def test_split(self):
# test a rational 2D surface
controlpoints = [[0, 0, 1], [-1, 1, .96], [0, 2, 1], [1, -1, 1],
[1, 0, .8], [1, 1, 1], [2, 1, .89], [2, 2, .9],
[2, 3, 1], [3, 0, 1], [4, 1, 1], [3, 2, 1]]
basis1 = BSplineBasis(3, [1, 1, 1, 1.4, 5, 5, 5])
basis2 = BSplineBasis(3, [2, 2, 2, 7, 7, 7])
surf = Surface(basis1, basis2, controlpoints, True)
split_u_surf = surf.split([1.1, 1.6, 4], 0)
split_v_surf = surf.split(3.1, 1)
self.assertEqual(len(split_u_surf), 4)
self.assertEqual(len(split_v_surf), 2)
# check that the u-vector is properly split
self.assertAlmostEqual(split_u_surf[0].start()[0], 1.0)
self.assertAlmostEqual(split_u_surf[0].end()[0], 1.1)
self.assertAlmostEqual(split_u_surf[1].start()[0], 1.1)
self.assertAlmostEqual(split_u_surf[1].end()[0], 1.6)
self.assertAlmostEqual(split_u_surf[2].start()[0], 1.6)
self.assertAlmostEqual(split_u_surf[2].end()[0], 4.0)
self.assertAlmostEqual(split_u_surf[3].start()[0], 4.0)
self.assertAlmostEqual(split_u_surf[3].end()[0], 5.0)
# check that the v-vectors remain unchanged
self.assertAlmostEqual(split_u_surf[2].start()[1], 2.0)
self.assertAlmostEqual(split_u_surf[2].end()[1], 7.0)
# check that the v-vector is properly split
self.assertAlmostEqual(split_v_surf[0].start()[1], 2.0)
self.assertAlmostEqual(split_v_surf[0].end()[1], 3.1)
self.assertAlmostEqual(split_v_surf[1].start()[1], 3.1)
self.assertAlmostEqual(split_v_surf[1].end()[1], 7.0)
# check that the u-vector remain unchanged
self.assertAlmostEqual(split_v_surf[1].start()[0], 1.0)
self.assertAlmostEqual(split_v_surf[1].end()[0], 5.0)
# check that evaluations remain unchanged
pt1 = surf(3.23, 2.12)
self.assertAlmostEqual(split_u_surf[2].evaluate(3.23, 2.12)[0], pt1[0])
self.assertAlmostEqual(split_u_surf[2].evaluate(3.23, 2.12)[1], pt1[1])
self.assertAlmostEqual(split_v_surf[0].evaluate(3.23, 2.12)[0], pt1[0])
self.assertAlmostEqual(split_v_surf[0].evaluate(3.23, 2.12)[1], pt1[1])
