Fix T90808: wrong BoundBox after undo curve selection

There are two functions that recalculate the boundbox of an object:
- One that considers the evaluated geometry
- Another that only considers the object's `data`.

Most of the time, the bound box is calculated on the final object
(with modifiers), so it doesn't seem right to just rely on `ob->data`
to recalculate the `ob->runtime.bb`.

Be sure to calculate the BoundBox based on the final geometry and
only use `ob->data` as a fallback

Differential Revision: https://developer.blender.org/D12282

source/blender/blenkernel/BKE_object.h

@@ -240,6 +240,7 @@ void BKE_object_dimensions_set(struct Object *ob, const float value[3], int axis
 void BKE_object_empty_draw_type_set(struct Object *ob, const int value);
 void BKE_object_boundbox_flag(struct Object *ob, int flag, const bool set);
 void BKE_object_boundbox_calc_from_mesh(struct Object *ob, const struct Mesh *me_eval);
+bool BKE_object_boundbox_calc_from_evaluated_geometry(struct Object *ob);
 void BKE_object_minmax(struct Object *ob, float r_min[3], float r_max[3], const bool use_hidden);
 bool BKE_object_minmax_dupli(struct Depsgraph *depsgraph,
                              struct Scene *scene,

source/blender/blenkernel/intern/displist.cc

@@ -66,8 +66,6 @@
 
 using blender::IndexRange;
 
-static void boundbox_displist_object(Object *ob);
-
 static void displist_elem_free(DispList *dl)
 {
   if (dl) {
@@ -1528,7 +1526,9 @@ void BKE_displist_make_curveTypes(Depsgraph *depsgraph,
     ob->runtime.geometry_set_eval = new GeometrySet(std::move(geometry));
   }
 
-  boundbox_displist_object(ob);
+  if (ob->runtime.bb) {
+    ob->runtime.bb->flag |= BOUNDBOX_DIRTY;
+  }
 }
 
 void BKE_displist_minmax(const ListBase *dispbase, float min[3], float max[3])
@@ -1551,30 +1551,3 @@ void BKE_displist_minmax(const ListBase *dispbase, float min[3], float max[3])
     zero_v3(max);
   }
 }
-
-/* this is confusing, there's also min_max_object, applying the obmat... */
-static void boundbox_displist_object(Object *ob)
-{
-  BLI_assert(ELEM(ob->type, OB_CURVE, OB_SURF, OB_FONT));
-  /* Curve's BB is already calculated as a part of modifier stack,
-   * here we only calculate object BB based on final display list. */
-
-  /* object's BB is calculated from final displist */
-  if (ob->runtime.bb == nullptr) {
-    ob->runtime.bb = (BoundBox *)MEM_callocN(sizeof(BoundBox), __func__);
-  }
-
-  const Mesh *mesh_eval = BKE_object_get_evaluated_mesh(ob);
-  if (mesh_eval) {
-    BKE_object_boundbox_calc_from_mesh(ob, mesh_eval);
-  }
-  else {
-    float min[3], max[3];
-
-    INIT_MINMAX(min, max);
-    BKE_displist_minmax(&ob->runtime.curve_cache->disp, min, max);
-    BKE_boundbox_init_from_minmax(ob->runtime.bb, min, max);
-
-    ob->runtime.bb->flag &= ~BOUNDBOX_DIRTY;
-  }
-}

source/blender/blenkernel/intern/object.cc

@@ -3965,6 +3965,37 @@ void BKE_object_boundbox_calc_from_mesh(Object *ob, const Mesh *me_eval)
   ob->runtime.bb->flag &= ~BOUNDBOX_DIRTY;
 }
 
+bool BKE_object_boundbox_calc_from_evaluated_geometry(Object *ob)
+{
+  blender::float3 min, max;
+  INIT_MINMAX(min, max);
+
+  if (ob->runtime.geometry_set_eval) {
+    ob->runtime.geometry_set_eval->compute_boundbox_without_instances(&min, &max);
+  }
+  else if (const Mesh *mesh_eval = BKE_object_get_evaluated_mesh(ob)) {
+    if (!BKE_mesh_wrapper_minmax(mesh_eval, min, max)) {
+      return false;
+    }
+  }
+  else if (ob->runtime.curve_cache) {
+    BKE_displist_minmax(&ob->runtime.curve_cache->disp, min, max);
+  }
+  else {
+    return false;
+  }
+
+  if (ob->runtime.bb == nullptr) {
+    ob->runtime.bb = (BoundBox *)MEM_callocN(sizeof(BoundBox), __func__);
+  }
+
+  BKE_boundbox_init_from_minmax(ob->runtime.bb, min, max);
+
+  ob->runtime.bb->flag &= ~BOUNDBOX_DIRTY;
+
+  return true;
+}
+
 /** \} */
 
 /* -------------------------------------------------------------------- */

source/blender/blenkernel/intern/object_update.c

@@ -282,7 +282,12 @@ void BKE_object_handle_data_update(Depsgraph *depsgraph, Scene *scene, Object *o
 /** Bounding box from evaluated geometry. */
 static void object_sync_boundbox_to_original(Object *object_orig, Object *object_eval)
 {
-  BoundBox *bb = BKE_object_boundbox_get(object_eval);
+  BoundBox *bb = object_eval->runtime.bb;
+  if (!bb || (bb->flag & BOUNDBOX_DIRTY)) {
+    BKE_object_boundbox_calc_from_evaluated_geometry(object_eval);
+  }
+
+  bb = BKE_object_boundbox_get(object_eval);
   if (bb != NULL) {
     if (object_orig->runtime.bb == NULL) {
       object_orig->runtime.bb = MEM_mallocN(sizeof(*object_orig->runtime.bb), __func__);