load_it.c

SDL_mixer 是一个基于 SDL 的混音器

/*	MikMod sound library
	(c) 1998, 1999, 2000 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_it.c 346 2001-09-11 18:49:18Z slouken $

  Impulse tracker (IT) module loader

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

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

#include <ctype.h>
#include <string.h>

#include "mikmod_internals.h"

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

/* header */
typedef struct ITHEADER {
	CHAR	songname[26];
	UBYTE	blank01[2];
	UWORD	ordnum;
	UWORD	insnum;
	UWORD	smpnum;
	UWORD	patnum;
	UWORD	cwt;		/* Created with tracker (y.xx = 0x0yxx) */
	UWORD	cmwt;		/* Compatible with tracker ver > than val. */
	UWORD	flags;
	UWORD	special;	/* bit 0 set = song message attached */
	UBYTE	globvol;
	UBYTE	mixvol;		/* mixing volume [ignored] */
	UBYTE	initspeed;
	UBYTE	inittempo;
	UBYTE	pansep;		/* panning separation between channels */
	UBYTE	zerobyte;
	UWORD	msglength;
	ULONG	msgoffset;
	UBYTE	blank02[4];
	UBYTE	pantable[64];
	UBYTE	voltable[64];
} ITHEADER;

/* sample information */
typedef struct ITSAMPLE {
	CHAR	filename[12];
	UBYTE	zerobyte;
	UBYTE	globvol;
	UBYTE	flag;
	UBYTE	volume;
	UBYTE	panning;
	CHAR	sampname[28];
	UWORD	convert;	/* sample conversion flag */
	ULONG	length;
	ULONG	loopbeg;
	ULONG	loopend;
	ULONG	c5spd;
	ULONG	susbegin;
	ULONG	susend;
	ULONG	sampoffset;
	UBYTE	vibspeed;
	UBYTE	vibdepth;
	UBYTE	vibrate;
	UBYTE	vibwave;	/* 0=sine, 1=rampdown, 2=square, 3=random (speed ignored) */
} ITSAMPLE;

/* instrument information */

#define ITENVCNT 25
#define ITNOTECNT 120
typedef struct ITINSTHEADER {
	ULONG	size;			/* (dword) Instrument size */
	CHAR	filename[12];	/* (char) Instrument filename */
	UBYTE	zerobyte;		/* (byte) Instrument type (always 0) */
	UBYTE	volflg;
	UBYTE	volpts;
	UBYTE	volbeg;			/* (byte) Volume loop start (node) */
	UBYTE	volend;			/* (byte) Volume loop end (node) */
	UBYTE	volsusbeg;		/* (byte) Volume sustain begin (node) */
	UBYTE	volsusend;		/* (byte) Volume Sustain end (node) */
	UBYTE	panflg;
	UBYTE	panpts;
	UBYTE	panbeg;			/* (byte) channel loop start (node) */
	UBYTE	panend;			/* (byte) channel loop end (node) */
	UBYTE	pansusbeg;		/* (byte) channel sustain begin (node) */
	UBYTE	pansusend;		/* (byte) channel Sustain end (node) */
	UBYTE	pitflg;
	UBYTE	pitpts;
	UBYTE	pitbeg;			/* (byte) pitch loop start (node) */
	UBYTE	pitend;			/* (byte) pitch loop end (node) */
	UBYTE	pitsusbeg;		/* (byte) pitch sustain begin (node) */
	UBYTE	pitsusend;		/* (byte) pitch Sustain end (node) */
	UWORD	blank;
	UBYTE	globvol;
	UBYTE	chanpan;
	UWORD	fadeout;		/* Envelope end / NNA volume fadeout */
	UBYTE	dnc;			/* Duplicate note check */
	UBYTE	dca;			/* Duplicate check action */
	UBYTE	dct;			/* Duplicate check type */
	UBYTE	nna;			/* New Note Action [0,1,2,3] */
	UWORD	trkvers;		/* tracker version used to save [files only] */
	UBYTE	ppsep;			/* Pitch-pan Separation */
	UBYTE	ppcenter;		/* Pitch-pan Center */
	UBYTE	rvolvar;		/* random volume varations */
	UBYTE	rpanvar;		/* random panning varations */
	UWORD	numsmp;			/* Number of samples in instrument [files only] */
	CHAR	name[26];		/* Instrument name */
	UBYTE	blank01[6];
	UWORD	samptable[ITNOTECNT];/* sample for each note [note / samp pairs] */
	UBYTE	volenv[200];	     /* volume envelope (IT 1.x stuff) */
	UBYTE	oldvoltick[ITENVCNT];/* volume tick position (IT 1.x stuff) */
	UBYTE	volnode[ITENVCNT];   /* amplitude of volume nodes */
	UWORD	voltick[ITENVCNT];   /* tick value of volume nodes */
	SBYTE	pannode[ITENVCNT];   /* panenv - node points */
	UWORD	pantick[ITENVCNT];   /* tick value of panning nodes */
	SBYTE	pitnode[ITENVCNT];   /* pitchenv - node points */
	UWORD	pittick[ITENVCNT];   /* tick value of pitch nodes */
} ITINSTHEADER;

