Pixman is a library that provides low-level pixel manipulation
features such as image compositing and trapezoid rasterization.
Questions, bug reports and patches should be directed to the pixman
You can also file bugs at
For real time discussions about pixman, feel free to join the IRC
channels #cairo and #xorg-devel on the FreeNode IRC network.
In order to contribute to pixman, you will need a working knowledge of
the git version control system. For a quick getting started guide,
there is the "Everyday Git With 20 Commands Or So guide"
from the Git homepage. For more in depth git documentation, see the
resources on the Git community documentation page:
Pixman uses the infrastructure from the freedesktop.org umbrella
project. For instructions about how to use the git service on
The Pixman master repository can be found at:
and browsed on the web here:
The general workflow for sending patches is to first make sure that
git can send mail on your system. Then,
- create a branch off of master in your local git repository
- make your changes as one or more commits
- use the
command to send the patch series to email@example.com.
In order for your patches to be accepted, please consider the
- This link:
describes how what a good patch series is, and to create one with
- At each point in the series, pixman should compile and the test
suite should pass.
The exception here is if you are changing the test suite to
demonstrate a bug. In this case, make one commit that makes the
test suite fail due to the bug, and then another commit that fixes
You can run the test suite with
It will take around two minutes to run on a modern PC.
- Follow the coding style described in the CODING_STYLE file
- For bug fixes, include an update to the test suite to make sure
the bug doesn't reappear.
- For new features, add tests of the feature to the test
suite. Also, add a program demonstrating the new feature to the
- Write descriptive commit messages. Useful information to include:
- Benchmark results, before and after
- Description of the bug that was fixed
- Detailed rationale for any new API
- Alternative approaches that were rejected (and why they
- If review comments were incorporated, a brief version
history describing what those changes were.
- For big patch series, send an introductory email with an overall
description of the patch series, including benchmarks and
motivation. Each commit message should still be descriptive and
include enough information to understand why this particular commit
Pixman has high standards for code quality and so almost everybody
should expect to have the first versions of their patches rejected.
If you think that the reviewers are wrong about something, or that the
guidelines above are wrong, feel free to discuss the issue on the
list. The purpose of the guidelines and code review is to ensure high
code quality; it is not an exercise in compliance.