load_gdm.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_gdm.c,v 1.5 1999/10/25 16:31:41 miod Exp $

  General DigiMusic (GDM) module loader

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

/*

   Written by Kev Vance<[e-mail]>
   based on the file format description written by 'MenTaLguY'
   <[e-mail]>

 */

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

#include <stdio.h>
#include <string.h>

#include "unimod_priv.h"

typedef struct GDMNOTE
  {
    UBYTE note;
    UBYTE samp;
    struct
      {
	UBYTE effect;
	UBYTE param;
      }
    effect[4];
  }
GDMNOTE;

typedef GDMNOTE GDMTRACK[64];

typedef struct GDMHEADER
  {
    CHAR id1[4];
    CHAR songname[32];
    CHAR author[32];
    CHAR eofmarker[3];
    CHAR id2[4];

    UBYTE majorver;
    UBYTE minorver;
    UWORD trackerid;
    UBYTE t_majorver;
    UBYTE t_minorver;
    UBYTE pantable[32];
    UBYTE mastervol;
    UBYTE mastertempo;
    UBYTE masterbpm;
    UWORD flags;

    ULONG orderloc;
    UBYTE ordernum;
    ULONG patternloc;
    UBYTE patternnum;
    ULONG samhead;
    ULONG samdata;
    UBYTE samnum;
    ULONG messageloc;
    ULONG messagelen;
    ULONG scrollyloc;
    UWORD scrollylen;
    ULONG graphicloc;
    UWORD graphiclen;
  }
GDMHEADER;

typedef struct GDMSAMPLE
  {
    CHAR sampname[32];
    CHAR filename[13];
    UBYTE ems;
    ULONG length;
    ULONG loopbeg;
    ULONG loopend;
    UBYTE flags;
    UWORD c4spd;
    UBYTE vol;
    UBYTE pan;
  }
GDMSAMPLE;

static GDMHEADER *mh = NULL;	/* pointer to GDM header */
static GDMNOTE *gdmbuf = NULL;	/* pointer to a complete GDM pattern */

CHAR GDM_Version[] = "General DigiMusic 1.xx";

BOOL 
GDM_Test (void)
{
  /* test for gdm magic numbers */
  UBYTE id[4];

  _mm_fseek (modreader, 0x00, SEEK_SET);
  if (!_mm_read_UBYTES (id, 4, modreader))
    return 0;
  if (!memcmp (id, "GDM\xfe", 4))
    {
      _mm_fseek (modreader, 71, SEEK_SET);
      if (!_mm_read_UBYTES (id, 4, modreader))
	return 0;
      if (!memcmp (id, "GMFS", 4))
	return 1;
    }
  return 0;
}

BOOL 
GDM_Init (void)
{
  if (!(gdmbuf = (GDMNOTE *) _mm_malloc (32 * 64 * sizeof (GDMNOTE))))
    return 0;
  if (!(mh = (GDMHEADER *) _mm_malloc (sizeof (GDMHEADER))))
    return 0;

  return 1;
}

void 
GDM_Cleanup (void)
{
  _mm_free (mh);
  _mm_free (gdmbuf);
}

BOOL 
GDM_ReadPattern (void)
{
  int pos, flag, ch, i, maxch;
  GDMNOTE n;
  UWORD length, x = 0;

  /* get pattern length */
  length = _mm_read_I_UWORD (modreader) - 2;

  /* clear pattern data */
  memset (gdmbuf, 255, 32 * 64 * sizeof (GDMNOTE));
  pos = 0;
  maxch = 0;

  while (x < length)
    {
      memset (&n, 255, sizeof (GDMNOTE));
      flag = _mm_read_UBYTE (modreader);
      x++;

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

      ch = flag & 31;
      if (ch > maxch)
	maxch = ch;
      if (!flag)
	{
	  pos++;
	  continue;
	}
      if (flag & 0x60)
	{
	  if (flag & 0x20)
	    {
	      /* new note */
	      n.note = _mm_read_UBYTE (modreader) & 127;
	      n.samp = _mm_read_UBYTE (modreader);
	      x += 2;
	    }
	  if (flag & 0x40)
	    {
	      do
		{
		  /* effect channel set */
		  i = _mm_read_UBYTE (modreader);
		  n.effect[i >> 6].effect = i & 31;
		  n.effect[i >> 6].param = _mm_read_UBYTE (modreader);
		  x += 2;
		}
	      while (i & 32);
	    }
	  memcpy (gdmbuf + (64U * ch) + pos, &n, sizeof (n));
	}
    }
  return 1;
}

