cljbox2d

2D physics engine.

A clojure wrapper for JBox2D, which is a close Java port of Erin Catto's excellent C++ Box2D physics engine.

API Docs

See http://floybix.github.com/cljbox2d/

Setup

Add the following the to your project.clj:

for the Quil-based visual display:

Usage

Start by looking at these examples, which are ports of the Box2D / JBox2D testbed tests. They can be run from source using Leiningen as:

cd testbed/
lein run -m org.nfrac.cljbox2d.testbed.tests.blob
lein run -m org.nfrac.cljbox2d.testbed.tests.collision-processing
lein run -m org.nfrac.cljbox2d.testbed.tests.rope-joint
lein run -m org.nfrac.cljbox2d.testbed.tests.raycast
...etc...

See the ball bounce (requires some imagination...)

(use 'org.nfrac.cljbox2d.core)
(def world (new-world))
(def ground (body! world {:type :static}
                   {:shape (edge [-40 0] [40 0])}))
(def ball (body! world {:position [0 10]}
                 {:shape (circle 1), :restitution 0.5}))
;; let it go
(dotimes [i 10]
  (println (position ball))
  (step! world (/ 1 3)))

;  [0.0 10.0]
;  [0.0 8.888889]
;  [0.0 6.8888893]
;  [0.0 4.8888893]
;  [0.0 2.8888893]
;  [0.0 1.0048437]   <- bounce!
;  [0.0 2.5603995]
;  [0.0 3.0048442]
;  [0.0 2.3381777]
;  [0.0 1.0048437]

License

Copyright © 2012-2015 Felix Andrews

Distributed under the Eclipse Public License, the same as Clojure.