🎹 Python钢琴节奏大师 · 第9章

系列：Python钢琴节奏大师：从零到游戏开发实战^[1]章节：第9章 / 共12章标题：游戏系统篇-状态管理与生命值机制设计上一章：第8章-节奏游戏篇^[2]下一章：第10章-视觉美化篇^[3]

计分与结束——真正的游戏

今日目标：完善计分系统，添加游戏结束判定，实现重新开始功能，完成游戏状态管理。

💡 本章核心：实现完整的游戏系统，让游戏有始有终

🎹 效果预览

完成本篇学习后，你的游戏会有：

• 开始菜单界面
• 生命值系统（错过音符扣血）
• 游戏结束判定
• 重新开始功能
• 最终成绩展示

┌────────────────────────────────────┐│                                    ││         🎹 钢琴节奏大师 🎹          ││                                    ││         最高分：5000               ││                                    ││      [按空格键开始游戏]            ││                                    │└────────────────────────────────────┘              ↓         游戏进行中              ↓┌────────────────────────────────────┐│  分数：3250  生命：❤️❤️❤️💔💔       ││                                    ││         游戏结束！                 ││                                    ││      最终得分：3250                ││      最高连击：45                  ││      准确率：87%                   ││                                    ││    [按R重新开始]  [按Q退出]        ││                                    │└────────────────────────────────────┘

🤔 什么是游戏状态？

游戏通常有多个"状态"：

为什么要分状态？

• 不同状态显示不同内容
• 不同状态响应不同操作
• 逻辑更清晰，代码更好维护

📝 第一步：定义游戏状态

# 游戏状态常量STATE_MENU = 0STATE_PLAYING = 1STATE_PAUSED = 2STATE_GAME_OVER = 3# 当前状态current_state = STATE_MENU

使用枚举（更专业）

from enum import EnumclassGameState(Enum):    MENU = 0    PLAYING = 1    PAUSED = 2    GAME_OVER = 3current_state = GameState.MENU

📝 第二步：添加生命值系统

生命值的实现

# 游戏参数MAX_LIVES = 5# 最大生命值lives = MAX_LIVES      # 当前生命值# 当错过音符时if note.y > JUDGMENT_LINE + JUDGMENT_RANGE andnot note.hit:    lives -= 1# 扣一滴血    combo = 0# 连击中断if lives <= 0:        current_state = STATE_GAME_OVER  # 生命为0，游戏结束

显示生命值

defdraw_lives(screen, lives):"""绘制生命值"""    heart_full = "❤️"# 满血    heart_empty = "💔"# 空血    lives_text = ""for i inrange(MAX_LIVES):if i < lives:            lives_text += heart_fullelse:            lives_text += heart_empty    text = font.render(f"生命：{lives_text}", True, WHITE)    screen.blit(text, (20, 100))

📝 第三步：菜单界面

菜单显示

defdraw_menu(screen):"""绘制菜单界面"""    screen.fill((30, 30, 50))  # 深蓝紫色背景# 标题    title = big_font.render("🎹 钢琴节奏大师 🎹", True, (255, 200, 100))    screen.blit(title, (SCREEN_WIDTH//2 - title.get_width()//2, 150))# 最高分    high_score_text = font.render(f"最高分：{high_score}", True, WHITE)    screen.blit(high_score_text, (SCREEN_WIDTH//2 - high_score_text.get_width()//2, 250))# 操作说明    instructions = ["操作说明：","A S D F G H J - 白键（do re mi fa sol la si）","W E T Y U - 黑键（#do #re #fa #sol #la）","","按空格键开始游戏"    ]    y = 350for line in instructions:        text = small_font.render(line, True, (200, 200, 200))        screen.blit(text, (SCREEN_WIDTH//2 - text.get_width()//2, y))        y += 30

菜单事件处理

if current_state == STATE_MENU:if event.type == pygame.KEYDOWN:if event.key == pygame.K_SPACE:            reset_game()           # 重置游戏            current_state = STATE_PLAYING

