def test_clockwise(self):
start = Vertex(2,1)
base_vector = Vector(start, Vertex(3,1))
clockwise = ((3,2),(2,2),(1,2))
not_clockwise = ((1,1),(1,0),(2,0),(3,0),(3,1))
self.assertListEqual([base_vector.is_clockwise(Vector(start, Vertex(v[0],v[1]))) for v in clockwise], [True for x in range(len(clockwise))])
self.assertListEqual([base_vector.is_clockwise(Vector(start, Vertex(v[0],v[1]))) for v in not_clockwise], [False for x in range(len(not_clockwise))])
def left_iter(self, around, right):
base_vec = Vector(around, right)
start_index, i, max_cos = None, 0, -2
edges = []
for edge in filter(lambda x: base_vec.is_clockwise(x), self.vertices[around]):
edges.append(edge)
angle_cos = base_vec.cos_angle(edge)
if angle_cos > max_cos:
start_index, max_cos = i, angle_cos
i = i + 1
i = start_index - len(edges)
while ( start_index > i):
yield edges[i].end
i = i + 1
