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

11 files changed, 37 insertions, 26 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;
         }
       }
 
diff --git a/source/blender/editors/mesh/editmesh_undo.cc b/source/blender/editors/mesh/editmesh_undo.cc
index d810e782a1b..5c837e61a79 100644
--- a/source/blender/editors/mesh/editmesh_undo.cc
+++ b/source/blender/editors/mesh/editmesh_undo.cc
@@ -597,6 +597,11 @@ static void *undomesh_from_editmesh(UndoMesh *um, BMEditMesh *em, Key *key, Undo
    * on it. Necessary to use the attribute API. */
   strcpy(um->me.id.name, "MEundomesh_from_editmesh");
 
+  /* Runtime data is necessary for some asserts in other code, and the overhead of creating it for
+   * undo meshes should be low. */
+  BLI_assert(um->me.runtime == nullptr);
+  um->me.runtime = new blender::bke::MeshRuntime();
+
   CustomData_MeshMasks cd_mask_extra{};
   cd_mask_extra.vmask = CD_MASK_SHAPE_KEYINDEX;
   BMeshToMeshParams params{};
diff --git a/source/blender/editors/physics/particle_edit.c b/source/blender/editors/physics/particle_edit.c
index 761a6702c6f..e6d0aca7902 100644
--- a/source/blender/editors/physics/particle_edit.c
+++ b/source/blender/editors/physics/particle_edit.c
@@ -3533,7 +3533,7 @@ static void PE_mirror_x(Depsgraph *depsgraph, Scene *scene, Object *ob, int tagg
   }
 
   const bool use_dm_final_indices = (psys->part->use_modifier_stack &&
-                                     !psmd_eval->mesh_final->runtime.deformed_only);
+                                     !BKE_mesh_is_deformed_only(psmd_eval->mesh_final));
 
   /* NOTE: this is not nice to use tessfaces but hard to avoid since pa->num uses tessfaces */
   BKE_mesh_tessface_ensure(me);
@@ -4353,7 +4353,7 @@ static void brush_add_count_iter(void *__restrict iter_data_v,
                               0,
                               0,
                               0)) {
-    if (psys->part->use_modifier_stack && !psmd_eval->mesh_final->runtime.deformed_only) {
+    if (psys->part->use_modifier_stack && !BKE_mesh_is_deformed_only(psmd_eval->mesh_final)) {
       add_pars[iter].num = add_pars[iter].num_dmcache;
       add_pars[iter].num_dmcache = DMCACHE_ISCHILD;
     }
@@ -4430,7 +4430,7 @@ static int brush_add(const bContext *C, PEData *data, short number)
 
   timestep = psys_get_timestep(&sim);
 
-  if (psys->part->use_modifier_stack || psmd_eval->mesh_final->runtime.deformed_only) {
+  if (psys->part->use_modifier_stack || BKE_mesh_is_deformed_only(psmd_eval->mesh_final)) {
     mesh = psmd_eval->mesh_final;
   }
   else {
diff --git a/source/blender/editors/physics/particle_object.c b/source/blender/editors/physics/particle_object.c
index 08db03db0e9..71ed32caede 100644
--- a/source/blender/editors/physics/particle_object.c
+++ b/source/blender/editors/physics/particle_object.c
@@ -732,7 +732,7 @@ static bool remap_hair_emitter(Depsgraph *depsgraph,
   invert_m4_m4(to_imat, to_mat);
 
   const bool use_dm_final_indices = (target_psys->part->use_modifier_stack &&
-                                     !target_psmd->mesh_final->runtime.deformed_only);
+                                     !BKE_mesh_is_deformed_only(target_psmd->mesh_final));
 
   if (use_dm_final_indices || !target_psmd->mesh_original) {
     mesh = target_psmd->mesh_final;
diff --git a/source/blender/editors/sculpt_paint/paint_image_proj.c b/source/blender/editors/sculpt_paint/paint_image_proj.c
index 8ffa78cd457..41d5090b38c 100644
--- a/source/blender/editors/sculpt_paint/paint_image_proj.c
+++ b/source/blender/editors/sculpt_paint/paint_image_proj.c
@@ -4074,7 +4074,7 @@ static bool proj_paint_state_mesh_eval_init(const bContext *C, ProjPaintState *p
   ps->totloop_eval = ps->me_eval->totloop;
 
   ps->mlooptri_eval = BKE_mesh_runtime_looptri_ensure(ps->me_eval);
-  ps->totlooptri_eval = ps->me_eval->runtime.looptris.len;
+  ps->totlooptri_eval = BKE_mesh_runtime_looptri_len(ps->me_eval);
 
   ps->poly_to_loop_uv = MEM_mallocN(ps->totpoly_eval * sizeof(MLoopUV *), "proj_paint_mtfaces");
 
