Fix World::clone() doesn't clone the collision detector

[jslee02]

No description provided.

[mxgrey]

There seems to be a bit of a conflict where this PR has introduced the function getStaticType() for derived CollisionDetector implementations while an earlier PR introduced getTypeStatic().

I think I prefer getStaticType(), so I'll choose that version as I merge this, unless someone has a reason for preferring getTypeStatic().

[jslee02]

To clarify, we use getStatic[Name]() for a static member function, and use get[Name]Static() for fixed-size version of get[Name]() (especially when the function returns Eigen's Vector objects) where get[Name]Static() is a non-static function, right?

[mxgrey]

Yes, that has been our convention so far.

I'm also spotting some conflicts in naming conventions for the strings of the different collision detectors. We'll need to choose between:

"DART" or "dart"
"Bullet" or "bullet"
"FCL" or "fcl"

I don't really have any personal preference for any of these, but a decision must be made 😆

[jslee02]

Yeah, I would slightly prefer lower letter versions though since it's been used in SKEL format to specify the collision detectors. As these type would be used to print messages, it would be good to use same strings.

[mxgrey]

Sounds good.

[jslee02]

Merged master branch into this. I think this is ready to merge.

[mxgrey]

I was also working on merging this, but I came across something fishy, and I'm seeing it in your merge as well.

cloneWithoutCollisionObjects() creates a unique_ptr, but setCollisionDetector(~) now expects a shared_ptr. So how is it that setCollisionDetector(cd->cloneWithoutCollisionObjects()); is being permitted? I can only guess it has to do with CollisionDetector inheriting std::enable_shared_from_this, but I thought the object needed to be managed by a shared_ptr to begin with, so can we really just implicitly cast from unique_ptr to shared_ptr?

[jslee02]

Oh, sorry for the confliction on work.

Good catch by the way. I think cloneWithoutCollisionObjects should be changed to return shared_ptr anyways because it should be able to be shared by collision groups.

Hm, I'm not sure how it was accepted the code. I'm trying to figure it out googling..

[mxgrey]

I'm happy with this PR. I'll merge it once the CI tests pass 👍