Box2D 2.4.0 Released

Box2D, the popular open source 2D physics engine, just released version 2.4.0. Among other changes the 2.4.0 release saw a change from the ZLib open source license to the very similar MIT open source license. Other details from the release notes:


  • Documentation in Doxygen format
  • CMake build system
  • Unit test support
  • Continuous integration testing using Travis CI
  • Limited use of C++11 (nullptr and override)
  • Restructured folders and renamed files to better match open-source standards
  • MIT License
  • Removed float32 and float64
  • Linked the Box2D project to GitHub Sponsors


  • Chain and edge shape must now be one-sided to eliminate ghost collisions
  • Broad-phase optimizations
  • Added b2ShapeCast for linear shape casting


  • Joint limits are now predictive and not stateful
  • Experimental 2D cloth (rope)
  • b2Body::SetActive -> b2Body::SetEnabled
  • Better support for running multiple worlds
  • Handle zero density better
    • The body behaves like a static body
    • The body is drawn with a red color
  • Added translation limit to wheel joint
  • World dump now writes to box2d_dump.inl
  • Static bodies are never awake
  • All joints with spring-dampers now use stiffness and damping
  • Added utility functions to convert frequency and damping ratio to stiffness and damping


  • Testbed uses dear imgui
  • glad OpenGL loader
  • OpenGL 3.3 required

Box2D is available in source form on GitHub. You can learn more about the release in the video below.

Scroll to Top