pacman2/scenes/game_objects/ghost.py

from random import random, randint

from pygame import Rect, image

from engine.entity import Entity
from engine.scene_manager import SceneManager
from engine.resources import res
from engine.components.collide_rect import CollideRect
from engine.components.sprite import Sprite

from .common import S, Direction


class Ghost(Entity):
    SPEED = 1

    def __init__(self, x, y):
        super().__init__(self.__repr__())
        sprite = Sprite(image.load(res('ghost.png')).convert(), 2)
        self.add(sprite)
        self.phys = CollideRect(Rect(self.x, self.y,
                                     sprite.width, sprite.width),
                                static=False,
                                solid=False,
                                cb=self.cb)
        self.add(self.phys)
        self.script = Ghost.script
        self.x = x
        self.y = y
        self.direction = Direction(randint(0, 3))

    def cb(self, c):
        if not c.solid:
            return

        if c.parent.name == 'pacman':
            print('Perdu !')
            exit(0)

        if self.direction == Direction.UP:
            self.direction = Direction.RIGHT if random() < .5 \
                else Direction.LEFT
            return
        if self.direction == Direction.RIGHT:
            self.direction = Direction.DOWN if random() < .5 \
                else Direction.UP
            return
        if self.direction == Direction.DOWN:
            self.direction = Direction.LEFT if random() < .5 \
                else Direction.RIGHT
            return
        if self.direction == Direction.LEFT:
            self.direction = Direction.UP if random() < .5 \
                else Direction.DOWN
            return

    def script(self):
        level = SceneManager().scene.entities['level']
        if self.x >= level.w:
            self.x = 0
        if self.x < 0:
            self.x = level.w-1

        if self.x % S != 0 or self.y % S != 0:
            return
        graph = SceneManager().scene.entities['level'].graph
        pacman = SceneManager().scene.entities['pacman']
        p = self.find_shortest_path(graph[pacman.y//S][pacman.x//S])
        cur_dir = p[0][1]
        if cur_dir == Direction.UP:
            self.phys.vx = 0
            self.phys.vy = -1
        elif cur_dir == Direction.DOWN:
            self.phys.vx = 0
            self.phys.vy = 1
        elif cur_dir == Direction.LEFT:
            self.phys.vx = -1
            self.phys.vy = 0
        else:
            self.phys.vx = 1
            self.phys.vy = 0

    def find_shortest_path(self, final_node):
        if final_node is None:
            print('oups')
            exit(1)
        graph = SceneManager().scene.entities['level'].graph
        cur_node = graph[self.y//S][self.x//S]
        children = cur_node.children
        child_ok = list(filter(lambda c: c[0] == final_node, children))
        if child_ok:
            return [child_ok[0]]
        trace = [cur_node] + [x[0] for x in children]
        paths = [[x] for x in children]
        while 1:
            cur_len = len(paths)
            for path in paths[:cur_len]:
                for child in path[-1][0].children:
                    if child[0] is not None and child[0] not in trace:
                        trace.append(child[0])
                        paths.append(path + [child])
                        if child[0] == final_node:
                            return path
            paths = paths[cur_len:]