Depsgraph: Use UUID to match modifiers

Solves possible pointer-based comparison fiasco.

Another nice outcome of this is that topology cache will now be
preserved throughout the undo system. For example, undo of object
transform will not require topology cache to be re-created.

Differential Revision: https://developer.blender.org/D8493

1 files changed, 12 insertions, 15 deletions

diff --git a/source/blender/depsgraph/intern/eval/deg_eval_runtime_backup_object.cc b/source/blender/depsgraph/intern/eval/deg_eval_runtime_backup_object.cc
index 88334e41192..addee3dc539 100644
--- a/source/blender/depsgraph/intern/eval/deg_eval_runtime_backup_object.cc
+++ b/source/blender/depsgraph/intern/eval/deg_eval_runtime_backup_object.cc
@@ -62,21 +62,18 @@ void ObjectRuntimeBackup::init_from_object(Object *object)
   backup_pose_channel_runtime_data(object);
 }
 
-inline ModifierDataBackupID create_modifier_data_id(const ModifierData *modifier_data)
-{
-  return ModifierDataBackupID(modifier_data->orig_modifier_data,
-                              static_cast<ModifierType>(modifier_data->type));
-}
-
 void ObjectRuntimeBackup::backup_modifier_runtime_data(Object *object)
 {
   LISTBASE_FOREACH (ModifierData *, modifier_data, &object->modifiers) {
     if (modifier_data->runtime == nullptr) {
       continue;
     }
+
+    const SessionUUID &session_uuid = modifier_data->session_uuid;
+    BLI_assert(BLI_session_uuid_is_generated(&session_uuid));
+
     BLI_assert(modifier_data->orig_modifier_data != nullptr);
-    ModifierDataBackupID modifier_data_id = create_modifier_data_id(modifier_data);
-    modifier_runtime_data.add(modifier_data_id, modifier_data->runtime);
+    modifier_runtime_data.add(session_uuid, ModifierDataBackup(modifier_data));
     modifier_data->runtime = nullptr;
   }
 }
@@ -153,17 +150,17 @@ void ObjectRuntimeBackup::restore_modifier_runtime_data(Object *object)
 {
   LISTBASE_FOREACH (ModifierData *, modifier_data, &object->modifiers) {
     BLI_assert(modifier_data->orig_modifier_data != nullptr);
-    ModifierDataBackupID modifier_data_id = create_modifier_data_id(modifier_data);
-    void *runtime = modifier_runtime_data.pop_default(modifier_data_id, nullptr);
-    if (runtime != nullptr) {
-      modifier_data->runtime = runtime;
+    const SessionUUID &session_uuid = modifier_data->session_uuid;
+    optional<ModifierDataBackup> backup = modifier_runtime_data.pop_try(session_uuid);
+    if (backup.has_value()) {
+      modifier_data->runtime = backup->runtime;
     }
   }
 
-  for (ModifierRuntimeDataBackup::Item item : modifier_runtime_data.items()) {
-    const ModifierTypeInfo *modifier_type_info = BKE_modifier_get_info(item.key.type);
+  for (ModifierDataBackup &backup : modifier_runtime_data.values()) {
+    const ModifierTypeInfo *modifier_type_info = BKE_modifier_get_info(backup.type);
     BLI_assert(modifier_type_info != nullptr);
-    modifier_type_info->freeRuntimeData(item.value);
+    modifier_type_info->freeRuntimeData(backup.runtime);
   }
 }