14c706e51b
Currently, Clutter does picking by drawing with Cogl and reading the pixel that's beneath the given point. Since Cogl has a journal that records drawing operations, and has optimizations to read a single pixel from a list of rectangle, it would be expected that we would hit this fast path and not flush the journal while picking. However, that's not the case: dithering, clipping with scissors, etc, can all flush the journal, issuing commands to the GPU and making picking slow. On NVidia-based systems, this glReadPixels() call is extremely costly. Introduce geometric picking, and avoid using the Cogl journal entirely. Do this by introducing a stack of actors in ClutterStage. This stack is cached, but for now, don't use the cache as much as possible. The picking routines are still tied to painting. When projecting the actor vertexes, do it manually and take the modelview matrix of the framebuffer into account as well. CPU usage on an Intel i7-7700, tested with two different GPUs/drivers: | | Intel | Nvidia | | ------: | --------: | -----: | | Moving the mouse: | | Before | 10% | 10% | | After | 6% | 6% | | Moving a window: | | Before | 23% | 81% | | After | 19% | 40% | Closes: https://gitlab.gnome.org/GNOME/mutter/issues/154, https://gitlab.gnome.org/GNOME/mutter/issues/691 Helps significantly with: https://gitlab.gnome.org/GNOME/mutter/issues/283, https://gitlab.gnome.org/GNOME/mutter/issues/590, https://gitlab.gnome.org/GNOME/mutter/issues/700 v2: Fix code style issues Simplify quadrilateral checks Remove the 0.5f hack Differentiate axis-aligned rectangles https://gitlab.gnome.org/GNOME/mutter/merge_requests/189 |
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| cogl | ||
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| meson | ||
| po | ||
| src | ||
| 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.
The coding style used is primarily the GNU flavor of the GNOME coding
style
with some minor additions such as preferring stdint.h types over GLib
fundamental types, and a soft 80 character line limit. However, in general,
look at the file you're editing for inspiration.
Commit messages should follow the GNOME commit message guidelines. We require an URL to either an issue or a merge request in each commit.
License
Mutter is distributed under the terms of the GNU General Public License, version 2 or later. See the COPYING file for detalis.