So you want to contribute your changes back to WPILib. Great! We have a few contributing rules that will help you make sure your changes will be accepted into the project. Please remember to follow the rules in the code of conduct, and behave with Gracious Professionalism.
WPILib uses modified Google style guides for both C++ and Java, which can be found in the styleguide repository. Autoformatters are available for many popular editors at https://github.com/google/styleguide. Running wpiformat is required for all contributions and is enforced by our continuous integration system. While the library should be fully formatted according to the styles, additional elements of the style guide were not followed when the library was initially created. All new code should follow the guidelines. If you are looking for some easy ramp-up tasks, finding areas that don't follow the style guide and fixing them is very welcome.
When writing math expressions in documentation, use https://www.unicodeit.net/ to convert LaTeX to a Unicode equivalent that's easier to read. Not all expressions will translate (e.g., superscripts of superscripts) so focus on making it readable by someone who isn't familiar with LaTeX. If content on multiple lines needs to be aligned in Doxygen/Javadoc comments (e.g., integration/summation limits, matrices packed with square brackets and superscripts for them), put them in @verbatim/@endverbatim blocks in Doxygen or <pre> tags in Javadoc so they render with monospace font.
The LaTeX to Unicode conversions can also be done locally via the unicodeit Python package. To install it, execute:
pip install --user unicodeit
Here's example usage:
$ python -m unicodeit.cli 'x_{k+1} = Ax_k + Bu_k' xₖ₊₁ = Axₖ + Buₖ
On Linux, this process can be streamlined further by adding the following Bash function to your .bashrc (requires wl-clipboard on Wayland or xclip on X11):
# Converts LaTeX to Unicode, prints the result, and copies it to the clipboard uc() { if [ $WAYLAND_DISPLAY ]; then python -m unicodeit.cli $@ | tee >(wl-copy -n) else python -m unicodeit.cli $@ | tee >(xclip -sel) fi }
Here's example usage:
$ uc 'x_{k+1} = Ax_k + Bu_k' xₖ₊₁ = Axₖ + Buₖ
Changes should be submitted as a Pull Request against the main branch of WPILib. For most changes, commits will be squashed upon merge. For particularly large changes, multiple commits are ok, but assume one commit unless asked otherwise. We may ask you to break a PR into multiple standalone PRs or commits for rebase within one PR to separate unrelated changes. No change will be merged unless it is up to date with the current main branch. We do this to make sure that the git history isn't too cluttered.
When you first submit changes, GitHub Actions will attempt to run ./gradlew check on your change. If this fails, you will need to fix any issues that it sees. Once Actions passes, we will begin the review process in more earnest. One or more WPILib team members will review your change. This will be a back-and-forth process with the WPILib team and the greater community. Once we are satisfied that your change is ready, we will allow our hosted instance to test it. This will run the full gamut of checks, including integration tests on actual hardware. Once all tests have passed and the team is satisfied, we will merge your change into the WPILib repository.
By contributing to WPILib, you agree that your code will be distributed with WPILib, and licensed under the license for the WPILib project. You should not contribute code that you do not have permission to relicense in this manner. This includes code that is licensed under the GPL that you do not have permission to relicense, as WPILib is not released under a copyleft license. Our license is the 3-clause BSD license, which you can find here.