www.iforce2d.net

Hey, thank you. That's very helpful. One last question:

What is the value of "b2_epsilon" - I've looked it up and assume that the logic in the code will work in other languages (I'm using Lua with Corona SDK) if I supplement 0.00002

Does that sound reasonable?

In the Buoyancy tutorial, under the section "Applying simple drag" (http://www.iforce2d.net/b2dtut/buoyancy) there is a code snippet: //find relative velocity between object and fluid b2Vec2 velDir = fixtureB->GetBody()->GetLinearVelocityFromWorldPoint( centroid ) - fixtureA->GetBody()->Ge...

Thank you!

Old versions of Box2D appear to have a library function called B2Cross. I've seen it used in this tutorial in the ComputeCentroid function:

http://www.iforce2d.net/b2dtut/buoyancy

I cannot find it in the current Box2D documentation. Does anyone know what it does?