Is this the right way to....

Game Mechanics
#1

lo,
Is this the right way to iterate the contacts and set the friction and bounce factors?

here is the code, please ignore all the PhysicsObject…etc code, its just a holding place for data.


      private void iterateContacts() {
            for (int i = 0; i < collision.getContactCount() - 1; i++) {
                  // obtain the names of the contacts that
                  // have collided
                  String nameOfGeom1 = contact.getGeom1().getName();
                  String nameOfGeom2 = contact.getGeom2().getName();

                  // set the index
                  contact.setIndex(i);
                  if (nameOfGeom1 != null) {
                        // get the PhysicsObject
                        PhysicsObject obj = (PhysicsObject) physicsObjects
                                    .get(nameOfGeom1);
                        // apply the contact information
                        contact.setMode(Ode.dContactBounce | Ode.dContactApprox1);
                        contact.setBounce(obj.getBounce());
                        contact.setBounceVel(obj.getBounceVelocity());
                        contact.setMu(Float.MAX_VALUE);
                  }

                  // set the index
                  contact.setIndex(i + 1);
                  if (nameOfGeom2 != null) {
                        // get the PhysicsObject
                        PhysicsObject obj = (PhysicsObject) physicsObjects
                                    .get(nameOfGeom2);
                        // apply the contact information
                        contact.setMode(Ode.dContactBounce | Ode.dContactApprox1);
                        contact.setBounce(obj.getBounce());
                        contact.setBounceVel(obj.getBounceVelocity());
                        contact.setMu(Float.MAX_VALUE);
                  }
            }
      }

Thx, DP

#2

I think contact.setIndex() should be the first line. Otherwise the geoms you are getting are from the previous contact (which could cause problems if there is no previous contact).

Also - Geoms and Bodies can store a miscellaneous Object using the set/getUserData methods. I find this very useful when iterating over the contacts as I can match up the geom to my game object without needing an extra lookup map.

Will.