Refactor: Remove `BKE_XXX_localize()`, in favor of using regular ID copying code.

Besides the NodeTree case (which remains unchanged), the localize code
is only used in one place (to generate previews of shading data-blocks).

This commit introduces a new `LIB_ID_CREATE_LOCAL` option for ID
creation/copying, which essentially implements the behavior of the
removed `BKE_XXX_localize()` functions into regular mainstream ID copy
code. When this option is set:
- new ID is tagged with `LIB_TAG_LOCALIZED`;
- Some ID copying callbacks have specific behaviors, mainly the root
  nodetree of shading IDs gets duplicated with specialized
  `ntreeLocalize()` function.

Note that I would not consider getting rid of `ntreeLocalize` for now,
this function is recursive, which should ideally never happen within ID
management copying code (this introduces all kind of complications).

No behavioral change expected from this commit.

1 files changed, 6 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/lib_id.c b/source/blender/blenkernel/intern/lib_id.c
index 8f3d05ce914..fd127f5871f 100644
--- a/source/blender/blenkernel/intern/lib_id.c
+++ b/source/blender/blenkernel/intern/lib_id.c
@@ -1035,6 +1035,8 @@ void *BKE_libblock_alloc_notest(short type)
 void *BKE_libblock_alloc(Main *bmain, short type, const char *name, const int flag)
 {
   BLI_assert((flag & LIB_ID_CREATE_NO_ALLOCATE) == 0);
+  BLI_assert((flag & LIB_ID_CREATE_NO_MAIN) != 0 || bmain != NULL);
+  BLI_assert((flag & LIB_ID_CREATE_NO_MAIN) != 0 || (flag & LIB_ID_CREATE_LOCAL) == 0);
 
   ID *id = BKE_libblock_alloc_notest(type);
 
@@ -1045,6 +1047,9 @@ void *BKE_libblock_alloc(Main *bmain, short type, const char *name, const int fl
     if ((flag & LIB_ID_CREATE_NO_USER_REFCOUNT) != 0) {
       id->tag |= LIB_TAG_NO_USER_REFCOUNT;
     }
+    if (flag & LIB_ID_CREATE_LOCAL) {
+      id->tag |= LIB_TAG_LOCALIZED;
+    }
 
     id->icon_id = 0;
     *((short *)id->name) = type;
@@ -1180,6 +1185,7 @@ void BKE_libblock_copy_ex(Main *bmain, const ID *id, ID **r_newid, const int ori
 
   BLI_assert((flag & LIB_ID_CREATE_NO_MAIN) != 0 || bmain != NULL);
   BLI_assert((flag & LIB_ID_CREATE_NO_MAIN) != 0 || (flag & LIB_ID_CREATE_NO_ALLOCATE) == 0);
+  BLI_assert((flag & LIB_ID_CREATE_NO_MAIN) != 0 || (flag & LIB_ID_CREATE_LOCAL) == 0);
   if (!is_private_id_data) {
     /* When we are handling private ID data, we might still want to manage usercounts, even
      * though that ID data-block is actually outside of Main... */