增加游戏的可玩性

上一节的游戏太过单调了，我们继续给游戏增加一些可玩性内容。

• 显示分数
• 游戏的进入界面和结算界面
• 让敌人的逻辑不那么单调
• 让角色的动作更生动

显示分数

这里我们将分数设置为玩家坚持的时间，每过一秒，分数+1。具体实现时用到了pygame.time.get_ticks()获取时间。相关代码：

def display_score(): current = pygame.time.get_ticks() // 1000 - start_time score_surf = test_font.render(f"Score:{current}", False, (64,64,64)) screen.blit(score_surf,score_surf.get_rect(center=(400,50))) return current

进入界面和结算界面

在游戏开始时，提示玩家玩法。在游戏结束时，进入结算界面，显示玩家得分。为了实现上述目的，我们需要设置一个全局变量game_activate来记录游戏状态。并且在游戏主循环中，（使用if~else）根据状态进行不同的显示。相关代码：

game_activate = False while True: ... if game_activate : # 正常游戏 ... else: # 显示游戏结束界面 ...

让敌人的逻辑不那么单调

只是一只蜗牛重复的跑，未免太单调了。我们创建一个列表，存放多个敌人。显示和碰撞检测也对列表进行操作。并且利用 random.randint()给敌人的种类和位置增加随机性。

相关代码：

obstacle_rect_list = [] def collisions(player , obstacles): if obstacles: for obstacle_rect in obstacles: if player.colliderect(obstacle_rect): return True return False

此外，为了定时生成敌人，用到了定时器Timer，其作用是每间隔一定时间，就生成一个pygame.event。

# Timer obstacle_timer = pygame.USEREVENT + 1 pygame.time.set_timer(obstacle_timer, 1500) for event in pygame.event.get(): if game_activate: ... if event.type == obstacle_timer: if random.randint(0,2): obstacle_rect_list.append(snail_surf.get_rect(bottomright=(random.randint(900, 1100), 300))) ...

让角色的动作更生动

通过两种图片的快速切换，可以制造出动画的效果：

利用这个原理，让人物的腿起来：

player_walk_1 = pygame.image.load('graphics/Player/player_walk_1.png').convert_alpha() player_walk_2 = pygame.image.load('graphics/Player/player_walk_2.png').convert_alpha() player_walk = [player_walk_1, player_walk_2] player_index = 0 player_jump = pygame.image.load('graphics/Player/jump.png').convert_alpha() player_surf = player_walk[player_index] player_rect = player_surf.get_rect(midbottom=(80, 300)) def player_animation(): global player_surf, player_index if player_rect.bottom <300: # jump player_surf = player_jump else: player_index += 0.1 # 我们不想腿变换的频率太快 if player_index >= len(player_walk): player_index = 0 player_surf = player_walk[int(player_index)]

对于蜗牛和苍蝇，我们使用timer 来更新动画。每次Timer触发，所有的蜗牛和苍蝇都会更新。（蜗牛和苍蝇有各自的timer）。(为什么这里要用Timer呢？为蜗牛和苍蝇分别设置各自的timer，方便我们分别控制蜗牛和苍蝇动画更新的频率。如果你乐意，也可以把人物动画用timer实现)

snail_animation_timer = pygame.USEREVENT + 2 pygame.time.set_timer(snail_animation_timer,800) fly_animation_timer = pygame.USEREVENT + 3 pygame.time.set_timer(fly_animation_timer,200) # 获取用户输入 for event in pygame.event.get(): if event.type == snail_animation_timer: snail_frames_index = ~snail_frames_index snail_surf = snail_frames[snail_frames_index] if event.type == fly_animation_timer: fly_frames_index = ~fly_frames_index fly_surf = fly_frames[fly_frames_index]