diff --git a/source/blender/editors/sculpt_paint/paint_utils.c b/source/blender/editors/sculpt_paint/paint_utils.c
index cb981a3bfb1..ce4a5151a20 100644
--- a/source/blender/editors/sculpt_paint/paint_utils.c
+++ b/source/blender/editors/sculpt_paint/paint_utils.c
@@ -286,7 +286,7 @@ static void imapaint_pick_uv(
   const ePaintCanvasSource mode = scene->toolsettings->imapaint.mode;
 
   const MLoopTri *lt = BKE_mesh_runtime_looptri_ensure(me_eval);
-  const int tottri = me_eval->runtime.looptris.len;
+  const int tottri = BKE_mesh_runtime_looptri_len(me_eval);
 
   const MVert *mvert = BKE_mesh_verts(me_eval);
   const MLoop *mloop = BKE_mesh_loops(me_eval);
diff --git a/source/blender/editors/space_info/info_stats.cc b/source/blender/editors/space_info/info_stats.cc
index cac0dbb0067..e8b005b2b67 100644
--- a/source/blender/editors/space_info/info_stats.cc
+++ b/source/blender/editors/space_info/info_stats.cc
@@ -40,6 +40,7 @@
 #include "BKE_key.h"
 #include "BKE_layer.h"
 #include "BKE_main.h"
+#include "BKE_mesh.h"
 #include "BKE_object.h"
 #include "BKE_paint.h"
 #include "BKE_particle.h"
@@ -94,8 +95,8 @@ static bool stats_mesheval(const Mesh *me_eval, bool is_selected, SceneStats *st
 
   int totvert, totedge, totface, totloop;
 
-  const SubdivCCG *subdiv_ccg = me_eval->runtime.subdiv_ccg;
-  const SubsurfRuntimeData *subsurf_runtime_data = me_eval->runtime.subsurf_runtime_data;
+  const SubdivCCG *subdiv_ccg = me_eval->runtime->subdiv_ccg;
+  const SubsurfRuntimeData *subsurf_runtime_data = me_eval->runtime->subsurf_runtime_data;
 
   if (subdiv_ccg != nullptr) {
     BKE_subdiv_ccg_topology_counters(subdiv_ccg, &totvert, &totedge, &totface, &totloop);
diff --git a/source/blender/editors/space_view3d/drawobject.c b/source/blender/editors/space_view3d/drawobject.c
index 36ced74a8b7..6370d56ae8c 100644
--- a/source/blender/editors/space_view3d/drawobject.c
+++ b/source/blender/editors/space_view3d/drawobject.c
@@ -17,6 +17,7 @@
 #include "BKE_editmesh.h"
 #include "BKE_global.h"
 #include "BKE_mesh.h"
+#include "BKE_mesh_runtime.h"
 #include "BKE_object.h"
 
 #include "DEG_depsgraph.h"
@@ -94,8 +95,8 @@ void ED_draw_object_facemap(Depsgraph *depsgraph,
 
     const MPoly *mp;
     int i;
-    if (me->runtime.looptris.array) {
-      const MLoopTri *mlt = me->runtime.looptris.array;
+    if (BKE_mesh_runtime_looptri_ensure(me)) {
+      const MLoopTri *mlt = BKE_mesh_runtime_looptri_ensure(me);
       for (mp = polys, i = 0; i < mpoly_len; i++, mp++) {
         if (facemap_data[i] == facemap) {
           for (int j = 2; j < mp->totloop; j++) {
diff --git a/source/blender/editors/space_view3d/view3d_gizmo_preselect_type.cc b/source/blender/editors/space_view3d/view3d_gizmo_preselect_type.cc
index c61eac3c777..793ada4f577 100644
--- a/source/blender/editors/space_view3d/view3d_gizmo_preselect_type.cc
+++ b/source/blender/editors/space_view3d/view3d_gizmo_preselect_type.cc
@@ -19,8 +19,10 @@
 
 #include "BKE_context.h"
 #include "BKE_editmesh.h"
+#include "BKE_editmesh_cache.h"
 #include "BKE_global.h"
 #include "BKE_layer.h"
+#include "BKE_mesh.h"
 
 #include "DEG_depsgraph.h"
 #include "DEG_depsgraph_query.h"
@@ -234,8 +236,8 @@ static int gizmo_preselect_elem_test_select(bContext *C, wmGizmo *gz, const int
       Object *ob = gz_ele->bases[gz_ele->base_index]->object;
       Depsgraph *depsgraph = CTX_data_ensure_evaluated_depsgraph(C);
       Mesh *me_eval = (Mesh *)DEG_get_evaluated_id(depsgraph, static_cast<ID *>(ob->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;
       }
     }
     EDBM_preselect_elem_update_from_single(gz_ele->psel, bm, best.ele, coords);
diff --git a/source/blender/editors/space_view3d/view3d_iterators.cc b/source/blender/editors/space_view3d/view3d_iterators.cc
index 204e4673aa4..932563863fe 100644
--- a/source/blender/editors/space_view3d/view3d_iterators.cc
+++ b/source/blender/editors/space_view3d/view3d_iterators.cc
@@ -576,7 +576,7 @@ void mesh_foreachScreenFace(
 
   BM_mesh_elem_table_ensure(vc->em->bm, BM_FACE);
 