📝 第四步：游戏结束界面

显示最终成绩

defdraw_game_over(screen):"""绘制游戏结束界面"""# 半透明黑色遮罩    overlay = pygame.Surface((SCREEN_WIDTH, SCREEN_HEIGHT))    overlay.fill(BLACK)    overlay.set_alpha(200)  # 透明度    screen.blit(overlay, (0, 0))# 游戏结束标题    title = big_font.render("游戏结束！", True, (255, 100, 100))    screen.blit(title, (SCREEN_WIDTH//2 - title.get_width()//2, 150))# 成绩统计    stats = [f"最终得分：{score}",f"最高连击：{max_combo}",f"击中次数：{hits}",f"错过次数：{misses}",f"准确率：{hits/(hits+misses)*100:.1f}%"if (hits+misses) > 0else"准确率：0%"    ]    y = 250for stat in stats:        text = font.render(stat, True, WHITE)        screen.blit(text, (SCREEN_WIDTH//2 - text.get_width()//2, y))        y += 40# 操作提示    hint = small_font.render("按 R 重新开始  按 Q 退出", True, (200, 200, 200))    screen.blit(hint, (SCREEN_WIDTH//2 - hint.get_width()//2, 500))

更新最高分

# 最高分记录（保存在内存中，游戏重启会重置）high_score = 0defupdate_high_score():"""更新最高分"""global high_scoreif score > high_score:        high_score = score

📝 第五步：重置游戏

defreset_game():"""重置游戏状态"""global score, combo, max_combo, hits, misses, livesglobal notes, spawn_timer, white_key_pressed    score = 0    combo = 0    max_combo = 0    hits = 0    misses = 0    lives = MAX_LIVES    notes = []    spawn_timer = 0    white_key_pressed = [False] * WHITE_KEY_COUNT

