2ead3874f5
The idea is that the state of the MetaCompositorView shall be up-to-date only in specific scenarios, thus allowing operations performed on it to be queued and aggregated to be handled in the right time, and only if they are still necessary. For example, in a following commit, the top window actor in each view will be planned (if needed) only once before painting a frame, rendering the top window actor in the MetaCompositorView potentially stale in all other times. Similarly, if a MetaCompositorView is destroyed before the beginning of the frame, a queued operation to update its top window actor can be discarded. As an interface segragation measure, and as part of an attempt to avoid the use of g_return_if_fail () to check the validity of the MetaCompositorView's state in multiple places (which is still prone to human error), the interfaces through which a MetaCompositorView is made available would only ones where it's state is gurenteed to be up-to-date. Specifically, this commit gurentees that the state of the MetaCompositorView would be up-to-date during the before_paint () and after_paint () vfuncs exposed to child classes of the MetaCompositor. The frame_in_progress variable will be used in a following commit to guarantee that the MetaCompositorView's state is not invalidated during this time. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2526>
Mutter
Mutter is a Wayland display server and X11 window manager and compositor library.
When used as a Wayland display server, it runs on top of KMS and libinput. It implements the compositor side of the Wayland core protocol as well as various protocol extensions. It also has functionality related to running X11 applications using Xwayland.
When used on top of Xorg it acts as a X11 window manager and compositing manager.
It contains functionality related to, among other things, window management, window compositing, focus tracking, workspace management, keybindings and monitor configuration.
Internally it uses a fork of Cogl, a hardware acceleration abstraction library used to simplify usage of OpenGL pipelines, as well as a fork of Clutter, a scene graph and user interface toolkit.
Mutter is used by, for example, GNOME Shell, the GNOME core user interface, and by Gala, elementary OS's window manager. It can also be run standalone, using the command "mutter", but just running plain mutter is only intended for debugging purposes.
Contributing
To contribute, open merge requests at https://gitlab.gnome.org/GNOME/mutter.
It can be useful to look at the documentation available at the Wiki.
The API documentation is available at:
- Meta: https://gnome.pages.gitlab.gnome.org/mutter/meta/
- Clutter: https://gnome.pages.gitlab.gnome.org/mutter/clutter/
- Cally: https://gnome.pages.gitlab.gnome.org/mutter/cally/
- Cogl: https://gnome.pages.gitlab.gnome.org/mutter/cogl/
- CoglPango: https://gnome.pages.gitlab.gnome.org/mutter/cogl-pango/
Coding style and conventions
See HACKING.md.
Git messages
Commit messages should follow the GNOME commit message
guidelines. We require an URL
to either an issue or a merge request in each commit. Try to always prefix
commit subjects with a relevant topic, such as compositor: or
clutter/actor:, and it's always better to write too much in the commit
message body than too little.
Default branch
The default development branch is main. If you still have a local
checkout under the old name, use:
git checkout master
git branch -m master main
git fetch
git branch --unset-upstream
git branch -u origin/main
git symbolic-ref refs/remotes/origin/HEAD refs/remotes/origin/main
License
Mutter is distributed under the terms of the GNU General Public License, version 2 or later. See the COPYING file for detalis.