ViewLayer: Lazy sync of scene data.

When a change happens which invalidates view layers the syncing will be postponed until the first usage.
This will improve importing or adding many objects in a single operation/script.

`BKE_view_layer_need_resync_tag` is used to tag the view layer to be out of sync. Before accessing
`BKE_view_layer_active_base_get`, `BKE_view_layer_active_object_get`, `BKE_view_layer_active_collection`
or `BKE_view_layer_object_bases` the caller should call `BKE_view_layer_synced_ensure`.

Having two functions ensures that partial syncing could be added as smaller patches in the future. Tagging a
view layer out of sync could be replaced with a partial sync. Eventually the number of full resyncs could be
reduced. After all tagging has been replaced with partial syncs the ensure_sync could be phased out.

This patch has been added to discuss the details and consequences of the current approach. For clarity
the call to BKE_view_layer_ensure_sync is placed close to the getters.
In the future this could be placed in more strategical places to reduce the number of calls or improve
performance. Finding those strategical places isn't that clear. When multiple operations are grouped
in a single script you might want to always check for resync.

Some areas found that can be improved. This list isn't complete.
These areas aren't addressed by this patch as these changes would be hard to detect to the reviewer.
The idea is to add changes to these areas as a separate patch. It might be that the initial commit would reduce
performance compared to master, but will be fixed by the additional patches.

**Object duplication**
During object duplication the syncing is temporarily disabled. With this patch this isn't useful as when disabled
the view_layer is accessed to locate bases. This can be improved by first locating the source bases, then duplicate
and sync and locate the new bases. Will be solved in a separate patch for clarity reasons ({D15886}).

**Object add**
`BKE_object_add` not only adds a new object, but also selects and activates the new base. This requires the
view_layer to be resynced. Some callers reverse the selection and activation (See `get_new_constraint_target`).
We should make the selection and activation optional. This would make it possible to add multiple objects
without having to resync per object.

**Postpone Activate Base**
Setting the basact is done in many locations. They follow a rule as after an action find the base and set
the basact. Finding the base could require a resync. The idea is to store in the view_layer the object which
base will be set in the basact during the next sync, reducing the times resyncing needs to happen.

Reviewed By: mont29

Maniphest Tasks: T73411

Differential Revision: https://developer.blender.org/D15885

14 files changed, 76 insertions, 38 deletions

diff --git a/source/blender/editors/transform/transform.c b/source/blender/editors/transform/transform.c
index 49258d63611..eb46da3579a 100644
--- a/source/blender/editors/transform/transform.c
+++ b/source/blender/editors/transform/transform.c
@@ -485,6 +485,7 @@ static void viewRedrawForce(const bContext *C, TransInfo *t)
       /* XXX how to deal with lock? */
       SpaceImage *sima = (SpaceImage *)t->area->spacedata.first;
       if (sima->lock) {
+        BKE_view_layer_synced_ensure(t->scene, t->view_layer);
         WM_event_add_notifier(
             C, NC_GEOM | ND_DATA, BKE_view_layer_edit_object_get(t->view_layer)->data);
       }
@@ -1478,6 +1479,7 @@ static void drawTransformPixel(const struct bContext *C, ARegion *region, void *
   if (region == t->region) {
     Scene *scene = t->scene;
     ViewLayer *view_layer = t->view_layer;
+    BKE_view_layer_synced_ensure(scene, view_layer);
     Object *ob = BKE_view_layer_active_object_get(view_layer);
 
