Genesis-Plus-GX/source/sound/eq.h

/*---------------------------------------------------------------------------
//
//                                3 Band EQ :)
//
// EQ.H - Header file for 3 band EQ
//
// (c) Neil C / Etanza Systems / 2K6
//
// Shouts / Loves / Moans = etanza at lycos dot co dot uk 
//
// This work is hereby placed in the public domain for all purposes, including
// use in commercial applications.
//
// The author assumes NO RESPONSIBILITY for any problems caused by the use of
// this software.
//
//----------------------------------------------------------------------------*/

#ifndef __EQ3BAND__
#define __EQ3BAND__

/* ------------
//| Structures |
// ------------*/

typedef struct {
    /* Filter #1 (Low band) */

    double lf;      /* Frequency */
    double f1p0;      /* Poles ... */
    double f1p1;
    double f1p2;
    double f1p3;

    /* Filter #2 (High band) */

    double hf;      /* Frequency */
    double f2p0;      /* Poles ... */
    double f2p1;
    double f2p2;
    double f2p3;

    /* Sample history buffer */

    double sdm1;      /* Sample data minus 1 */
    double sdm2;      /*                   2 */
    double sdm3;      /*                   3 */

    /* Gain Controls */

    double lg;      /* low  gain */
    double mg;      /* mid  gain */
    double hg;      /* high gain */

} EQSTATE;


/* ---------
//| Exports |
// ---------*/

extern void init_3band_state(EQSTATE * es, int lowfreq, int highfreq,
           int mixfreq);
extern double do_3band(EQSTATE * es, int sample);


#endif        /* #ifndef __EQ3BAND__ */