原文： https://pythonspot.com/snake-ai-in-pygame/

在本文中，我们将向您展示如何创建基本的游戏 AI（人工智能）。 本文将介绍游戏蛇的 AI。

在此游戏（蛇）中，计算机和您都在玩蛇，而计算机蛇会尝试抓住您。 简而言之：对手 AI 会根据您在棋盘上的位置尝试确定并前往目的地。

添加计算机玩家：

我们使用名为Computer的新类扩展了代码，它将成为我们的计算机玩家。 这包含绘制和移动计算机蛇的例程。

  1. class Computer:
  2.     x = [0]
  3.     y = [0]
  4.     step = 44
  5.     direction = 0
  6.     length = 3
  8.     updateCountMax = 2
  9.     updateCount = 0
  11.     def __init__(self, length):
  12.        self.length = length
  13.        for i in range(0,2000):
  14.            self.x.append(-100)
  15.            self.y.append(-100)
  17.        # initial positions, no collision.
  18.        self.x[0] = 1*44
  19.        self.y[0] = 4*44
  21.     def update(self):
  23.         self.updateCount = self.updateCount + 1
  24.         if self.updateCount > self.updateCountMax:
  26.             # update previous positions
  27.             for i in range(self.length-1,0,-1):
  28.                 self.x[i] = self.x[i-1]
  29.                 self.y[i] = self.y[i-1]
  31.             # update position of head of snake
  32.             if self.direction == 0:
  33.                 self.x[0] = self.x[0] + self.step
  34.             if self.direction == 1:
  35.                 self.x[0] = self.x[0] - self.step
  36.             if self.direction == 2:
  37.                 self.y[0] = self.y[0] - self.step
  38.             if self.direction == 3:
  39.                 self.y[0] = self.y[0] + self.step
  41.             self.updateCount = 0
  43.     def moveRight(self):
  44.         self.direction = 0
  46.     def moveLeft(self):
  47.         self.direction = 1
  49.     def moveUp(self):
  50.         self.direction = 2
  52.     def moveDown(self):
  53.         self.direction = 3 
  55.     def draw(self, surface, image):
  56.         for i in range(0,self.length):
  57.             surface.blit(image,(self.x[i],self.y[i]))

然后，我们调用计算机的更新和绘制方法。

  1.     def on_loop(self):
  2.         self.player.update()
  3.         self.computer.update()
  5. ....
  7.     def on_render(self):
  8.         self._display_surf.fill((0,0,0))
  9.         self.player.draw(self._display_surf, self._image_surf)
  10.         self.apple.draw(self._display_surf, self._apple_surf)
  11.         self.computer.draw(self._display_surf, self._image_surf)
  12.         pygame.display.flip()

这将使计算机蛇移动并在屏幕上绘制。 它具有与人类玩家相同的属性。

为计算机玩家添加智能

因为这是一个简单的游戏，所以我们无需在游戏内部创建完整的思维机。 我们只需要计算机玩家展示一些基本情报即可。 游戏中的智能通常非常有限，因为在大多数情况下，不需要复杂性或根本没有时间实现聪明的算法。

我们将添加的算法将仅到达目的地。 它将忽略任何障碍（人类玩家）。

  1. def target(self,dx,dy):
  2.     if self.x[0] > dx:
  3.         self.moveLeft()
  5.     if self.x[0] < dx:
  6.         self.moveRight()
  8.     if self.x[0] == dx:
  9.         if self.y[0] < dy:
  10.             self.moveDown()
  12.         if self.y[0] > dy:
  13.             self.moveUp()

