Box2D
Box2D is a 2D physics engine for games.
For help with Box2D, please visit http://www.box2d.org. There is a forum there where you may post your questions.
Please see Building.md to learn how to build Box2D and run the testbed.
Demos
To run the demos, set Testbed as your startup project and press F5. Some test bed commands are:
- r to reset the current test
- SPACE to launch a bomb
- ← → keys to pan
- x and z to zoom in/out
- use the mouse to click and drag objects
Contributing
Please do not submit pull requests with new features. Instead, please file an issue first for discussion. For bugs, I prefer detailed bug reports over pull requests.
Features
Collision
- Continuous collision detection
- Contact callbacks: begin, end, pre-solve, post-solve
- Convex polygons and circles
- Multiple shapes per body
- One-shot contact manifolds
- Dynamic tree broadphase
- Efficient pair management
- Fast broadphase AABB queries
- Collision groups and categories
Physics
- Continuous physics with time of impact solver
- Persistent body-joint-contact graph
- Island solution and sleep management
- Contact, friction, and restitution
- Stable stacking with a linear-time solver
- Revolute, prismatic, distance, pulley, gear, mouse joint, and other joint types
- Joint limits, motors, and friction
- Momentum decoupled position correction
- Fairly accurate reaction forces/impulses
System
- Small block and stack allocators
- Centralized tuning parameters
- Highly portable C++ with no use of STL containers
Testbed
- OpenGL with GLFW
- Graphical user interface with imgui
- Easily switch between tests using GUI
- Test framework for easily adding new tests
- Mouse picking and the bomb!
- CMake build system files
Documentation
You can find documentation related to the project in the documentation page and in the documentation folder in GitHub
- User manual
- Doxygen document with code comments
- subreddit
- Discord server
- User forum (legacy)
You can also visit the project wiki where you will find the FAQ's page
License
Box2D is developed by Erin Catto, and has the zlib license. While the zlib license does not require acknowledgement, we encourage you to give credit to Box2D in your product.