UBYTE *
GDM_ConvertTrack (GDMNOTE * tr)
{
  int t, i = 0;
  UBYTE note, ins;

  UniReset ();
  for (t = 0; t < 64; t++)
    {
      note = tr[t].note;
      ins = tr[t].samp;

      if ((ins) && (ins != 255))
	UniInstrument (ins - 1);
      if (note != 255)
	{
	  UniNote (((note >> 4) * OCTAVE) + (note & 0xf) - 1);
	}
      for (i = 0; i < 4; i++)
	{
	  switch (tr[t].effect[i].effect)
	    {
	    case 1:		/* toneslide up */
	      UniEffect (UNI_S3MEFFECTF, tr[t].effect[i].param);
	      break;
	    case 2:		/* toneslide down */
	      UniEffect (UNI_S3MEFFECTE, tr[t].effect[i].param);
	      break;
	    case 3:		/* glissando to note */
	      UniEffect (UNI_ITEFFECTG, tr[t].effect[i].param);
	      break;
	    case 4:		/* vibrato */
	      UniEffect (UNI_ITEFFECTH, tr[t].effect[i].param);
	      break;
	    case 5:		/* portamento+volslide */
	      UniEffect (UNI_ITEFFECTG, 0);
	      UniEffect (UNI_S3MEFFECTD, tr[t].effect[i].param);
	      break;
	    case 6:		/* vibrato+volslide */
	      UniEffect (UNI_ITEFFECTH, 0);
	      UniEffect (UNI_S3MEFFECTD, tr[t].effect[i].param);
	      break;
	    case 7:		/* tremolo */
	      UniEffect (UNI_S3MEFFECTR, tr[t].effect[i].param);
	      break;
	    case 8:		/* tremor */
	      UniEffect (UNI_S3MEFFECTI, tr[t].effect[i].param);
	      break;
	    case 9:		/* offset */
	      UniPTEffect (0x09, tr[t].effect[i].param);
	      break;
	    case 0x0a:		/* volslide */
	      UniEffect (UNI_S3MEFFECTD, tr[t].effect[i].param);
	      break;
	    case 0x0b:		/* jump to order */
	      UniPTEffect (0x0b, tr[t].effect[i].param);
	      break;
	    case 0x0c:		/* volume set */
	      UniPTEffect (0x0c, tr[t].effect[i].param);
	      break;
	    case 0x0d:		/* pattern break */
	      UniPTEffect (0x0d, tr[t].effect[i].param);
	      break;
	    case 0x0e:		/* extended */
	      switch (tr[t].effect[i].param & 0xf0)
		{
		case 0x10:	/* fine portamento up */
		  UniEffect (UNI_S3MEFFECTF,
			     0x0f | ((tr[t].effect[i].param << 4) & 0x0f));
		  break;
		case 0x20:	/* fine portamento down */
		  UniEffect (UNI_S3MEFFECTE,
			     0xf0 | (tr[t].effect[i].param & 0x0f));
		  break;
		case 0x30:	/* glissando control */
		  UniEffect (SS_GLISSANDO,
			     tr[t].effect[i].param & 0x0f);
		  break;
		case 0x40:	/* vibrato waveform */
		  UniEffect (SS_VIBWAVE,
			     tr[t].effect[i].param & 0x0f);
		  break;
		case 0x50:	/* set c4spd */
		  UniEffect (SS_FINETUNE,
			     tr[t].effect[i].param & 0x0f);
		  break;
		case 0x60:	/* loop fun */
		  UniEffect (UNI_ITEFFECTS0,
			     (tr[t].effect[i].param & 0x0f) | 0xb0);
		  break;
		case 0x70:	/* tremolo waveform */
		  UniEffect (SS_TREMWAVE,
			     tr[t].effect[i].param & 0x0f);
		  break;
		case 0x80:	/* extra fine porta up */
		  UniEffect (UNI_S3MEFFECTF,
			     0x0e | ((tr[t].effect[i].param << 4) & 0x0f));
		  break;
		case 0x90:	/* extra fine porta down */
		  UniEffect (UNI_S3MEFFECTE,
			     0xe0 | (tr[t].effect[i].param & 0x0f));
		  break;
		case 0xa0:	/* fine volslide up */
		  UniEffect (UNI_S3MEFFECTD,
			     0x0f | ((tr[t].effect[i].param << 4) & 0x0f));
		  break;
		case 0xb0:	/* fine volslide down */
		  UniEffect (UNI_S3MEFFECTE,
			     0xf0 | (tr[t].effect[i].param & 0x0f));
		  break;
		case 0xc0:	/* note cut */
		case 0xd0:	/* note delay */
		case 0xe0:	/* extend row */
		  UniPTEffect (0xe, tr[t].effect[i].param);
		  break;
		}
	      break;
	    case 0x0f:		/* set tempo */
	      UniEffect (UNI_S3MEFFECTA, tr[t].effect[i].param);
	      break;
	    case 0x10:		/* arpeggio */
	      UniPTEffect (0x0, tr[t].effect[i].param);
	      break;
	    case 0x12:		/* retrigger */
	      UniEffect (UNI_S3MEFFECTQ, tr[t].effect[i].param);
	      break;
	    case 0x13:		/* set global volume */
	      UniEffect (UNI_XMEFFECTG, tr[t].effect[i].param);
	      break;
	    case 0x14:		/* fine vibrato */
	      UniEffect (UNI_ITEFFECTU, tr[t].effect[i].param);
	      break;
	    case 0x1e:		/* special */
	      switch (tr[t].effect[i].param & 0xf0)
		{
		case 8:	/* set pan position */
		  if (tr[t].effect[i].param >= 128)
		    UniPTEffect (0x08, 255);
		  else
		    UniPTEffect (0x08, tr[t].effect[i].param << 1);
		  break;
		}
	      break;
	    case 0x1f:		/* set bpm */
	      if (tr[t].effect[i].param >= 0x20)
		UniEffect (UNI_S3MEFFECTT, tr[t].effect[i].param);
	      break;
	    }
	}
      UniNewline ();
    }
  return UniDup ();
}

