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Diffstat (limited to 'src/libs/mikmod/munitrk.c')
| -rw-r--r-- | src/libs/mikmod/munitrk.c | 303 |
1 files changed, 303 insertions, 0 deletions
diff --git a/src/libs/mikmod/munitrk.c b/src/libs/mikmod/munitrk.c new file mode 100644 index 0000000..2818969 --- /dev/null +++ b/src/libs/mikmod/munitrk.c @@ -0,0 +1,303 @@ +/* MikMod sound library + (c) 1998, 1999, 2000, 2001 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. +*/ + +/*============================================================================== + + $Id$ + + All routines dealing with the manipulation of UNITRK streams + +==============================================================================*/ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include "mikmod_internals.h" + +#include <string.h> + +/* Unibuffer chunk size */ +#define BUFPAGE 128 + +UWORD unioperands[UNI_LAST]={ + 0, /* not used */ + 1, /* UNI_NOTE */ + 1, /* UNI_INSTRUMENT */ + 1, /* UNI_PTEFFECT0 */ + 1, /* UNI_PTEFFECT1 */ + 1, /* UNI_PTEFFECT2 */ + 1, /* UNI_PTEFFECT3 */ + 1, /* UNI_PTEFFECT4 */ + 1, /* UNI_PTEFFECT5 */ + 1, /* UNI_PTEFFECT6 */ + 1, /* UNI_PTEFFECT7 */ + 1, /* UNI_PTEFFECT8 */ + 1, /* UNI_PTEFFECT9 */ + 1, /* UNI_PTEFFECTA */ + 1, /* UNI_PTEFFECTB */ + 1, /* UNI_PTEFFECTC */ + 1, /* UNI_PTEFFECTD */ + 1, /* UNI_PTEFFECTE */ + 1, /* UNI_PTEFFECTF */ + 1, /* UNI_S3MEFFECTA */ + 1, /* UNI_S3MEFFECTD */ + 1, /* UNI_S3MEFFECTE */ + 1, /* UNI_S3MEFFECTF */ + 1, /* UNI_S3MEFFECTI */ + 1, /* UNI_S3MEFFECTQ */ + 1, /* UNI_S3MEFFECTR */ + 1, /* UNI_S3MEFFECTT */ + 1, /* UNI_S3MEFFECTU */ + 0, /* UNI_KEYOFF */ + 1, /* UNI_KEYFADE */ + 2, /* UNI_VOLEFFECTS */ + 1, /* UNI_XMEFFECT4 */ + 1, /* UNI_XMEFFECT6 */ + 1, /* UNI_XMEFFECTA */ + 1, /* UNI_XMEFFECTE1 */ + 1, /* UNI_XMEFFECTE2 */ + 1, /* UNI_XMEFFECTEA */ + 1, /* UNI_XMEFFECTEB */ + 1, /* UNI_XMEFFECTG */ + 1, /* UNI_XMEFFECTH */ + 1, /* UNI_XMEFFECTL */ + 1, /* UNI_XMEFFECTP */ + 1, /* UNI_XMEFFECTX1 */ + 1, /* UNI_XMEFFECTX2 */ + 1, /* UNI_ITEFFECTG */ + 1, /* UNI_ITEFFECTH */ + 1, /* UNI_ITEFFECTI */ + 1, /* UNI_ITEFFECTM */ + 1, /* UNI_ITEFFECTN */ + 1, /* UNI_ITEFFECTP */ + 1, /* UNI_ITEFFECTT */ + 1, /* UNI_ITEFFECTU */ + 1, /* UNI_ITEFFECTW */ + 1, /* UNI_ITEFFECTY */ + 2, /* UNI_ITEFFECTZ */ + 1, /* UNI_ITEFFECTS0 */ + 2, /* UNI_ULTEFFECT9 */ + 2, /* UNI_MEDSPEED */ + 0, /* UNI_MEDEFFECTF1 */ + 0, /* UNI_MEDEFFECTF2 */ + 0, /* UNI_MEDEFFECTF3 */ + 2, /* UNI_OKTARP */ +}; + +/* Sparse description of the internal module format + ------------------------------------------------ + + A UNITRK stream is an array of bytes representing a single track of a pattern. +It's made up of 'repeat/length' bytes, opcodes and operands (sort of a assembly +language): + +rrrlllll +[REP/LEN][OPCODE][OPERAND][OPCODE][OPERAND] [REP/LEN][OPCODE][OPERAND].. +^ ^ ^ +|-------ROWS 0 - 0+REP of a track---------| |-------ROWS xx - xx+REP of a track... + + The rep/len byte contains the number of bytes in the current row, _including_ +the length byte itself (So the LENGTH byte of row 0 in the previous example +would have a value of 5). This makes it easy to search through a stream for a +particular row. A track is concluded by a 0-value length byte. + + The upper 3 bits of the rep/len byte contain the number of times -1 this row +is repeated for this track. (so a value of 7 means this row is repeated 8 times) + + Opcodes can range from 1 to 255 but currently only opcodes 1 to 62 are being +used. Each opcode can have a different number of operands. You can find the +number of operands to a particular opcode by using the opcode as an index into +the 'unioperands' table. + +*/ + +/*========== Reading routines */ + +static UBYTE *rowstart; /* startadress of a row */ +static UBYTE *rowend; /* endaddress of a row (exclusive) */ +static UBYTE *rowpc; /* current unimod(tm) programcounter */ + +static UBYTE lastbyte; /* for UniSkipOpcode() */ + +void UniSetRow(UBYTE* t) +{ + rowstart = t; + rowpc = rowstart; + rowend = t?rowstart+(*(rowpc++)&0x1f):t; +} + +UBYTE UniGetByte(void) +{ + return lastbyte = (rowpc<rowend)?