LibOverride: Abstract a bit handling of local items of RNA collections.

RNA collections that support insertion of new items in liboverride
data-block need a special way to distiguish between locale and
orig-from-linked items (since some operations are allowed on the forer,
but no the latter).

In future we want a proper solution to abstract that at the
`BKE_lib_override` level, but for now we need to add some code for each
case.

Note that this commit also fixes a few potential issues with GPencil
modifiers, and constraints, regarding their handling of local overrides.

6 files changed, 48 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_constraint.h b/source/blender/blenkernel/BKE_constraint.h
index 4b9f480e091..1589bff7501 100644
--- a/source/blender/blenkernel/BKE_constraint.h
+++ b/source/blender/blenkernel/BKE_constraint.h
@@ -177,6 +177,9 @@ struct bConstraint *BKE_constraint_find_from_target(struct Object *ob,
                                                     struct bConstraintTarget *tgt,
                                                     struct bPoseChannel **r_pchan);
 
+bool BKE_constraint_is_local_in_liboverride(const struct Object *ob,
+                                            const struct bConstraint *con);
+
 struct bConstraint *BKE_constraint_add_for_object(struct Object *ob, const char *name, short type);
 struct bConstraint *BKE_constraint_add_for_pose(struct Object *ob,
                                                 struct bPoseChannel *pchan,
diff --git a/source/blender/blenkernel/BKE_gpencil_modifier.h b/source/blender/blenkernel/BKE_gpencil_modifier.h
index 7729d2c53ab..bdc583048b8 100644
--- a/source/blender/blenkernel/BKE_gpencil_modifier.h
+++ b/source/blender/blenkernel/BKE_gpencil_modifier.h
@@ -278,6 +278,9 @@ void BKE_gpencil_modifiers_foreach_tex_link(struct Object *ob,
                                             GreasePencilTexWalkFunc walk,
                                             void *userData);
 
+bool BKE_gpencil_modifier_is_local_in_liboverride(const struct Object *ob,
+                                                  const struct GpencilModifierData *gmd);
+
 typedef struct GpencilVirtualModifierData {
   ArmatureGpencilModifierData amd;
   LatticeGpencilModifierData lmd;
diff --git a/source/blender/blenkernel/BKE_modifier.h b/source/blender/blenkernel/BKE_modifier.h
index b0a7d89e3d8..37f566d6f8e 100644
--- a/source/blender/blenkernel/BKE_modifier.h
+++ b/source/blender/blenkernel/BKE_modifier.h
@@ -431,6 +431,7 @@ bool BKE_modifier_is_non_geometrical(ModifierData *md);
 bool BKE_modifier_is_enabled(const struct Scene *scene,
                              struct ModifierData *md,
                              int required_mode);
+bool BKE_modifier_is_local_in_liboverride(const struct Object *ob, const struct ModifierData *md);
 void BKE_modifier_set_error(const struct Object *ob,
                             struct ModifierData *md,
                             const char *format,
diff --git a/source/blender/blenkernel/intern/constraint.c b/source/blender/blenkernel/intern/constraint.c
index 28121206a90..982e91dd1e0 100644
--- a/source/blender/blenkernel/intern/constraint.c
+++ b/source/blender/blenkernel/intern/constraint.c
@@ -5754,6 +5754,7 @@ bConstraint *BKE_constraint_duplicate_ex(bConstraint *src, const int flag, const
   bConstraint *dst = MEM_dupallocN(src);
   constraint_copy_data_ex(dst, src, flag, do_extern);
   dst->next = dst->prev = NULL;
+  dst->flag |= CONSTRAINT_OVERRIDE_LIBRARY_LOCAL;
   return dst;
 }
 
@@ -5788,6 +5789,7 @@ void BKE_constraints_copy_ex(ListBase *dst, const ListBase *src, const int flag,
   for (con = dst->first, srccon = src->first; con && srccon;
        srccon = srccon->next, con = con->next) {
     constraint_copy_data_ex(con, srccon, flag, do_extern);
+    con->flag |= CONSTRAINT_OVERRIDE_LIBRARY_LOCAL;
   }
 }
 
@@ -5954,6 +5956,19 @@ static bConstraint *constraint_find_original_for_update(bConstraintOb *cob, bCon
   return orig_con;
 }
 
+/**
+ * Check whether given constraint is local when the object is a library override.
+ *
+ * \param con May be NULL, in which case we consider it as a non-local constraint case.
+ *
+ * \note This check is only valid for a liboverride data-block, it always return \a true otherwise.
+ */
+bool BKE_constraint_is_local_in_liboverride(const Object *ob, const bConstraint *con)
+{
+  return (!ID_IS_OVERRIDE_LIBRARY(ob) ||
+          (con != NULL && (con->flag & CONSTRAINT_OVERRIDE_LIBRARY_LOCAL) != 0));
+}
+
 /* -------- Constraints and Proxies ------- */
 
 /* Rescue all constraints tagged as being CONSTRAINT_PROXY_LOCAL
diff --git a/source/blender/blenkernel/intern/gpencil_modifier.c b/source/blender/blenkernel/intern/gpencil_modifier.c
index 09f9e9e891c..7425a1a5f7a 100644
--- a/source/blender/blenkernel/intern/gpencil_modifier.c
+++ b/source/blender/blenkernel/intern/gpencil_modifier.c
@@ -531,6 +531,19 @@ void BKE_gpencil_modifier_set_error(GpencilModifierData *md, const char *_format
 }
 
 /**
+ * Check whether given modifier is local when the object is a library override.
+ *
+ * \param gmd May be NULL, in which case we consider it as a non-local modifier case.
+ *
+ * \note This check is only valid for a liboverride data-block, it always return \a true otherwise.
+ */
+bool BKE_gpencil_modifier_is_local_in_liboverride(const Object *ob, const GpencilModifierData *gmd)
+{
+  return (!ID_IS_OVERRIDE_LIBRARY(ob) ||
+          (gmd != NULL && (gmd->flag & eGpencilModifierFlag_OverrideLibrary_Local) != 0));
+}
+
+/**
  * Link grease pencil modifier related IDs.
  * \param ob: Grease pencil object
  * \param walk: Walk option
diff --git a/source/blender/blenkernel/intern/modifier.c b/source/blender/blenkernel/intern/modifier.c
index c9bdaecfa2a..7865d44c446 100644
--- a/source/blender/blenkernel/intern/modifier.c
+++ b/source/blender/blenkernel/intern/modifier.c
@@ -574,6 +574,19 @@ bool BKE_modifier_is_enabled(const struct Scene *scene, ModifierData *md, int re
   return true;
 }
 
+/**
+ * Check whether given modifier is local when the object is a library override.
+ *
+ * \param md May be NULL, in which case we consider it as a non-local modifier case.
+ *
+ * \note This check is only valid for a liboverride data-block, it always return \a true otherwise.
+ */
+bool BKE_modifier_is_local_in_liboverride(const Object *ob, const ModifierData *md)
+{
+  return (!ID_IS_OVERRIDE_LIBRARY(ob) ||
+          (md != NULL && (md->flag & eModifierFlag_OverrideLibrary_Local) != 0));
+}
+
 CDMaskLink *BKE_modifier_calc_data_masks(struct Scene *scene,
                                          Object *ob,
                                          ModifierData *md,