0320649a1c
It's currently possible that some last_paint_volumes don't get updated during a paint cycle, this can happen when a ClutterOffscreenEffect is used: The offscreen effect might skip painting the content and the children of an actor because it uses its own offscreened texture instead. This means the offscreen effect doesn't call clutter_actor_continue_paint(), and thus the the last_paint_volumes of the children won't be updated. Now one might think that isn't a problem, because as soon as a child changes it's size or position, the offscreened texture would get invalidated and clutter_actor_continue_paint() would get called. It's not that easy though: Because the last_paint_volume includes all the transformation matrices up to eye-coordinates, it has to be updated on any changes to matrices, which includes position/transformation changes to any actor up the hierarchy. Now that's where get into problems with the offscreen effect: In case of transformation changes to the offscreened actor or an actor up the hierarchy, the offscreened texture won't get invalidated (that makes sense, we can simply paint it transformed) and the last_paint_volumes won't get updated even though they should. This leaves us around with outdated last_paint_volumes where last_paint_volume_valid is still set to TRUE. It can cause issues with culling and clipped redraws. So fix that by ensuring that all children that would get painted by Clutter get their last_paint_volumes updated in case a ClutterEffect decided not to call clutter_actor_continue_paint(). This ignores the case where a paint() vfunc override does the same and doesn't call clutter_actor_paint() on children. Let's ignore this case for now, there shouldn't be any implementation which does that and ideally in a world that's painted solely by ClutterContent, we can get rid of that vfunc in the future. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1591> |
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| .gitlab/issue_templates | ||
| .gitlab-ci | ||
| clutter | ||
| cogl | ||
| data | ||
| doc | ||
| meson | ||
| po | ||
| src | ||
| subprojects | ||
| tools | ||
| .gitignore | ||
| .gitlab-ci.yml | ||
| config.h.meson | ||
| COPYING | ||
| meson_options.txt | ||
| meson.build | ||
| mutter.doap | ||
| NEWS | ||
| README.md | ||
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 af 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.
Coding style and conventions
The coding style used is primarily the GNU flavor of the GNOME coding style with some additions:
-
Use regular C types and
stdint.htypes instead of GLib fundamental types, except forgboolean, andguint/gulongfor GSource ids and signal handler ids. That means e.g.uint64_tinstead ofguint64,intinstead ofgint,unsigned intinstead ofguintif unsignedness is of importance,uint8_tinstead ofguchar, and so on. -
Try to to limit line length to 80 characters, although it's not a strict limit.
-
Usage of g_autofree and g_autoptr are encouraged. The style used is
g_autofree char *text = NULL;
g_autoptr (MetaSomeThing) thing = NULL;
text = g_strdup_printf ("The text: %d", a_number);
thing = g_object_new (META_TYPE_SOME_THING,
"text", text,
NULL);
thinger_use_thing (rocket, thing);
-
Declare variables at the top of the block they are used, but avoid non-trivial logic among variable declarations. Non-trivial logic can be getting a pointer that may be
NULL, any kind of math, or anything that may have side effects. -
Instead of boolean arguments in functions, prefer enums or flags when they're more expressive.
-
Use
g_new0()etc instead ofg_slice_new0(). -
Initialize and assign floating point variables (i.e.
floatordouble) using the formfloating_point = 3.14159orratio = 2.0.
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.
License
Mutter is distributed under the terms of the GNU General Public License, version 2 or later. See the COPYING file for detalis.