/*	----------------------------------------------------------------------------
	CHANNEL.hpp

	Describes a CHANNEL object, which represents an ASIO compliant sound
	channel.

	The most important aspect of this CHANNEL idea is that these objects 
	are simply a convienient way of loading the g_Layla table.  The bufSW
	routine then uses this table to process sound buffers efficiently.
	bufSW does most of the work.  The CHANNEL instantiations are simply
	a convienent way to map waveforms or memory locations to sound buffers.
	Nothing really happens until Go or Ramp are called, only house keeping
	is being set up.


	CHANNEL has to know how to use a wave object because he knows WHEN
	a sound buffer needs to be initiialized and he knows WHERE the buffer
	is.  WAVE knows how to initialize the buffer, but not WHERE or WHEN.


	Some typical call sequences are given below:

		CHANNEL		chTX( 2 ,CH_OUT )	,chNULL( 4 ,CH_OUT );
		CHANNEL		chMeas( 1 ,CH_IN );
		CHANNEL		chMaster;

		chTX.link	( &waveTX );
		chNULL.link	( &waveNULL );
		chMeas.link	( &measurement ,LenMeasurement );

		chTX.play();							// Plays just this channel
		chMeas.record();						// Records just this channel

		chMaster.Go();							// Starts playing all outputs and recording all inputs
		chMaster.Ramp( FADE_IN | FADE_OUT );	// Ramps all outputs up or down

		chMaster.Stop();						// Shuts down the ASIO driver, releasing resources


		????
		chTX.update();							// Lets channel know that underlying waveform has changed

		OR...

		WAVE tracks change with a flag... output CHANNELs check this flag
		to see if a sound buffer update is requried.
*/


#ifndef _CHANNEL_
#define _CHANNEL_

#include "misctyps.h"
#include "globals.h"
#include "WAVES2.hpp"


typedef enum {

	 CH_NULL
	,CH_IN
	,CH_OUT

} CHDIR;


class CHANNEL {

//------------- Class construction/destruction
  public:
				CHANNEL	( void );								// Constructs a master channel
				CHANNEL	( long SoundBufSZ );					// Constructs a master channel, setting sound buffer size
				CHANNEL	( WAVE *pwave ,int Channel );			// Constructs an output (D/A) channel
				CHANNEL	( void *pv ,ulong WVsize ,int Channel );// Constructs an input (A/D) channel

				~CHANNEL( void );								// Destructor
  private:
	int			channel	( void * ,ulong ,int ,CHDIR );	// Common initializer

  protected:											// Define but don't implement to prevent these operations
				CHANNEL	( CHANNEL &refCHANNEL );		// Copy constructors (disallow?)
				CHANNEL	( CHANNEL *pCHANNEL );
	CHANNEL	&operator =	( CHANNEL &refCHANNEL );


//------------- Class methods
  public:
	void		chan	( int Channel );				// Remaps the channel (deactivated after call to .go)
	void		link	( WAVE *pwave );				// Links channel to waveform
	void		link	( void *pvMem ,ulong Len );		// Links to general memory

	void		lock	( void );						// Lock waveform away from sound buffer manager
	void		unlock	( void );						// Un lock waveform
	void		change	( void );						// Flags channel as updated so appropriate sound buffer can be loaded
	void		convert	( void );						// Converts channel from binary to floating point representation
	void		convert	( WAVEPTR pWV );
	void		cvrtSeg	( WAVEPTR wpToSegment );		// Converts only a channel segment from binary to fp representation

	void		go		( void );						// Starts playing/recording all linked channels
	void		ramp	( void );						// Ramps all linked output channels
	void		stop	( void );						// Stops playing/recording all linked channels

	int			clear	( void );						// Returns true if channels can be accessed
	int			done	( void );						// Returns true if entire waveform has been read/written
	int			busy	( void );						// Returns non-zero parameter indicating how close to being done
	void		GetNew	( void );						// Forces channel to load an entire new waveform
	int			seg		( int WhichSegment );			// Returns true if passed segment has been read/written
	int			NextSeg	( void );						// Returns next segment to be read/written
	int			NextSeg	( int SegmentOffset );			// Returns the next segment plus the indicated offset
	int			CurSeg	( void );						// Returns the most recently read in segment
	WAVEPTR		SegAddr	( int WhichSegment );			// Returns address of the indicated segement

	uint		Missed	( void );						// Returns missed channels
	uint		BufStat	( void );						// Returns sound buffer service status
	uint		Status	( void );						// Returns channel object status



//------------- Member variables
  public:

	int			m_Ch;									// Active channel number
	CHDIR		m_Dir;									// Channel direction
	WAVE		*m_pWAVE;								// Linked waveform
	long		*m_plWave;
	ulong		m_WVsize;
	int			m_TblIdx;								// Index into LAYA wave/chan mapping table


	static int	g_ON;									// Flag to indicate if the ASIO driver has been turned on
	static int	g_Init;
	static int	g_NumCh;
	static WAVE	*g_pWAVE;								// General waveform processor
	static uint	g_Status;
};


#endif