Mesh: Move runtime data out of DNA

This commit replaces the `Mesh_Runtime` struct embedded in `Mesh`
with `blender::bke::MeshRuntime`. This has quite a few benefits:
- It's possible to use C++ types like `std::mutex`, `Array`,
  `BitVector`, etc. more easily
- Meshes saved in files are slightly smaller
- Copying and writing meshes is a bit more obvious without
  clearing of runtime data, etc.

The first is by far the most important. It will allows us to avoid a
bunch of manual memory management boilerplate that is error-prone and
annoying. It should also simplify future CoW improvements for runtime
data.

This patch doesn't change anything besides changing `mesh.runtime.data`
to `mesh.runtime->data`. The cleanups above will happen separately.

Differential Revision: https://developer.blender.org/D16180

1 files changed, 4 insertions, 2 deletions

diff --git a/source/blender/editors/mesh/editmesh_select.cc b/source/blender/editors/mesh/editmesh_select.cc
index 0d1e3c08d84..76d0bab8a52 100644
--- a/source/blender/editors/mesh/editmesh_select.cc
+++ b/source/blender/editors/mesh/editmesh_select.cc
@@ -22,7 +22,9 @@
 #include "BKE_customdata.h"
 #include "BKE_deform.h"
 #include "BKE_editmesh.h"
+#include "BKE_editmesh_cache.h"
 #include "BKE_layer.h"
+#include "BKE_mesh.h"
 #include "BKE_report.h"
 
 #include "WM_api.h"
@@ -1065,8 +1067,8 @@ bool EDBM_unified_findnearest_from_raycast(ViewContext *vc,
       {
         Mesh *me_eval = (Mesh *)DEG_get_evaluated_id(vc->depsgraph,
                                                      static_cast<ID *>(obedit->data));
-        if (me_eval->runtime.edit_data) {
-          coords = me_eval->runtime.edit_data->vertexCos;
+        if (me_eval->runtime->edit_data) {
+          coords = me_eval->runtime->edit_data->vertexCos;
         }
       }