Thank you for your interest in contributing to OpenColorIO. This document explains our contribution process and procedures, so please review it first.
The first thing to do, before anything else, is talk to us! Whether you're reporting an issue, requesting or implementing a feature, or just asking a question; please don’t hesitate to reach out to project maintainers or the community as a whole. This is an important first step because your issue, feature, or the question may have been solved or discussed already, and you’ll save yourself a lot of time by asking first.
How do you talk to us? There are several ways to get in touch:
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ocio-dev: This is a development focused mail list with a deep history of technical conversations and decisions that have shaped the project.
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ocio-user: This is an end-user oriented mail list, focused on how to use OCIO’s features within a host application. Common topics include crafting configs, DCC behavior, and general color questions.
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Slack: The OpenColorIO Slack group is where developers and expert users go to have real-time communication around OCIO. The group is invitation only, but just email us and we'll add anyone who is interested in participating in the discussion.
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GitHub Issues: GitHub issues are a great place to start a conversation! Issues aren’t restricted to bugs; we happily welcome feature requests and other suggestions submitted as issues. The only conversations we would direct away from issues are questions in the form of “How do I do X”. Please direct these to the ocio-dev or ocio-user mail lists, and consider contributing what you've learned to our docs if appropriate!
So you’ve broken the ice and chatted with us, and it turns out you’ve found a gnarly bug that you have a beautiful solution for. Wonderful!
From here on out we’ll be using a significant amount of Git and GitHub based terminology. If you’re unfamiliar with these tools or their lingo, please look at the GitHub Glossary or browse GitHub Help. It can be a bit confusing at first, but feel free to reach out if you need assistance.
The first requirement for contributing is to have a GitHub account. This is needed in order to push changes to the upstream repository. After setting up your account you should then fork the OpenColorIO repository to your account. This creates a copy of the repository under your user namespace and serves as the “home base” for your development branches, from which you will submit pull requests to the upstream repository to be merged.
You will also need Git installed on your local development machine. If you need setup assistance, please see the official Git Documentation.
Once your Git environment is operational, the next step is to locally clone your forked OpenColorIO repository, and add a remote pointing to the upstream OpenColorIO repository. These topics are covered in Cloning a repository and Configuring a remote for a fork, but again, if you need assistance feel free to reach out on the ocio-dev mail list.
You are now ready to contribute.
The OpenColorIO repository has a relatively straight-forward structure, and a simple branching and merging strategy.
All development work is done directly on the master branch. This represents the bleeding-edge of the project and any contributions should be done on top of it.
After sufficient work is done on the master branch and OCIO leadership determines that a release is due, we will bump the relevant internal versioning and tag a commit with the corresponding version number, e.g. v2.0.1. Each Minor version also has its own “Release Branch”, e.g. RB-1.1. This marks a branch of code dedicated to that Major.Minor version, which allows upstream bug fixes to be cherry-picked to a given version while still allowing the master branch to continue forward onto higher versions. This basic repository structure keeps maintenance low, while remaining simple to understand.
Contributions should be submitted as Github pull requests. See Creating a pull request if you're unfamiliar with this concept.
The development cycle for a code change should follow this protocol:
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Create a topic branch in your local repository, following the naming format "feature/" or "bugfix/".
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Make changes, compile, and test thoroughly. Code style should match existing style and conventions, and changes should be focused on the topic the pull request will be addressing. Make unrelated changes in a separate topic branch with a separate pull request.
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Push commits to your fork.
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Create a Github pull request from your topic branch.
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All pull requests trigger CI builds on Travis CI for Linux and Mac OS and AppVeyor for Windows. These builds verify that code compiles and all unit tests succeed. CI build status is displayed on the GitHub PR page, and changes will only be considered for merging after all builds have succeeded.
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Pull requests will be reviewed by project Committers and Contributors, who may discuss, offer constructive feedback, request changes, or approve the work.
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Upon receiving the required number of Committer approvals (as outlined in Required Approvals), a Committer other than the PR contributor may squash and merge changes into the master branch.
Modifications of the contents of the OpenColorIO repository are made on a collaborative basis. Anyone with a GitHub account may propose a modification via pull request and it will be considered by the project Committers.
Pull requests must meet a minimum number of Committer approvals prior to being merged. Rather than having a hard rule for all PRs, the requirement is based on the complexity and risk of the proposed changes, factoring in the length of time the PR has been open to discussion. The following guidelines outline the project's established approval rules for merging:
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Core design decisions, large new features, or anything that might be perceived as changing the overall direction of the project should be discussed at length in the mail list before any PR is submitted, in order to: solicit feedback, try to get as much consensus as possible, and alert all the stakeholders to be on the lookout for the eventual PR when it appears.
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Small changes (bug fixes, docs, tests, cleanups) can be approved and merged by a single Committer.
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Big changes that can alter behavior, add major features, or present a high degree of risk should be signed off by TWO Committers, ideally one of whom should be the "owner" for that section of the codebase (if a specific owner has been designated). If the person submitting the PR is him/herself the "owner" of that section of the codebase, then only one additional Committer approval is sufficient. But in either case, a 48 hour minimum is helpful to give everybody a chance to see it, unless it's a critical emergency fix (which would probably put it in the previous "small fix" category, rather than a "big feature").
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Escape valve: big changes can nonetheless be merged by a single Committer if the PR has been open for over two weeks without any unaddressed objections from other Committers. At some point, we have to assume that the people who know and care are monitoring the PRs and that an extended period without objections is really assent.
Approval must be from Committers who are not authors of the change. If one or more Committers oppose a proposed change, then the change cannot be accepted unless:
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Discussions and/or additional changes result in no Committers objecting to the change. Previously-objecting Committers do not necessarily have to sign-off on the change, but they should not be opposed to it.
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The change is escalated to the TSC and the TSC votes to approve the change. This should only happen if disagreements between Committers cannot be resolved through discussion.
Committers may opt to elevate significant or controversial modifications to the
TSC by assigning the tsc-review label to a pull request or issue. The TSC
should serve as the final arbiter where required.