🎯 完整代码

import pygameimport randompygame.init()pygame.mixer.init()# 窗口SCREEN_WIDTH, SCREEN_HEIGHT = 800, 600screen = pygame.display.set_mode((SCREEN_WIDTH, SCREEN_HEIGHT))pygame.display.set_caption("钢琴节奏大师 - 完整版")clock = pygame.time.Clock()# 颜色BLACK, WHITE, GRAY, DARK_GRAY = (0,0,0), (255,255,255), (200,200,200), (50,50,50)YELLOW, NOTE_COLOR, RED = (255,255,0), (255,100,100), (255,100,100)# 游戏状态STATE_MENU = 0STATE_PLAYING = 1STATE_PAUSED = 2STATE_GAME_OVER = 3current_state = STATE_MENU# 钢琴键参数WHITE_KEY_WIDTH, WHITE_KEY_HEIGHT = 80, 300WHITE_KEY_COUNT = 7START_X, START_Y = 100, 350JUDGMENT_LINE = START_YJUDGMENT_RANGE = 30# 键盘映射WHITE_KEY_MAPPING = {    pygame.K_a: 0, pygame.K_s: 1, pygame.K_d: 2,    pygame.K_f: 3, pygame.K_g: 4, pygame.K_h: 5, pygame.K_j: 6,}WHITE_KEY_NAMES = ["do", "re", "mi", "fa", "sol", "la", "si"]WHITE_KEY_CHARS = ["A", "S", "D", "F", "G", "H", "J"]# 音符类classNote:def__init__(self, lane):self.lane = laneself.y = -50self.speed = 5self.active = Trueself.hit = Falsedefupdate(self):self.y += self.speedifself.y > SCREEN_HEIGHT + 50:self.active = Falsedefdraw(self, screen):ifself.active:            x = START_X + self.lane * WHITE_KEY_WIDTH + WHITE_KEY_WIDTH // 2            pygame.draw.circle(screen, NOTE_COLOR, (int(x), int(self.y)), 15)            pygame.draw.line(screen, NOTE_COLOR, (int(x), int(self.y)), (int(x), int(self.y)-40), 4)# 字体font = pygame.font.SysFont(None, 36)big_font = pygame.font.SysFont(None, 72)small_font = pygame.font.SysFont(None, 24)# 游戏状态变量score = combo = max_combo = hits = misses = 0lives = 5MAX_LIVES = 5high_score = 0notes = []spawn_timer = 0SPAWN_INTERVAL = 45white_key_pressed = [False] * WHITE_KEY_COUNT# 辅助函数defreset_game():global score, combo, max_combo, hits, misses, lives, notes, spawn_timer, white_key_pressed    score = combo = max_combo = hits = misses = 0    lives = MAX_LIVES    notes = []    spawn_timer = 0    white_key_pressed = [False] * WHITE_KEY_COUNTdefcheck_hit(lane):for note in notes:if note.active andnot note.hit and note.lane == lane:            distance = abs(note.y - JUDGMENT_LINE)if distance <= JUDGMENT_RANGE:                note.hit, note.active = True, FalsereturnTrue, distancereturnFalse, Nonedefadd_score(distance):global score, combo, hits, max_comboif distance <= 10:        points, combo = 100, combo + 1        judgment = "Perfect!"elif distance <= 20:        points, combo = 80, combo + 1        judgment = "Great!"elif distance <= 30:        points, combo = 50, combo + 1        judgment = "Good"else:        points, combo = 0, 0        judgment = "Miss"    score += points + combo * 5    hits += 1    max_combo = max(max_combo, combo)return judgment, pointsdefspawn_note():    notes.append(Note(random.randint(0, WHITE_KEY_COUNT - 1)))defdraw_menu():    screen.fill((30, 30, 50))    title = big_font.render("钢琴节奏大师", True, (255, 200, 100))    screen.blit(title, (SCREEN_WIDTH//2 - title.get_width()//2, 150))    high = font.render(f"最高分：{high_score}", True, WHITE)    screen.blit(high, (SCREEN_WIDTH//2 - high.get_width()//2, 250))    hint = small_font.render("按空格键开始游戏", True, (200, 200, 200))    screen.blit(hint, (SCREEN_WIDTH//2 - hint.get_width()//2, 350))defdraw_game_over():    overlay = pygame.Surface((SCREEN_WIDTH, SCREEN_HEIGHT))    overlay.fill(BLACK)    overlay.set_alpha(200)    screen.blit(overlay, (0, 0))    title = big_font.render("游戏结束！", True, RED)    screen.blit(title, (SCREEN_WIDTH//2 - title.get_width()//2, 150))    stats = [f"最终得分：{score}",f"最高连击：{max_combo}",f"准确率：{hits/(hits+misses)*100:.1f}%"if (hits+misses) > 0else"准确率：0%"    ]    y = 250for stat in stats:        text = font.render(stat, True, WHITE)        screen.blit(text, (SCREEN_WIDTH//2 - text.get_width()//2, y))        y += 50    hint = small_font.render("按 R 重新开始  按 Q 退出", True, (200, 200, 200))    screen.blit(hint, (SCREEN_WIDTH//2 - hint.get_width()//2, 500))defdraw_lives():    lives_text = f"生命：{'❤️' * lives}{'💔' * (MAX_LIVES - lives)}"    text = font.render(lives_text, True, WHITE)    screen.blit(text, (20, 100))# 游戏循环running = Truejudgment_text = ""judgment_timer = 0while running:    clock.tick(60)# 事件处理for event in pygame.event.get():if event.type == pygame.QUIT:            running = Falseif current_state == STATE_MENU:if event.type == pygame.KEYDOWN and event.key == pygame.K_SPACE:                reset_game()                current_state = STATE_PLAYINGelif current_state == STATE_PLAYING:if event.type == pygame.KEYDOWN:if event.key == pygame.K_ESCAPE:                    current_state = STATE_MENUelif event.key in WHITE_KEY_MAPPING:                    idx = WHITE_KEY_MAPPING[event.key]                    white_key_pressed[idx] = True                    hit, dist = check_hit(idx)if hit:                        j, p = add_score(dist)                        judgment_text, judgment_timer = f"{j} +{p}", 30else:                        judgment_text, judgment_timer = "空按", 20elif event.type == pygame.KEYUP:if event.key in WHITE_KEY_MAPPING:                    white_key_pressed[WHITE_KEY_MAPPING[event.key]] = Falseelif current_state == STATE_GAME_OVER:if event.type == pygame.KEYDOWN:if event.key == pygame.K_r:                    reset_game()                    current_state = STATE_PLAYINGelif event.key == pygame.K_q:                    running = False# 更新if current_state == STATE_PLAYING:        spawn_timer += 1if spawn_timer >= SPAWN_INTERVAL:            spawn_note()            spawn_timer = 0for note in notes:            note.update()if note.active and note.y > JUDGMENT_LINE + JUDGMENT_RANGE andnot note.hit:                lives -= 1                combo = 0                misses += 1                judgment_text, judgment_timer = "Miss!", 30                note.active = Falseif lives <= 0:                    current_state = STATE_GAME_OVERif score > high_score:                        high_score = score        notes = [n for n in notes if n.active]        judgment_timer = max(0, judgment_timer - 1)if judgment_timer == 0:            judgment_text = ""# 绘制    screen.fill(DARK_GRAY)if current_state == STATE_MENU:        draw_menu()elif current_state == STATE_PLAYING:# 判定线        pygame.draw.line(screen, YELLOW, (START_X, JUDGMENT_LINE),                        (START_X + WHITE_KEY_COUNT * WHITE_KEY_WIDTH, JUDGMENT_LINE), 3)# 音符for note in notes:            note.draw(screen)# 白键for i inrange(WHITE_KEY_COUNT):            x = START_X + i * WHITE_KEY_WIDTH            color = YELLOW if white_key_pressed[i] else WHITE            pygame.draw.rect(screen, color, (x, START_Y, WHITE_KEY_WIDTH, WHITE_KEY_HEIGHT))            pygame.draw.rect(screen, GRAY, (x, START_Y, WHITE_KEY_WIDTH, WHITE_KEY_HEIGHT), 1)            screen.blit(small_font.render(WHITE_KEY_CHARS[i], True, DARK_GRAY), (x + 35, START_Y + 10))            screen.blit(font.render(WHITE_KEY_NAMES[i], True, BLACK), (x + 25, START_Y + 250))# UI        screen.blit(font.render(f"分数：{score}", True, WHITE), (20, 20))        screen.blit(font.render(f"连击：{combo}", True, WHITE), (20, 60))        draw_lives()if combo > 0:            screen.blit(big_font.render(str(combo), True, YELLOW), (SCREEN_WIDTH//2 - 20, 80))if judgment_text:            screen.blit(big_font.render(judgment_text, True, YELLOW), (SCREEN_WIDTH//2 - 100, 150))elif current_state == STATE_GAME_OVER:# 先绘制游戏画面        pygame.draw.line(screen, YELLOW, (START_X, JUDGMENT_LINE),                        (START_X + WHITE_KEY_COUNT * WHITE_KEY_WIDTH, JUDGMENT_LINE), 3)for note in notes:            note.draw(screen)for i inrange(WHITE_KEY_COUNT):            x = START_X + i * WHITE_KEY_WIDTH            pygame.draw.rect(screen, WHITE, (x, START_Y, WHITE_KEY_WIDTH, WHITE_KEY_HEIGHT))# 再绘制结束界面        draw_game_over()    pygame.display.flip()pygame.quit()

