load_imf.c

MIDI解码程序(用VC编写)

/*      MikMod sound library
   (c) 1998, 1999 Miodrag Vallat and others - see file AUTHORS for
   complete list.

   This library is free software; you can redistribute it and/or modify
   it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 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 Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
   02111-1307, USA.
 */

/*==============================================================================

  $Id: load_imf.c,v 1.12 1999/10/25 16:31:41 miod Exp $

  Imago Orpheus (IMF) module loader

==============================================================================*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <string.h>

#include "unimod_priv.h"

/*========== Module structure */

/* module header */
typedef struct IMFHEADER
  {
    CHAR songname[32];
    UWORD ordnum;
    UWORD patnum;
    UWORD insnum;
    UWORD flags;
    UBYTE initspeed;
    UBYTE inittempo;
    UBYTE mastervol;
    UBYTE mastermult;
    UBYTE orders[256];
  }
IMFHEADER;

/* channel settings */
typedef struct IMFCHANNEL
  {
    CHAR name[12];
    UBYTE chorus;
    UBYTE reverb;
    UBYTE pan;
    UBYTE status;
  }
IMFCHANNEL;

/* instrument header */
#define IMFNOTECNT (10*OCTAVE)
#define IMFENVCNT (16*2)
typedef struct IMFINSTHEADER
  {
    CHAR name[32];
    UBYTE what[IMFNOTECNT];
    UWORD volenv[IMFENVCNT];
    UWORD panenv[IMFENVCNT];
    UWORD pitenv[IMFENVCNT];
    UBYTE volpts;
    UBYTE volsus;
    UBYTE volbeg;
    UBYTE volend;
    UBYTE volflg;
    UBYTE panpts;
    UBYTE pansus;
    UBYTE panbeg;
    UBYTE panend;
    UBYTE panflg;
    UBYTE pitpts;
    UBYTE pitsus;
    UBYTE pitbeg;
    UBYTE pitend;
    UBYTE pitflg;
    UWORD volfade;
    UWORD numsmp;
    ULONG signature;
  }
IMFINSTHEADER;

/* sample header */
typedef struct IMFWAVHEADER
  {
    CHAR samplename[13];
    ULONG length;
    ULONG loopstart;
    ULONG loopend;
    ULONG samplerate;
    UBYTE volume;
    UBYTE pan;
    UBYTE flags;
  }
IMFWAVHEADER;

typedef struct IMFNOTE
  {
    UBYTE note, ins, eff1, dat1, eff2, dat2;
  }
IMFNOTE;

/*========== Loader variables */

static CHAR IMF_Version[] = "Imago Orpheus";

static IMFNOTE *imfpat = NULL;
static IMFHEADER *mh = NULL;

/*========== Loader code */

BOOL 
IMF_Test (void)
{
  UBYTE id[4];

  _mm_fseek (modreader, 0x3c, SEEK_SET);
  if (!_mm_read_UBYTES (id, 4, modreader))
    return 0;
  if (!memcmp (id, "IM10", 4))
    return 1;
  return 0;
}

BOOL 
IMF_Init (void)
{
  if (!(imfpat = (IMFNOTE *) _mm_malloc (32 * 256 * sizeof (IMFNOTE))))
    return 0;
  if (!(mh = (IMFHEADER *) _mm_malloc (sizeof (IMFHEADER))))
    return 0;

  return 1;
}

void 
IMF_Cleanup (void)
{
  FreeLinear ();

  _mm_free (imfpat);
  _mm_free (mh);
}

static BOOL 
IMF_ReadPattern (SLONG size, UWORD rows)
{
  int row = 0, flag, ch;
  IMFNOTE *n, dummy;

  /* clear pattern data */
  memset (imfpat, 255, 32 * 256 * sizeof (IMFNOTE));

  while ((size > 0) && (row < rows))
    {
      flag = _mm_read_UBYTE (modreader);
      size--;

      if (_mm_eof (modreader))
	{
	  _mm_errno = MMERR_LOADING_PATTERN;
	  return 0;
	}

      if (flag)
	{
	  ch = remap[flag & 31];

	  if (ch != -1)
	    n = &imfpat[256 * ch + row];
	  else
	    n = &dummy;

	  if (flag & 32)
	    {
	      n->note = _mm_read_UBYTE (modreader);
	      if (n->note >= 0xa0)
		n->note = 0xa0;	/* note off */
	      n->ins = _mm_read_UBYTE (modreader);
	      size -= 2;
	    }
	  if (flag & 64)
	    {
	      size -= 2;
	      n->eff2 = _mm_read_UBYTE (modreader);
	      n->dat2 = _mm_read_UBYTE (modreader);
	    }
	  if (flag & 128)
	    {
	      n->eff1 = _mm_read_UBYTE (modreader);
	      n->dat1 = _mm_read_UBYTE (modreader);
	      size -= 2;
	    }
	}
      else
	row++;
    }
  if ((size) || (row != rows))
    {
      _mm_errno = MMERR_LOADING_PATTERN;
      return 0;
    }
  return 1;
}

