Thanks for your interest in contributing to Processing! Processing is a collaborative project with contributions from many volunteers. Our community is always looking for contributors and appreciates involvement in all forms. We acknowledge that not everyone has the capacity, time, or financial means to participate actively or in the same ways. We want to expand the meaning of the word “contributor.” Whether you're an experienced developer or just starting out, we value your involvement. Your unique perspectives, skills, and experiences enrich our community, and we encourage you to get involved in a way that works for you. It includes documentation, teaching, writing code, making art, writing, design, activism, organizing, curating, or anything else you might imagine. The p5.js contribute page gives a great overview of different ways to get involved and contribute.
The Processing project follows the all-contributors specification, recognizing all types of contributions, not just code. We use the @all-contributors bot to handle adding people to the README.md file. You can ask the @all-contributors bot to add you in an issue or PR comment like so:
@all-contributors please add @[your GitHub handle] for [your contribution type]
We usually add contributors automatically after merging a PR, but feel free to request addition yourself by commenting on this issue.
First, please visit our troubleshooting page for common issues—you might find the answer there!
For coding questions or help getting started, our online forum is a fantastic resource. Make sure to read the forum guidelines before posting.
If your issue remains unresolved after exploring these options, we'd appreciate it if you could file a bug report. Your feedback is crucial as it helps us address issues we might not be aware of yet.
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Help Wanted – Most issues marked help wanted are a good place to start. Issues are marked with this tag when:
- They are isolated enough that someone can jump into it without significant reworking of other code.
- Ben knows that it’s unlikely that he’ll have time to work on them.
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The Old Repository – There are also many “help wanted” issues in the 3.x repository. Some of these are very old, so if you're interested in one of these, check in about the priority before putting in too much work!
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JavaFX – There are several active issues for the JavaFX renderer as well.
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The
todo.txtFile – This is not a good place to start. It’s Ben’s rambling to-do list, and dates back to the very start of the project over twenty years ago. It shouldn’t be used as a guideline for work to be done, because there are lots of things there that are no longer relevant. Consider it the dusty attic of what’s inside his head. If you see something of interest there, open an issue to see if it’s still a priority, or how it should be approached. But really, there are so many open issues, which represent actual problems identified by community members, and they are by far the best place to start. -
Style Guidelines – Keep the style guidelines in mind when submitting pull requests. If you don’t, someone else will have to reformat your code so that it fits everything else (or we’ll have to reject it if it’ll take us too long to clean it up).
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Larger Projects – If you’re looking for a larger project, check out the Project List for other ideas.
Nearly all new features are first introduced as a Library or a Mode, or even as an example. The current OpenGL renderer and Video library began as separate projects by Andrés Colubri, who needed a more performant, more sophisticated version of what we had in Processing for work that he was creating. The original loadShape() implementation came from the “Candy” library by Michael Chang (“mflux“).
Similarly, Tweak Mode began as a separate project by Gal Sasson before being incorporated. PDE X was a Google Summer of code project by Manindra Moharana that updated the PDE to include basic refactoring and better error checking.
Developing features separately from the main software has several benefits:
- It’s easier for the contributor to develop the software without it needing to work for tens or hundreds of thousands of Processing users.
- It provides a way to get feedback on that code independently of everything else, and the ability to iterate on it rapidly.
- This feedback process also helps gauge the level of interest for the community, and how it should be prioritized for the software.
- We can delay the process of “normalizing” the features so that they’re consistent with the rest of Processing (function naming, structure, etc).
A major consideration for any new feature is the level of maintenance that it might require in the future. If the original maintainer loses interest over time (which is normal), any ongoing work usually falls to Ben, or it sits on the issues list unfixed, which isn’t good for the community, or for Ben, who has plenty of issues of his own—whether Processing or otherwise.
Processing is a massive project that has existed for more than 20 years. Part of its longevity comes from the effort that’s gone into keeping things as simple as we can, and in particular, making a lot of difficult decisions about what to leave out. Adding a new feature always has to be weighed against the potential confusion of one more thing—whether it’s a menu item, a dialog box, a function that needs to be added to the reference, etc. Adding a new graphics function means making it work across all the renderers that we ship (Java2D, OpenGL, JavaFX, PDF, etc) and across platforms (macOS, Windows, Linux). Does the feature help enough people that it's worth making the reference longer? Or the additional burden of maintaining that feature? It's no fun to say “no,” especially to people volunteering their time, but we often have to.
The current Editor, based on the ancient JEditSyntax package has held up long past its expiration date. Exhaustive work has been done to look at replacing the component with something more modern, like RSyntaxArea, but it’s simply not feasible without breaking a massive amount of code, and likely introducing a lot of regressions in the process. All for… code folding? An incrementally better experience? But with potential for major setbacks in low-level code? It’s simply not a path that makes sense.
With that in mind, any work on updating the editor and adding new features should be focused on further adapting the preprocessor and compiler to be wrapped using the Language Server Protocol, so that we can link to other existing editors (Visual Studio Code and many others). It should be possible to create a Java-only, headless implementation that wraps the current source in this repository and can communicate via LSP.
The initial work was completed in Processing 4.1, and now needs more testing and implementation of Language Server clients such as this one.
We can start building a new PDE that’s as simple to use as the current application, based on something like Theia, a new editor platform that uses LSP as its basis.
With that in mind, nearly all editor enhancement requests will be redirected to this aim. The current editor does what we want it to, for the intended audience, and improving it requires a better foundation as a starting point.
Refactoring is fun! There’s always more cleaning to do. It’s also often not very helpful.
Broadly speaking, the code is built the way it is for a reason. There are so many things that can be improved, but those improvements need to come from an understanding of what’s been built so far. Changes that include refactoring are typically only accepted from contributors who have an established record of working on the code. With a better understanding of the software, the refactoring decisions come from a better, more useful place.
This document was hastily thrown together in an attempt to improve the bug reporting and development/contribution process. It doesn’t yet include detail about our intent with the project, the community behind it, our values, and an explanation of how the code itself is designed.