Refactor BKE_bpath module.

The main goal of this refactor is to make BPath module use `IDTypeInfo`,
and move each ID-specific part of the `foreach_path` looper into their
own IDTypeInfo struct, using a new `foreach_path` callback.

Additionally, following improvements/cleanups are included:
* Attempt to get better, more consistent namings.
** In particular, move from `path_visitor` to more standard `foreach_path`.
* Update and extend documentation.
** API doc was moved to header, according to recent discussions on this
   topic.
* Remove `BKE_bpath_relocate_visitor` from API, this is specific
  callback that belongs in `lib_id.c` user code.

NOTE: This commit is expected to be 100% non-behavioral-change. This
implies that several potential further changes were only noted as
comments (like using a more generic solution for
`lib_id_library_local_paths`, addressing inconsistencies like path of
packed libraries always being skipped, regardless of the
`BKE_BPATH_FOREACH_PATH_SKIP_PACKED` `eBPathForeachFlag` flag value,
etc.).

NOTE: basic unittests were added to master already in
rBdcc500e5a265093bc9cc.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D13381

1 files changed, 1 insertions, 0 deletions

diff --git a/source/blender/makesdna/DNA_scene_types.h b/source/blender/makesdna/DNA_scene_types.h
index 634e97f782f..c66ac3a6211 100644
--- a/source/blender/makesdna/DNA_scene_types.h
+++ b/source/blender/makesdna/DNA_scene_types.h
@@ -720,6 +720,7 @@ typedef struct RenderData {
 
   /* path to render output */
   /** 1024 = FILE_MAX. */
+  /* NOTE: Excluded from `BKE_bpath_foreach_path_` / `scene_foreach_path` code. */
   char pic[1024];
 
   /* stamps flags. */