保姆级python教程写个贪吃蛇大冒险(立方体循环)

导语

贪吃蛇，大家应该都玩过。当初第一次接触贪吃蛇的时候，还是我爸的数字手机，考试成绩比较好，就会得到一些小奖励，玩手机游戏肯定也在其中首位，毕竟小孩子天性都喜欢~

当时都能玩的不亦乐乎。今天，我们用Python编程一个贪吃蛇游戏哦~

正文

1.将使用两个主要的类(蛇和立方体)。

#Snake Tutorial Python
 
import math
import random
import pygame
import tkinter as tk
from tkinter import messagebox
 
class cube(object):
 rows = 20
 w = 500
 def __init__(self,start,dirnx=1,dirny=0,color=(255,0,0)):
  pass
  
 def move(self, dirnx, dirny):
  pass
 
 def draw(self, surface, eyes=False):
  pass
  
 
class snake(object):
 def __init__(self, color, pos):
  pass
 
 def move(self):
  pass
  
 
 def reset(self, pos):
  pass
 
 def addCube(self):
  pass
  
 
 def draw(self, surface):
  pass
 
 
def drawGrid(w, rows, surface):
 pass
  
 
def redrawWindow(surface):
 pass
 
 
def randomSnack(rows, item):
 pass
 
 
def message_box(subject, content):
 pass
 
 
def main():
 pass
 
 
 
main()

2.创造游戏循环：

在所有的游戏中，我们都有一个叫做“主循环”或“游戏循环”的循环。该循环将持续运行，直到游戏退出。它主要负责检查事件，并基于这些事件调用函数和方法。

我们将在main()功能。在函数的顶部声明一些变量，然后进入while循环，这将代表我们的游戏循环。

def main(): 
 global width, rows, s
 width = 500  # Width of our screen
 height = 500  # Height of our screen
 rows = 20  # Amount of rows
 
 win = pygame.display.set_mode((width, height))  # Creates our screen object
 
 s = snake((255,0,0), (10,10))  # Creates a snake object which we will code later
  
 clock = pygame.time.Clock() # creating a clock object
 
 flag = True
 # STARTING MAIN LOOP
 while flag:
  pygame.time.delay(50)  # This will delay the game so it doesn't run too quickly
  clock.tick(10)  # Will ensure our game runs at 10 FPS
  redrawWindow(win)  # This will refresh our screen

3.更新屏幕：通常，在一个函数或方法中绘制所有对象是一种很好的做法。我们将使用重绘窗口函数来更新显示。我们在游戏循环中每一帧调用一次这个函数。稍后我们将向该函数添加更多内容。然而，现在我们将简单地绘制网格线。

def redrawWindow(surface):
 surface.fill((0,0,0))  # Fills the screen with black
 drawGrid(surface)  # Will draw our grid lines
 pygame.display.update()  # Updates the screen

4.绘制网格：现在将绘制代表20x20网格的线条。

def drawGrid(w, rows, surface):
 sizeBtwn = w // rows  # Gives us the distance between the lines
 
 x = 0  # Keeps track of the current x
 y = 0  # Keeps track of the current y
 for l in range(rows):  # We will draw one vertical and one horizontal line each loop
  x = x + sizeBtwn
  y = y + sizeBtwn
 
  pygame.draw.line(surface, (255,255,255), (x,0),(x,w))
  pygame.draw.line(surface, (255,255,255), (0,y),(w,y))

5.现在当我们运行程序时，我们可以看到网格线被画出来。

6.开始制作贪吃蛇：蛇对象将包含一个代表蛇身体的立方体列表。我们将把这些立方体存储在一个名为body的列表中，它将是一个类变量。我们还将有一个名为turns的类变量。为了开始蛇类，对__init__()方法并添加类变量。

class snake(object):
 body = []
 turns = {}
 def __init__(self, color, pos):
  self.color = color
  self.head = cube(pos)  # The head will be the front of the snake
  self.body.append(self.head)  # We will add head (which is a cube object)
  # to our body list
 