     /* draw auto-key-framing hint in the corner
@@ -1538,6 +1540,7 @@ void saveTransform(bContext *C, TransInfo *t, wmOperator *op)
     if (!(t->options & CTX_NO_PET)) {
       if ((prop = RNA_struct_find_property(op->ptr, "use_proportional_edit")) &&
           !RNA_property_is_set(op->ptr, prop)) {
+        BKE_view_layer_synced_ensure(t->scene, t->view_layer);
         const Object *obact = BKE_view_layer_active_object_get(t->view_layer);
 
         if (t->spacetype == SPACE_GRAPH) {
diff --git a/source/blender/editors/transform/transform_convert.c b/source/blender/editors/transform/transform_convert.c
index 948f49a97a4..1e29411fe84 100644
--- a/source/blender/editors/transform/transform_convert.c
+++ b/source/blender/editors/transform/transform_convert.c
@@ -1001,6 +1001,7 @@ static void init_TransDataContainers(TransInfo *t,
 static TransConvertTypeInfo *convert_type_get(const TransInfo *t, Object **r_obj_armature)
 {
   ViewLayer *view_layer = t->view_layer;
+  BKE_view_layer_synced_ensure(t->scene, t->view_layer);
   Object *ob = BKE_view_layer_active_object_get(view_layer);
 
   /* if tests must match recalcData for correct updates */
@@ -1144,8 +1145,8 @@ void createTransData(bContext *C, TransInfo *t)
     init_TransDataContainers(t, ob_armature, &ob_armature, 1);
   }
   else {
-    ViewLayer *view_layer = t->view_layer;
-    Object *ob = BKE_view_layer_active_object_get(view_layer);
+    BKE_view_layer_synced_ensure(t->scene, t->view_layer);
+    Object *ob = BKE_view_layer_active_object_get(t->view_layer);
     init_TransDataContainers(t, ob, NULL, 0);
   }
 
diff --git a/source/blender/editors/transform/transform_convert_action.c b/source/blender/editors/transform/transform_convert_action.c
index 83e47d9acc0..8c6f2baf84a 100644
--- a/source/blender/editors/transform/transform_convert_action.c
+++ b/source/blender/editors/transform/transform_convert_action.c
@@ -576,6 +576,8 @@ static void recalcData_actedit(TransInfo *t)
   bAnimListElem *ale;
   int filter;
 
+  BKE_view_layer_synced_ensure(t->scene, t->view_layer);
+
   /* initialize relevant anim-context 'context' data from TransInfo data */
   /* NOTE: sync this with the code in ANIM_animdata_get_context() */
   ac.bmain = CTX_data_main(t->context);
diff --git a/source/blender/editors/transform/transform_convert_gpencil.c b/source/blender/editors/transform/transform_convert_gpencil.c
index 5056b30f77f..b3d58f25ad3 100644
--- a/source/blender/editors/transform/transform_convert_gpencil.c
+++ b/source/blender/editors/transform/transform_convert_gpencil.c
@@ -682,6 +682,7 @@ static void createTransGPencil(bContext *C, TransInfo *t)
   Depsgraph *depsgraph = CTX_data_ensure_evaluated_depsgraph(C);
   const Scene *scene = CTX_data_scene(C);
   ToolSettings *ts = scene->toolsettings;
+  BKE_view_layer_synced_ensure(t->scene, t->view_layer);
   Object *obact = BKE_view_layer_active_object_get(t->view_layer);
   bGPdata *gpd = obact->data;
   BLI_assert(gpd != NULL);
diff --git a/source/blender/editors/transform/transform_convert_graph.c b/source/blender/editors/transform/transform_convert_graph.c
index fad192d54db..4bcbce8bc83 100644
--- a/source/blender/editors/transform/transform_convert_graph.c
+++ b/source/blender/editors/transform/transform_convert_graph.c
@@ -908,6 +908,8 @@ static void recalcData_graphedit(TransInfo *t)
   bAnimListElem *ale;
   int dosort = 0;
 
+  BKE_view_layer_synced_ensure(t->scene, t->view_layer);
+
   /* initialize relevant anim-context 'context' data from TransInfo data */
   /* NOTE: sync this with the code in ANIM_animdata_get_context() */
   ac.bmain = CTX_data_main(t->context);
diff --git a/source/blender/editors/transform/transform_convert_object.c b/source/blender/editors/transform/transform_convert_object.c
index 7056933a0ea..caa11fa5db4 100644
--- a/source/blender/editors/transform/transform_convert_object.c
+++ b/source/blender/editors/transform/transform_convert_object.c
@@ -291,9 +291,10 @@ static void ObjectToTransData(TransInfo *t, TransData *td, Object *ob)
   }
 }
 
