9ef3e70040
In commit c6901a8b, the frame clock reported time was changed from
simply reporting the time we ran the frame clock cycle to reporting a
smoothed value that increased by the frame interval each time it was
called.
However, this change caused some problems, such as:
https://gitlab.gnome.org/GNOME/gtk/-/merge_requests/1415
https://gitlab.gnome.org/GNOME/gtk/-/merge_requests/1416
https://gitlab.gnome.org/GNOME/gtk/-/merge_requests/1482
I think a lot of this is caused by the fact that we just overwrote the
old frame time with the smoothed, monotonous timestamp, breaking
some things that relied on knowing the actual time something happened.
This is a new approach to doing the smoothing that is more explicit.
The "frame_time" we store is the actual time we ran the update cycle,
and then we separately compute and store the derived smoothed time and
its period, allowing us to easily return a smoothed time at any time
by rounding the time difference to an integer number of frames.
The initial frame_time can be somewhat arbitrary, as it depends on the
first cycle which is not driven by the frame clock. But follow-up
cycles are typically tied to the the compositor sending the drawn
signal. It may happen that the initial frame is exactly in the middle
between two frames where jitter causes us to randomly round in
different directions when rounding to nearest frame. To fix this we
additionally do a quadratic convergence towards the "real" time,
during presentation driven clock cycles (i.e. when the frame times are
small).
GTK — The GTK toolkit
General information
GTK is a multi-platform toolkit for creating graphical user interfaces. Offering a complete set of widgets, GTK is suitable for projects ranging from small one-off projects to complete application suites.
GTK is free software and part of the GNU Project. However, the licensing terms for GTK, the GNU LGPL, allow it to be used by all developers, including those developing proprietary software, without any license fees or royalties.
The official download location
The official web site
The official developers blog
Discussion forum
Nightly documentation can be found at
- Gtk: https://gnome.pages.gitlab.gnome.org/gtk/gtk/
- Gdk: https://gnome.pages.gitlab.gnome.org/gtk/gdk/
- Gsk: https://gnome.pages.gitlab.gnome.org/gtk/gsk/
Building and installing
In order to build GTK you will need:
You will also need various dependencies, based on the platform you are building for:
If you are building the X11 backend, you will also need:
- Xlib, and the following X extensions:
- xrandr
- xrender
- xi
- xext
- xfixes
- xcursor
- xdamage
- xcomposite
- atk-bridge-2.0
If you are building the Wayland backend, you will also need:
- Wayland-client
- Wayland-protocols
- Wayland-cursor
- Wayland-EGL
Once you have all the necessary dependencies, you can build GTK by using Meson:
$ meson _build .
$ cd _build
$ ninja
You can run the test suite using:
$ meson test
And, finally, you can install GTK using:
$ sudo ninja install
Complete information about installing GTK+ and related libraries can be found in the file:
docs/reference/gtk/html/gtk-building.html
Or online
How to report bugs
Bugs should be reported on the issues page.
In the bug report please include:
-
Information about your system. For instance:
- which version of GTK you are using
- what operating system and version
- for Linux, which distribution
- if you built GTK, the list of options used to configure the build
And anything else you think is relevant.
-
How to reproduce the bug.
If you can reproduce it with one of the demo applications that are built in the demos/ subdirectory, on one of the test programs that are built in the tests/ subdirectory, that will be most convenient. Otherwise, please include a short test program that exhibits the behavior. As a last resort, you can also provide a pointer to a larger piece of software that can be downloaded.
-
If the bug was a crash, the exact text that was printed out when the crash occurred.
-
Further information such as stack traces may be useful, but is not necessary.
Contributing to GTK
Please, follow the contribution guide to know how to start contributing to GTK.
Release notes
The release notes for GTK are part of the migration guide in the API reference. See:
Licensing terms
GTK is released under the terms of the GNU Lesser General Public License, version 2.1 or, at your option, any later version, as published by the Free Software Foundation.
Please, see the COPYING file for further information.