snake/game_functions.py

import pygame
import sys


def check_events(settings):
    for event in pygame.event.get():
        # 当按关闭或者按ESC键退出游戏
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()
        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_ESCAPE:
                pygame.quit()
                sys.exit()
            # 按1键选择手动模式
            elif event.key == pygame.K_1:
                settings.game_mode = 1
            # 按2键选择自动模式
            elif event.key == pygame.K_2:
                settings.game_mode = 2


def show_start(settings, screen):
    """模式选择界面"""
    title_Font = pygame.font.Font(settings.font_name, 80)  # 设置标题字体
    title_image = title_Font.render("贪吃蛇", True, (255, 255, 255), (0, 0, 0))
    title_rect = title_image.get_rect()
    title_rect.center = screen.get_rect().center

    presskey_font = pygame.font.Font(settings.font_name, 15)  # 设置说明文字的字体
    presskey_image = presskey_font.render(
        '按1为手动模式,按2为自动模式,按ESC可退出游戏', True, (255, 255, 255), (0, 0, 0))
    presskey_rect = presskey_image.get_rect()
    presskey_rect.centerx = title_rect.centerx
    presskey_rect.top = title_rect.bottom
    while True:
        screen.fill(settings.bg_color)  # 绘制屏幕
        screen.blit(title_image, title_rect)  # 绘制标题
        screen.blit(presskey_image, presskey_rect)  # 绘制说明文字
        check_events(settings)  # 检测键盘
        if settings.game_mode != 0:  # 说明按了1或2，退出循环
            break
        pygame.display.flip()


def show_end(settings, screen):
    """失败结算界面"""
    title_font = pygame.font.Font(settings.font_name, 80)
    game_image = title_font.render('Game', True, (233, 150, 122))
    over_image = title_font.render('Over', True, (233, 150, 122))
    game_rect = game_image.get_rect()
    over_rect = over_image.get_rect()
    screen_rect = screen.get_rect()
    game_rect.midtop = (settings.width / 2, screen_rect.top + 70)
    over_rect.midtop = (settings.width / 2, game_rect.bottom + 50)
    screen.blit(game_image, game_rect)
    screen.blit(over_image, over_rect)
    pygame.display.flip()
    pygame.time.wait(1500)
    settings.game_mode = 0

def draw_grid(settings, screen):
	#绘制横向线
	for x in range(0, settings.width, settings.cell_size):
		pygame.draw.line(screen,(40,40,40),(x,0),(x,settings.height))
	#绘制竖向线
	for y in range(0, settings.height, settings.cell_size):
		pygame.draw.line(screen,(40,40,40),(0, y),(settings.width,y))
 
def update_screen(settings, screen):
	screen.fill(settings.bg_color)
	draw_grid(settings, screen)

#绘制蛇
def draw_snake(ai_settings, screen, snake):
	#头部用白色
	x = snake.coords[0]['x'] * ai_settings.cell_size
	y = snake.coords[0]['y'] * ai_settings.cell_size
	snake_head_rect = pygame.Rect(x, y, ai_settings.cell_size, ai_settings.cell_size)
	pygame.draw.rect(screen,(255,255,255), snake_head_rect)
	#蛇身内部用浅绿，外框用深绿
	for coord in snake.coords[1: -1]:
		x = coord['x'] * ai_settings.cell_size
		y = coord['y'] * ai_settings.cell_size
		snake_part_rect = pygame.Rect(x, y, ai_settings.cell_size, ai_settings.cell_size)
		pygame.draw.rect(screen,(0,155,0), snake_part_rect)
		snake_part_inner_rect = pygame.Rect(x + 4, y + 4, ai_settings.cell_size - 8, ai_settings.cell_size - 8)
		pygame.draw.rect(screen,(0,255,0), snake_part_inner_rect)
	#蛇尾用浅绿
	coord = snake.coords[-1]
	x = coord['x'] * ai_settings.cell_size
	y = coord['y'] * ai_settings.cell_size
	snake_tail_rect = pygame.Rect(x, y, ai_settings.cell_size, ai_settings.cell_size)
	pygame.draw.rect(screen,(0,255,0), snake_tail_rect)
 
#绘制游戏界面
def update_screen(settings, screen, snake):
	screen.fill(settings.bg_color)
	draw_grid(settings, screen)
	#移动蛇
	del snake.coords[-1]#加蛇头
	snake.update()#去蛇尾
	if not is_game_over(settings, snake):
		settings.game_mode = -1
	else:
		draw_snake(settings, screen, snake)
		pygame.display.flip()
		#暂停一下
		settings.my_clock.tick(settings.clock_frq)

def is_game_over(settings,snake):
	#碰到左右墙壁
	if (snake.coords[snake.head_index]['x'] == -1 or snake.coords[snake.head_index]['x'] == settings.cell_w):
		return False
	#碰到上下墙壁
	if(snake.coords[snake.head_index]['y'] == -1 or snake.coords[snake.head_index]['y'] == settings.cell_h):
		return False
	#碰到自己
	if(snake.coords[snake.head_index] in snake.coords[1:]):
		return False
	return True
      

#检测游戏过程中的按键
def check_play_events(snake):
	for event in pygame.event.get():
		if event.type == pygame.QUIT:
			pygame.quit()
			sys.exit()
		elif event.type == pygame.KEYDOWN:
			if event.key == pygame.K_ESCAPE:
				pygame.quit()
				sys.exit()
			elif event.key == pygame.K_LEFT and not snake.direction == 'right':
				snake.direction = 'left'
			elif event.key == pygame.K_RIGHT and not snake.direction == 'left':
				snake.direction = 'right'
			elif event.key == pygame.K_UP and not snake.direction == 'down':
				snake.direction = 'up'
			elif event.key == pygame.K_DOWN and not snake.direction == 'up':
				snake.direction = 'down'