title: How can i extrapolate a new quaternion rotation from two previous packets?
body: <p>I'm at my wits end here! I'm working on lag-reduction in my First Person Shooter, and now it's just a case of adding some extrapolation.
  I can extrapolate position; getting the last two positions and the velocity from them, then adding the velocity to the existing position (* delta time).
  However, i cannot do the same for rotation.
  By default, the angles are Euler, but i can (and do) convert them to quaternions as they can suffer gimball lock.
  How would i extrapolate a new orientation from 2 previous orientations?
  I have time between packets, 2 packets and current orientation.</p>