*(rowpc++):0; +} + +UWORD UniGetWord(void) +{ + return ((UWORD)UniGetByte()<<8)|UniGetByte(); +} + +void UniSkipOpcode(void) +{ + if (lastbyte < UNI_LAST) { + UWORD t = unioperands[lastbyte]; + + while (t--) + UniGetByte(); + } +} + +/* Finds the address of row number 'row' in the UniMod(tm) stream 't' returns + NULL if the row can't be found. */ +UBYTE *UniFindRow(UBYTE* t,UWORD row) +{ + UBYTE c,l; + + if(t) + while(1) { + c = *t; /* get rep/len byte */ + if(!c) return NULL; /* zero ? -> end of track.. */ + l = (c>>5)+1; /* extract repeat value */ + if(l>row) break; /* reached wanted row? -> return pointer */ + row -= l; /* haven't reached row yet.. update row */ + t += c&0x1f; /* point t to the next row */ + } + return t; +} + +/*========== Writing routines */ + +static UBYTE *unibuf; /* pointer to the temporary unitrk buffer */ +static UWORD unimax; /* buffer size */ + +static UWORD unipc; /* buffer cursor */ +static UWORD unitt; /* current row index */ +static UWORD lastp; /* previous row index */ + +/* Resets index-pointers to create a new track. */ +void UniReset(void) +{ + unitt = 0; /* reset index to rep/len byte */ + unipc = 1; /* first opcode will be written to index 1 */ + lastp = 0; /* no previous row yet */ + unibuf[0] = 0; /* clear rep/len byte */ +} + +/* Expands the buffer */ +static BOOL UniExpand(int wanted) +{ + if ((unipc+wanted)>=unimax) { + UBYTE *newbuf; + + /* Expand the buffer by BUFPAGE bytes */ + newbuf=(UBYTE*)MikMod_realloc(unibuf,(unimax+BUFPAGE)*sizeof(UBYTE)); + + /* Check if realloc succeeded */ + if(newbuf) { + unibuf = newbuf; + unimax+=BUFPAGE; + return 1; + } else + return 0; + } + return 1; +} + +/* Appends one byte of data to the current row of a track. */ +void UniWriteByte(UBYTE data) +{ + if (UniExpand(1)) + /* write byte to current position and update */ + unibuf[unipc++]=data; +} + +void UniWriteWord(UWORD data) +{ + if (UniExpand(2)) { + unibuf[unipc++]=data>>8; + unibuf[unipc++]=data&0xff; + } +} + +static BOOL MyCmp(UBYTE* a,UBYTE* b,UWORD l) +{ + UWORD t; + + for(t=0;t<l;t++) + if(*(a++)!=*(b++)) return 0; + return 1; +} + +/* Closes the current row of a unitrk stream (updates the rep/len byte) and sets + pointers to start a new row. */ +void UniNewline(void) +{ + UWORD n,l,len; + + n = (unibuf[lastp]>>5)+1; /* repeat of previous row */ + l = (unibuf[lastp]&0x1f); /* length of previous row */ + + len = unipc-unitt; /* length of current row */ + + /* Now, check if the previous and the current row are identical.. when they + are, just increase the repeat field of the previous row */ + if(n<8 && len==l && MyCmp(&unibuf[lastp+1],&unibuf[unitt+1],len-1)) { + unibuf[lastp]+=0x20; + unipc = unitt+1; + } else { + if (UniExpand(unitt-unipc)) { + /* current and previous row aren't equal... update the pointers */ + unibuf[unitt] = len; + lastp = unitt; + unitt = unipc++; + } + } +} + +/* Terminates the current unitrk stream and returns a pointer to a copy of the + stream. */ +UBYTE* UniDup(void) +{ + UBYTE *d; + + if (!UniExpand(unitt-unipc)) return NULL; + unibuf[unitt] = 0; + + if(!(d=(UBYTE *)MikMod_malloc(unipc))) return NULL; + memcpy(d,unibuf,unipc); + + return d; +} + +BOOL UniInit(void) +{ + unimax = BUFPAGE; + + if(!(unibuf=(UBYTE*)MikMod_malloc(unimax*sizeof(UBYTE)))) return 0; + return 1; +} + +void UniCleanup(void) +{ + if(unibuf) MikMod_free(unibuf); + unibuf = NULL; +} + +/* ex:set ts=4: */ |