Python游戏练习之贪吃蛇示例
2020-02-01 本文已影响0人
极客匠
这篇文章主要介绍了python实现贪吃蛇小游戏，由键盘控制snake方向，吃食物功能。游戏基于pygame框架制作的
基础知识
- 基于python面向对象编程思想
- pygame知识了解
- python数组操作
需求描述
- 游戏界面分辨率是640x480，蛇和食物都是由1个或多个20x20像素的正方形块儿（为了方便，下文用点表示20x20像素的正方形块儿）组成，这样共有32x24个点，使用pygame.draw.rect来绘制每一个点。
- 初始化时蛇的长度是3，食物是1个点，蛇初始的移动的方向是右，用一个数组代表蛇，数组的每个元素是蛇每个点的坐标，因此数组的第一个坐标是蛇尾，最后一个坐标是蛇头。
- 游戏开始后，根据蛇的当前移动方向，将蛇运动方向的前方的那个点append到蛇数组的末位，再把蛇尾去掉，蛇的坐标数组就相当于往前挪了一位。
- 如果蛇吃到了食物，即蛇头的坐标等于食物的坐标，那么在第2点中蛇尾就不用去掉，就产生了蛇长度增加的效果；食物被吃掉后，随机在空的位置（不能与蛇的身体重合）再生成一个
- 通过PyGame的event监控按键，改变蛇的方向，例如当蛇向右时，下一次改变方向只能向上或者向下。
- 当蛇撞上自身或墙壁，游戏结束，蛇头装上自身，那么蛇坐标数组里就有和舌头坐标重复的数据，撞上墙壁则是蛇头坐标超过了边界，都很好判断。
- 其他细节：做了个开始的欢迎界面；食物的颜色随机生成。
代码示例
import pygame
import sys, os
from time import sleep
from random import choice
from itertools import product
from pygame.locals import QUIT, KEYDOWN
class Snake(object):
def __init__(self):
self.map = {(x, y): 0 for x in range(32) for y in range(24)}
self.body = [[100, 100], [120, 100], [140, 100]]
self.head = [140, 100]
self.moving_direction = 'right'
self.speed = 10
self.game_started = False
def check_game_status(self):
if self.body.count(self.head) > 1:
return True
if self.head[0] < 0 or self.head[0] > 620 or self.head[1] < 0 or self.head[1] > 460:
return True
return False
def move_head(self):
moves = {
'right': (20, 0),
'up': (0, -20),
'down': (0, 20),
'left': (-20, 0)
}
step = moves[self.moving_direction]
self.head[0] += step[0]
self.head[1] += step[1]
class Food(object):
def __init__(self, pos, colors):
self.colors = colors
self.food_postion = [pos[0], pos[1]]
class GameSnake(object):
def __init__(self, snake):
self.snake = snake
self.generate_food()
def generate_food(self):
self.snake.speed = len(self.snake.body) // 16 if len(self.snake.body) // 16 > 4 else self.snake.speed
for seg in self.snake.body:
x, y = seg
self.snake.map[x // 20, y // 20] = 1
empty_pos = [pos for pos in self.snake.map.keys() if not self.snake.map[pos]]
result = choice(empty_pos)
self.food = Food(([result[0] * 20, result[1] * 20]), list(choice(list(product([0, 64, 128, 192, 255], repeat=3))[1:-1])))
def direction_check(self, moving_direction, change_direction):
directions = [['up', 'down'], ['left', 'right']]
if moving_direction in directions[0] and change_direction in directions[1]:
return change_direction
elif moving_direction in directions[1] and change_direction in directions[0]:
return change_direction
return moving_direction
def run(self):
key_direction_dict = {
119: 'up', # W
115: 'down', # S
97: 'left', # A
100: 'right', # D
273: 'up', # UP
274: 'down', # DOWN
276: 'left', # LEFT
275: 'right', # RIGHT
}
fps_clock = pygame.time.Clock()
pygame.init()
pygame.mixer.init()
title_font = pygame.font.SysFont('arial', 32)
welcome_words = title_font.render('Welcome to My Snake', True, (0, 0, 0), (255, 255, 255))
tips_font = pygame.font.SysFont('arial', 24)
start_game_words = tips_font.render('Click to Start Game', True, (0, 0, 0), (255, 255, 255))
close_game_words = tips_font.render('Press ESC to Close', True, (0, 0, 0), (255, 255, 255))
gameover_words = title_font.render('GAME OVER', True, (205, 92, 92), (255, 255, 255))
win_words = title_font.render('THE SNAKE IS LONG ENOUGH AND YOU WIN!', True, (0, 0, 205), (255, 255, 255))
screen = pygame.display.set_mode((640, 480), 0, 32)
pygame.display.set_caption('My Snake')
new_direction = self.snake.moving_direction
while 1:
for event in pygame.event.get():
if event.type == QUIT:
exit()
elif event.type == KEYDOWN:
if event.key == 27:
exit()
if self.snake.game_started and event.key in key_direction_dict:
direction = key_direction_dict[event.key]
new_direction = self.direction_check(self.snake.moving_direction, direction)
elif (not self.snake.game_started) and event.type == pygame.MOUSEBUTTONDOWN:
x, y = pygame.mouse.get_pos()
if 213 <= x <= 422 and 304 <= y <= 342:
self.snake.game_started = True
screen.fill((255, 255, 255))
if self.snake.game_started:
self.snake.moving_direction = new_direction # 在这里赋值，而不是在event事件的循环中赋值，避免按键太快
self.snake.move_head()
self.snake.body.append(self.snake.head[:])
if self.snake.head == self.food.food_postion:
self.generate_food()
else:
self.snake.body.pop(0)
for seg in self.snake.body:
pygame.draw.rect(screen, [0, 0, 0], [seg[0], seg[1], 20, 20], 0)
pygame.draw.rect(screen, self.food.colors, [self.food.food_postion[0], self.food.food_postion[1], 20, 20], 0)
if self.snake.check_game_status():
screen.blit(gameover_words, (241, 310))
pygame.display.update()
self.snake = Snake()
new_direction = self.snake.moving_direction
sleep(3)
elif len(self.snake.body) == 512:
screen.blit(win_words, (33, 210))
pygame.display.update()
self.snake = Snake()
new_direction = self.snake.moving_direction
sleep(3)
else:
screen.blit(welcome_words, (188, 100))
screen.blit(start_game_words, (236, 310))
screen.blit(close_game_words, (233, 350))
pygame.display.update()
fps_clock.tick(self.snake.speed)
if __name__ == '__main__':
gameSanke = GameSnake(Snake())
gameSanke.run()
代码链接：https://github.com/trk-huang/Game-snake.git
总结：练习python数组操作，pygame的api，训练基于python面向对象编程思想。
每天多努力那么一点点，积少成多
