def test_make_twin(self):
#
# New HalfEdge
#
v1 = Vertex((0,0))
v2 = Vertex((2,2))
h12 = HalfEdge(v1,v2)
h21 = h12.make_twin()
self.assertIsNotNone(h12.twin())
self.assertIsNotNone(h21.twin())
self.assertEqual(h12.base(),h21.head())
self.assertEqual(h21.base(),h12.head())
def test_split(self):
# Rectangle
v1 = Vertex((0, 0))
v2 = Vertex((1, 0))
v3 = Vertex((1, 1))
v4 = Vertex((0, 1))
v5 = Vertex((2, 0))
v6 = Vertex((2, 1))
h12 = HalfEdge(v1, v2)
h23 = HalfEdge(v2, v3)
h34 = HalfEdge(v3, v4)
h41 = HalfEdge(v4, v1)
cell = QuadCell([h12, h23, h34, h41])
cell.split()
self.assertTrue(cell.has_children())
# Check that interior half_edges are twinned
child_0 = cell.get_child(0)
child_1 = cell.get_child(1)
self.assertEqual(child_0.get_half_edge(1).twin(), \
child_1.get_half_edge(3))
# Make another cell, check that it is a neighbor, and then split it
h25 = HalfEdge(v2, v5)
h56 = HalfEdge(v5, v6)
h63 = HalfEdge(v6, v3)
h32 = h23.make_twin()
cell_1 = QuadCell([h25, h56, h63, h32])
# Check that they are neighbors
self.assertEqual(cell_1.get_neighbors(h32), cell)
# Child_s doesn't have a neighbor
self.assertIsNone(child_1.get_neighbors(child_1.get_half_edge(1)))
cell_1.split()
# Now the child has a neighbor
self.assertEqual(child_1.get_neighbors(child_1.get_half_edge(1)),
cell_1.get_child(0))
def test_get_neighbors(self):
#
# HalfEdge pivot
#
#
# Cell with no neighbors
#
v1 = Vertex((0,0))
v2 = Vertex((1,0))
v3 = Vertex((0,1))
h12 = HalfEdge(v1, v2)
h23 = HalfEdge(v2, v3)
h31 = HalfEdge(v3, v1)
#
# Make triangle
#
cell = Cell([h12, h23, h31])
# No neighbors
self.assertIsNone(cell.get_neighbors(h12))
self.assertEqual(cell.get_neighbors(v1),[])
# Add a new neighboring triangle
v4 = Vertex((1,1))
h24 = HalfEdge(v2, v4)
h43 = HalfEdge(v4 ,v3)
h32 = h23.make_twin()
ncell_1 = Cell([h24, h43, h32])
# Make sure they are neighbors wrt halfedge
self.assertEqual(cell.get_neighbors(h23),ncell_1)
# Neighbors wrt vertices
self.assertEqual(cell.get_neighbors(v2),[ncell_1])
self.assertEqual(cell.get_neighbors(v3),[ncell_1])
#
# Add a third neighboring triangle
#
v5 = Vertex((1,2))
h34 = h43.make_twin()
h45 = HalfEdge(v4, v5)
h53 = HalfEdge(v5, v3)
ncell_2 = Cell([h34, h45, h53])
# Check if it's a neighbor wrt halfedge
self.assertEqual(ncell_1.get_neighbors(h43), ncell_2)
# 2 Neighbors wrt v3
self.assertEqual(cell.get_neighbors(v3),[ncell_1, ncell_2])
self.assertEqual(ncell_1.get_neighbors(v3), [ncell_2, cell])
self.assertEqual(ncell_2.get_neighbors(v3), [cell, ncell_1])
#
# Split h31 and make an illegal neighbor
#
v6 = Vertex((-1,0.5))
h31.split()
h331 = h31.get_child(0)
h133 = h331.make_twin()
h36 = HalfEdge(v3, v6)
h613 = HalfEdge(v6, h133.base())
ncell_3 = Cell([h133, h36, h613])
# No neighbors wrt shared edges
self.assertIsNone(cell.get_neighbors(h31))
self.assertIsNone(ncell_3.get_neighbors(h133))
# Neighbors wrt vertices remain as they are.
self.assertEqual(cell.get_neighbors(v3),[ncell_1, ncell_2])
self.assertEqual(ncell_1.get_neighbors(v3), [ncell_2, cell])
self.assertEqual(ncell_2.get_neighbors(v3), [cell, ncell_1])
self.assertEqual(ncell_3.get_neighbors(v3), [])