BOOL 
GDM_Load (BOOL curious)
{
  int i, x, u, track;
  SAMPLE *q;
  GDMSAMPLE s;
  ULONG position;

  /* read header */
  _mm_read_string (mh->id1, 4, modreader);
  _mm_read_string (mh->songname, 32, modreader);
  _mm_read_string (mh->author, 32, modreader);
  _mm_read_string (mh->eofmarker, 3, modreader);
  _mm_read_string (mh->id2, 4, modreader);

  mh->majorver = _mm_read_UBYTE (modreader);
  mh->minorver = _mm_read_UBYTE (modreader);
  mh->trackerid = _mm_read_I_UWORD (modreader);
  mh->t_majorver = _mm_read_UBYTE (modreader);
  mh->t_minorver = _mm_read_UBYTE (modreader);
  _mm_read_UBYTES (mh->pantable, 32, modreader);
  mh->mastervol = _mm_read_UBYTE (modreader);
  mh->mastertempo = _mm_read_UBYTE (modreader);
  mh->masterbpm = _mm_read_UBYTE (modreader);
  mh->flags = _mm_read_I_UWORD (modreader);

  mh->orderloc = _mm_read_I_ULONG (modreader);
  mh->ordernum = _mm_read_UBYTE (modreader);
  mh->patternloc = _mm_read_I_ULONG (modreader);
  mh->patternnum = _mm_read_UBYTE (modreader);
  mh->samhead = _mm_read_I_ULONG (modreader);
  mh->samdata = _mm_read_I_ULONG (modreader);
  mh->samnum = _mm_read_UBYTE (modreader);
  mh->messageloc = _mm_read_I_ULONG (modreader);
  mh->messagelen = _mm_read_I_ULONG (modreader);
  mh->scrollyloc = _mm_read_I_ULONG (modreader);
  mh->scrollylen = _mm_read_I_UWORD (modreader);
  mh->graphicloc = _mm_read_I_ULONG (modreader);
  mh->graphiclen = _mm_read_I_UWORD (modreader);

  /* have we ended abruptly? */
  if (_mm_eof (modreader))
    {
      _mm_errno = MMERR_LOADING_HEADER;
      return 0;
    }

  /* any orders? */
  if (mh->ordernum == 255)
    {
      _mm_errno = MMERR_LOADING_PATTERN;
      return 0;
    }

  /* now we fill */
  of.modtype = strdup (GDM_Version);
  of.modtype[18] = mh->majorver + '0';
  of.modtype[20] = mh->minorver / 10 + '0';
  of.modtype[21] = mh->minorver % 10 + '0';
  of.songname = DupStr (mh->songname, 32, 0);
  of.numpat = mh->patternnum + 1;
  of.reppos = 0;
  of.numins = of.numsmp = mh->samnum + 1;
  of.initspeed = mh->mastertempo;
  of.inittempo = mh->masterbpm;
  of.initvolume = mh->mastervol << 1;
  of.flags |= UF_S3MSLIDES;

  /* read the order data */
  if (!AllocPositions (mh->ordernum + 1))
    {
      _mm_errno = MMERR_OUT_OF_MEMORY;
      return 0;
    }

