mesh_normals_tag_dirty(result);
-
   /* TODO(sybren): also copy flags & tags? */
   return result;
 }
diff --git a/source/blender/modifiers/intern/MOD_collision.c b/source/blender/modifiers/intern/MOD_collision.c
index 1cb308bb2a0..593610f5bad 100644
--- a/source/blender/modifiers/intern/MOD_collision.c
+++ b/source/blender/modifiers/intern/MOD_collision.c
@@ -120,7 +120,7 @@ static void deformVerts(ModifierData *md,
     uint mvert_num = 0;
 
     BKE_mesh_vert_coords_apply(mesh_src, vertexCos);
-    BKE_mesh_calc_normals(mesh_src);
+    BKE_mesh_normals_tag_dirty(mesh_src);
 
     current_time = DEG_get_ctime(ctx->depsgraph);
 
diff --git a/source/blender/modifiers/intern/MOD_decimate.c b/source/blender/modifiers/intern/MOD_decimate.c
index 67515478be5..70f028d6907 100644
--- a/source/blender/modifiers/intern/MOD_decimate.c
+++ b/source/blender/modifiers/intern/MOD_decimate.c
@@ -212,8 +212,6 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *
   TIMEIT_END(decim);
 #endif
 
-  BKE_mesh_normals_tag_dirty(result);
-
   return result;
 }
 
diff --git a/source/blender/modifiers/intern/MOD_edgesplit.c b/source/blender/modifiers/intern/MOD_edgesplit.c
index 14431e5ff2e..49ddcb9a61d 100644
--- a/source/blender/modifiers/intern/MOD_edgesplit.c
+++ b/source/blender/modifiers/intern/MOD_edgesplit.c
@@ -102,7 +102,6 @@ Mesh *doEdgeSplit(const Mesh *mesh, EdgeSplitModifierData *emd)
   result = BKE_mesh_from_bmesh_for_eval_nomain(bm, NULL, mesh);
   BM_mesh_free(bm);
 
-  BKE_mesh_normals_tag_dirty(result);
   return result;
 }
 
diff --git a/source/blender/modifiers/intern/MOD_explode.c b/source/blender/modifiers/intern/MOD_explode.c
index 87ff648f13d..9e2bb79138e 100644
--- a/source/blender/modifiers/intern/MOD_explode.c
+++ b/source/blender/modifiers/intern/MOD_explode.c
@@ -1102,7 +1102,6 @@ static Mesh *explodeMesh(ExplodeModifierData *emd,
   /* finalization */
   BKE_mesh_calc_edges_tessface(explode);
   BKE_mesh_convert_mfaces_to_mpolys(explode);
-  BKE_mesh_normals_tag_dirty(explode);
 
   if (psmd->psys->lattice_deform_data) {
     BKE_lattice_deform_data_destroy(psmd->psys->lattice_deform_data);
diff --git a/source/blender/modifiers/intern/MOD_mask.cc b/source/blender/modifiers/intern/MOD_mask.cc
index cb26bd1b26b..900dee98268 100644
--- a/source/blender/modifiers/intern/MOD_mask.cc
+++ b/source/blender/modifiers/intern/MOD_mask.cc
@@ -748,7 +748,6 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *UNUSED(ctx)
   }
 
   BKE_mesh_calc_edges_loose(result);
-  BKE_mesh_normals_tag_dirty(result);
 
   return result;
 }
diff --git a/source/blender/modifiers/intern/MOD_ocean.c b/source/blender/modifiers/intern/MOD_ocean.c
index 6ded702ceda..fbc5b7c288f 100644
--- a/source/blender/modifiers/intern/MOD_ocean.c
+++ b/source/blender/modifiers/intern/MOD_ocean.c
@@ -302,8 +302,6 @@ static Mesh *generate_ocean_geometry(OceanModifierData *omd, Mesh *mesh_orig, co
     }
   }
 