-static void trans_object_base_deps_flag_prepare(ViewLayer *view_layer)
+static void trans_object_base_deps_flag_prepare(const Scene *scene, ViewLayer *view_layer)
 {
-  LISTBASE_FOREACH (Base *, base, &view_layer->object_bases) {
+  BKE_view_layer_synced_ensure(scene, view_layer);
+  LISTBASE_FOREACH (Base *, base, BKE_view_layer_object_bases_get(view_layer)) {
     base->object->id.tag &= ~LIB_TAG_DOIT;
   }
 }
@@ -323,11 +324,14 @@ static void flush_trans_object_base_deps_flag(Depsgraph *depsgraph, Object *obje
                                      NULL);
 }
 
-static void trans_object_base_deps_flag_finish(const TransInfo *t, ViewLayer *view_layer)
+static void trans_object_base_deps_flag_finish(const TransInfo *t,
+                                               const Scene *scene,
+                                               ViewLayer *view_layer)
 {
 
   if ((t->options & CTX_OBMODE_XFORM_OBDATA) == 0) {
-    LISTBASE_FOREACH (Base *, base, &view_layer->object_bases) {
+    BKE_view_layer_synced_ensure(scene, view_layer);
+    LISTBASE_FOREACH (Base *, base, BKE_view_layer_object_bases_get(view_layer)) {
       if (base->object->id.tag & LIB_TAG_DOIT) {
         base->flag_legacy |= BA_SNAP_FIX_DEPS_FIASCO;
       }
@@ -356,9 +360,10 @@ static void set_trans_object_base_flags(TransInfo *t)
   /* Make sure depsgraph is here. */
   DEG_graph_relations_update(depsgraph);
   /* Clear all flags we need. It will be used to detect dependencies. */
-  trans_object_base_deps_flag_prepare(view_layer);
+  trans_object_base_deps_flag_prepare(scene, view_layer);
   /* Traverse all bases and set all possible flags. */
-  LISTBASE_FOREACH (Base *, base, &view_layer->object_bases) {
+  BKE_view_layer_synced_ensure(scene, view_layer);
+  LISTBASE_FOREACH (Base *, base, BKE_view_layer_object_bases_get(view_layer)) {
     base->flag_legacy &= ~(BA_WAS_SEL | BA_TRANSFORM_LOCKED_IN_PLACE);
     if (BASE_SELECTED_EDITABLE(v3d, base)) {
       Object *ob = base->object;
@@ -392,7 +397,7 @@ static void set_trans_object_base_flags(TransInfo *t)
   /* Store temporary bits in base indicating that base is being modified
    * (directly or indirectly) by transforming objects.
    */
-  trans_object_base_deps_flag_finish(t, view_layer);
+  trans_object_base_deps_flag_finish(t, scene, view_layer);
 }
 