static void 
IMF_ProcessCmd (UBYTE eff, UBYTE inf)
{
  if ((eff) && (eff != 255))
    switch (eff)
      {
      case 0x01:		/* set tempo */
	UniEffect (UNI_S3MEFFECTA, inf);
	break;
      case 0x02:		/* set BPM */
	if (inf >= 0x20)
	  UniEffect (UNI_S3MEFFECTT, inf);
	break;
      case 0x03:		/* tone portamento */
	UniEffect (UNI_ITEFFECTG, inf);
	break;
      case 0x04:		/* porta + volslide */
	UniEffect (UNI_ITEFFECTG, inf);
	UniEffect (UNI_S3MEFFECTD, 0);
	break;
      case 0x05:		/* vibrato */
	UniPTEffect (0x4, inf);
	break;
      case 0x06:		/* vibrato + volslide */
	UniPTEffect (0x4, inf);
	UniEffect (UNI_S3MEFFECTD, 0);
	break;
      case 0x07:		/* fine vibrato */
	UniEffect (UNI_ITEFFECTU, inf);
	break;
      case 0x08:		/* tremolo */
	UniEffect (UNI_S3MEFFECTR, inf);
	break;
      case 0x09:		/* arpeggio */
	UniPTEffect (0x0, inf);
	break;
      case 0x0a:		/* panning */
	UniPTEffect (0x8, (inf >= 128) ? 255 : (inf << 1));
	break;
      case 0x0b:		/* pan slide */
	UniEffect (UNI_XMEFFECTP, inf);
	break;
      case 0x0c:		/* set channel volume */
	if (inf <= 64)
	  UniPTEffect (0xc, inf);
	break;
      case 0x0d:		/* volume slide */
	UniEffect (UNI_S3MEFFECTD, inf);
	break;
      case 0x0e:		/* fine volume slide */
	if (inf)
	  {
	    if (inf >> 4)
	      UniEffect (UNI_S3MEFFECTD, 0x0f | inf);
	    else
	      UniEffect (UNI_S3MEFFECTD, 0xf0 | inf);
	  }
	else
	  UniEffect (UNI_S3MEFFECTD, 0);
	break;
      case 0x0f:		/* set finetune */
	UniPTEffect (0xe, 0x50 | (inf >> 4));
	break;
#ifdef MIKMOD_DEBUG
      case 0x10:		/* note slide up */
      case 0x11:		/* not slide down */
	fprintf (stderr, "\rIMF effect 0x10/0x11 (note slide)"
		 " not implemented (eff=%2X inf=%2X)\n", eff, inf);
	break;
#endif
      case 0x12:		/* slide up */
	UniEffect (UNI_S3MEFFECTF, inf);
	break;
      case 0x13:		/* slide down */
	UniEffect (UNI_S3MEFFECTE, inf);
	break;
      case 0x14:		/* fine slide up */
	if (inf)
	  {
	    if (inf < 0x40)
	      UniEffect (UNI_S3MEFFECTF, 0xe0 | (inf / 4));
	    else
	      UniEffect (UNI_S3MEFFECTF, 0xf0 | (inf >> 4));
	  }
	else
	  UniEffect (UNI_S3MEFFECTF, 0);
	break;
      case 0x15:		/* fine slide down */
	if (inf)
	  {
	    if (inf < 0x40)
	      UniEffect (UNI_S3MEFFECTE, 0xe0 | (inf / 4));
	    else
	      UniEffect (UNI_S3MEFFECTE, 0xf0 | (inf >> 4));
	  }
	else
	  UniEffect (UNI_S3MEFFECTE, 0);
	break;
	/* 0x16 set filter cutoff (awe32) */
	/* 0x17 filter side + resonance (awe32) */
      case 0x18:		/* sample offset */
	UniPTEffect (0x9, inf);
	break;
#ifdef MIKMOD_DEBUG
      case 0x19:		/* set fine sample offset */
	fprintf (stderr, "\rIMF effect 0x19 (fine sample offset)"
		 " not implemented (inf=%2X)\n", inf);
	break;
#endif
      case 0x1a:		/* keyoff */
	UniWriteByte (UNI_KEYOFF);
	break;
      case 0x1b:		/* retrig */
	UniEffect (UNI_S3MEFFECTQ, inf);
	break;
      case 0x1c:		/* tremor */
	UniEffect (UNI_S3MEFFECTI, inf);
	break;
      case 0x1d:		/* position jump */
	UniPTEffect (0xb, inf);
	break;
      case 0x1e:		/* pattern break */
	UniPTEffect (0xd, (inf >> 4) * 10 + (inf & 0xf));
	break;
      case 0x1f:		/* set master volume */
	if (inf <= 64)
	  UniEffect (UNI_XMEFFECTG, inf);
	break;
      case 0x20:		/* master volume slide */
	UniEffect (UNI_XMEFFECTH, inf);
	break;
      case 0x21:		/* extended effects */
	switch (inf >> 4)
	  {
	  case 0x1:		/* set filter */
	  case 0x5:		/* vibrato waveform */
	  case 0x8:		/* tremolo waveform */
	    UniPTEffect (0xe, inf - 0x10);
	    break;
	  case 0xa:		/* pattern loop */
	    UniPTEffect (0xe, 0x60 | (inf & 0xf));
	    break;
	  case 0xb:		/* pattern delay */
	    UniPTEffect (0xe, 0xe0 | (inf & 0xf));
	    break;
	  case 0x3:		/* glissando */
	  case 0xc:		/* note cut */
	  case 0xd:		/* note delay */
	  case 0xf:		/* invert loop */
	    UniPTEffect (0xe, inf);
	    break;
	  case 0xe:		/* ignore envelope */
	    UniEffect (UNI_ITEFFECTS0, 0x77);	/* vol */
	    UniEffect (UNI_ITEFFECTS0, 0x79);	/* pan */
	    UniEffect (UNI_ITEFFECTS0, 0x7b);	/* pit */
	    break;
	  }
	break;
	/* 0x22 chorus (awe32) */
	/* 0x23 reverb (awe32) */
      }
}

static UBYTE *
IMF_ConvertTrack (IMFNOTE * tr, UWORD rows)
{
  int t;
  UBYTE note, ins;

  UniReset ();
  for (t = 0; t < rows; t++)
    {
      note = tr[t].note;
      ins = tr[t].ins;

      if ((ins) && (ins != 255))
	UniInstrument (ins - 1);
      if (note != 255)
	{
	  if (note == 0xa0)
	    {