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, 2 insertions, 2 deletions

diff --git a/source/blender/modifiers/intern/MOD_util.cc b/source/blender/modifiers/intern/MOD_util.cc
index 509ce95b073..589a3d28ad9 100644
--- a/source/blender/modifiers/intern/MOD_util.cc
+++ b/source/blender/modifiers/intern/MOD_util.cc
@@ -188,7 +188,7 @@ Mesh *MOD_deform_mesh_eval_get(Object *ob,
                                     &mesh_prior_modifiers->id,
                                     nullptr,
                                     (LIB_ID_COPY_LOCALIZE | LIB_ID_COPY_CD_REFERENCE));
-      mesh->runtime.deformed_only = 1;
+      mesh->runtime->deformed_only = 1;
     }
 
     if (em != nullptr) {
@@ -218,7 +218,7 @@ Mesh *MOD_deform_mesh_eval_get(Object *ob,
     }
   }
 
-  if (mesh && mesh->runtime.wrapper_type == ME_WRAPPER_TYPE_MDATA) {
+  if (mesh && mesh->runtime->wrapper_type == ME_WRAPPER_TYPE_MDATA) {
     BLI_assert(mesh->totvert == verts_num);
   }