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, 1 insertions, 1 deletions

diff --git a/source/blender/draw/intern/draw_cache_impl_subdivision.cc b/source/blender/draw/intern/draw_cache_impl_subdivision.cc
index 9f445be9750..6a9e6c126e9 100644
--- a/source/blender/draw/intern/draw_cache_impl_subdivision.cc
+++ b/source/blender/draw/intern/draw_cache_impl_subdivision.cc
@@ -2036,7 +2036,7 @@ static bool draw_subdiv_create_requested_buffers(Object *ob,
                                                  const bool use_hide,
                                                  OpenSubdiv_EvaluatorCache *evaluator_cache)
 {
-  SubsurfRuntimeData *runtime_data = mesh->runtime.subsurf_runtime_data;
+  SubsurfRuntimeData *runtime_data = mesh->runtime->subsurf_runtime_data;
   BLI_assert(runtime_data && runtime_data->has_gpu_subdiv);
 
   if (runtime_data->settings.level == 0) {