完整代码

我们得到以下完整代码：

  1. from pygame.locals import *
  2. from random import randint
  3. import pygame
  4. import time
  6. class Apple:
  7.     x = 0
  8.     y = 0
  9.     step = 44
  11.     def __init__(self,x,y):
  12.         self.x = x * self.step
  13.         self.y = y * self.step
  15.     def draw(self, surface, image):
  16.         surface.blit(image,(self.x, self.y)) 
  18. class Player:
  19.     x = [0]
  20.     y = [0]
  21.     step = 44
  22.     direction = 0
  23.     length = 3
  25.     updateCountMax = 2
  26.     updateCount = 0
  28.     def __init__(self, length):
  29.        self.length = length
  30.        for i in range(0,2000):
  31.            self.x.append(-100)
  32.            self.y.append(-100)
  34.        # initial positions, no collision.
  35.        self.x[0] = 1*44
  36.        self.x[0] = 2*44
  38.     def update(self):
  40.         self.updateCount = self.updateCount + 1
  41.         if self.updateCount > self.updateCountMax:
  43.             # update previous positions
  44.             for i in range(self.length-1,0,-1):
  45.                 self.x[i] = self.x[i-1]
  46.                 self.y[i] = self.y[i-1]
  48.             # update position of head of snake
  49.             if self.direction == 0:
  50.                 self.x[0] = self.x[0] + self.step
  51.             if self.direction == 1:
  52.                 self.x[0] = self.x[0] - self.step
  53.             if self.direction == 2:
  54.                 self.y[0] = self.y[0] - self.step
  55.             if self.direction == 3:
  56.                 self.y[0] = self.y[0] + self.step
  58.             self.updateCount = 0
  60.     def moveRight(self):
  61.         self.direction = 0
  63.     def moveLeft(self):
  64.         self.direction = 1
  66.     def moveUp(self):
  67.         self.direction = 2
  69.     def moveDown(self):
  70.         self.direction = 3 
  72.     def draw(self, surface, image):
  73.         for i in range(0,self.length):
  74.             surface.blit(image,(self.x[i],self.y[i])) 
  76. class Computer:
  77.     x = [0]
  78.     y = [0]
  79.     step = 44
  80.     direction = 0
  81.     length = 3
  83.     updateCountMax = 2
  84.     updateCount = 0
  86.     def __init__(self, length):
  87.        self.length = length
  88.        for i in range(0,2000):
  89.            self.x.append(-100)
  90.            self.y.append(-100)
  92.        # initial positions, no collision.
  93.        self.x[0] = 1*44
  94.        self.y[0] = 4*44
  96.     def update(self):
  98.         self.updateCount = self.updateCount + 1
  99.         if self.updateCount > self.updateCountMax:
  101.             # update previous positions
  102.             for i in range(self.length-1,0,-1):
  103.                 self.x[i] = self.x[i-1]
  104.                 self.y[i] = self.y[i-1]
  106.             # update position of head of snake
  107.             if self.direction == 0:
  108.                 self.x[0] = self.x[0] + self.step
  109.             if self.direction == 1:
  110.                 self.x[0] = self.x[0] - self.step
  111.             if self.direction == 2:
  112.                 self.y[0] = self.y[0] - self.step
  113.             if self.direction == 3:
  114.                 self.y[0] = self.y[0] + self.step
  116.             self.updateCount = 0
  118.     def moveRight(self):
  119.         self.direction = 0
  121.     def moveLeft(self):
  122.         self.direction = 1
  124.     def moveUp(self):
  125.         self.direction = 2
  127.     def moveDown(self):
  128.         self.direction = 3 
  130.     def target(self,dx,dy):
  131.         if self.x[0] > dx:
  132.             self.moveLeft()
  134.         if self.x[0] < dx:
  135.             self.moveRight()
  137.         if self.x[0] == dx:
  138.             if self.y[0] < dy:
  139.                 self.moveDown()
  141.             if self.y[0] > dy:
  142.                 self.moveUp()
  144.     def draw(self, surface, image):
  145.         for i in range(0,self.length):
  146.             surface.blit(image,(self.x[i],self.y[i])) 
