text: //! Structure storing ReplayGain configuration: album/track source data modes, gain/peak processing modes and preamp values.
  struct t_replaygain_config
  {
  	enum /*t_source_mode*/ {
  		source_mode_none,
  		source_mode_track,
  		source_mode_album, 
  		// New in 1.3.8
  		// SPECIAL MODE valid only for playback settings; if set, track gain will be used for random & shuffle-tracks modes, album for shuffle albums & ordered playback.
  		source_mode_byPlaybackOrder 
  	};
  	enum /*t_processing_mode*/ {processing_mode_none,processing_mode_gain,processing_mode_gain_and_peak,processing_mode_peak};
  	typedef t_uint32 t_source_mode; typedef t_uint32 t_processing_mode;
  
  	t_replaygain_config() {reset();}
  	t_replaygain_config(t_source_mode p_source_mode,t_processing_mode p_processing_mode,float p_preamp_without_rg, float p_preamp_with_rg)
  		: m_source_mode(p_source_mode), m_processing_mode(p_processing_mode), m_preamp_without_rg(p_preamp_without_rg), m_preamp_with_rg(p_preamp_with_rg) {}
  
  	
  	t_source_mode m_source_mode;
  	t_processing_mode m_processing_mode;
  	float m_preamp_without_rg, m_preamp_with_rg;//preamp values in dB
  
  	void reset();
  	audio_sample query_scale(const file_info & info) const;
  	audio_sample query_scale(const metadb_handle_ptr & info) const;
  	audio_sample query_scale(const replaygain_info & info) const;
  
  	void format_name(pfc::string_base & p_out) const;
  	bool is_active() const;
  
  	static bool equals(const t_replaygain_config & v1, const t_replaygain_config & v2) {
  		return v1.m_source_mode == v2.m_source_mode && v1.m_processing_mode == v2.m_processing_mode && v1.m_preamp_without_rg == v2.m_preamp_without_rg && v1.m_preamp_with_rg == v2.m_preamp_with_rg;
  	}
  	bool operator==(const t_replaygain_config & other) const {return equals(*this, other);}
  	bool operator!=(const t_replaygain_config & other) const {return !equals(*this, other);}
  };
  
  FB2K_STREAM_READER_OVERLOAD(t_replaygain_config) {
  	return stream >> value.m_source_mode >> value.m_processing_mode >> value.m_preamp_with_rg >> value.m_preamp_without_rg;
  }
  FB2K_STREAM_WRITER_OVERLOAD(t_replaygain_config) {
  	return stream << value.m_source_mode << value.m_processing_mode << value.m_preamp_with_rg << value.m_preamp_without_rg;
  }
  
  //! Core service providing methods to retrieve/alter playback ReplayGain settings, as well as use ReplayGain configuration dialog.
  class NOVTABLE replaygain_manager : public service_base {
  public:
  	//! Retrieves playback ReplayGain settings.
  	virtual void get_core_settings(t_replaygain_config & p_out) = 0;
  
  	//! Creates embedded version of ReplayGain settings dialog. Note that embedded dialog sends WM_COMMAND with id/BN_CLICKED to parent window when user makes changes to settings.
  	virtual HWND configure_embedded(const t_replaygain_config & p_initdata,HWND p_parent,unsigned p_id,bool p_from_modal) = 0;
  	//! Retrieves settings from embedded version of ReplayGain settings dialog.
  	virtual void configure_embedded_retrieve(HWND wnd,t_replaygain_config & p_data) = 0;
  	
  	//! Shows popup/modal version of ReplayGain settings dialog. Returns true when user changed the settings, false when user cancelled the operation. Title parameter can be null to use default one.
  	virtual bool configure_popup(t_replaygain_config & p_data,HWND p_parent,const char * p_title) = 0;
  
  	//! Alters playback ReplayGain settings.
  	virtual void set_core_settings(const t_replaygain_config & p_config) = 0;
  
  	//! New in 1.0
  	virtual void configure_embedded_set(HWND wnd, t_replaygain_config const & p_data) = 0;
  	//! New in 1.0
  	virtual void get_core_defaults(t_replaygain_config & out) = 0;
  
  	//! Helper; queries scale value for specified item according to core playback settings.
  	audio_sample core_settings_query_scale(const file_info & p_info);
  	//! Helper; queries scale value for specified item according to core playback settings.
  	audio_sample core_settings_query_scale(const metadb_handle_ptr & info);
  
  	FB2K_MAKE_SERVICE_COREAPI(replaygain_manager);
  };
  
  //! \since 1.4
  class NOVTABLE replaygain_core_settings_notify {
  public:
  	virtual void on_changed( t_replaygain_config const & cfg ) = 0;
  };
  
  //! \since 1.4
  //! Adds new method for getting notified about core RG settings changing
  class NOVTABLE replaygain_manager_v2 : public replaygain_manager {
  	FB2K_MAKE_SERVICE_COREAPI_EXTENSION( replaygain_manager_v2, replaygain_manager );
  public:
  	virtual void add_notify(replaygain_core_settings_notify *) = 0;
  	virtual void remove_notify(replaygain_core_settings_notify *) = 0;
  };