 static bool mark_children(Object *ob)
@@ -420,11 +425,11 @@ static int count_proportional_objects(TransInfo *t)
   Scene *scene = t->scene;
   Depsgraph *depsgraph = BKE_scene_ensure_depsgraph(bmain, scene, view_layer);
   /* Clear all flags we need. It will be used to detect dependencies. */
-  trans_object_base_deps_flag_prepare(view_layer);
+  trans_object_base_deps_flag_prepare(scene, view_layer);
   /* Rotations around local centers are allowed to propagate, so we take all objects. */
   if (!((t->around == V3D_AROUND_LOCAL_ORIGINS) && (ELEM(t->mode, TFM_ROTATION, TFM_TRACKBALL)))) {
     /* Mark all parents. */
-    LISTBASE_FOREACH (Base *, base, &view_layer->object_bases) {
+    LISTBASE_FOREACH (Base *, base, BKE_view_layer_object_bases_get(view_layer)) {
       if (BASE_SELECTED_EDITABLE(v3d, base) && BASE_SELECTABLE(v3d, base)) {
         Object *parent = base->object->parent;
         /* flag all parents */
@@ -435,7 +440,7 @@ static int count_proportional_objects(TransInfo *t)
       }
     }
     /* Mark all children. */
-    LISTBASE_FOREACH (Base *, base, &view_layer->object_bases) {
+    LISTBASE_FOREACH (Base *, base, BKE_view_layer_object_bases_get(view_layer)) {
       /* all base not already selected or marked that is editable */
       if ((base->object->flag & (BA_TRANSFORM_CHILD | BA_TRANSFORM_PARENT)) == 0 &&
           (base->flag & BASE_SELECTED) == 0 &&
@@ -445,7 +450,7 @@ static int count_proportional_objects(TransInfo *t)
     }
   }
   /* Flush changed flags to all dependencies. */
-  LISTBASE_FOREACH (Base *, base, &view_layer->object_bases) {
+  LISTBASE_FOREACH (Base *, base, BKE_view_layer_object_bases_get(view_layer)) {
     Object *ob = base->object;
     /* If base is not selected, not a parent of selection or not a child of
      * selection and it is editable and selectable.
@@ -460,16 +465,17 @@ static int count_proportional_objects(TransInfo *t)
   /* Store temporary bits in base indicating that base is being modified
    * (directly or indirectly) by transforming objects.
    */
-  trans_object_base_deps_flag_finish(t, view_layer);
+  trans_object_base_deps_flag_finish(t, scene, view_layer);
   return total;
 }
 
 static void clear_trans_object_base_flags(TransInfo *t)
 {
+  Scene *scene = t->scene;
   ViewLayer *view_layer = t->view_layer;
-  Base *base;
 
-  for (base = view_layer->object_bases.first; base; base = base->next) {
+  BKE_view_layer_synced_ensure(scene, view_layer);
+  LISTBASE_FOREACH (Base *, base, BKE_view_layer_object_bases_get(view_layer)) {
     if (base->flag_legacy & BA_WAS_SEL) {
       ED_object_base_select(base, BA_SELECT);
     }
@@ -559,11 +565,12 @@ static void createTransObject(bContext *C, TransInfo *t)
   CTX_DATA_END;
 
   if (is_prop_edit) {
+    Scene *scene = t->scene;
     ViewLayer *view_layer = t->view_layer;
     View3D *v3d = t->view;
-    Base *base;
 
-    for (base = view_layer->object_bases.first; base; base = base->next) {
+    BKE_view_layer_synced_ensure(scene, view_layer);
+    LISTBASE_FOREACH (Base *, base, BKE_view_layer_object_bases_get(view_layer)) {
       Object *ob = base->object;
 
       /* if base is not selected, not a parent of selection
@@ -592,10 +599,12 @@ static void createTransObject(bContext *C, TransInfo *t)
       }
     }
 
+    Scene *scene = t->scene;
     ViewLayer *view_layer = t->view_layer;
     View3D *v3d = t->view;
 
-    LISTBASE_FOREACH (Base *, base, &view_layer->object_bases) {
+    BKE_view_layer_synced_ensure(scene, view_layer);
+    LISTBASE_FOREACH (Base *, base, BKE_view_layer_object_bases_get(view_layer)) {
       Object *ob = base->object;
 
       /* if base is not selected, not a parent of selection
@@ -640,9 +649,11 @@ static void createTransObject(bContext *C, TransInfo *t)
       }
     }
 
+    Scene *scene = t->scene;
     ViewLayer *view_layer = t->view_layer;
 
