def METHOD_NAME(self, vertex, controlpoint):
    for fraction in [0.2, 0.4, 0.6, 0.8, 1.0]:
        lnode1 = self.prevnode + fraction * (self.prevcp - self.prevnode)
        lnode2 = self.prevcp + fraction * (controlpoint - self.prevcp)
        lnode3 = controlpoint + fraction * (vertex - controlpoint)
        lnode4 = lnode1 + fraction * (lnode2 - lnode1)
        lnode5 = lnode2 + fraction * (lnode3 - lnode2)
        vnew = lnode4 + fraction * (lnode5 - lnode4)
        glu.gluTessVertex(PolygonSet.tess, vnew, vnew)