6e8c7c5f84
Allow scale-aware Xwayland clients to scale by an integer scale themselves, instead of letting them render them at 1x scale and then scaling up the texture, making it look blurry. When monitor framebuffers are scaled, this special cases Xwayland and sends output regions in a way that Xwayland think everything is N times as large as the logical region, where N is the ceil of the max monitor scale. This is done by introducing a "stage" vs "protocol" coordinate space for X11, where the "protocol" coordinate space is "stage" multiplied by a scaling factor. Xwayland thus will have its own "effective scale", sent via wl_output.scale. The effective Xwayland scale is also used for the internal MetaWaylandSurface scale internally, unless there is a viewport dst size set on the same surface, in which case the scale is still set to 1, to not interfere with wp_viewport semantics. We're guarding this behind a new experimental feature "xwayland-native-scaling", which can only come into effect when enabled together with "scale-monitor-framebuffer". [v2]: Move stage_to_protocol/protocol_to_stage to generic window class. This means parts that aren't aware of any windowing system specific logic, only that coordinates originate from there for a given window, can still get their coordinates properly handled. In particular, this means coordinates from IBus that originates from the client, can be scaled properly when that client is using X11. Also make them properly introspected. [v3]: Split up coordinate transform API. Make it one that takes a MtkRectangle, and another that takes a point. This means the rounding strategy becames explicit when transforming a point, while when it's a rectangle, it's still always "grow". Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3567>
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 first look at the GNOME Handbook and the documentation and API references below first.
Documentation
- Coding style and conventions
- Git conventions
- Code overview
- Building and Running
- Debugging
- Monitor configuration
API Reference
- Meta: https://mutter.gnome.org/meta/
- Clutter: https://mutter.gnome.org/clutter/
- Cogl: https://mutter.gnome.org/cogl/
- CoglPango: https://mutter.gnome.org/cogl-pango/
- Mtk: https://mutter.gnome.org/mtk/
Meetings
There are recurring meetings to discuss development of GNOME Shell, mutter and related components.
License
Mutter is distributed under the terms of the GNU General Public License, version 2 or later. See the COPYING file for detalis.