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.

5 files changed, 46 insertions, 135 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... */
diff --git a/source/blender/blenkernel/intern/light.c b/source/blender/blenkernel/intern/light.c
index 1ce079b006e..437e61a5fca 100644
--- a/source/blender/blenkernel/intern/light.c
+++ b/source/blender/blenkernel/intern/light.c
@@ -81,13 +81,21 @@ static void light_copy_data(Main *bmain, ID *id_dst, const ID *id_src, const int
 {
   Light *la_dst = (Light *)id_dst;
   const Light *la_src = (const Light *)id_src;
+
+  const bool is_localized = (flag & LIB_ID_CREATE_LOCAL) != 0;
   /* We always need allocation of our private ID data. */
   const int flag_private_id_data = flag & ~LIB_ID_CREATE_NO_ALLOCATE;
 
   la_dst->curfalloff = BKE_curvemapping_copy(la_src->curfalloff);
 
   if (la_src->nodetree) {
-    BKE_id_copy_ex(bmain, (ID *)la_src->nodetree, (ID **)&la_dst->nodetree, flag_private_id_data);
+    if (is_localized) {
+      la_dst->nodetree = ntreeLocalize(la_src->nodetree);
+    }
+    else {
+      BKE_id_copy_ex(
+          bmain, (ID *)la_src->nodetree, (ID **)&la_dst->nodetree, flag_private_id_data);
+    }
   }
 
   if ((flag & LIB_ID_COPY_NO_PREVIEW) == 0) {
@@ -219,33 +227,6 @@ Light *BKE_light_copy(Main *bmain, const Light *la)
   return la_copy;
 }
 
-Light *BKE_light_localize(Light *la)
-{
-  /* TODO(bastien): Replace with something like:
-   *
-   *   Light *la_copy;
-   *   BKE_id_copy_ex(bmain, &la->id, (ID **)&la_copy,
-   *                  LIB_ID_COPY_NO_MAIN | LIB_ID_COPY_NO_PREVIEW | LIB_ID_COPY_NO_USER_REFCOUNT,
-   *                  false);
-   *   return la_copy;
-   *
-   * NOTE: Only possible once nested node trees are fully converted to that too. */
-
-  Light *lan = BKE_libblock_copy_for_localize(&la->id);
-
-  lan->curfalloff = BKE_curvemapping_copy(la->curfalloff);
-
-  if (la->nodetree) {
-    lan->nodetree = ntreeLocalize(la->nodetree);
-  }
-
-  lan->preview = NULL;
-
-  lan->id.tag |= LIB_TAG_LOCALIZED;
-
-  return lan;
-}
-
 void BKE_light_eval(struct Depsgraph *depsgraph, Light *la)
 {
   DEG_debug_print_eval(depsgraph, __func__, la->id.name, la);
diff --git a/source/blender/blenkernel/intern/material.c b/source/blender/blenkernel/intern/material.c
index d8c0b5d6dce..8c09cb551a1 100644
--- a/source/blender/blenkernel/intern/material.c
+++ b/source/blender/blenkernel/intern/material.c
@@ -100,12 +100,20 @@ static void material_copy_data(Main *bmain, ID *id_dst, const ID *id_src, const
   Material *material_dst = (Material *)id_dst;
   const Material *material_src = (const Material *)id_src;
 
+  const bool is_localized = (flag & LIB_ID_CREATE_LOCAL) != 0;
   /* We always need allocation of our private ID data. */
   const int flag_private_id_data = flag & ~LIB_ID_CREATE_NO_ALLOCATE;
 
