audio.h

Go to the documentation of this file.

//            Copyright (C) 2004-2007 by The Allacrost Project
//                         All Rights Reserved
//
// This code is licensed under the GNU GPL version 2. It is free software
// and you may modify it and/or redistribute it under the terms of this license.
// See http://www.gnu.org/copyleft/gpl.html for details.

#ifndef __AUDIO_HEADER__
#define __AUDIO_HEADER__

#ifdef __APPLE__
  #include <SDL_mixer/SDL_mixer.h>
#else
  #include <SDL/SDL_mixer.h>
#endif

#include "utils.h"
#include "defs.h"
#include "audio_sound.h"
#include "audio_music.h"

namespace hoa_audio {

extern GameAudio* AudioManager;
extern bool AUDIO_DEBUG;

const uint8 AUDIO_STATE_UNLOADED     = 0x01;
const uint8 AUDIO_STATE_STOPPED      = 0x02;
const uint8 AUDIO_STATE_PAUSED       = 0x04;
const uint8 AUDIO_STATE_PLAYING      = 0x08;
const uint8 AUDIO_STATE_FADING_IN    = 0x10;
const uint8 AUDIO_STATE_FADING_OUT   = 0x20;


const int32 AUDIO_LOOP_FOREVER = -1;
const int32 AUDIO_LOOP_ONCE = 0;
const uint32 AUDIO_NO_FADE = 0;
const uint32 AUDIO_STANDARD_FADE = 500;

const uint32 AUDIO_ERROR_NONE          = 0x00000000;
const uint32 AUDIO_ERROR_NO_DATA       = 0x00000001;
const uint32 AUDIO_ERROR_PLAY_FAILURE  = 0x00000002;

namespace private_audio {

const uint32 SOUND_CHANNELS = 16;
const int32 ALL_CHANNELS = -1;
const int32 ANY_CHANNEL = -1;
const int32 BUFFER_SIZE = 1024;

} // namespace private_audio

/*!****************************************************************************
 * \brief A singleton class for managing and interfacing with audio data.
 *
 * This class manages all audio data allocation and manipulation. The OpenAL sources
 * are wrapped inside this class and OpenAL buffers (which are represented by the
 * SoundDescriptor and MusicObject classes) grab these sources as they need them. The
 * buffers are stored in map structures so that audio data is not loaded when it already
 * exists.
 *
 * \note 1) Operations that load audio data should be done during parts of the game
 * when game modes are being created and destroyed. In other words, ideally you should
 * load data into SoundSource and MusicSource objects when a new game mode class object is created,
 * instead of creating them only immediately before they are needed.
 *
 * \note 2) This audio engine uses smart memory management so that loaded audio
 * data is not re-loaded if the user requests a load operation on the same
 * data. Audio data is only freed once there are no more references to the
 * data.
 *****************************************************************************/
class GameAudio : public hoa_utils::Singleton<GameAudio>
{
  friend class hoa_utils::Singleton<GameAudio>;
  friend class private_audio::SoundData;
  friend class SoundDescriptor;
  friend class private_audio::MusicData;
  friend class MusicDescriptor;

public:
  ~GameAudio();

  bool SingletonInitialize ();

  uint32 CheckErrors()
    { uint32 return_code; return_code = _audio_errors; _audio_errors = AUDIO_ERROR_NONE; return return_code; }

  void Update();

  float GetMusicVolume()
    { return _music_volume; }
  float GetSoundVolume()
    { return _sound_volume; }
  void SetMusicVolume(float vol);
  void SetSoundVolume(float vol);

  void PlaySound(std::string filename);

  void PauseAudio();
  void ResumeAudio();
  void StopAudio();
  void RewindAudio();

  void PauseAllSounds();
  void ResumeAllSounds();
  void StopAllSounds();
//  void RewindAllSounds();

  void PauseAllMusic();
  void ResumeAllMusic();
  void StopAllMusic();
  void RewindAllMusic();

  void DEBUG_PrintInfo();

private:
  GameAudio();

  float _music_volume;
  float _sound_volume;
  uint32 _audio_errors;

  std::map<std::string, private_audio::MusicData*> _music_data;
  std::map<std::string, private_audio::SoundData*> _sound_data;

  private_audio::SoundData* _AcquireSoundData(std::string filename);
  private_audio::MusicData* _AcquireMusicData(std::string filename);

  std::list<SoundDescriptor*> _temp_sounds;

}; // class GameAudio

} // namespace hoa_audio

#endif /* #ifndef __AUDIO_HEADER__ */

---