![Box2D Logo](https://box2d.org/images/logo.svg)

# Build Status
[![Build Status](https://github.com/erincatto/box2d/actions/workflows/build.yml/badge.svg)](https://github.com/erincatto/box2d/actions)

# Box2D 
Box2D is a 2D physics engine for games.

[![Box2D Version 3.0 Release Demo](https://img.youtube.com/vi/dAoM-xjOWtA/0.jpg)](https://www.youtube.com/watch?v=dAoM-xjOWtA)

## Features

### Collision
- Continuous collision detection
- Contact events and sensors
- Convex polygons, capsules, circles, rounded polygons, segments, and chains
- Multiple shapes per body
- Collision filtering
- Ray casts, shape casts, and overlap queries

### Physics
- Robust _Soft Step_ rigid body solver
- Continuous physics for fast translations and rotations
- Island based sleep
- Revolute, prismatic, distance, mouse joint, weld, and wheel joints
- Joint limits, motors, springs, and friction
- Joint and contact forces
- Body movement events and sleep notification

### System
- Data-oriented design
- Written in portable C17
- Extensive multithreading and SIMD

### Samples
- OpenGL with GLFW and enkiTS
- Graphical user interface with imgui
- Many samples to demonstrate features and performance

## Building
- Install [CMake](https://cmake.org/)
- Ensure CMake is in the user `PATH`
- Visual Studio: run `build.bat` from the command prompt
- Otherwise: run `build.sh` from a bash shell
- Results are in the build sub-folder
- On Windows you can open box2d.sln

## Building for Xcode
- Install [CMake](https://cmake.org)
- Add Cmake to the path in .zprofile (the default Terminal shell is zsh)
    - export PATH="/Applications/CMake.app/Contents/bin:$PATH"
- mkdir build
- cd build
- cmake -G Xcode ..
- open box2d.xcodeproj
- Select the samples scheme
- Edit the scheme to set a custom working directory to the box2d directory
- You can now build and run the samples

## Compatibility
The Box2D library and samples build and run on Windows, Linux, and Mac.

Box2D should be built on recent versions of clang and gcc. You will need the latest Visual Studio version for C11 atomics to compile (17.8.3+).

AVX2 CPU support is assumed on x64. You can turn this off in the CMake options and use SSE2 instead. There are some compatibility issues with very old CPUs.

## Documentation
- [Manual](https://box2d.org/documentation/)
- [Migration Guide](https://github.com/erincatto/box2d/blob/main/docs/migration.md)

## Community
- [Discord](https://discord.gg/NKYgCBP)

## Contributing
Please do not submit pull requests. Instead, please file an issue for bugs or feature requests. For support, please visit the Discord server.

# Giving Feedback
Please file an issue or start a chat on discord.

## License
Box2D is developed by Erin Catto and uses the [MIT license](https://en.wikipedia.org/wiki/MIT_License).

## Sponsorship
Support development of Box2D through [Github Sponsors](https://github.com/sponsors/erincatto)

## Ports, wrappers, and bindings
- https://github.com/EnokViking/Box2DBeef
- https://github.com/HolyBlackCat/box2cpp