最终效果：

完整代码：

import random import pygame from sys import exit def display_score(): # 显示分数 current = pygame.time.get_ticks() // 1000 - start_time score_surf = test_font.render(f"Score:{current}", False, (64, 64, 64)) screen.blit(score_surf, score_surf.get_rect(center=(400, 50))) return current def player_animation(): # 播放主角跑步和跳跃的动画 global player_surf, player_index if player_rect.bottom < 300: # jump player_surf = player_jump else: player_index += 0.1 # 我们不想腿变换的频率太快 if player_index >= len(player_walk): player_index = 0 player_surf = player_walk[int(player_index)] # 初始化 引擎 pygame.init() # 设置屏幕 screen = pygame.display.set_mode((800, 400)) # 宽度800，高度400 pygame.display.set_caption('Runner') # 设置标题 # 时钟 clock = pygame.time.Clock() # 字体 test_font = pygame.font.Font('font/Pixeltype.ttf', 50) # 背景 sky_surf = pygame.image.load('graphics/Sky.png').convert() ground_surf = pygame.image.load('graphics/ground.png').convert() # 得分 score_surf = test_font.render("My game", False, 'Black') score_rect = score_surf.get_rect(center=(400, 50)) # 游戏简介 game_name_surf = test_font.render("Runner", False, 'Black') game_name_rect = game_name_surf.get_rect(center=(400, 80)) game_message_surf = test_font.render("Press space to run", False, (111, 196, 169)) game_message_rect = game_message_surf.get_rect(center=(400, 320)) # Obstacles （障碍，有蜗牛和苍蝇） snail_frame_1 = pygame.image.load('graphics/snail/snail1.png').convert_alpha() snail_frame_2 = pygame.image.load('graphics/snail/snail2.png').convert_alpha() snail_frames = [snail_frame_1, snail_frame_2] snail_frames_index = 0 snail_surf = snail_frames[snail_frames_index] fly_frame_1 = pygame.image.load('graphics/Fly/Fly1.png').convert_alpha() fly_frame_2 = pygame.image.load('graphics/Fly/Fly2.png').convert_alpha() fly_frames = [fly_frame_1, fly_frame_2] fly_frames_index = 0 fly_surf = fly_frames[fly_frames_index] obstacle_rect_list = [] # 人物 player_walk_1 = pygame.image.load('graphics/Player/player_walk_1.png').convert_alpha() player_walk_2 = pygame.image.load('graphics/Player/player_walk_2.png').convert_alpha() player_walk = [player_walk_1, player_walk_2] player_index = 0 player_jump = pygame.image.load('graphics/Player/jump.png').convert_alpha() player_surf = player_walk[player_index] player_rect = player_surf.get_rect(midbottom=(80, 300)) player_stand_surf = pygame.image.load('graphics/Player/player_stand.png').convert_alpha() player_stand_surf = pygame.transform.rotozoom(player_stand_surf, 0, 2) player_stand_rect = player_stand_surf.get_rect(midbottom=(400, 300)) player_gravity = 0 game_activate = False start_time = 0 score = 0 # Timer obstacle_timer = pygame.USEREVENT + 1 pygame.time.set_timer(obstacle_timer, 1500) snail_animation_timer = pygame.USEREVENT + 2 pygame.time.set_timer(snail_animation_timer, 800) fly_animation_timer = pygame.USEREVENT + 3 pygame.time.set_timer(fly_animation_timer, 200) def obstacle_movement(obstacle_rect_list): # 移动障碍 if obstacle_rect_list: for obstacle_rect in obstacle_rect_list: obstacle_rect.x -= 5 if obstacle_rect.bottom == 300: screen.blit(snail_surf, obstacle_rect) else: screen.blit(fly_surf, obstacle_rect) obstacle_rect_list = [obstacle_rect for obstacle_rect in obstacle_rect_list if obstacle_rect.x > 0] else: obstacle_rect_list = [] return obstacle_rect_list def collisions(player, obstacles): # 碰撞检测 if obstacles: for obstacle_rect in obstacles: if player.colliderect(obstacle_rect): return True return False while True: # 获取用户输入 for event in pygame.event.get(): # 用户点击退出，关闭游戏 if event.type == pygame.QUIT: pygame.quit() exit() if game_activate: if event.type == pygame.KEYDOWN: if event.key == pygame.K_SPACE and player_rect.bottom >= 300: player_gravity -= 20 if event.type == obstacle_timer: if random.randint(0, 2): obstacle_rect_list.append(snail_surf.get_rect(bottomright=(random.randint(900, 1100), 300))) else: obstacle_rect_list.append(fly_surf.get_rect(bottomright=(random.randint(900, 1100), 210))) if event.type == snail_animation_timer: snail_frames_index = ~snail_frames_index snail_surf = snail_frames[snail_frames_index] if event.type == fly_animation_timer: fly_frames_index = ~fly_frames_index fly_surf = fly_frames[fly_frames_index] else: if event.type == pygame.KEYDOWN: if event.key == pygame.K_SPACE: game_activate = True start_time = pygame.time.get_ticks() // 1000 # 游戏运行：绘图,更新 if game_activate: pygame.draw.rect(screen, '#c0e8ec', score_rect) pygame.draw.rect(screen, '#c0e8ec', score_rect, 10) screen.blit(sky_surf, (0, 0)) # 将test_surface放到screen上。(0,0)：放置后test_surface的左上角位于screen的(0,0)处 screen.blit(ground_surf, (0, 300)) score = display_score() obstacle_rect_list = obstacle_movement(obstacle_rect_list) player_gravity += 1 player_rect.y += player_gravity if player_rect.bottom >= 300: player_rect.bottom = 300 player_gravity = 0 player_animation() screen.blit(player_surf, player_rect) if collisions(player_rect, obstacle_rect_list): game_activate = False # 游戏结束： else: obstacle_rect_list.clear() player_rect.midbottom = (80, 300) player_gravity = 0 screen.fill((94, 129, 162)) screen.blit(player_stand_surf, player_stand_rect) screen.blit(game_name_surf, game_name_rect) if score == 0: screen.blit(game_message_surf, game_message_rect) else: score_message = test_font.render(f'Your score:{score}', False, (111, 196, 169)) score_message_rect = score_message.get_rect(center=(400, 320)) screen.blit(score_message, score_message_rect) pygame.display.update() clock.tick(60) # 不超过60 fps