This is Go a port of Box2D (https://github.com/erincatto/Box2D), a 2D physics engine for games written in C++ by Erin Catto.

The port is complete and based on Box2D version 2.4.1 (https://github.com/erincatto/box2d/commit/9ebbbcd960ad424e03e5de6e66a40764c16f51bc)

The ByteArena team did the original port based on Box2D commit (https://github.com/erincatto/Box2D/commit/f655c603ba9d83f07fc566d38d2654ba35739102). Erin Catto, the author of the original software, was not involved in the port.

This fork ported changes up to version 2.4.1.

We kept the source code as close to the C++ as we possibly could. So the documentation you'll find on Box2D is relevant.

https://box2d.org/documentation/

The API had to change a tiny bit due to the fact that :

• Go has no constructors as a language feature, thus code for constructors has been placed in Make$NAME_OF_TYPE functions
• Go has no support for function overloading; some functions implemented multiple times for different sets of parameters under the same name in C++ are distinguished by name in the golang version; we tried to make names explicit so that should not be an issue
• Go has no support for operator overloading; this C++ feature is used extensively throughout the C++ version of Box2D (mainly for the vector and matrix arithmethic), and has been converted to good old, albeit verbose function calls

No opengl testbed for the moment.

Our tests verify the output of position and rotation of bodies over time against those generated by the C++ reference.

Right now, there's a test (passing) checking all the supported body shape collisions in cmd/test-character-collision.

Have a look at cpp_compliance_test.go.

The original Box2D is developed by Erin Catto, and has the zlib license. Thank you, Erin, for this incredible piece of software.

Box2D Go has the zlib license. While the zlib license does not require acknowledgement, we encourage you to give credit to Box2D Go in your product.