GTK is a multi-platform toolkit for creating graphical user interfaces.
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Sebastian Keller f1d44635bd gsk/gl: Always align offscreen rendering with the pixel grid
This fixes two issues with the offscreen rendering code for nodes with
bounds not aligned with the pixel grid:

1.) When drawing to an offscreen buffer the size of the offscreen buffer
was rounded up, but then later when used as texture the vertices
correspond to the original bounds with the unrounded size. This could
then result in the offscreen texture being drawn onscreen at a slightly
smaller size, which then lead to it being visually shifted and blurry.

This is fixed by adjusting the u/v coordinates to ignore the padding
region in the offscreen texture that got added by the size increase from
rounding.

2.) The viewport used when rendering to the offscreen buffer was not
aligned with the pixel grid for nodes at coordinates not aligned with
the pixel grid. Then because the content of the offscreen buffer is not
aligned with the pixel grid and later when used as textures sampling
from it will result in interpolated values for an onscreen pixel. This
could also result in shifting and blurriness, especially for nested
offscreen rendering at different offsets.

This is fixed by adding similar padding at the beginning of the
texture and also adjusting the u/v coordinates to ignore this region.

Fixes: https://gitlab.gnome.org/GNOME/gtk/-/issues/3833
2022-04-21 19:23:06 -04:00
.gitlab/issue_templates Update references to master in the repository 2021-11-29 17:37:49 -05:00
.gitlab-ci CI: clean up MSYS2 build dependencies 2022-04-21 19:15:52 -04:00
build-aux flatpak: Use "main" branch for wayland 2022-01-28 01:25:04 +00:00
demos print-editor: Use gtk_window_present() 2022-03-16 19:50:21 +01:00
docs Check for 'rst2man' misses installed 'rst2man.py' (#4728) 2022-04-21 19:13:54 -04:00
examples examples: Use textures over pixbufs 2021-09-17 04:31:46 +02:00
gdk Remove #ifdef ENABLE_NLS 2022-04-21 19:18:00 -04:00
gsk gsk/gl: Always align offscreen rendering with the pixel grid 2022-04-21 19:23:06 -04:00
gtk application: Add link and inline code blocks 2022-04-21 19:22:38 -04:00
modules media: support OpenGL-based video playback on macOS 2022-02-16 21:31:20 -08:00
po Update Indonesian translation 2022-04-01 04:10:57 +00:00
po-properties Update Indonesian translation 2022-04-01 04:04:49 +00:00
subprojects meson: switch some .wrap files to stable branches 2022-03-17 12:54:58 +02:00
tests tests: Make fontchooser test build on macOS 2021-12-29 09:15:26 -05:00
testsuite filefilter: Fix <suffixes> in buildable 2022-03-17 16:18:28 -04:00
tools Remove #ifdef ENABLE_NLS 2022-04-21 19:18:00 -04:00
.clang-format ci: Add a style check pass 2020-02-11 14:47:22 +00:00
.editorconfig Add editorconfig file 2021-10-28 18:17:02 +01:00
.gitignore .gitignore: Ignore all subdirs in the subprojects dir 2018-10-12 14:23:53 +05:30
.gitlab-ci.yml ci: Only use letters in "expose_as" 2022-01-19 18:51:29 +01:00
AUTHORS AUTHORS: some updates 2020-09-12 11:52:14 -04:00
CONTRIBUTING.md Update references to master in the repository 2021-11-29 17:37:49 -05:00
COPYING Change FSF Address 2012-02-27 17:06:11 +00:00
gtk.doap Update the gtk.doap file 2021-01-18 09:14:50 -05:00
gtk.supp Ignore pthread allocations in valgrind 2021-03-27 21:43:59 -04:00
lsan.supp asan: Ignore leaks from librsvg 2021-03-27 21:03:43 -04:00
make-pot Add bug reporting address to pot files 2020-12-08 17:51:38 -05:00
make-release.sh Actually build docs for releases 2021-03-30 11:00:54 -04:00
meson_options.txt meson: Use proper type for bools 2022-04-21 19:18:55 -04:00
meson.build 4.6.2 2022-03-18 20:38:15 -04:00
NEWS 4.6.2 2022-03-18 20:38:15 -04:00
NEWS.pre-1.0 Split NEWS 2018-01-10 19:06:45 -05:00
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README.md Mention main in NEWS and README.md 2021-11-29 17:42:40 -05:00

GTK — The GTK toolkit

Build status

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 a free and open-source software project. 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.

GTK is hosted by the GNOME project (thanks!) and used by a wide variety of applications and projects.

The official download location

The official web site

The official developers blog

Discussion forum

Nightly documentation can be found at

Nightly flatpaks of our demos can be installed from the GNOME Nightly repository:

  • flatpak remote-add --if-not-exists gnome-nightly https://nightly.gnome.org/gnome-nightly.flatpakrepo
  • flatpak install gnome-nightly org.gtk.Demo4
  • flatpak install gnome-nightly org.gtk.WidgetFactory4
  • flatpak install gnome-nightly org.gtk.IconBrowser4

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

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

Default branch renamed to main

The default development branch of GTK has been renamed to main. To update your local checkout, 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

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.

If you want to support GTK financially, please consider donating to the GNOME project, which runs the infrastructure hosting 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.

GTK includes a small number of source files under the Apache license:

  • A fork of the roaring bitmaps implementation in gtk/roaring
  • An adaptation of timsort from python in gtk/timsort