-  BKE_mesh_normals_tag_dirty(result);
-
   return result;
 }
 
@@ -361,7 +359,6 @@ static Mesh *doOcean(ModifierData *md, const ModifierEvalContext *ctx, Mesh *mes
 
   if (omd->geometry_mode == MOD_OCEAN_GEOM_GENERATE) {
     result = generate_ocean_geometry(omd, mesh, resolution);
-    BKE_mesh_normals_tag_dirty(result);
   }
   else if (omd->geometry_mode == MOD_OCEAN_GEOM_DISPLACE) {
     result = (Mesh *)BKE_id_copy_ex(NULL, &mesh->id, NULL, LIB_ID_COPY_LOCALIZE);
@@ -472,6 +469,8 @@ static Mesh *doOcean(ModifierData *md, const ModifierEvalContext *ctx, Mesh *mes
     }
   }
 
+  BKE_mesh_normals_tag_dirty(mesh);
+
   if (allocated_ocean) {
     BKE_ocean_free(omd->ocean);
     omd->ocean = NULL;
@@ -490,15 +489,7 @@ static Mesh *doOcean(ModifierData *UNUSED(md), const ModifierEvalContext *UNUSED
 
 static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *mesh)
 {
-  Mesh *result;
-
-  result = doOcean(md, ctx, mesh);
-
-  if (result != mesh) {
-    BKE_mesh_normals_tag_dirty(result);
-  }
-
-  return result;
+  return doOcean(md, ctx, mesh);
 }
 // #define WITH_OCEANSIM
 static void panel_draw(const bContext *UNUSED(C), Panel *panel)
diff --git a/source/blender/modifiers/intern/MOD_particleinstance.c b/source/blender/modifiers/intern/MOD_particleinstance.c
index 205a1986552..5af95a0f289 100644
--- a/source/blender/modifiers/intern/MOD_particleinstance.c
+++ b/source/blender/modifiers/intern/MOD_particleinstance.c
@@ -530,8 +530,6 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *
   MEM_SAFE_FREE(vert_part_index);
   MEM_SAFE_FREE(vert_part_value);
 
-  BKE_mesh_normals_tag_dirty(result);
-
   return result;
 }
 
diff --git a/source/blender/modifiers/intern/MOD_particlesystem.c b/source/blender/modifiers/intern/MOD_particlesystem.c
index 7df7ba7c1db..032227307e7 100644
--- a/source/blender/modifiers/intern/MOD_particlesystem.c
+++ b/source/blender/modifiers/intern/MOD_particlesystem.c
@@ -158,7 +158,6 @@ static void deformVerts(ModifierData *md,
   /* make new mesh */
   psmd->mesh_final = BKE_mesh_copy_for_eval(mesh_src, false);
   BKE_mesh_vert_coords_apply(psmd->mesh_final, vertexCos);
-  BKE_mesh_calc_normals(psmd->mesh_final);
 
   BKE_mesh_tessface_ensure(psmd->mesh_final);
 
diff --git a/source/blender/modifiers/intern/MOD_remesh.c b/source/blender/modifiers/intern/MOD_remesh.c
index f6f4746f44f..288faee247f 100644
--- a/source/blender/modifiers/intern/MOD_remesh.c
+++ b/source/blender/modifiers/intern/MOD_remesh.c
@@ -206,7 +206,6 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *UNUSED(ctx)
 
   BKE_mesh_copy_parameters_for_eval(result, mesh);
   BKE_mesh_calc_edges(result, true, false);
-  BKE_mesh_normals_tag_dirty(result);
   return result;
 }
 
diff --git a/source/blender/modifiers/intern/MOD_screw.c b/source/blender/modifiers/intern/MOD_screw.c
index 4ace6404388..8166c44539d 100644
--- a/source/blender/modifiers/intern/MOD_screw.c
+++ b/source/blender/modifiers/intern/MOD_screw.c
@@ -384,7 +384,6 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *
 
   mvert_new = result->mvert;
   float(*vert_normals_new)[3] = BKE_mesh_vertex_normals_for_write(result);
-  BKE_mesh_vertex_normals_clear_dirty(result);
   mpoly_new = result->mpoly;
   mloop_new = result->mloop;
   medge_new = result->medge;
@@ -1120,7 +1119,6 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *
   }
 
   if ((ltmd->flag & MOD_SCREW_MERGE) && (screw_ofs == 0.0f)) {
-    Mesh *result_prev = result;
     result = mesh_remove_doubles_on_axis(result,
                                          mvert_new,
                                          totvert,
@@ -1128,13 +1126,10 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *
                                          axis_vec,
                                          ob_axis != NULL ? mtx_tx[3] : NULL,
                                          ltmd->merge_dist);
-    if (result != result_prev) {
-      BKE_mesh_normals_tag_dirty(result);
-    }
   }
 
