looper/playback.h

#pragma once
#include <SDL_mixer.h>
#include <thread>
#include <SDL.h>
#include <SDL_audio.h>
#include <string>
#include <atomic>
#include <mutex>
#include <SoundTouch.h>
#include <span>
#include <optional>
#include <vector>
#include <queue>
using namespace soundtouch;
using std::span;
using std::optional;
using std::vector;
using std::queue;
enum {
    PlaybackSignalNone = 0,
    PlaybackSignalFileChanged = 1 << 0,
    PlaybackSignalSpeedChanged = 1 << 1,
    PlaybackSignalTempoChanged = 1 << 2,
    PlaybackSignalPitchChanged = 1 << 3,
    PlaybackSignalPaused = 1 << 4,
    PlaybackSignalResumed = 1 << 5,
    PlaybackSignalStopped = 1 << 6,
    PlaybackSignalErrorOccurred = 1 << 7,
    PlaybackSignalSeeked = 1 << 8,
    PlaybackSignalStarted = 1 << 9
};
class Playback {
private:
    std::string filePath;
    std::atomic_bool running;
    std::atomic_bool file_changed;
    std::atomic_bool seeking;
    std::atomic_bool update;
    std::atomic_bool restart;
    std::atomic_bool playback_ready;
    std::atomic_bool speed_changed;
    std::atomic_bool tempo_changed;
    std::atomic_bool pitch_changed;
    std::atomic_bool pause_changed;
    std::mutex flag_mutex;
    std::mutex error_mutex;
    std::thread thread;
    double position;
    double length;
    bool paused;
    Uint8* buf;
    size_t bufsize;
    Mix_CommonMixer_t general_mixer;
    SDL_AudioDeviceID device;
    SoundTouch *st;
    SDL_AudioSpec spec;
    /// @brief A fake SDL_AudioSpec used to trick SDL Mixer X into allocating a bigger buffer.
    SDL_AudioSpec fakespec;
    void SDLCallbackInner(Uint8 *stream, int len);
    static void SDLCallback(void *userdata, Uint8 *stream, int len);
    Mix_Music *Load(const char* file);
    void Unload(Mix_Music* music);
    void ThreadFunc();
    void UpdateST();
    double GetMaxSeconds();
    queue<std::string> errors;
    std::mutex current_file_mutex;
    std::optional<std::string> current_file;
    uint16_t signals_occurred = PlaybackSignalNone;
    std::mutex signal_mutex;
    void set_signal(uint16_t signal);
    float prev_pitch, prev_speed, prev_tempo;
public:
    Playback();
    ~Playback();
    std::optional<std::string> get_current_file();
    double GetPosition();
    double GetLength();
    void Seek(double position);
    void Start(std::string filePath);
    bool IsPaused();
    void Pause();
    void Stop();
    void Update();
    bool IsStopped();
    float volume;
    float speed;
    float tempo;
    float pitch;
    float MaxSeconds = 100.0;
    float MaxSpeed = 4.0;
    float MaxPitch = 4.0;
    float MaxTempo = 4.0;
    float MinSpeed = 0.25;
    float MinPitch = 0.25;
    float MinTempo = 0.25;

    uint16_t handle_signals(uint16_t signal);
    optional<std::string> GetError();
    bool ErrorExists();
};