/box2d

Box2D is a 2D physics engine for games

Primary LanguageC++MIT LicenseMIT

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Build Status

Build Status

Box2D

Box2D is a 2D physics engine for games.

Contributing

Please do not submit pull requests with new features or core library changes. 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
  • Extensible test framework
  • Support for loading world dumps

Building

  • Install CMake
  • 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
  • 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 testbed scheme
  • Edit the scheme to set a custom working directory, make this be in box2d/testbed
  • You can now build and run the testbed

Documentation

License

Box2D is developed by Erin Catto, and uses the MIT license.

Sponsorship

Support development of Box2D through Github Sponsors