import pygame

import random

# 初始化pygame

pygame.init()

# 游戏区域大小

width = 500

height = 500

# 创建游戏窗口

screen = pygame.display.set_mode((width, height))

# 设置游戏标题

pygame.display.set_caption("贪吃蛇")

# 定义颜色

white = (255, 255, 255)

black = (0, 0, 0)

red = (255, 0, 0)

# 定义蛇的初始位置和大小

snake_block = 10

snake_speed = 15

# 定义字体

font_style = pygame.font.SysFont(None, 30)

def our_snake(snake_block, snake_list):

    for x in snake_list:

        pygame.draw.rect(screen, black, [x[0], x[1], snake_block, snake_block])

def message(msg, color):

    mesg = font_style.render(msg, True, color)

    screen.blit(mesg, [width / 6, height / 3])

# 游戏循环

def game_loop():

    game_over = False

    game_close = False

    x1 = width / 2

    y1 = height / 2

    x1_change = 0

    y1_change = 0

    snake_List = []

    Length_of_snake = 1

    foodx = round(random.randrange(0, width - snake_block) / 10.0) * 10.0

    foody = round(random.randrange(0, height - snake_block) / 10.0) * 10.0

    # 游戏主循环

    while not game_over:

        while game_close == True:

            screen.fill(white)

            message("你输了，按Q退出，按C重新开始", red)

            pygame.display.update()

            # 重新开始或退出游戏

            for event in pygame.event.get():

                if event.type == pygame.KEYDOWN:

                    if event.key == pygame.K_q:

                        game_over = True

                        game_close = False

                    if event.key == pygame.K_c:

                        game_loop()

        # 处理按键事件

        for event in pygame.event.get():

            if event.type == pygame.QUIT:

                game_over = True

            if event.type == pygame.KEYDOWN:

                if event.key == pygame.K_LEFT:

                    x1_change = -snake_block

                    y1_change = 0

                elif event.key == pygame.K_RIGHT:

                    x1_change = snake_block

                    y1_change = 0

                elif event.key == pygame.K_UP:

                    y1_change = -snake_block

                    x1_change = 0

                elif event.key == pygame.K_DOWN:

                    y1_change = snake_block

                    x1_change = 0

        # 判断是否撞墙

        if x1 >= width or x1 < 0 or y1 >= height or y1 < 0:

            game_close = True

        # 更新蛇的位置

        x1 += x1_change

        y1 += y1_change

        screen.fill(white)

        pygame.draw.rect(screen, red, [foodx, foody, snake_block, snake_block])

        snake_Head = []

        snake_Head.append(x1)

        snake_Head.append(y1)

        snake_List.append(snake_Head)

        # 控制蛇的长度

        if len(snake_List) > Length_of_snake:

            del snake_List[0]

        # 判断是否吃到食物

        for x in snake_List[:-1]:

            if x == snake_Head:

                game_close = True

        our_snake(snake_block, snake_List)

        pygame.display.update()

        # 判断是否吃到食物，更新食物位置

        if x1 == foodx and y1 == foody:

            foodx = round(random.randrange(0, width - snake_block) / 10.0) * 10.0

            foody = round(random.randrange(0, height - snake_block) / 10.0) * 10.0

            Length_of_snake += 1

        # 控制游戏速度

        pygame.time.delay(snake_speed)

    # 退出pygame

    pygame.quit()

# 启动游戏循环

game_loop()