/**
 * \file music_channel_fader.h
 * \brief CMusicChannelFader
 * \date 2008-09-04 21:49GMT
 * \author Jan Boon (Kaetemi)
 * CMusicChannelFader roughly based on music_channel_fmod.h
 */

// NeL - MMORPG Framework <http://dev.ryzom.com/projects/nel/>
// Copyright (C) 2010  Winch Gate Property Limited
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

#ifndef NLSOUND_MUSIC_CHANNEL_FADER_H
#define NLSOUND_MUSIC_CHANNEL_FADER_H
#include "stdsound.h"

// STL includes

// NeL includes

// Project includes

namespace NLSOUND {
	class ISoundDriver;
	class IMusicChannel;

/**
 * \brief CMusicChannelFader
 * \date 2008-09-04 21:49GMT
 * \author Jan Boon (Kaetemi)
 * Roughly based on stuff in old CMusicChannelFMod
 */
class CMusicChannelFader
{
private:
	struct _CMusicFader
	{
		_CMusicFader() : MusicChannel(NULL), XFadeVolume(0.f), XFadeDVolume(0.f), Playing(false), Fade(false) { }
		IMusicChannel *MusicChannel;
		float XFadeVolume; // 0--1
		float XFadeDVolume; // delta
		bool Playing;
		bool Fade;

		inline void fadeIn(uint xFadeTime)
		{
			XFadeVolume = 0.f;
			XFadeDVolume = 1000.f / xFadeTime;
			Fade = true; 
		}

		inline void fadeOut(uint xFadeTime)
		{
			XFadeDVolume = -1000.f / xFadeTime;
			Fade = true;
		}
	};

protected:
	// const
	static const uint _MaxMusicFader = 2;

	// outside pointers
	ISoundDriver *_SoundDriver;
	
	// pointers
	_CMusicFader _MusicFader[_MaxMusicFader];
	
	// instances
	uint _ActiveMusicFader;
	float _Gain;
	NLMISC::TTime _LastTime;
public:
	CMusicChannelFader();
	virtual ~CMusicChannelFader();
	void init(ISoundDriver *soundDriver);
	void release();

	void update(); // time in seconds
	inline bool isInitOk() { return _SoundDriver != NULL; }

private:
	void updateVolume();

public:
	/** Play some music (.ogg etc...)
	 *	NB: if an old music was played, it is first stop with stopMusic()
	 *	\param filepath file path, CPath::lookup is done here
	 *  \param async stream music from hard disk, preload in memory if false
	 *	\param loop must be true to play the music in loop. 
	 */
	bool play(const std::string &filepath, uint xFadeTime = 0, bool async = true, bool loop = true); 

	/// Stop the music previously loaded and played (the Memory is also freed)
	void stop(uint xFadeTime = 0);

	/// Pause the music previously loaded and played (the Memory is not freed)
	void pause();
	
	/// Resume the music previously paused
	void resume();

	/// Return true if all songs are finished.
	bool isEnded();
	
	/// Return the total length (in second) of the music currently played
	float getLength();
	
	/// Set the music volume (if any music played). (volume value inside [0 , 1]) (default: 1)
	/// NB: the volume of music is NOT affected by IListener::setGain()
	void setVolume(float gain);
}; /* class CMusicChannelFader */

} /* namespace NLSOUND */

#endif /* #ifndef NLSOUND_MUSIC_CHANNEL_FADER_H */

/* end of file */