  _mm_fseek (modreader, mh->orderloc, SEEK_SET);
  for (i = 0; i < mh->ordernum + 1; i++)
    of.positions[i] = _mm_read_UBYTE (modreader);

  of.numpos = 0;
  for (i = 0; i < mh->ordernum + 1; i++)
    {
      of.positions[of.numpos] = of.positions[i];
      if (of.positions[i] < 254)
	of.numpos++;
    }

  /* have we ended abruptly yet? */
  if (_mm_eof (modreader))
    {
      _mm_errno = MMERR_LOADING_HEADER;
      return 0;
    }

  /* time to load the samples */
  if (!AllocSamples ())
    {
      _mm_errno = MMERR_OUT_OF_MEMORY;
      return 0;
    }

  q = of.samples;
  position = mh->samdata;

  /* seek to instrument position */
  _mm_fseek (modreader, mh->samhead, SEEK_SET);

  for (i = 0; i < of.numins; i++)
    {
      /* load sample info */
      _mm_read_UBYTES (s.sampname, 32, modreader);
      _mm_read_UBYTES (s.filename, 12, modreader);
      s.ems = _mm_read_UBYTE (modreader);
      s.length = _mm_read_I_ULONG (modreader);
      s.loopbeg = _mm_read_I_ULONG (modreader);
      s.loopend = _mm_read_I_ULONG (modreader);
      s.flags = _mm_read_UBYTE (modreader);
      s.c4spd = _mm_read_I_UWORD (modreader);
      s.vol = _mm_read_UBYTE (modreader);
      s.pan = _mm_read_UBYTE (modreader);

      if (_mm_eof (modreader))
	{
	  _mm_errno = MMERR_LOADING_SAMPLEINFO;
	  return 0;
	}
      q->samplename = DupStr (s.sampname, 32, 0);
      q->speed = s.c4spd;
      q->length = s.length;
      q->loopstart = s.loopbeg;
      q->loopend = s.loopend;
      q->volume = s.vol;
      q->panning = s.pan;
      q->seekpos = position;

      position += s.length;

      if (s.flags & 1)
	q->flags |= SF_LOOP;
      if (s.flags & 2)
	q->flags |= SF_16BITS;
      if (s.flags & 16)
	q->flags |= SF_STEREO;
      q++;
    }

  /* set the panning */
  for (i = x = 0; i < 32; i++)
    {
      of.panning[i] = mh->pantable[i];
      if (!of.panning[i])
	of.panning[i] = PAN_LEFT;
      else if (of.panning[i] == 8)
	of.panning[i] = PAN_CENTER;
      else if (of.panning[i] == 15)
	of.panning[i] = PAN_RIGHT;
      else if (of.panning[i] == 16)
	of.panning[i] = PAN_SURROUND;
      else if (of.panning[i] == 255)
	of.panning[i] = 128;
      else
	of.panning[i] <<= 3;
      of.panning[i] = PAN_CENTER;
      if (mh->pantable[i] != 255)
	x = i;
    }

  of.numchn = x + 1;
  if (of.numchn < 1)
    of.numchn = 1;		/* for broken counts */

  /* load the pattern info */
  of.numtrk = of.numpat * of.numchn;

  /* jump to patterns */
  _mm_fseek (modreader, mh->patternloc, SEEK_SET);

  if (!AllocTracks ())
    {
      _mm_errno = MMERR_OUT_OF_MEMORY;
      return 0;
    }

  if (!AllocPatterns ())
    {
      _mm_errno = MMERR_OUT_OF_MEMORY;
      return 0;
    }

  for (i = track = 0; i < of.numpat; i++)
    {
      if (!GDM_ReadPattern ())
	{
	  _mm_errno = MMERR_LOADING_PATTERN;
	  return 0;
	}
      for (u = 0; u < of.numchn; u++, track++)
	{
	  of.tracks[track] = GDM_ConvertTrack (&gdmbuf[u << 6]);
	  if (!of.tracks[track])
	    {
	      _mm_errno = MMERR_LOADING_TRACK;
	      return 0;
	    }
	}
    }
  return 1;
}

CHAR *
GDM_LoadTitle (void)
{
  CHAR s[32];

  _mm_fseek (modreader, 4, SEEK_SET);
  if (!_mm_read_UBYTES (s, 32, modreader))
    return NULL;

  return DupStr (s, 28, 0);
}

MLOADER load_gdm =
{
  NULL,
  "GDM",
  "GDM (General DigiMusic)",
  GDM_Init,
  GDM_Test,
  GDM_Load,
  GDM_Cleanup,
  GDM_LoadTitle
};

/* ex:set ts=4: */