  148. class Game:
  149.     def isCollision(self,x1,y1,x2,y2,bsize):
  150.         if x1 >= x2 and x1 <= x2 + bsize:
  151.             if y1 >= y2 and y1 <= y2 + bsize:
  152.                 return True
  153.         return False
  155. class App:
  157.     windowWidth = 800
  158.     windowHeight = 600
  159.     player = 0
  160.     apple = 0
  162.     def __init__(self):
  163.         self._running = True
  164.         self._display_surf = None
  165.         self._image_surf = None
  166.         self._apple_surf = None
  167.         self.game = Game()
  168.         self.player = Player(5) 
  169.         self.apple = Apple(8,5)
  170.         self.computer = Computer(5)
  172.     def on_init(self):
  173.         pygame.init()
  174.         self._display_surf = pygame.display.set_mode((self.windowWidth,self.windowHeight), pygame.HWSURFACE)
  176.         pygame.display.set_caption('Pygame pythonspot.com example')
  177.         self._running = True
  178.         self._image_surf = pygame.image.load("pygame.png").convert()
  179.         self._apple_surf = pygame.image.load("apple.png").convert()
  181.     def on_event(self, event):
  182.         if event.type == QUIT:
  183.             self._running = False
  185.     def on_loop(self):
  186.         self.computer.target(self.apple.x, self.apple.y)
  187.         self.player.update()
  188.         self.computer.update()
  190.         # does snake eat apple?
  191.         for i in range(0,self.player.length):
  192.             if self.game.isCollision(self.apple.x,self.apple.y,self.player.x[i], self.player.y[i],44):
  193.                 self.apple.x = randint(2,9) * 44
  194.                 self.apple.y = randint(2,9) * 44
  195.                 self.player.length = self.player.length + 1
  197.         # does computer eat apple?
  198.         for i in range(0,self.player.length):
  199.             if self.game.isCollision(self.apple.x,self.apple.y,self.computer.x[i], self.computer.y[i],44):
  200.                 self.apple.x = randint(2,9) * 44
  201.                 self.apple.y = randint(2,9) * 44
  202.                 #self.computer.length = self.computer.length + 1
  204.         # does snake collide with itself?
  205.         for i in range(2,self.player.length):
  206.             if self.game.isCollision(self.player.x[0],self.player.y[0],self.player.x[i], self.player.y[i],40):
  207.                 print "You lose! Collision: "
  208.                 print "x[0] (" + str(self.player.x[0]) + "," + str(self.player.y[0]) + ")"  
  209.                 print "x[" + str(i) + "] (" + str(self.player.x[i]) + "," + str(self.player.y[i]) + ")"  
  210.                 exit(0)
  212.         pass
  214.     def on_render(self):
  215.         self._display_surf.fill((0,0,0))
  216.         self.player.draw(self._display_surf, self._image_surf)
  217.         self.apple.draw(self._display_surf, self._apple_surf)
  218.         self.computer.draw(self._display_surf, self._image_surf)
  219.         pygame.display.flip()
  221.     def on_cleanup(self):
  222.         pygame.quit()
  224.     def on_execute(self):
  225.         if self.on_init() == False:
  226.             self._running = False
  228.         while( self._running ):
  229.             pygame.event.pump()
  230.             keys = pygame.key.get_pressed() 
  232.             if (keys[K_RIGHT]):
  233.                 self.player.moveRight()
  235.             if (keys[K_LEFT]):
  236.                 self.player.moveLeft()
  238.             if (keys[K_UP]):
  239.                 self.player.moveUp()
  241.             if (keys[K_DOWN]):
  242.                 self.player.moveDown()
  244.             if (keys[K_ESCAPE]):
  245.                 self._running = False
  247.             self.on_loop()
  248.             self.on_render()
  250.             time.sleep (50.0 / 1000.0);
  251.         self.on_cleanup()
  253. if __name__ == "__main__" :
  254.     theApp = App()
  255.     theApp.on_execute()

Pygame 中的贪食蛇 AI - 图1

python 贪食蛇

结论

您学习了如何使用非常简单的 AI 算法创建基本的计算机玩家。

下一步：学习基本的侧滑器逻辑