mutter/clutter
Jonas Dreßler 3d17e8d590 clutter/actor: Properly invalidate cached paint volumes of actors
The priv->paint_volume field of ClutterActor stores the cached paint
volume in the actors local coordinate system. It consist of the actors
paint volume itself and the union of all children paint volumes.

We want to invalidate those cached paint volumes according to the
following rules:

- If an actors transformation matrix changes, all paint volumes of the
parent-tree need to be invalidated (that's because the parent-volumes
have unioned the actors paint volume). Our own paint volume does not
need invalidation since the transformation matrix is not applied to it.

- If an actors allocation-size changes, its own paint volume and all the
volumes of the parent-tree need to be invalidated. That's because the
allocation-size is used as the size of the paint volume.

- If a clip gets set or clip_to_allocation gets enabled for an actor,
its own paint volume and all the volumes of the parent-tree need to be
invalidated. That's because the clip is factored in when creating the
paint volume.

So far we did this invalidation in various places and the invalidation
up the parent-tree happened inside clutter_actor_real_queue_relayout().
We did not invalidate on changes to the actors transformation matrices
and the invalidation in clutter_actor_real_queue_relayout() was more
like a "big hammer" that probably invalidated unnecessarily a few times.

So introduce proper infrastructure to invalidate those cached paint
volumes of actors only in the cases where they actually need to be
invalidated. To do that, we reuse the transform_changed() function and
introduce a new function queue_update_paint_volume() that invalidates
the paint volumes up the actor tree.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1773>
2021-04-12 15:18:31 +00:00
..
clutter clutter/actor: Properly invalidate cached paint volumes of actors 2021-04-12 15:18:31 +00:00
.gitignore clutter: Remove clutter specific version 2018-11-06 17:17:36 +01:00
meson.build clutter: Include semi private cogl API 2020-07-02 19:36:50 +02:00