def polygon(self, done=None):
        '''return a polygon for the waypoints'''
        indexes = self.view_indexes(done)
        points = []
        for idx in indexes:
            w = self.wp(idx)
            points.append((w.x, w.y))
        return points
def polygon ( self , done = None ) : indexes = self . view_indexes ( done ) points = [ ] for idx in indexes : w = self . wp ( idx ) points . append ( ( w . x , w . y ) ) return points
return a polygon for the waypoints