-    LISTBASE_FOREACH (Base *, base, &view_layer->object_bases) {
+    BKE_view_layer_synced_ensure(scene, view_layer);
+    LISTBASE_FOREACH (Base *, base, BKE_view_layer_object_bases_get(view_layer)) {
       Object *ob = base->object;
       if (ob->parent != NULL) {
         if (ob->parent && !BLI_gset_haskey(objects_in_transdata, ob->parent) &&
@@ -672,7 +683,7 @@ static void createTransObject(bContext *C, TransInfo *t)
       }
     }
 
-    LISTBASE_FOREACH (Base *, base, &view_layer->object_bases) {
+    LISTBASE_FOREACH (Base *, base, BKE_view_layer_object_bases_get(view_layer)) {
       Object *ob = base->object;
 
       if (BASE_XFORM_INDIRECT(base) || BLI_gset_haskey(objects_in_transdata, ob)) {
@@ -782,6 +793,7 @@ static void autokeyframe_object(
       }
       else if (ELEM(tmode, TFM_ROTATION, TFM_TRACKBALL)) {
         if (scene->toolsettings->transform_pivot_point == V3D_AROUND_ACTIVE) {
+          BKE_view_layer_synced_ensure(scene, view_layer);
           if (ob != BKE_view_layer_active_object_get(view_layer)) {
             do_loc = true;
           }
@@ -796,6 +808,7 @@ static void autokeyframe_object(
       }
       else if (tmode == TFM_RESIZE) {
         if (scene->toolsettings->transform_pivot_point == V3D_AROUND_ACTIVE) {
+          BKE_view_layer_synced_ensure(scene, view_layer);
           if (ob != BKE_view_layer_active_object_get(view_layer)) {
             do_loc = true;
           }
diff --git a/source/blender/editors/transform/transform_convert_object_texspace.c b/source/blender/editors/transform/transform_convert_object_texspace.c
index 4dc4218c433..839bf6b77b3 100644
--- a/source/blender/editors/transform/transform_convert_object_texspace.c
+++ b/source/blender/editors/transform/transform_convert_object_texspace.c
@@ -38,6 +38,7 @@ static void createTransTexspace(bContext *UNUSED(C), TransInfo *t)
   ID *id;
   char *texflag;
 
+  BKE_view_layer_synced_ensure(t->scene, t->view_layer);
   ob = BKE_view_layer_active_object_get(view_layer);
 
   if (ob == NULL) { /* Shouldn't logically happen, but still. */
diff --git a/source/blender/editors/transform/transform_convert_particle.c b/source/blender/editors/transform/transform_convert_particle.c
index 354402a305f..3e056b6a048 100644
--- a/source/blender/editors/transform/transform_convert_particle.c
+++ b/source/blender/editors/transform/transform_convert_particle.c
@@ -35,6 +35,7 @@ static void createTransParticleVerts(bContext *UNUSED(C), TransInfo *t)
 
     TransData *td = NULL;
     TransDataExtension *tx;
+    BKE_view_layer_synced_ensure(t->scene, t->view_layer);
     Object *ob = BKE_view_layer_active_object_get(t->view_layer);
     ParticleEditSettings *pset = PE_settings(t->scene);
     PTCacheEdit *edit = PE_get_current(t->depsgraph, t->scene, ob);
@@ -184,6 +185,7 @@ static void flushTransParticles(TransInfo *t)
   FOREACH_TRANS_DATA_CONTAINER (t, tc) {
     Scene *scene = t->scene;
     ViewLayer *view_layer = t->view_layer;
+    BKE_view_layer_synced_ensure(scene, view_layer);
     Object *ob = BKE_view_layer_active_object_get(view_layer);
     PTCacheEdit *edit = PE_get_current(t->depsgraph, scene, ob);
     ParticleSystem *psys = edit->psys;
@@ -224,7 +226,7 @@ static void flushTransParticles(TransInfo *t)
       }
     }
 
