btRigidBody::upcast() is a downcast?

[B_old]

Hi everybody,

I'm currently a bit confused by the name of the btRigidBody::upcast() method. We are casting from btCollisionObject to btRigidBody, which is derived from btCollisionObject, so we are moving down the class-hierarchy.
Or am I getting something wrong here?

[robagar]

yup, it's the wrong way round. But it kind of makes sense as opposed to going "up" towards the "base"

[B_old]

But it kind of makes sense as opposed to going "up" towards the "base"

I agree, that this can sound confusing at first. But once you are used to viewing and calling it this way, it is even more confusing to encounter stuff that does it the other way round.
What is the intention behind this naming-choice?

[Flix]

I'm not a C++ expert at all, but I've always thought that "upast" is the cast that goes up in the hierarchy (more derived classes).

[B_old]

Well, upcasting doesn't have to do with c++ in particular I suppose. I assumed you move upwards the hierarchy in the sense of an UML-diagram for instance ("less" derived class).
http://www.c-sharpcorner.com/UploadFile ... sting.aspx

Maybe there are two different standards as to what means what, although that would be awkward.

[Erwin Coumans]

My bad, the name is wrong indeed, it should be a downcast.

Best not to break the API for this, we can put a warning there and fix it for a Bullet 3.x release.
Thanks!
Erwin

[B_old]

OK, thanks for clearing it up.