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/render/intern/bake.c b/source/blender/render/intern/bake.c
index 59719fb4590..8fd62f7ec34 100644
--- a/source/blender/render/intern/bake.c
+++ b/source/blender/render/intern/bake.c
@@ -590,7 +590,7 @@ bool RE_bake_pixels_populate_from_objects(struct Mesh *me_low,
     me_highpoly[i] = highpoly[i].me;
     BKE_mesh_runtime_looptri_ensure(me_highpoly[i]);
 
-    if (me_highpoly[i]->runtime.looptris.len != 0) {
+    if (BKE_mesh_runtime_looptri_len(me_highpoly[i]) != 0) {
       /* Create a BVH-tree for each `highpoly` object. */
       BKE_bvhtree_from_mesh_get(&treeData[i], me_highpoly[i], BVHTREE_FROM_LOOPTRI, 2);