Here's the stuff you asked for.

To use the collision stuff, you build an mci file with the mcibuild
utility.  mci.c contains a function which loads these things in, and
collide.c contains a bunch of functions that do the collision tests.
It's missing some things at the moment, most importantly it doesn't
check which object is nearer if there is more than one tree involved.
Also, the "range" argument causes it to break occasionally.  Other than
that, it should be fairly self explanatory...

Cheers,
Nik.

  