-  if ((ltmd->flag & MOD_SCREW_NORMAL_CALC) == 0) {
-    BKE_mesh_normals_tag_dirty(result);
+  if ((ltmd->flag & MOD_SCREW_NORMAL_CALC)) {
+    BKE_mesh_vertex_normals_clear_dirty(mesh);
   }
 
   return result;
diff --git a/source/blender/modifiers/intern/MOD_skin.c b/source/blender/modifiers/intern/MOD_skin.c
index b950578ff1b..7f96dcb82fb 100644
--- a/source/blender/modifiers/intern/MOD_skin.c
+++ b/source/blender/modifiers/intern/MOD_skin.c
@@ -1950,8 +1950,6 @@ static Mesh *base_skin(Mesh *origmesh, SkinModifierData *smd, eSkinErrorFlag *r_
   result = BKE_mesh_from_bmesh_for_eval_nomain(bm, NULL, origmesh);
   BM_mesh_free(bm);
 
-  BKE_mesh_normals_tag_dirty(result);
-
   skin_set_orig_indices(result);
 
   return result;
diff --git a/source/blender/modifiers/intern/MOD_solidify_nonmanifold.c b/source/blender/modifiers/intern/MOD_solidify_nonmanifold.c
index 8a84cd0a3bf..8a5b600974c 100644
--- a/source/blender/modifiers/intern/MOD_solidify_nonmanifold.c
+++ b/source/blender/modifiers/intern/MOD_solidify_nonmanifold.c
@@ -2016,8 +2016,6 @@ Mesh *MOD_solidify_nonmanifold_modifyMesh(ModifierData *md,
     }
   }
 
-  BKE_mesh_normals_tag_dirty(result);
-
   /* Make edges. */
   {
     uint i = 0;
diff --git a/source/blender/modifiers/intern/MOD_surface.c b/source/blender/modifiers/intern/MOD_surface.c
index 3e75e325e44..c2869e590bd 100644
--- a/source/blender/modifiers/intern/MOD_surface.c
+++ b/source/blender/modifiers/intern/MOD_surface.c
@@ -129,7 +129,7 @@ static void deformVerts(ModifierData *md,
     MVert *x, *v;
 
     BKE_mesh_vert_coords_apply(surmd->mesh, vertexCos);
-    BKE_mesh_calc_normals(surmd->mesh);
+    BKE_mesh_normals_tag_dirty(surmd->mesh);
 
     mesh_verts_num = surmd->mesh->totvert;
 
diff --git a/source/blender/modifiers/intern/MOD_triangulate.c b/source/blender/modifiers/intern/MOD_triangulate.c
index d7e57c1f6e5..f1e8ef5bf38 100644
--- a/source/blender/modifiers/intern/MOD_triangulate.c
+++ b/source/blender/modifiers/intern/MOD_triangulate.c
@@ -89,8 +89,6 @@ static Mesh *triangulate_mesh(Mesh *mesh,
     me->flag |= ME_EDGEDRAW | ME_EDGERENDER;
   }
 
-  BKE_mesh_normals_tag_dirty(result);
-
   return result;
 }
 
diff --git a/source/blender/modifiers/intern/MOD_wireframe.c b/source/blender/modifiers/intern/MOD_wireframe.c
index dae7d19844e..b657ea87244 100644
--- a/source/blender/modifiers/intern/MOD_wireframe.c
+++ b/source/blender/modifiers/intern/MOD_wireframe.c
@@ -97,8 +97,6 @@ static Mesh *WireframeModifier_do(WireframeModifierData *wmd, Object *ob, Mesh *
   result = BKE_mesh_from_bmesh_for_eval_nomain(bm, NULL, mesh);
   BM_mesh_free(bm);
 
-  BKE_mesh_normals_tag_dirty(result);
-
   return result;
 }