[ODE] how to create new geometry classes within new collision detection system

[Tim Schmidt]

Hi!

I am a little bit confused about how to create new geometry classes.
collision_kernel.cpp says something about C++ subclassing and a 
'cumbersome' C interface to support legacy code.

I have already created new geometry classes as it is described in the 
ODE docs (chapter 9.8) and it worked fine with the old collision 
detection system. It seems to me that I have used the mentioned C 
interface at that time, providing collider-, selector- and aabb-function.

Is this further on the way to create user geom or is C++ subclassing the 
preferred one? What must be provided or changed in the latter case and 
can the code be integrated within separate .h and .cpp files?

kind regards,	
    	Tim