-  if (me->runtime.subsurf_face_dot_tags != nullptr) {
+  if (me->runtime->subsurf_face_dot_tags != nullptr) {
     BKE_mesh_foreach_mapped_subdiv_face_center(
         me, mesh_foreachScreenFace__mapFunc, &data, MESH_FOREACH_NOP);
   }
diff --git a/source/blender/editors/transform/transform_snap_object.cc b/source/blender/editors/transform/transform_snap_object.cc
index 90a13722b63..f2711db5011 100644
--- a/source/blender/editors/transform/transform_snap_object.cc
+++ b/source/blender/editors/transform/transform_snap_object.cc
@@ -105,7 +105,7 @@ struct SnapData_EditMesh {
   /* Looptris. */
   BVHTreeFromEditMesh treedata_editmesh;
 
-  struct Mesh_Runtime *mesh_runtime;
+  blender::bke::MeshRuntime *mesh_runtime;
   float min[3], max[3];
 
   void clear()
@@ -189,14 +189,14 @@ static const Mesh *mesh_for_snap(Object *ob_eval, eSnapEditType edit_mode_type,
     const Mesh *editmesh_eval_cage = BKE_object_get_editmesh_eval_cage(ob_eval);
 
     if ((edit_mode_type == SNAP_GEOM_FINAL) && editmesh_eval_final) {
-      if (editmesh_eval_final->runtime.wrapper_type == ME_WRAPPER_TYPE_BMESH) {
+      if (editmesh_eval_final->runtime->wrapper_type == ME_WRAPPER_TYPE_BMESH) {
         return nullptr;
       }
       me_eval = editmesh_eval_final;
       use_hide = true;
     }
     else if ((edit_mode_type == SNAP_GEOM_CAGE) && editmesh_eval_cage) {
-      if (editmesh_eval_cage->runtime.wrapper_type == ME_WRAPPER_TYPE_BMESH) {
+      if (editmesh_eval_cage->runtime->wrapper_type == ME_WRAPPER_TYPE_BMESH) {
         return nullptr;
       }
       me_eval = editmesh_eval_cage;
@@ -253,21 +253,21 @@ static SnapData_Mesh *snap_object_data_mesh_get(SnapObjectContext *sctx,
     sod = sod_p->get();
     bool is_dirty = false;
     if (sod->treedata_mesh.tree && sod->treedata_mesh.cached &&
-        !bvhcache_has_tree(me_eval->runtime.bvh_cache, sod->treedata_mesh.tree)) {
+        !bvhcache_has_tree(me_eval->runtime->bvh_cache, sod->treedata_mesh.tree)) {
       /* The tree is owned by the Mesh and may have been freed since we last used. */
       is_dirty = true;
     }
     else if (sod->bvhtree[0] && sod->cached[0] &&
-             !bvhcache_has_tree(me_eval->runtime.bvh_cache, sod->bvhtree[0])) {
+             !bvhcache_has_tree(me_eval->runtime->bvh_cache, sod->bvhtree[0])) {
       /* The tree is owned by the Mesh and may have been freed since we last used. */
       is_dirty = true;
     }
     else if (sod->bvhtree[1] && sod->cached[1] &&
-             !bvhcache_has_tree(me_eval->runtime.bvh_cache, sod->bvhtree[1])) {
+             !bvhcache_has_tree(me_eval->runtime->bvh_cache, sod->bvhtree[1])) {
       /* The tree is owned by the Mesh and may have been freed since we last used. */
       is_dirty = true;
     }
-    else if (sod->treedata_mesh.looptri != me_eval->runtime.looptris.array) {
+    else if (sod->treedata_mesh.looptri != me_eval->looptris().data()) {
       is_dirty = true;
     }
     else if (sod->treedata_mesh.vert != verts.data()) {
@@ -330,19 +330,19 @@ static SnapData_Mesh *snap_object_data_mesh_get(SnapObjectContext *sctx,
 
 /* Searches for the #Mesh_Runtime associated with the object that is most likely to be updated due
  * to changes in the `edit_mesh`. */
-static Mesh_Runtime *snap_object_data_editmesh_runtime_get(Object *ob_eval)
+static blender::bke::MeshRuntime *snap_object_data_editmesh_runtime_get(Object *ob_eval)
 {
   Mesh *editmesh_eval_final = BKE_object_get_editmesh_eval_final(ob_eval);
   if (editmesh_eval_final) {
-    return &editmesh_eval_final->runtime;
+    return editmesh_eval_final->runtime;
   }
 
   Mesh *editmesh_eval_cage = BKE_object_get_editmesh_eval_cage(ob_eval);
   if (editmesh_eval_cage) {
-    return &editmesh_eval_cage->runtime;
+    return editmesh_eval_cage->runtime;
   }
 
-  return &((Mesh *)ob_eval->data)->runtime;
+  return ((Mesh *)ob_eval->data)->runtime;
 }
 
 static SnapData_EditMesh *snap_object_data_editmesh_get(SnapObjectContext *sctx,