Left-click to create an object. Right-click to show next example.

What's this

Box2DJS is a JavaScript port of Box2D Physics Engine. To tell the truth, this is converted from Box2DFlashAS3_1.4.3.1 in an automatic manner. (The reason why not Box2DFlashAS3_2.0.0 based is simply because I overlooked the renewal.)

How to use

Because this libray does not have a lazy-loading system now, you should load all classes before starting your simulation. To make things worse, each library has a bit complecated dependency each other so that loading libraries in wrong order may cause a fatal error. To avoid such a trouble, it is strongly recomended to copy the header part of this file or `index.html' including the downloaded zip file.

Concerning the Box2D APIs of the library, they are completely same as Box2DFlashAS3. Please google information about it.

Sample code

Create a world

var worldAABB = new b2AABB();
worldAABB.minVertex.Set(-1000, -1000);
worldAABB.maxVertex.Set(1000, 1000);
var gravity = new b2Vec2(0, 300);
var doSleep = true;
var world = new b2World(worldAABB, gravity, doSleep); 

Create a circle body

var circleSd = new b2CircleDef();
circleSd.density = 1.0;
circleSd.radius = 20;
circleSd.restitution = 1.0;
circleSd.friction = 0;
var circleBd = new b2BodyDef();
circleBd.AddShape(circleSd);
circleBd.position.Set(x,y);
var circleBody = world.CreateBody(circleBd);

Create a revolute joint

var jointDef = new b2RevoluteJointDef();
jointDef.anchorPoint.Set(250, 200);
jointDef.body1 = world.GetGroundBody();
jointDef.body2 = circleBody;
world.CreateJoint(jointDef);

Step a world

world.Step();

Dependencies

• prototype.js
• IECanvas (when you use a canvas tag to display the result of your physics simulation)

Links

• Project Page (SF)
• Download Page (SF)
• Box2D
• Box2DFlashAS3
• API Doc (Box2DFlashAS3)

Contact

If you have some requests or find any bugs, please tell me about them.