13class SHIT_API AudioTrack {

14public:

15 AudioTrack(const AudioTrack&) = delete;

16 AudioTrack& operator=(const AudioTrack&) = delete;

17 AudioTrack(AudioTrack&&) noexcept;

18 AudioTrack& operator=(AudioTrack&&) noexcept;

19 ~AudioTrack();

20

21 void pause();

22 void resume();

23 void stop();

24 void setVolume(float gain);

25 float getVolume() const;

26 void setLooping(int loopCount); // -1 = 无限, 0 = 不循环, N = N 次

27 int getLooping() const { return m_loops; }

28

29 bool isPlaying() const;

30 bool isPaused() const;

31 bool isFinished() const;

32

33private:

34 friend class AudioPlayer;

35 friend class AudioTrackGroup;

36 AudioTrack() = default;

37 explicit AudioTrack(MIX_Track* handle);

38

39 MIX_Track* m_handle = nullptr;

40 float m_gain = 1.0f;

41 int m_loops = 0;

42 AudioTrackGroup* m_group = nullptr;

43 // 组生命周期令牌：本 track 仍存活期间持有组引用，组对象不会先于 track 销毁，

44 // 析构时 m_group->unregisterTrack(this) 不会访问已释放的组内存

45 std::shared_ptr<AudioTrackGroup> m_groupOwner;

46 bool m_started = false;

47 bool m_paused = false;

48};