effectcraft/CONTRIBUTING.md

Contributing to EffectCraft

Thanks for helping. Please read AGENTS.md first: its rules on assets and clean-room work apply to everyone, people and AI agents alike, and they are not negotiable.

Setup

You need Rust 1.95 or newer.

On Linux the desktop app plays preview sound through cpal, so the build needs a usable ALSA pkg-config package: an alsa.pc that pkg-config can find, naming the linkable ALSA runtime library (usually libasound.so.2). alsa-sys runs pkg-config at build time; it does not compile ALSA's headers. Without a usable package the build fails at link time with an unrelated-looking error; cargo xtask ci probes pkg-config up front and names the package:

sudo dnf install alsa-lib-devel        # Fedora
sudo apt install libasound2-dev        # Debian / Ubuntu
sudo pacman -S alsa-lib                # Arch

If you cannot install the package, point PKG_CONFIG_PATH at a directory holding an alsa.pc whose Libs line names your system's libasound (usually libasound.so.2); every CI run needs that variable set.

cargo run -p effectcraft -- --demo       # the desktop app, with the demo project
cargo test --workspace
cargo xtask ci                           # what every commit must pass (dev-profile checks and tests)

The default dev profile keeps debug info to line tables: builds are fast and panics/backtraces still name the file and line, but a debugger cannot show local variables. For an interactive debugger session use the dev-full profile, which is the same build with full debug info:

cargo run --profile dev-full -p effectcraft -- --demo

Windows

The MSVC toolchain, rustup's default on Windows, is what the releases use: with the Visual Studio C++ build tools installed, the commands above work as they are.

The GNU toolchain (x86_64-pc-windows-gnu) needs a current mingw-w64 GCC and binutils first on PATH. They provide the linker and the Windows import libraries, such as libshlwapi.a for opening links from the app. With MSYS2:

C:\msys64\usr\bin\pacman.exe -S --needed mingw-w64-x86_64-gcc
$env:PATH = "C:\msys64\mingw64\bin;$env:PATH"
cargo +stable-x86_64-pc-windows-gnu run -p effectcraft -- --demo

An older MinGW earlier on PATH can break the build: CodeBlocks' GCC 8.1 fails to link boa_engine (#1882).

Rust's bundled LLD and self-contained libraries don't include every import library EffectCraft needs, so on their own they stop with unable to find library for -lshlwapi, -lktmw32, -lpropsys and -lversion (#1886). To link that way, copy those four from mingw-w64 into a folder of its own and add that folder to the search path in your own Cargo config (%USERPROFILE%\.cargo\config.toml). Don't add all of mingw-w64's lib folder: its C runtime clashes with Rust's bundled one (undefined symbol: DllEntryPoint).

New-Item -ItemType Directory -Force C:\gnu-import-libs
foreach ($lib in "shlwapi", "ktmw32", "propsys", "version") {
    Copy-Item "C:\msys64\mingw64\lib\lib$lib.a" C:\gnu-import-libs\
}

[target.x86_64-pc-windows-gnu]
linker = "rust-lld"
rustflags = ["-C", "link-self-contained=yes", "-L", "native=C:/gnu-import-libs"]

Ground rules

• Clean room. Work from After Effects' public documentation and its observable behaviour only. Never use Adobe artwork, presets or code, and never copy GPL/LGPL/AGPL code.
• Every asset is attributed. Add a .attribution sidecar and an ATTRIBUTION.md row; cargo xtask assets checks it.
• Layering. Nothing below the interface layer depends on UI or OS crates; see docs/architecture.md.
• Everything is a command. New features are engine commands with an id, label, menu path, shortcut and parameters, so the UI, the CLI and the MCP server get them at once. Interactive widgets register an automation id.
• Never crash. Non-test code returns errors instead of panicking: no unwrap(), expect(), panic!, unreachable!, todo!, unimplemented! or unsafe, checked indexing and arithmetic on input-derived values, and a regression test with every crash fix. See the "Never crash" section of AGENTS.md.
• Tests with every change, and green cargo xtask ci before every commit. One task per commit.

How to add…

• An effect: add an EffectSpec in crates/effects (AE display name, category, parameters with AE's names, defaults and ranges) and its render function, with a determinism test and a behaviour test. If it reads the clock directly, add it to TIME_DEPENDENT.
• A command: register it with cmd! in crates/engine/src/commands/, place it in the menu tree in crates/engine/src/menus.rs, and test it including undo.
• A panel or dialog: crates/ui-egui/src/panels/; look at the result with the headless snapshot tool described in docs/testing.md.

Talk to us

Questions, ideas and bug reports are welcome on Discord and in GitHub issues.