Use the `foreach_action_slot_use(id, callback)` iterator function to find
all action/slot uses of an ID. That already handles the action constraint,
and thus solves the issue.
Pull Request: https://projects.blender.org/blender/blender/pulls/128090
For an NLA strip to use a slotted Action, it needs to specify which slot
to use in that action. This is now handled by two new properties on the
strip in DNA & RNA: `action_slot_handle` and `action_slot_name`.
These serve the same purpose as their counterparts on the `AnimData`
struct.
Note that this commit does NOT add NLA evaluation support for slotted
Actions. It merely allows assigning them. Evaluation, tweak mode
support, etc. will be implemented in future commits.
Pull Request: https://projects.blender.org/blender/blender/pulls/127359
Rename 'Binding' to 'Slot'. The old term was causing all kind of
confusion, and 'slot' was considered to be a better term for the
intended functionality.
This commit breaks existing blend files that were using the new layered
Action for their animation. The animation data will be lost due to the
rename, as there is no versioning code or DNA renaming logic. At this
time the new system is still marked as experimental, so shouldn't be
used for anything serious anyway.
Pull Request: https://projects.blender.org/blender/blender/pulls/124170
Keep track of which IDs are animated by which Action Binding. This will
be necessary for display in the Action editor, where animation data that
is unrelated to the active object can be shown (when "show all bindings"
is on).
Note: animation evaluation will not be using this cache, at least not in
the near future. Potentially when we introduce animation-level
constraints this will change, but that's for the future.
The user cache isn't actually used in this commit. It will be used soon
in !122672.
Pull Request: https://projects.blender.org/blender/blender/pulls/123187
Pull Request: https://projects.blender.org/blender/blender/pulls/123187