  # These will represent the direction our snake is moving
  self.dirnx = 0 
  self.dirny = 1

7.这款游戏最复杂的部分就是翻蛇。我们需要记住我们把我们的蛇转向了哪里和哪个方向，这样当头部后面的立方体到达那个位置时，我们也可以把它们转向。这就是为什么每当我们转向时，我们会将头部的位置添加到转向字典中，其中值是我们转向的方向。这样，当其他立方体到达这个位置时，我们就知道如何转动它们了。

class snake(object):
 ...
 def move(self):
  for event in pygame.event.get():
if event.type == pygame.QUIT:
 pygame.quit()
 
keys = pygame.key.get_pressed()
 
for key in keys:
 if keys[pygame.K_LEFT]:
  self.dirnx = -1
  self.dirny = 0
  self.turns[self.head.pos[:]] = [self.dirnx, self.dirny]
 
 elif keys[pygame.K_RIGHT]:
  self.dirnx = 1
  self.dirny = 0
  self.turns[self.head.pos[:]] = [self.dirnx, self.dirny]
 
 elif keys[pygame.K_UP]:
  self.dirnx = 0
  self.dirny = -1
  self.turns[self.head.pos[:]] = [self.dirnx, self.dirny]
 
 elif keys[pygame.K_DOWN]:
  self.dirnx = 0
  self.dirny = 1
  self.turns[self.head.pos[:]] = [self.dirnx, self.dirny]
 
  for i, c in enumerate(self.body):  # Loop through every cube in our body
p = c.pos[:]  # This stores the cubes position on the grid
if p in self.turns:  # If the cubes current position is one where we turned
 turn = self.turns[p]  # Get the direction we should turn
 c.move(turn[0],turn[1])  # Move our cube in that direction
 if i == len(self.body)-1:  # If this is the last cube in our body remove the turn from the dict
  self.turns.pop(p)
else:  # If we are not turning the cube
 # If the cube reaches the edge of the screen we will make it appear on the opposite side
 if c.dirnx == -1 and c.pos[0] <= 0: c.pos = (c.rows-1, c.pos[1])
 elif c.dirnx == 1 and c.pos[0] >= c.rows-1: c.pos = (0,c.pos[1])
 elif c.dirny == 1 and c.pos[1] >= c.rows-1: c.pos = (c.pos[0], 0)
 elif c.dirny == -1 and c.pos[1] <= 0: c.pos = (c.pos[0],c.rows-1)
 else: c.move(c.dirnx,c.dirny)  # If we haven't reached the edge just move in our current direction

8.画蛇：我们只需画出身体中的每个立方体对象。我们将在蛇身上做这个绘制()方法。

class snake(object):
 ...
 def draw(self):
  for i, c in enumerate(self.body):
if i == 0:  # for the first cube in the list we want to draw eyes
 c.draw(surface, True)  # adding the true as an argument will tell us to draw eyes
else:
 c.draw(surface)  # otherwise we will just draw a cube

9.结束游戏当我们的蛇物体与自己碰撞时，我们就输了。为了检查这一点，我们在main()游戏循环中的功能。

for x in range(len(s.body)):
 if s.body[x].pos in list(map(lambda z:z.pos,s.body[x+1:])): # This will check if any of the positions in our body list overlap
  print('Score: ', len(s.body))
  message_box('You Lost!', 'Play again...')
  s.reset((10,10))
  break

10.蛇类–重置()方法现在我们将对重置()方法。所有这些将会做的是重置蛇，这样我们可以在之后再次玩。

class snake():
 ...
 def reset(self, pos):
  self.head = cube(pos)
  self.body = []
  self.body.append(self.head)
  self.turns = {}
  self.dirnx = 0
  self.dirny = 1

下面我们先看看效果：