-  if (material_src->nodetree) {
-    BKE_id_copy_ex(
-        bmain, (ID *)material_src->nodetree, (ID **)&material_dst->nodetree, flag_private_id_data);
+  if (material_src->nodetree != NULL) {
+    if (is_localized) {
+      material_dst->nodetree = ntreeLocalize(material_src->nodetree);
+    }
+    else {
+      BKE_id_copy_ex(bmain,
+                     (ID *)material_src->nodetree,
+                     (ID **)&material_dst->nodetree,
+                     flag_private_id_data);
+    }
   }
 
   if ((flag & LIB_ID_COPY_NO_PREVIEW) == 0) {
@@ -116,7 +124,8 @@ static void material_copy_data(Main *bmain, ID *id_dst, const ID *id_src, const
   }
 
   if (material_src->texpaintslot != NULL) {
-    material_dst->texpaintslot = MEM_dupallocN(material_src->texpaintslot);
+    /* TODO: Think we can also skip copying this data in the more generic `NO_MAIN` case? */
+    material_dst->texpaintslot = is_localized ? NULL : MEM_dupallocN(material_src->texpaintslot);
   }
 
   if (material_src->gp_style != NULL) {
@@ -315,41 +324,6 @@ Material *BKE_material_copy(Main *bmain, const Material *ma)
   return ma_copy;
 }
 
-/* XXX (see above) material copy without adding to main dbase */
-Material *BKE_material_localize(Material *ma)
-{
-  /* TODO(bastien): Replace with something like:
-   *
-   *   Material *ma_copy;
-   *   BKE_id_copy_ex(bmain, &ma->id, (ID **)&ma_copy,
-   *                  LIB_ID_COPY_NO_MAIN | LIB_ID_COPY_NO_PREVIEW | LIB_ID_COPY_NO_USER_REFCOUNT,
-   *                  false);
-   *   return ma_copy;
-   *
-   * NOTE: Only possible once nested node trees are fully converted to that too. */
-
-  Material *man = BKE_libblock_copy_for_localize(&ma->id);
-
-  man->texpaintslot = NULL;
-  man->preview = NULL;
-
-  if (ma->nodetree != NULL) {
-    man->nodetree = ntreeLocalize(ma->nodetree);
-  }
-
-  if (ma->gp_style != NULL) {
-    man->gp_style = MEM_dupallocN(ma->gp_style);
-  }
-
-  BLI_listbase_clear(&man->gpumaterial);
-
-  /* TODO Duplicate Engine Settings and set runtime to NULL */
-
-  man->id.tag |= LIB_TAG_LOCALIZED;
-
-  return man;
-}
-
 Material ***BKE_object_material_array_p(Object *ob)
 {
   if (ob->type == OB_MESH) {
diff --git a/source/blender/blenkernel/intern/texture.c b/source/blender/blenkernel/intern/texture.c
index b74b7d57b2e..4d113597745 100644
--- a/source/blender/blenkernel/intern/texture.c
+++ b/source/blender/blenkernel/intern/texture.c
@@ -87,6 +87,7 @@ static void texture_copy_data(Main *bmain, ID *id_dst, const ID *id_src, const i
   Tex *texture_dst = (Tex *)id_dst;
   const Tex *texture_src = (const Tex *)id_src;
 
+  const bool is_localized = (flag & LIB_ID_CREATE_LOCAL) != 0;
   /* We always need allocation of our private ID data. */
   const int flag_private_id_data = flag & ~LIB_ID_CREATE_NO_ALLOCATE;
 
@@ -101,8 +102,14 @@ static void texture_copy_data(Main *bmain, ID *id_dst, const ID *id_src, const i
     if (texture_src->nodetree->execdata) {
       ntreeTexEndExecTree(texture_src->nodetree->execdata);
     }
-    BKE_id_copy_ex(
-        bmain, (ID *)texture_src->nodetree, (ID **)&texture_dst->nodetree, flag_private_id_data);
+
+    if (is_localized) {
+      texture_dst->nodetree = ntreeLocalize(texture_src->nodetree);
+    }
+    else {
+      BKE_id_copy_ex(
+          bmain, (ID *)texture_src->nodetree, (ID **)&texture_dst->nodetree, flag_private_id_data);
+    }
   }
 
   if ((flag & LIB_ID_COPY_NO_PREVIEW) == 0) {
@@ -455,40 +462,6 @@ Tex *BKE_texture_copy(Main *bmain, const Tex *tex)
   return tex_copy;
 }
 