/* unpacked note */

typedef struct ITNOTE {
	UBYTE note,ins,volpan,cmd,inf;
} ITNOTE;

/*========== Loader data */

static ULONG *paraptr=NULL;	/* parapointer array (see IT docs) */
static ITHEADER *mh=NULL;
static ITNOTE *itpat=NULL;	/* allocate to space for one full pattern */
static UBYTE *mask=NULL;	/* arrays allocated to 64 elements and used for */
static ITNOTE *last=NULL;	/* uncompressing IT's pattern information */
static int numtrk=0;
static int old_effect;		/* if set, use S3M old-effects stuffs */

static CHAR* IT_Version[]={
	"ImpulseTracker  .  ",
	"Compressed ImpulseTracker  .  ",
	"ImpulseTracker 2.14p3",
	"Compressed ImpulseTracker 2.14p3",
	"ImpulseTracker 2.14p4",
	"Compressed ImpulseTracker 2.14p4",
};

/* table for porta-to-note command within volume/panning column */
static UBYTE portatable[10]= {0,1,4,8,16,32,64,96,128,255};

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

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

	if(!_mm_read_UBYTES(id,4,modreader)) return 0;
	if(!memcmp(id,"IMPM",4)) return 1;
	return 0;
}

BOOL IT_Init(void)
{
	if(!(mh=(ITHEADER*)_mm_malloc(sizeof(ITHEADER)))) return 0;
	if(!(poslookup=(UBYTE*)_mm_malloc(256*sizeof(UBYTE)))) return 0;
	if(!(itpat=(ITNOTE*)_mm_malloc(200*64*sizeof(ITNOTE)))) return 0;
	if(!(mask=(UBYTE*)_mm_malloc(64*sizeof(UBYTE)))) return 0;
	if(!(last=(ITNOTE*)_mm_malloc(64*sizeof(ITNOTE)))) return 0;

	return 1;
}

void IT_Cleanup(void)
{
	FreeLinear();

	_mm_free(mh);
	_mm_free(poslookup);
	_mm_free(itpat);
	_mm_free(mask);
	_mm_free(last);
	_mm_free(paraptr);
	_mm_free(origpositions);
}

/* Because so many IT files have 64 channels as the set number used, but really
   only use far less (usually from 8 to 24 still), I had to make this function,
   which determines the number of channels that are actually USED by a pattern.

   NOTE: You must first seek to the file location of the pattern before calling
         this procedure.

   Returns 1 on error
*/
static BOOL IT_GetNumChannels(UWORD patrows)
{
	int row=0,flag,ch;

	do {
		if((flag=_mm_read_UBYTE(modreader))==EOF) {
			_mm_errno=MMERR_LOADING_PATTERN;
			return 1;
		}
		if(!flag)
			row++;
		else {
			ch=(flag-1)&63;
			remap[ch]=0;
			if(flag & 128) mask[ch]=_mm_read_UBYTE(modreader);
			if(mask[ch]&1)   _mm_read_UBYTE(modreader);
			if(mask[ch]&2)   _mm_read_UBYTE(modreader);
			if(mask[ch]&4)   _mm_read_UBYTE(modreader);
			if(mask[ch]&8) { _mm_read_UBYTE(modreader);_mm_read_UBYTE(modreader); }
		}
	} while(row<patrows);

	return 0;
}

static UBYTE* IT_ConvertTrack(ITNOTE* tr,UWORD numrows)
{
	int t;
	UBYTE note,ins,volpan;

	UniReset();

	for(t=0;t<numrows;t++) {
		note=tr[t*of.numchn].note;
		ins=tr[t*of.numchn].ins;
		volpan=tr[t*of.numchn].volpan;

		if(note!=255) {
			if(note==253)
				UniWriteByte(UNI_KEYOFF);
			else if(note==254) {
				UniPTEffect(0xc,-1);	/* note cut command */
				volpan=255;
			} else
				UniNote(note);
		}

		if((ins)&&(ins<100))
			UniInstrument(ins-1);
		else if(ins==253)
			UniWriteByte(UNI_KEYOFF);
		else if(ins!=255) { /* crap */
			_mm_errno=MMERR_LOADING_PATTERN;
			return NULL;
		}