🔍 核心概念

1. 游戏状态管理

if current_state == STATE_MENU:# 显示菜单elif current_state == STATE_PLAYING:# 游戏进行中elif current_state == STATE_GAME_OVER:# 游戏结束

2. 生命值系统

lives = MAX_LIVES  # 初始满血# 受伤lives -= 1# 检查死亡if lives <= 0:    game_over()

3. 最高分记录

if score > high_score:    high_score = score  # 更新最高分

🎨 动手改造

改造1：添加暂停功能

if event.key == pygame.K_SPACE:if current_state == STATE_PLAYING:        current_state = STATE_PAUSEDelif current_state == STATE_PAUSED:        current_state = STATE_PLAYING

改造2：难度递增

# 随着分数增加，速度加快note.speed = 5 + score // 1000

改造3：保存最高分到文件

# 保存withopen("highscore.txt", "w") as f:    f.write(str(high_score))# 读取try:withopen("highscore.txt", "r") as f:        high_score = int(f.read())except:    high_score = 0

❓ 常见问题

Q1：游戏结束后无法重新开始

检查：reset_game() 函数是否正确重置所有变量？

Q2：生命值显示异常

检查：lives 是否可能变成负数？添加保护：lives = max(0, lives)

Q3：状态切换没反应

检查：事件处理是否在正确的状态分支中？

Q4：最高分没保存

说明：当前版本最高分只在内存中，重启游戏会重置。

🎉 恭喜你完成第9课！

今天你已经：

• ✅ 学会了游戏状态管理
• ✅ 实现了生命值系统
• ✅ 完成了游戏结束判定
• ✅ 添加了重新开始功能

你的钢琴游戏现在是一个完整的游戏了！