I want to create an interface for an AI to take control of the snake. It wouldn’t be fair if the state of the game is simply passed to the AI on each iteration b/c it could then just take as long as it want to compute the next move. Hence why it should be synchronous and non-blocking.

因此,要获得所需的内容,您需要一个抽象.在下面的示例中,我创建了一个做到这一点的Controller类. KeyboardController处理键盘输入,而AsyncController启动线程并使用Queue类传递游戏状态和“ AI”的决定.请注意,您必须在主线程上获取pygame事件,因此我在主循环中执行此操作,并将事件简单地传递给控制器​​.

您的AI必须由worker函数调用.如您所见,当前,辅助函数中的“ AI”仅每0.5秒起作用一次,而帧速率为120.对于游戏来说,AI花费这么长时间做出决定并不重要.

这是代码：

import pygame
import time
import random
from queue import Queue,Empty
from threading import Thread

class Controller():
    def __init__(self,color,message,actor):
        self.color = color
        self.message = message
        if actor: self.attach(actor)

    def attach(self,actor):
        self.actor = actor
        self.actor.controller = self
        self.actor.image.fill(self.color)

class AsyncController(Controller):
    def __init__(self,actor=None):
        super().__init__(pygame.Color('orange'),"AI is in control.",actor)
        self.out_queue = Queue()
        self.in_queue  = Queue()
        t = Thread(target=self.worker)
        t.daemon = True
        t.start()

    def update(self,events,dt):
        for e in events:
            if e.type == pygame.KEYDOWN:
                if e.key == pygame.K_SPACE: self.actor.controller = KeyboardController(self.actor)

        self.out_queue.put_nowait((self.actor,dt))
        try: return self.in_queue.get_nowait()
        except Empty: pass

    def worker(self):
        while True:
            try:
                actor,dt = self.out_queue.get_nowait()
                if actor.rect.x < 100: self.in_queue.put_nowait(pygame.Vector2(1,0))
                if actor.rect.x > 600: self.in_queue.put_nowait(pygame.Vector2(-1,0))
                if actor.rect.y < 100: self.in_queue.put_nowait(pygame.Vector2(0,1))
                if actor.rect.y > 400: self.in_queue.put_nowait(pygame.Vector2(0,-1))
                if random.randrange(1,100) < 15:
                    self.in_queue.put_nowait(random.choice([
                        pygame.Vector2(1,0),pygame.Vector2(-1,pygame.Vector2(0,-1),1)]))

                time.sleep(0.5)
            except Empty:
                pass

class KeyboardController(Controller):
    def __init__(self,actor=None):
        super().__init__(pygame.Color('dodgerblue'),"You're in control.",actor)

    def update(self,dt):
        for e in events:
            if e.type == pygame.KEYDOWN:
                if e.key == pygame.K_SPACE: self.actor.controller = AsyncController(self.actor)
                if e.key == pygame.K_UP: return pygame.Vector2(0,-1)
                if e.key == pygame.K_DOWN: return pygame.Vector2(0,1)
                if e.key == pygame.K_LEFT: return pygame.Vector2(-1,0)
                if e.key == pygame.K_RIGHT: return pygame.Vector2(1,0)

class Actor(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__()
        self.image = pygame.Surface((32,32))
        self.image.fill(pygame.Color('dodgerblue'))
        self.rect = self.image.get_rect(center=(100,100))
        self.direction = pygame.Vector2(1,0)
        self.pos = self.rect.center

    def update(self,dt):
        new_direction = self.controller.update(events,dt)
        if new_direction:
            self.direction = new_direction
        self.pos += (self.direction * dt * 0.2)
        self.rect.center = self.pos

def main():
    pygame.init()

    actor   = Actor()
    sprites = pygame.sprite.Group(actor)
    screen  = pygame.display.set_mode([800,600])
    clock   = pygame.time.Clock()
    font    = pygame.font.SysFont("consolas",20,True)
    dt      = 0
    KeyboardController(actor)

    while True:
        events = pygame.event.get()
        for e in events:
            if e.type == pygame.QUIT:
                return

        sprites.update(events,dt)
        screen.fill(pygame.Color('grey12'))
        screen.blit(font.render(actor.controller.message + ' [SPACE] to change to keyboard control.',True,pygame.Color('white')),(10,10))
        sprites.draw(screen)
        dt = clock.tick(120)
        pygame.display.update()

if __name__ == '__main__':
    main()

请注意,此实现使用无限队列.您想添加一些逻辑来清除队列,以免您的游戏占用大量内存.