Traktor/source/astar.py

from area.constants import TILE_SIZE, ROWS
import copy
import heapq
from area.field import tiles, fieldX, fieldY
from bfs import get_moves

class Node:

    def __init__(self, priority, x, y, direction, parent, action, cost=0):
        self.x = x
        self.y = y
        self.direction = direction
        self.action = action
        self.parent = parent
        self.cost = cost
        self.priority = priority


    def __int__(self):
        return self.priority

        # getters and setters:

    def get_parent(self):
        return self.parent

    def set_parent(self, _parent):
        self.parent = _parent

    def get_action(self):
        return self.action

    def set_action(self, _action):
        self.parent = _action

    def get_x(self):
        return self.x

    def set_x(self, _x):
        self.x = _x

    def get_y(self):
        return self.y

    def set_y(self, _y):
        self.y = _y

    def get_direction(self):
        return self.direction

    def set_direction(self, _direction):
        self.parent = _direction

    def get_cost(self):
        return self.cost

    def set_cost(self, _cost):
        self.cost = _cost

    def get_priority(self):
        return self.priority

    def set_priority(self, _priority):
        self.priority = _priority

    def __lt__(self, other):
        return self.get_priority() < other.get_priority()

    def copy(self):
        return copy.copy(self)


def goal_test(elem, goalstate):
    if elem.get_x() == goalstate[0] and elem.get_y() == goalstate[1]:
        return True
    else:
        return False

def tile_cost(tile):
    if tile.image == "resources/images/sampling.png":
        return 100
    if tile.image == "resources/images/rock_dirt.png":
        return 500
    else:
        return 1

def heuristic(current_x, current_y, end_x, end_y):
    return abs(end_x - current_x) + abs(end_y - current_y)
# State as a tuple (x,y,direction)

# actions(string): move, rotate_to_left, rotate_to_right

# main search function:
def a_star(istate, succ_astar, goaltest):
    fringe = []
    explored = set()
    node = Node(0, istate.get_x(), istate.get_y(), istate.get_direction(), None, None, 0)
    heapq.heappush(fringe, node)

    while True:

        if not fringe:
            return False

        elem = heapq.heappop(fringe)
        temp = copy.copy(elem)
        if goal_test(elem, goaltest) is True:  # jesli True zwroc ciag akcji
            return get_moves(elem)

        explored.add(elem)

        for (action, state) in succ_astar(temp):
            fringe_tuple = []
            explored_tuple = []

            for node in fringe:
                fringe_tuple.append((node.get_x(), node.get_y(), node.get_direction()))
            for node in explored:
                explored_tuple.append((node.get_x(), node.get_y(), node.get_direction()))


            tile = int((temp.get_y() - fieldY) / TILE_SIZE) * ROWS + int((temp.get_x() - fieldX) / TILE_SIZE)
            cost = temp.cost + tile_cost(tiles[tile])
            priority = cost + heuristic(state[0], state[1], goaltest[0], goaltest[1])

            x = Node(priority, state[0], state[1], state[2], elem, action, cost)

            if state not in fringe_tuple and state not in explored_tuple:
                heapq.heappush(fringe, x)

            elif state in fringe_tuple and elem.get_priority() < priority:
                elem.set_priority(priority)