Box2dWeb missing ApplyLinearImpuse() and ApplyAngularImpulse() methods?

Question

I have been trying to get to grips with HTML5 game writing coming from an XNA / Farseer background.

It seems that box2dweb is missing ApplyLinearImpuse() and ApplyAngularImpulse() methods.

I have even looked at the source here and it seems to be the case.

Does anyone know why these methods are not provided?

Probably because they did not exist in the version of Box2D that box2dweb was ported from at the time. — iforce2d, Dec 15 '12 at 05:18

andypaxo · Accepted Answer · 2013-08-04T22:29:24.900

Just now I needed the same thing. Fortunately the implementation or ApplyAngularImpulse is very simple. You can add the following to your code to patch it in to box2d:

Box2Dweb

b2Body.prototype.ApplyAngularImpulse = function(impulse) {
    if (this.IsAwake() == false) {
        this.SetAwake(true);
    }
    this.m_angularVelocity += this.m_invI * impulse;
};

Box2Djs

b2Body.prototype.ApplyAngularImpulse = function(impulse) {
    if (this.IsSleeping() == false)
    {
        this.m_angularVelocity += this.m_invI * impulse;
    }
};

In general, to get at features in the C++ version that haven't been ported to the Flash or JavaScript versions, you can have a look at the original source, and port them over yourself as above. Even if you're not familiar with C++, the code is fairly approachable.

Box2dWeb missing ApplyLinearImpuse() and ApplyAngularImpulse() methods?

1 Answers1