How to properly delete a box2d body in version: Box2dWeb-2.1.a.3, Box2D_v2.3.1r3? Box2D bug?

Question

Update

Since the problem has been found I\'ve also find out that Box2D for web is leaking on every side :/

To show this I made a simple circle moving in a

Answer 1

Totti did you ever figure this out? It looks like box2dweb requires manual destruction and memory management.

I think I have found your leaks, un-implemented ( static class ) destruction functions:

b2Joint.Destroy = function (joint, allocator) {}
b2CircleContact.Destroy = function (contact, allocator) {}< 
b2PolygonContact.Destroy = function (contact, allocator) {}
b2EdgeAndCircleContact.Destroy = function (contact, allocator) {}<
b2PolyAndCircleContact.Destroy = function (contact, allocator) {}
b2PolyAndEdgeContact.Destroy = function (contact, allocator) {}
[UPDATE...]     
b2DestructionListener.b2DestructionListener = function () {};
b2DestructionListener.prototype.SayGoodbyeJoint = function (joint) {}
b2DestructionListener.prototype.SayGoodbyeFixture = function (fixture) {}

b2Contact.prototype.Reset(fixtureA, fixtureB)

called with with one/both fixture arguments resets passed in fixture/s BUT ALSO pass in NO arguments and it 'nulls' all the the b2Contact properties! (UNTESTED:) but I suggest set your YOURcontactListener class up to handle all contact callbacks EVERY call with Reset(??) dynamically configureable as logic requies EVERY call (there are more than you'd imagine each and every world step).

Also take Colt McAnlis clever advice and strategically pre allocate all the memory the life of your game will need (by creating game and box2d object pools now you know objects can be reset) so the garbage collector NEVER runs until, you destroy object pools at times of your own convenience.... i.e when you close the tab, or your device needs recharging! ;D
[...UPDATE]

// you can define and assign your own contact listener ...via...

YOUR.b2world.b2ContactManager.m_world.m_contactList = new YOURcontactlistener();<br>[edit]...if you dont it actually does have Box2D.Dynamics.b2ContactListener.b2_defaultListener.

// box2d in the worldStep calls YOURcontactlistener.update() via: this.b2world.b2ContactManager.m_world.m_contactList.Update(this.m_contactListener)
// this.m_contactListener being YOURS || b2_defaultListener;

// which instantiates ALL your listed leaking object like so: {b2Contact which instantiates {b2ContactEdge} and {b2Manifold which instantiates {b2ManifoldPoint{which instantiates m_id.key == ContactID{which instantiates Features}}}} along with {B2Vec2} are instantiated in b2ContactResult ...which I can not actually find but assume it must be instantiated in the Solver.

// There is a Contacts.destroyFcn callback is CREATED in....

b2ContactFactory.prototype.Destroy = function (contact) {...}

// then Contacts.destroyFcn callback(s) are privately REGISTERED in....

b2ContactFactory.prototype.InitializeRegisters() {...}

...via...

this.AddType = function (createFcn, destroyFcn, type1, type2) {...}

...BUT... THOSE privately registered ARE four of the un-implimented static class function from above...

b2PolygonContact.Destroy = function (contact, allocator) {}
b2EdgeAndCircleContact.Destroy = function (contact, allocator) {}
b2PolyAndCircleContact.Destroy = function (contact, allocator) {} 
b2PolyAndEdgeContact.Destroy = function (contact, allocator) {}

So I havn't tested it yet but it looks like box2dweb just gives you the Destroy callback/handler functions and you have to read the source to find all the properties you need to null. [Edit] In combination with b2Contact.prototype.Reset(fixtureA, fixtureB)

But either way pretty confident the functions above(possibly incomplete) are callback/handlers, and can be used to null your way back to performance for anyone else who stumbles across this problem. Pretty sure Totti's moved on
(dont forget to handle your 'this' scope in callbacks).

Answer 2

I have the same problem, but I think I find out from where it comes.

Instead of m_* try functions, like GetFixtureA() instead of m_fixtureA.