Yoga bindings

Fast Bun FFI bindings for Facebook's Yoga layout engine, providing a yoga-layout compatible API built on Zig.

Supported Platforms

Pre-built binaries are included in the npm package for:

| Platform | Architecture | Binary | | -------- | --------------------- | --------------- | | macOS | ARM64 (Apple Silicon) | libyoga.dylib | | macOS | x64 (Intel) | libyoga.dylib | | Linux | x64 | libyoga.so | | Linux | ARM64 | libyoga.so | | Windows | x64 | yoga.dll |

The correct binary is automatically loaded at runtime based on your platform.

Installation

bun add @simonklee/yoga

Usage

import Yoga, { Node, Config, Edge, FlexDirection } from "@simonklee/yoga";

const config = Config.create();
const root = Node.create(config);

root.setFlexDirection(FlexDirection.Column);
root.setWidth(100);
root.setHeight(100);

const child = Node.create(config);
child.setFlexGrow(1);
root.insertChild(child, 0);

root.calculateLayout(100, 100);
console.log(root.getComputedLayout());
// { left: 0, top: 0, right: 0, bottom: 0, width: 100, height: 100 }

root.freeRecursive();
config.free();

API

The API mirrors yoga-layout. All enums, constants, and methods are compatible.

Building from source

Requirements: Bun and Zig 0.15.2+.

# Build the native library (debug)
zig build

# Build native library and dist placeholders (debug)
bun run build:native:dev

# Build the native library (release)
zig build -Doptimize=ReleaseFast

# Build native library and dist placeholders (release, for bun --compile)
bun run build:native

# Build TypeScript to dist/
bun run build:ts
# or
bun run build

# Tests
zig build test
bun run build:native:dev # Prepare dist placeholders for bun test
bun test

Benchmarks

bun run bench

Development notes

• src/yoga_ffi.zig exposes Yoga's C API via Zig export fn.
• src/index.ts uses bun:ffi and prefers a local zig-out library when present, falling back to the platform-specific binary in dist/.

License

MIT