def get_path(self, pos_a: Position, pos_b: Position) -> List[Field]:
"""
Calculates a passable path between the two given positions
:param pos_a:
:param pos_b:
:return:
"""
class Node:
def __init__(self, node, cost, expected, parent):
self.node = node
# same position reference that Field-Object has
self.pos = node.position
self.cost = cost
self.expected = expected
self.total = self.cost + self.expected
self.parent = parent
def __eq__(self, other):
return self.pos == other.pos
current_field = Node(self.get(pos_a.tuple), 0, pos_a.distance_to(pos_b), None)
path = [current_field]
already_checked = []
while current_field.pos != pos_b:
valid_neighbours = filter(
lambda x: x.passable,
self._get_neighbours(current_field.pos)
)
for field in valid_neighbours:
# calculate the values of each field
cost = current_field.pos.distance_to(field.position)
h = field.position.distance_to(pos_b)
node = Node(field, cost, h, current_field)
# dont want duplicates
if node not in path and node not in already_checked:
already_checked.append(node)
already_checked.sort(key=lambda x: x.total)
current_field = already_checked[0]
already_checked.remove(current_field)
path.append(current_field)
ordered_path = []
while current_field is not None:
ordered_path.append(current_field.node)
current_field = current_field.parent
ordered_path.reverse()
return ordered_path
def test_position_range(self):
p1 = Position(0, 0)
p2 = Position(10, 0)
p3 = Position(10, 10)
self.assertTrue(p1.in_range(p2, 20), "Position.in_range function not working")
self.assertTrue(p1.in_range(p2, 10), "Position.in_range function not working")
self.assertFalse(p1.in_range(p2, 9.9999), "Position.in_range function not working")
self.assertFalse(p1.in_range(p2, 0), "Position.in_range function not working")
self.assertTrue(p1.in_range(p3, 14.15), "Position.in_range function not working")
self.assertFalse(p1.in_range(p3, 14), "Position.in_range function not working")
with self.assertRaises(TypeError):
p1.in_range(p2)
def test_position_distance(self):
p1 = Position(0, 0)
p2 = Position(10, 0)
p3 = Position(10, 10)
self.assertEqual(p1.distance_to(p2), 10, "Position.distance_to not working as expected")
self.assertEqual(p2.distance_to(p1), 10, "Position.distance_to not working as expected")
self.assertAlmostEqual(p1.distance_to(p3), sqrt(200), 5, "Position.distance_to not working as expected")
with self.assertRaises(TypeError):
p1.distance_to("nothing")