Mesh: skip conversion from edit-mesh to mesh in edit-mode

This resolves a performance regression in 2.8x where every edit-mode
update performed an edit-mesh to mesh conversion.

Now the conversion will be lazily initialized if/when it's required.

New BKE_mesh_wrapper_* functions abstract over mesh data access.
Currently only edit-mesh and regular meshes are supported.
In the future sub-surface meshes may be supported too.

1 files changed, 16 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/mesh_evaluate.c b/source/blender/blenkernel/intern/mesh_evaluate.c
index f0d19f01aab..433db26ded8 100644
--- a/source/blender/blenkernel/intern/mesh_evaluate.c
+++ b/source/blender/blenkernel/intern/mesh_evaluate.c
@@ -46,6 +46,7 @@
 #include "BLI_utildefines.h"
 
 #include "BKE_customdata.h"
+#include "BKE_editmesh_cache.h"
 #include "BKE_global.h"
 #include "BKE_mesh.h"
 #include "BKE_multires.h"
@@ -396,6 +397,21 @@ void BKE_mesh_ensure_normals(Mesh *mesh)
  */
 void BKE_mesh_ensure_normals_for_display(Mesh *mesh)
 {
+  switch ((eMeshWrapperType)mesh->runtime.wrapper_type) {
+    case ME_WRAPPER_TYPE_MDATA:
+      /* Run code below. */
+      break;
+    case ME_WRAPPER_TYPE_BMESH: {
+      struct BMEditMesh *em = mesh->edit_mesh;
+      EditMeshData *emd = mesh->runtime.edit_data;
+      if (emd->vertexCos) {
+        BKE_editmesh_cache_ensure_vert_normals(em, emd);
+        BKE_editmesh_cache_ensure_poly_normals(em, emd);
+      }
+      return;
+    }
+  }
+
   float(*poly_nors)[3] = CustomData_get_layer(&mesh->pdata, CD_NORMAL);
   const bool do_vert_normals = (mesh->runtime.cd_dirty_vert & CD_MASK_NORMAL) != 0;
   const bool do_poly_normals = (mesh->runtime.cd_dirty_poly & CD_MASK_NORMAL || poly_nors == NULL);