-    PE_update_object(t->depsgraph, scene, BKE_view_layer_active_object_get(view_layer), 1);
+    PE_update_object(t->depsgraph, scene, ob, 1);
     BKE_particle_batch_cache_dirty_tag(psys, BKE_PARTICLE_BATCH_DIRTY_ALL);
     DEG_id_tag_update(&ob->id, ID_RECALC_PSYS_REDO);
   }
diff --git a/source/blender/editors/transform/transform_convert_sculpt.c b/source/blender/editors/transform/transform_convert_sculpt.c
index 86dc9f42b6b..3792cfefe06 100644
--- a/source/blender/editors/transform/transform_convert_sculpt.c
+++ b/source/blender/editors/transform/transform_convert_sculpt.c
@@ -34,6 +34,7 @@ static void createTransSculpt(bContext *C, TransInfo *t)
     return;
   }
 
+  BKE_view_layer_synced_ensure(t->scene, t->view_layer);
   Object *ob = BKE_view_layer_active_object_get(t->view_layer);
   SculptSession *ss = ob->sculpt;
 
@@ -97,6 +98,7 @@ static void createTransSculpt(bContext *C, TransInfo *t)
 
 static void recalcData_sculpt(TransInfo *t)
 {
+  BKE_view_layer_synced_ensure(t->scene, t->view_layer);
   Object *ob = BKE_view_layer_active_object_get(t->view_layer);
   ED_sculpt_update_modal_transform(t->context, ob);
 }
@@ -109,6 +111,7 @@ static void special_aftertrans_update__sculpt(bContext *C, TransInfo *t)
     return;
   }
 
+  BKE_view_layer_synced_ensure(t->scene, t->view_layer);
   Object *ob = BKE_view_layer_active_object_get(t->view_layer);
   BLI_assert(!(t->options & CTX_PAINT_CURVE));
   ED_sculpt_end_transform(C, ob);
diff --git a/source/blender/editors/transform/transform_generics.c b/source/blender/editors/transform/transform_generics.c
index 9ba5c9ebfe8..03c53e1b3d2 100644
--- a/source/blender/editors/transform/transform_generics.c
+++ b/source/blender/editors/transform/transform_generics.c
@@ -176,6 +176,7 @@ void initTransInfo(bContext *C, TransInfo *t, wmOperator *op, const wmEvent *eve
 {
   Scene *sce = CTX_data_scene(C);
   ViewLayer *view_layer = CTX_data_view_layer(C);
+  BKE_view_layer_synced_ensure(sce, view_layer);
   Object *obact = BKE_view_layer_active_object_get(view_layer);
   const eObjectMode object_mode = obact ? obact->mode : OB_MODE_OBJECT;
   ToolSettings *ts = CTX_data_tool_settings(C);
@@ -333,6 +334,7 @@ void initTransInfo(bContext *C, TransInfo *t, wmOperator *op, const wmEvent *eve
   }
   else if (t->spacetype == SPACE_IMAGE) {
     SpaceImage *sima = area->spacedata.first;
+    BKE_view_layer_synced_ensure(t->scene, t->view_layer);
     if (ED_space_image_show_uvedit(sima, BKE_view_layer_active_object_get(t->view_layer))) {
       /* UV transform */
     }
@@ -1066,8 +1068,8 @@ bool calculateCenterActive(TransInfo *t, bool select_only, float r_center[3])
     }
   }
   else if (t->options & CTX_POSE_BONE) {
-    ViewLayer *view_layer = t->view_layer;
-    Object *ob = BKE_view_layer_active_object_get(view_layer);
+    BKE_view_layer_synced_ensure(t->scene, t->view_layer);
+    Object *ob = BKE_view_layer_active_object_get(t->view_layer);
     if (ED_object_calc_active_center_for_posemode(ob, select_only, r_center)) {
       mul_m4_v3(ob->obmat, r_center);
       return true;
@@ -1083,11 +1085,10 @@ bool calculateCenterActive(TransInfo *t, bool select_only, float r_center[3])
   }
   else {
     /* object mode */
-    ViewLayer *view_layer = t->view_layer;
-    Object *ob = BKE_view_layer_active_object_get(view_layer);
-    Base *base = view_layer->basact;
-    if (ob && ((!select_only) || ((base->flag & BASE_SELECTED) != 0))) {
-      copy_v3_v3(r_center, ob->obmat[3]);
+    BKE_view_layer_synced_ensure(t->scene, t->view_layer);
+    Base *base = BKE_view_layer_active_base_get(t->view_layer);
+    if (base && ((!select_only) || ((base->flag & BASE_SELECTED) != 0))) {
+      copy_v3_v3(r_center, base->object->obmat[3]);
       return true;
     }
   }
@@ -1464,6 +1465,7 @@ Object *transform_object_deform_pose_armature_get(const TransInfo *t, Object *ob
    * Lines below just check is also visible. */
   Object *ob_armature = BKE_modifiers_is_deformed_by_armature(ob);
   if (ob_armature && ob_armature->mode & OB_MODE_POSE) {
+    BKE_view_layer_synced_ensure(t->scene, t->view_layer);
     Base *base_arm = BKE_view_layer_base_find(t->view_layer, ob_armature);
     if (base_arm) {
       View3D *v3d = t->view;
diff --git a/source/blender/editors/transform/transform_gizmo_3d.c b/source/blender/editors/transform/transform_gizmo_3d.c
index 16d99c23bd9..8e6a6c2c411 100644
--- a/source/blender/editors/transform/transform_gizmo_3d.c
+++ b/source/blender/editors/transform/transform_gizmo_3d.c
@@ -639,6 +639,7 @@ int ED_transform_calc_gizmo_stats(const bContext *C,
                                  (params->orientation_index - 1) :
                                  BKE_scene_orientation_get_index(scene, SCE_ORIENT_DEFAULT);
 