-/* texture copy without adding to main dbase */
-Tex *BKE_texture_localize(Tex *tex)
-{
-  /* TODO(bastien): Replace with something like:
-   *
-   *   Tex *tex_copy;
-   *   BKE_id_copy_ex(bmain, &tex->id, (ID **)&tex_copy,
-   *                  LIB_ID_COPY_NO_MAIN | LIB_ID_COPY_NO_PREVIEW | LIB_ID_COPY_NO_USER_REFCOUNT,
-   *                  false);
-   *   return tex_copy;
-   *
-   * NOTE: Only possible once nested node trees are fully converted to that too. */
-
-  Tex *texn;
-
-  texn = BKE_libblock_copy_for_localize(&tex->id);
-
-  /* image texture: texture_free_data also doesn't decrease */
-
-  if (texn->coba) {
-    texn->coba = MEM_dupallocN(texn->coba);
-  }
-
-  texn->preview = NULL;
-
-  if (tex->nodetree) {
-    texn->nodetree = ntreeLocalize(tex->nodetree);
-  }
-
-  texn->id.tag |= LIB_TAG_LOCALIZED;
-
-  return texn;
-}
-
 /* ------------------------------------------------------------------------- */
 
 Tex *give_current_linestyle_texture(FreestyleLineStyle *linestyle)
diff --git a/source/blender/blenkernel/intern/world.c b/source/blender/blenkernel/intern/world.c
index d5142e2d1a4..7590afeaaff 100644
--- a/source/blender/blenkernel/intern/world.c
+++ b/source/blender/blenkernel/intern/world.c
@@ -99,12 +99,19 @@ static void world_copy_data(Main *bmain, ID *id_dst, const ID *id_src, const int
 {
   World *wrld_dst = (World *)id_dst;
   const World *wrld_src = (const World *)id_src;
+
+  const bool is_localized = (flag & LIB_ID_CREATE_LOCAL) != 0;
   /* We always need allocation of our private ID data. */
   const int flag_private_id_data = flag & ~LIB_ID_CREATE_NO_ALLOCATE;
 
   if (wrld_src->nodetree) {
-    BKE_id_copy_ex(
-        bmain, (ID *)wrld_src->nodetree, (ID **)&wrld_dst->nodetree, flag_private_id_data);
+    if (is_localized) {
+      wrld_dst->nodetree = ntreeLocalize(wrld_src->nodetree);
+    }
+    else {
+      BKE_id_copy_ex(
+          bmain, (ID *)wrld_src->nodetree, (ID **)&wrld_dst->nodetree, flag_private_id_data);
+    }
   }
 
   BLI_listbase_clear(&wrld_dst->gpumaterial);
@@ -210,36 +217,6 @@ World *BKE_world_add(Main *bmain, const char *name)
   return wrld;
 }
 
-World *BKE_world_localize(World *wrld)
-{
-  /* TODO(bastien): Replace with something like:
-   *
-   *   World *wrld_copy;
-   *   BKE_id_copy_ex(bmain, &wrld->id, (ID **)&wrld_copy,
-   *                  LIB_ID_COPY_NO_MAIN | LIB_ID_COPY_NO_PREVIEW | LIB_ID_COPY_NO_USER_REFCOUNT,
-   *                  false);
-   *   return wrld_copy;
-   *
-   * NOTE: Only possible once nested node trees are fully converted to that too. */
-
-  World *wrldn;
-
-  wrldn = BKE_libblock_copy_for_localize(&wrld->id);
-
-  if (wrld->nodetree) {
-    wrldn->nodetree = ntreeLocalize(wrld->nodetree);
-  }
-
-  wrldn->preview = NULL;
-
-  BLI_listbase_clear(&wrldn->gpumaterial);
-  BLI_listbase_clear((ListBase *)&wrldn->drawdata);
-
-  wrldn->id.tag |= LIB_TAG_LOCALIZED;
-
-  return wrldn;
-}
-
 void BKE_world_eval(struct Depsgraph *depsgraph, World *world)
 {
   DEG_debug_print_eval(depsgraph, __func__, world->id.name, world);