/*      VU.H
 *
 * Real VU meter routines
 *
 * Copyright 1995 Petteri Kangaslampi and Jarno Paananen
 *
 * This file is part of the MIDAS Sound System, and may only be
 * used, modified and distributed under the terms of the MIDAS
 * Sound System license, LICENSE.TXT. By continuing to use,
 * modify or distribute this file you indicate that you have
 * read the license and understand and accept it fully.
*/

#ifndef __VU_H
#define __VU_H


/****************************************************************************\
*       struct vuInstrument
*       -------------------
* Description:  VU-meter internal instrument structure
\****************************************************************************/

typedef struct
{
    uchar       *vuInfo;                /* pointer to VU information or NULL*/
    ushort      slength;                /* sample length */
    ushort      loopStart;              /* sample loop start */
    ushort      loopEnd;                /* sample loop end or 0 if no
                                           looping */
} vuInstrument;



#ifdef __cplusplus
extern "C" {
#endif



/****************************************************************************\
*
* Function:     int vuInit(void);
*
* Description:  Initializes VU-meters, allocating room for MAXINSTS
*               instruments.
*
* Returns:      MIDAS error code
*
\****************************************************************************/

int CALLING vuInit(void);



/****************************************************************************\
*
* Function:     int vuClose(void);
*
* Description:  Uninitializes VU-meters
*
* Returns:      MIDAS error code
*
\****************************************************************************/

int CALLING vuClose(void);



/****************************************************************************\
*
* Function:     int vuPrepare(ushort inst, uchar *sample, ushort slength,
*                             ushort loopStart, ushort loopEnd
*
* Description:  Prepares the VU information for an instrument
*
* Input:        ushort inst             instrument number
*               uchar *sample           pointer to sample data
*               ushort slength          sample length
*               ushort loopStart        sample loop start
*               ushort loopEnd          sample loop end (0 if no looping)
*
* Returns:      MIDAS error code
*
\****************************************************************************/

int CALLING vuPrepare(ushort inst, uchar *sample, ushort slength,
    ushort loopStart, ushort loopEnd);



/****************************************************************************\
*
* Function:     int vuRemove(ushort inst);
*
* Description:  Removes and deallocates the VU information for an instrument
*
* Input:        ushort inst             instrument number
*
* Returns:      MIDAS error code
*
\****************************************************************************/

int CALLING vuRemove(ushort inst);




/****************************************************************************\
*
* Function:     int vuMeter(ushort inst, ulong rate, ushort pos,
*                           ushort volume, ushort *meter);
*
* Description:  Calculates the VU-meter value (0-64) for the next 1/50th of
*               a second
*
* Input:        ushort inst             instrument that is played
*               ulong rate              playing rate
*               ushort pos              sample playing position
*               ushort volume           playing volume (0-64)
*               ushort *meter           pointer to VU-meter value
*
* Returns:      MIDAS error code.
*               VU-meter value (0-64) is stored in *meter
*
\****************************************************************************/

int CALLING vuMeter(ushort inst, ulong rate, ushort pos, ushort volume,
    ushort *meter);


#ifdef __cplusplus
}
#endif



/****************************************************************************\
*       enum vuFunctIDs
*       ---------------
* Description:  ID numbers for real VU-meter functions
\****************************************************************************/

enum vuFunctIDs
{
    ID_vuInit = ID_vu,
    ID_vuClose,
    ID_vuPrepare,
    ID_vuRemove,
    ID_vuMeter
};


#endif