+  BKE_view_layer_synced_ensure(scene, view_layer);
   Object *ob = BKE_view_layer_active_object_get(view_layer);
   Object *obedit = OBEDIT_FROM_OBACT(ob);
   if (ob && ob->mode & OB_MODE_WEIGHT_PAINT) {
@@ -1014,13 +1015,14 @@ int ED_transform_calc_gizmo_stats(const bContext *C,
   else {
 
     /* we need the one selected object, if its not active */
-    base = view_layer->basact;
-    ob = BKE_view_layer_active_object_get(view_layer);
+    BKE_view_layer_synced_ensure(scene, view_layer);
+    base = BKE_view_layer_active_base_get(view_layer);
+    ob = base ? base->object : NULL;
     if (base && ((base->flag & BASE_SELECTED) == 0)) {
       ob = NULL;
     }
 
-    for (base = view_layer->object_bases.first; base; base = base->next) {
+    for (base = BKE_view_layer_object_bases_get(view_layer)->first; base; base = base->next) {
       if (!BASE_SELECTED_EDITABLE(v3d, base)) {
         continue;
       }
@@ -1103,6 +1105,7 @@ static void gizmo_prepare_mat(const bContext *C,
           /* pass */
         }
         else {
+          BKE_view_layer_synced_ensure(scene, view_layer);
           Object *ob = BKE_view_layer_active_object_get(view_layer);
           if (ob != NULL) {
             if ((ob->mode & OB_MODE_ALL_SCULPT) && ob->sculpt) {
diff --git a/source/blender/editors/transform/transform_orientations.c b/source/blender/editors/transform/transform_orientations.c
index 89c5e62d799..212df5978e4 100644
--- a/source/blender/editors/transform/transform_orientations.c
+++ b/source/blender/editors/transform/transform_orientations.c
@@ -476,6 +476,7 @@ void ED_transform_calc_orientation_from_type(const bContext *C, float r_mat[3][3
   Object *obedit = CTX_data_edit_object(C);
   View3D *v3d = CTX_wm_view3d(C);
   RegionView3D *rv3d = region->regiondata;
+  BKE_view_layer_synced_ensure(scene, view_layer);
   Object *ob = BKE_view_layer_active_object_get(view_layer);
   const short orient_index = BKE_scene_orientation_get_index(scene, SCE_ORIENT_DEFAULT);
   const int pivot_point = scene->toolsettings->transform_pivot_point;
@@ -744,7 +745,7 @@ static uint bm_mesh_faces_select_get_n(BMesh *bm, BMVert **elems, const uint n)
 }
 #endif
 
