[Bf-blender-cvs] [581fb2da10a] master: LibLink/Append: tweak instantiation of collections in viewlayers.

[Bastien Montagne]

Commit: 581fb2da10a6143bab2ac1538d4eed9f910aec2a
Author: Bastien Montagne
Date:   Tue Nov 30 15:48:09 2021 +0100
Branches: master
https://developer.blender.org/rB581fb2da10a6143bab2ac1538d4eed9f910aec2a

LibLink/Append: tweak instantiation of collections in viewlayers.

When appended collections are instantiated in viewlayers, do not add to
viewlayers collections children of other instantiated collections.

This default behavior is required for proper copy/paste behavior. If
previous behavior needs to be brought back for regular append operation,
this can be decided and done, but think this default behavior also makes
sense in normal append case.

part of T91414: Unify link/append between WM operators and BPY context
manager API, and cleanup usages of `BKE_library_make_local`.

===================================================================

M	source/blender/blenkernel/intern/blendfile_link_append.c

===================================================================

diff --git a/source/blender/blenkernel/intern/blendfile_link_append.c b/source/blender/blenkernel/intern/blendfile_link_append.c
index 933083efe40..e52988f775d 100644
--- a/source/blender/blenkernel/intern/blendfile_link_append.c
+++ b/source/blender/blenkernel/intern/blendfile_link_append.c
@@ -570,6 +570,22 @@ static void loose_data_instantiate_obdata_preprocess(
   }
 }
 
+/* Test whether some ancestor collection is also tagged for instantiation (return true) or not
+ * (return false). */
+static bool loose_data_instantiate_collection_parents_check_recursive(Collection *collection)
+{
+  for (CollectionParent *parent_collection = collection->parents.first; parent_collection != NULL;
+       parent_collection = parent_collection->next) {
+    if ((parent_collection->collection->id.tag & LIB_TAG_DOIT) != 0) {
+      return true;
+    }
+    if (loose_data_instantiate_collection_parents_check_recursive(parent_collection->collection)) {
+      return true;
+    }
+  }
+  return false;
+}
+
 static void loose_data_instantiate_collection_process(
     LooseDataInstantiateContext *instantiate_context)
 {
@@ -580,9 +596,13 @@ static void loose_data_instantiate_collection_process(
   const View3D *v3d = lapp_context->params->context.v3d;
 
   const bool do_append = (lapp_context->params->flag & FILE_LINK) == 0;
+  const bool do_instantiate_as_empty = (lapp_context->params->flag &
+                                        BLO_LIBLINK_COLLECTION_INSTANCE) != 0;
 
   /* NOTE: For collections we only view_layer-instantiate duplicated collections that have
-   * non-instantiated objects in them. */
+   * non-instantiated objects in them.
+   * NOTE: Also avoid viewlayer-instantiating of collections children of other instantiated
+   * collections. This is why we need two passes here. */
   LinkNode *itemlink;
   for (itemlink = lapp_context->items.list; itemlink; itemlink = itemlink->next) {
     BlendfileLinkAppendContextItem *item = itemlink->link;
@@ -591,7 +611,7 @@ static void loose_data_instantiate_collection_process(
       continue;
     }
 
-    /* We do not want to force instantiation of indirectly appended collections. Users can now
+    /* Forced instantiation of indirectly appended collections is not wanted. Users can now
      * easily instantiate collections (and their objects) as needed by themselves. See T67032. */
     /* We need to check that objects in that collections are already instantiated in a scene.
      * Otherwise, it's better to add the collection to the scene's active collection, than to
@@ -601,9 +621,9 @@ static void loose_data_instantiate_collection_process(
      * children.
      */
     Collection *collection = (Collection *)id;
-    /* We always add collections directly selected by the user. */
+    /* Always consider adding collections directly selected by the user. */
     bool do_add_collection = (item->tag & LINK_APPEND_TAG_INDIRECT) == 0;
-    /* In linking case, we do not enforce instantiating non-directly linked collections/objects.
+    /* In linking case, do not enforce instantiating non-directly linked collections/objects.
      * This avoids cluttering the ViewLayers, user can instantiate themselves specific collections
      * or objects easily from the Outliner if needed. */
     if (!do_add_collection && do_append) {
@@ -615,17 +635,38 @@ static void loose_data_instantiate_collection_process(
         }
       }
     }
-    if (!do_add_collection) {
+    if (do_add_collection) {
+      collection->id.tag |= LIB_TAG_DOIT;
+    }
+  }
+
+  /* Second loop to actually instantiate collections tagged as such in first loop, unless some of
+   * their ancestor is also instantiated in case this is not an empty-instantiation. */
+  for (itemlink = lapp_context->items.list; itemlink; itemlink = itemlink->next) {
+    BlendfileLinkAppendContextItem *item = itemlink->link;
+    ID *id = loose_data_instantiate_process_check(instantiate_context, item);
+    if (id == NULL || GS(id->name) != ID_GR) {
+      continue;
+    }
+
+    Collection *collection = (Collection *)id;
+    bool do_add_collection = (id->tag & LIB_TAG_DOIT) != 0;
+
+    /* When instantiated into viewlayer, do not add collections if one of their parents is also
+     * instantiated. In case of empty-instantiation though, instantiation of all user-selected
+     * collections is the desired behavior. */
+    if (!do_add_collection ||
+        (!do_instantiate_as_empty &&
+         loose_data_instantiate_collection_parents_check_recursive(collection))) {
       continue;
     }
 
     loose_data_instantiate_ensure_active_collection(instantiate_context);
     Collection *active_collection = instantiate_context->active_collection;
 
-    /* In case user requested instantiation of collections as empties, we do so for the one they
+    /* In case user requested instantiation of collections as empties, do so for the one they
      * explicitly selected (originally directly linked IDs) only. */
-    if ((lapp_context->params->flag & BLO_LIBLINK_COLLECTION_INSTANCE) != 0 &&
-        (item->tag & LINK_APPEND_TAG_INDIRECT) == 0) {
+    if (do_instantiate_as_empty && (item->tag & LINK_APPEND_TAG_INDIRECT) == 0) {
       /* BKE_object_add(...) messes with the selection. */
       Object *ob = BKE_object_add_only_object(bmain, OB_EMPTY, collection->id.name + 2);
       ob->type = OB_EMPTY;