def _find_path(self, from_node: Node, to_node: Node):
def is_free_cell(cell):
return self._board.get_cell(cell[0], cell[1]) == PLAYER_NONE
def finalize_path(path_to_finalize):
beg = from_node.tuple()
end = to_node.tuple()
beg_p = [beg] if is_free_cell(beg) else []
end_p = [end] if is_free_cell(end) else []
return merge_paths(beg_p, path_to_finalize, end_p)
shortest_path = self._astar.find_path(self._for_player, from_node.x(), from_node.y(), to_node.x(), to_node.y())
shortest_path = [p for p in filter(lambda c: is_free_cell(c), shortest_path)]
if len(shortest_path) >= SHORTEST_PATH_LENGTH_TO_ANALYZE:
for i1, chain1 in self._chains:
beg_path, n1 = self._find_path_from_node_to_chain(from_node, chain1)
if n1 is not None:
for i2, chain2 in self._chains:
end_path, n2 = self._find_path_from_node_to_chain(to_node, chain2)
if n2 is not None:
mid_path = self._find_path_between_chains(i1, i2) if i1 != i2 else []
path = finalize_path(merge_paths(beg_path, mid_path, end_path))
if len(path) < len(shortest_path):
shortest_path = path
return shortest_path
def choose_node(self, nodes, dst_node: Node):
min_cost = INFINITY
best_node = None
for node in nodes:
cost_start_to_node = node.get_cost()
cost_node_to_goal = get_distance(node.x(), node.y(), dst_node.x(), dst_node.y())
total_cost = cost_start_to_node + cost_node_to_goal
if min_cost > total_cost:
min_cost = total_cost
best_node = node
return best_node
def build_path(to_node: Node):
path = []
while to_node is not None:
path.append((to_node.x(), to_node.y()))
to_node = to_node.get_previous()
return path
def _construct_full_path(self, src: Node, dst: Node, path):
board = self._board.copy(check_bounds=False)
board.set_cells(path, self._for_player)
walker = WalkerPathfinder(board)
return walker.find_path(self._for_player, src.x(), src.y(), dst.x(), dst.y())