		/* process volume / panning column
		   volume / panning effects do NOT all share the same memory address
		   yet. */
		if(volpan<=64)
			UniVolEffect(VOL_VOLUME,volpan);
		else if(volpan<=74)	/* fine volume slide up (65-74) */
			UniVolEffect(VOL_VOLSLIDE,0x0f+((volpan-65)<<4));
		else if(volpan<=84)	/* fine volume slide down (75-84) */
			UniVolEffect(VOL_VOLSLIDE,0xf0+(volpan-75));
		else if(volpan<=94)	/* volume slide up (85-94) */
			UniVolEffect(VOL_VOLSLIDE,((volpan-85)<<4));
		else if(volpan<=104)/* volume slide down (95-104) */
			UniVolEffect(VOL_VOLSLIDE,(volpan-95));
		else if(volpan<=114)/* pitch slide down (105-114) */
			UniVolEffect(VOL_PITCHSLIDEDN,(volpan-105));
		else if(volpan<=124)/* pitch slide up (115-124) */
			UniVolEffect(VOL_PITCHSLIDEUP,(volpan-115));
		else if(volpan<=127) { /* crap */
			_mm_errno=MMERR_LOADING_PATTERN;
			return NULL;
		} else if(volpan<=192)
			UniVolEffect(VOL_PANNING,((volpan-128)==64)?255:((volpan-128)<<2));
		else if(volpan<=202)/* portamento to note */
			UniVolEffect(VOL_PORTAMENTO,portatable[volpan-193]);
		else if(volpan<=212)/* vibrato */
			UniVolEffect(VOL_VIBRATO,(volpan-203));
		else if((volpan!=239)&&(volpan!=255)) { /* crap */
			_mm_errno=MMERR_LOADING_PATTERN;
			return NULL;
		}

		S3MIT_ProcessCmd(tr[t*of.numchn].cmd,tr[t*of.numchn].inf,old_effect|2);

		UniNewline();
	}
	return UniDup();
}

static BOOL IT_ReadPattern(UWORD patrows)
{
	int row=0,flag,ch,blah;
	ITNOTE *itt=itpat,dummy,*n,*l;

	memset(itt,255,200*64*sizeof(ITNOTE));

	do {
		if((flag=_mm_read_UBYTE(modreader))==EOF) {
			_mm_errno = MMERR_LOADING_PATTERN;
			return 0;
		}
		if(!flag) {
			itt=&itt[of.numchn];
			row++;
		} else {
			ch=remap[(flag-1)&63];
			if(ch!=-1) {
				n=&itt[ch];
				l=&last[ch];
			} else
				n=l=&dummy;

			if(flag&128) mask[ch]=_mm_read_UBYTE(modreader);
			if(mask[ch]&1)
				/* convert IT note off to internal note off */
				if((l->note=n->note=_mm_read_UBYTE(modreader))==255)
					l->note=n->note=253;
			if(mask[ch]&2)
				l->ins=n->ins=_mm_read_UBYTE(modreader);
			if(mask[ch]&4)
				l->volpan=n->volpan=_mm_read_UBYTE(modreader);
			if(mask[ch]&8) {
				l->cmd=n->cmd=_mm_read_UBYTE(modreader);
				l->inf=n->inf=_mm_read_UBYTE(modreader);
			}
			if(mask[ch]&16)
				n->note=l->note;
			if(mask[ch]&32)
				n->ins=l->ins;
			if(mask[ch]&64)
				n->volpan=l->volpan;
			if(mask[ch]&128) {
				n->cmd=l->cmd;
				n->inf=l->inf;
			}
		}
	} while(row<patrows);

	for(blah=0;blah<of.numchn;blah++) {
		if(!(of.tracks[numtrk++]=IT_ConvertTrack(&itpat[blah],patrows)))
			return 0;
	}

	return 1;
}

static void LoadMidiString(MREADER* modreader,CHAR* dest)
{
	CHAR *cur,*last;

	_mm_read_UBYTES(dest,32,modreader);
	cur=last=dest;
	/* remove blanks and uppercase all */
	while(*last) {
		if(isalnum((int)*last)) *(cur++)=toupper((int)*last);
		last++;
	}
	*cur=0;
}

