def _find_one_after_last_labeled_index(self):
        body_index = 0
        while self.bodies[body_index].segment_id in self.state.body_labels:
            body_index += 1
        return body_index
def EVT_MOTION(event):
  global _mpos
  if event.LeftIsDown():
    if _mpos:
      (x,y),(mx,my) = event.Position,_mpos
      rotangles[0] += y-my
      rotangles[1] += x-mx
      refresh()    
    _mpos = event.Position