AI-Project/survival/graph_search.py
2021-04-19 17:20:40 +02:00

89 lines
2.6 KiB
Python

from enum import Enum
from survival import GameMap
from survival.components.position_component import PositionComponent
from survival.enums import Direction
class Action(Enum):
ROTATE_LEFT = 0
ROTATE_RIGHT = 1
MOVE = 2
class State:
def __init__(self, position, direction):
self.position = position
self.direction = direction
class Node:
def __init__(self, state: State, parent=None, action=None):
self.state = state
self.parent = parent
self.action = action
def get_moved_position(position, direction):
vector = Direction.get_vector(direction)
return position[0] + vector[0], position[1] + vector[1]
def get_states(state: State, game_map: GameMap):
states = list()
states.append((Action.ROTATE_LEFT, State(state.position, state.direction.rotate_left(state.direction))))
states.append((Action.ROTATE_RIGHT, State(state.position, state.direction.rotate_right(state.direction))))
target_state = get_moved_position(state.position, state.direction)
if not game_map.is_colliding(target_state):
states.append((Action.MOVE, State(target_state, state.direction)))
return states
def graph_search(game_map: GameMap, start: PositionComponent, goal: tuple):
fringe = list()
explored = list()
explored_states = set()
fringe_states = set()
start = State(start.grid_position, start.direction)
fringe.append(Node(start))
fringe_states.add((tuple(start.position), start.direction))
while True:
# No solutions found
if not any(fringe):
return []
node = fringe.pop(0)
fringe_states.remove((tuple(node.state.position), node.state.direction))
# Check goal
if node.state.position == goal:
actions = [node.action]
parent = node.parent
while parent is not None:
if parent.action is not None:
actions.append(parent.action)
parent = parent.parent
actions.reverse()
return actions
explored.append(node)
explored_states.add((tuple(node.state.position), node.state.direction))
# Get all possible states
for state in get_states(node.state, game_map):
sub_state = (tuple(state[1].position), state[1].direction)
if sub_state not in fringe_states and sub_state not in explored_states:
new_node = Node(state=state[1],
parent=node,
action=state[0])
fringe.append(new_node)
fringe_states.add((tuple(new_node.state.position), new_node.state.direction))