def switchin(self, *args):
"""args should be a tuple of exactly 1 element, a Formation object"""
State.switchin(self)
if len(args) > 1:
raise ValueError("MainGame.switchin() should take 1 or fewer arguments!")
if len(args) == 1:
if not isinstance(args[0],Formation):
raise ValueError("MainGame.switchin() needs a Formation object!")
if len(args) == 1:
self.playerFlock.changeFormation(args[0])
#register sprites
self.screen.add(self.playerFlock)
#no widgets to register
#switch camera
self.screen.cam = roughTrack(self.playerFlock.anchor.position)
