[ODE] nearCallback() question

[David McClurg]

I've noticed two methods of passing bodies to dJointAttach() in the test programs for ODE...

#1)
static void nearCallback (void *data, dGeomID o1, dGeomID o2)
{
  <snip>
  n = dCollide (o1,o2,N,&contact[0].geom,sizeof(dContact));
  for (i=0; i<n; i++) {
    <snip>
    dJointAttach (c,
                dGeomGetBody(contact[i].geom.g1),
                dGeomGetBody(contact[i].geom.g2));
  }
}

#2)
static void nearCallback (void *data, dGeomID o1, dGeomID o2)
{
 dBodyID b1 = dGeomGetBody(o1);
 dBodyID b2 = dGeomGetBody(o2);
  <snip>
  n = dCollide (o1,o2,N,&contact[0].geom,sizeof(dContact));
  for (i=0; i<n; i++) {
    <snip>
    dJointAttach (c, b1, b2);
  }
}


Method #2 fails in some cases because b1 & b2 are reversed and the joint subsequently gets reversed.  But in the case of a geom transform like in test_boxstack.cpp if you don't use method #2 then the body comes up NULL.

So my question is, how do I properly get the bodies to pass to dJointAttach() in all cases?

Ta