-int getTransformOrientation_ex(const Scene *UNUSED(scene),
+int getTransformOrientation_ex(const Scene *scene,
                                ViewLayer *view_layer,
                                const View3D *v3d,
                                struct Object *ob,
@@ -1253,6 +1254,7 @@ int getTransformOrientation_ex(const Scene *UNUSED(scene),
         ok = true;
       }
       else {
+        BKE_view_layer_synced_ensure(scene, view_layer);
         Base *base = BKE_view_layer_base_find(view_layer, ob);
         if (UNLIKELY(base == NULL)) {
           /* This is very unlikely, if it happens allow the value to be set since the caller
diff --git a/source/blender/editors/transform/transform_snap.c b/source/blender/editors/transform/transform_snap.c
index f1f3181d34f..b47592b61cd 100644
--- a/source/blender/editors/transform/transform_snap.c
+++ b/source/blender/editors/transform/transform_snap.c
@@ -722,8 +722,8 @@ static eSnapMode snap_mode_from_spacetype(TransInfo *t)
 
 static eSnapTargetSelect snap_target_select_from_spacetype(TransInfo *t)
 {
-  ViewLayer *view_layer = t->view_layer;
-  Base *base_act = view_layer->basact;
+  BKE_view_layer_synced_ensure(t->scene, t->view_layer);
+  Base *base_act = BKE_view_layer_active_base_get(t->view_layer);
 
   eSnapTargetSelect ret = SCE_SNAP_TARGET_ALL;
 
@@ -960,7 +960,8 @@ static void setSnappingCallback(TransInfo *t)
   }
   else if (t->spacetype == SPACE_IMAGE) {
     SpaceImage *sima = t->area->spacedata.first;
-    Object *obact = t->view_layer->basact ? t->view_layer->basact->object : NULL;
+    BKE_view_layer_synced_ensure(t->scene, t->view_layer);
+    Object *obact = BKE_view_layer_active_object_get(t->view_layer);
 
     const bool is_uv_editor = sima->mode == SI_MODE_UV;
     const bool has_edit_object = obact && BKE_object_is_in_editmode(obact);
diff --git a/source/blender/editors/transform/transform_snap_object.cc b/source/blender/editors/transform/transform_snap_object.cc
index c72511d213d..503452b312e 100644
--- a/source/blender/editors/transform/transform_snap_object.cc
+++ b/source/blender/editors/transform/transform_snap_object.cc
@@ -543,11 +543,13 @@ static void iter_snap_objects(SnapObjectContext *sctx,
                               IterSnapObjsCallback sob_callback,
                               void *data)
 {
+  Scene *scene = DEG_get_input_scene(sctx->runtime.depsgraph);
   ViewLayer *view_layer = DEG_get_input_view_layer(sctx->runtime.depsgraph);
   const eSnapTargetSelect snap_target_select = params->snap_target_select;
-  Base *base_act = view_layer->basact;
+  BKE_view_layer_synced_ensure(scene, view_layer);
+  Base *base_act = BKE_view_layer_active_base_get(view_layer);
 
-  LISTBASE_FOREACH (Base *, base, &view_layer->object_bases) {
+  LISTBASE_FOREACH (Base *, base, BKE_view_layer_object_bases_get(view_layer)) {
     if (!snap_object_is_snappable(sctx, snap_target_select, base_act, base)) {
       continue;
     }