/* Load embedded midi information for resonant filters */
static void IT_LoadMidiConfiguration(MREADER* modreader)
{
	int i;

	memset(filtermacros,0,sizeof(filtermacros));
	memset(filtersettings,0,sizeof(filtersettings));

	if (modreader) { /* information is embedded in file */
		UWORD dat;
		CHAR midiline[33];

		dat=_mm_read_I_UWORD(modreader);
		_mm_fseek(modreader,8*dat+0x120,SEEK_CUR);

		/* read midi macros */
		for(i=0;i<16;i++) {
			LoadMidiString(modreader,midiline);
			if((!strncmp(midiline,"F0F00",5))&&
			   ((midiline[5]=='0')||(midiline[5]=='1')))
					filtermacros[i]=(midiline[5]-'0')|0x80;
		}

		/* read standalone filters */
		for(i=0x80;i<0x100;i++) {
			LoadMidiString(modreader,midiline);
			if((!strncmp(midiline,"F0F00",5))&&
			   ((midiline[5]=='0')||(midiline[5]=='1'))) {
				filtersettings[i].filter=(midiline[5]-'0')|0x80;
				dat=(midiline[6])?(midiline[6]-'0'):0;
				if(midiline[7])dat=(dat<<4)|(midiline[7]-'0');
				filtersettings[i].inf=(UBYTE)dat;
			}
		}
	} else { /* use default information */
		filtermacros[0]=FILT_CUT;
		for(i=0x80;i<0x90;i++) {
			filtersettings[i].filter=FILT_RESONANT;
			filtersettings[i].inf=(i&0x7f)<<3;
		}
	}
	activemacro=0;
	for(i=0;i<0x80;i++) {
		filtersettings[i].filter=filtermacros[0];
		filtersettings[i].inf=i;
	}
}

BOOL IT_Load(BOOL curious)
{
	int t,u,lp;
	INSTRUMENT *d;
	SAMPLE *q;
	BOOL compressed=0;

	numtrk=0;
	filters=0;

	/* try to read module header */
	_mm_read_I_ULONG(modreader);	/* kill the 4 byte header */
	_mm_read_string(mh->songname,26,modreader);
	_mm_read_UBYTES(mh->blank01,2,modreader);
	mh->ordnum      =_mm_read_I_UWORD(modreader);
	mh->insnum      =_mm_read_I_UWORD(modreader);
	mh->smpnum      =_mm_read_I_UWORD(modreader);
	mh->patnum      =_mm_read_I_UWORD(modreader);
	mh->cwt         =_mm_read_I_UWORD(modreader);
	mh->cmwt        =_mm_read_I_UWORD(modreader);
	mh->flags       =_mm_read_I_UWORD(modreader);
	mh->special     =_mm_read_I_UWORD(modreader);
	mh->globvol     =_mm_read_UBYTE(modreader);
	mh->mixvol      =_mm_read_UBYTE(modreader);
	mh->initspeed   =_mm_read_UBYTE(modreader);
	mh->inittempo   =_mm_read_UBYTE(modreader);
	mh->pansep      =_mm_read_UBYTE(modreader);
	mh->zerobyte    =_mm_read_UBYTE(modreader);
	mh->msglength   =_mm_read_I_UWORD(modreader);
	mh->msgoffset   =_mm_read_I_ULONG(modreader);
	_mm_read_UBYTES(mh->blank02,4,modreader);
	_mm_read_UBYTES(mh->pantable,64,modreader);
	_mm_read_UBYTES(mh->voltable,64,modreader);

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

	/* set module variables */
	of.songname    = DupStr(mh->songname,26,0); /* make a cstr of songname  */
	of.reppos      = 0;
	of.numpat      = mh->patnum;
	of.numins      = mh->insnum;
	of.numsmp      = mh->smpnum;
	of.initspeed   = mh->initspeed;
	of.inittempo   = mh->inittempo;
	of.initvolume  = mh->globvol;
	of.flags      |= UF_BGSLIDES|UF_ARPMEM;

	if(mh->songname[25]) {
		of.numvoices=1+mh->songname[25];
#ifdef MIKMOD_DEBUG
		fprintf(stderr,"Embedded IT limitation to %d voices\n",of.numvoices);
#endif
	}

	/* set the module type */
	/* 2.17 : IT 2.14p4 */
	/* 2.16 : IT 2.14p3 with resonant filters */
	/* 2.15 : IT 2.14p3 (improved compression) */
	if((mh->cwt<=0x219)&&(mh->cwt>=0x217))
		of.modtype=strdup(IT_Version[mh->cmwt<0x214?4:5]);
	else if (mh->cwt>=0x215)