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.

1 files changed, 2 insertions, 1 deletions

diff --git a/source/blender/editors/mesh/mesh_data.c b/source/blender/editors/mesh/mesh_data.c
index 6f5c9d410c7..f6f4260b762 100644
--- a/source/blender/editors/mesh/mesh_data.c
+++ b/source/blender/editors/mesh/mesh_data.c
@@ -1092,7 +1092,8 @@ void ED_mesh_update(Mesh *mesh, bContext *C, bool calc_edges, bool calc_edges_lo
   /* Default state is not to have tessface's so make sure this is the case. */
   BKE_mesh_tessface_clear(mesh);
 
-  BKE_mesh_calc_normals(mesh);
+  /* Tag lazily calculated data as dirty. */
+  BKE_mesh_normals_tag_dirty(mesh);
 
   DEG_id_tag_update(&mesh->id, 0);
   WM_event_add_notifier(C, NC_GEOM | ND_DATA, mesh);