1 /* MikMod sound library
2 (c) 1998, 1999 Miodrag Vallat and others - see file AUTHORS for
5 This library is free software; you can redistribute it and/or modify
6 it under the terms of the GNU Library General Public License as
7 published by the Free Software Foundation; either version 2 of
8 the License, or (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU Library General Public License for more details.
15 You should have received a copy of the GNU Library General Public
16 License along with this library; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
21 /*==============================================================================
25 All routines dealing with the manipulation of UNITRK streams
27 ==============================================================================*/
33 #include "unimod_priv.h"
37 /* Unibuffer chunk size */
40 UWORD unioperands[UNI_LAST] =
44 1, /* UNI_INSTRUMENT */
45 1, /* UNI_PTEFFECT0 */
46 1, /* UNI_PTEFFECT1 */
47 1, /* UNI_PTEFFECT2 */
48 1, /* UNI_PTEFFECT3 */
49 1, /* UNI_PTEFFECT4 */
50 1, /* UNI_PTEFFECT5 */
51 1, /* UNI_PTEFFECT6 */
52 1, /* UNI_PTEFFECT7 */
53 1, /* UNI_PTEFFECT8 */
54 1, /* UNI_PTEFFECT9 */
55 1, /* UNI_PTEFFECTA */
56 1, /* UNI_PTEFFECTB */
57 1, /* UNI_PTEFFECTC */
58 1, /* UNI_PTEFFECTD */
59 1, /* UNI_PTEFFECTE */
60 1, /* UNI_PTEFFECTF */
61 1, /* UNI_S3MEFFECTA */
62 1, /* UNI_S3MEFFECTD */
63 1, /* UNI_S3MEFFECTE */
64 1, /* UNI_S3MEFFECTF */
65 1, /* UNI_S3MEFFECTI */
66 1, /* UNI_S3MEFFECTQ */
67 1, /* UNI_S3MEFFECTR */
68 1, /* UNI_S3MEFFECTT */
69 1, /* UNI_S3MEFFECTU */
72 2, /* UNI_VOLEFFECTS */
73 1, /* UNI_XMEFFECT4 */
74 1, /* UNI_XMEFFECTA */
75 1, /* UNI_XMEFFECTE1 */
76 1, /* UNI_XMEFFECTE2 */
77 1, /* UNI_XMEFFECTEA */
78 1, /* UNI_XMEFFECTEB */
79 1, /* UNI_XMEFFECTG */
80 1, /* UNI_XMEFFECTH */
81 1, /* UNI_XMEFFECTL */
82 1, /* UNI_XMEFFECTP */
83 1, /* UNI_XMEFFECTX1 */
84 1, /* UNI_XMEFFECTX2 */
85 1, /* UNI_ITEFFECTG */
86 1, /* UNI_ITEFFECTH */
87 1, /* UNI_ITEFFECTI */
88 1, /* UNI_ITEFFECTM */
89 1, /* UNI_ITEFFECTN */
90 1, /* UNI_ITEFFECTP */
91 1, /* UNI_ITEFFECTT */
92 1, /* UNI_ITEFFECTU */
93 1, /* UNI_ITEFFECTW */
94 1, /* UNI_ITEFFECTY */
95 2, /* UNI_ITEFFECTZ */
96 1, /* UNI_ITEFFECTS0 */
97 2, /* UNI_ULTEFFECT9 */
99 0, /* UNI_MEDEFFECTF1 */
100 0, /* UNI_MEDEFFECTF2 */
101 0 /* UNI_MEDEFFECTF3 */
104 /* Sparse description of the internal module format
105 ------------------------------------------------
107 A UNITRK stream is an array of bytes representing a single track of a pattern.
108 It's made up of 'repeat/length' bytes, opcodes and operands (sort of a assembly
112 [REP/LEN][OPCODE][OPERAND][OPCODE][OPERAND] [REP/LEN][OPCODE][OPERAND]..
114 |-------ROWS 0 - 0+REP of a track---------| |-------ROWS xx - xx+REP of a track...
116 The rep/len byte contains the number of bytes in the current row, _including_
117 the length byte itself (So the LENGTH byte of row 0 in the previous example
118 would have a value of 5). This makes it easy to search through a stream for a
119 particular row. A track is concluded by a 0-value length byte.
121 The upper 3 bits of the rep/len byte contain the number of times -1 this row
122 is repeated for this track. (so a value of 7 means this row is repeated 8 times)
124 Opcodes can range from 1 to 255 but currently only opcodes 1 to 52 are being
125 used. Each opcode can have a different number of operands. You can find the
126 number of operands to a particular opcode by using the opcode as an index into
127 the 'unioperands' table.
131 /*========== Reading routines */
133 static UBYTE *rowstart; /* startadress of a row */
134 static UBYTE *rowend; /* endaddress of a row (exclusive) */
135 static UBYTE *rowpc; /* current unimod(tm) programcounter */
139 UniSetRow (UBYTE * t)
143 rowend = t ? rowstart + (*(rowpc++) & 0x1f) : t;
149 return (rowpc < rowend) ? *(rowpc++) : 0;
155 return ((UWORD) UniGetByte () << 8) | UniGetByte ();
159 UniSkipOpcode (UBYTE op)
163 UWORD t = unioperands[op];
170 /* Finds the address of row number 'row' in the UniMod(tm) stream 't' returns
171 NULL if the row can't be found. */
173 UniFindRow (UBYTE * t, UWORD row)
180 c = *t; /* get rep/len byte */
182 return NULL; /* zero ? -> end of track.. */
183 l = (c >> 5) + 1; /* extract repeat value */
185 break; /* reached wanted row? -> return pointer */
186 row -= l; /* haven't reached row yet.. update row */
187 t += c & 0x1f; /* point t to the next row */
192 /*========== Writing routines */
194 static UBYTE *unibuf; /* pointer to the temporary unitrk buffer */
195 static UWORD unimax; /* buffer size */
197 static UWORD unipc; /* buffer cursor */
198 static UWORD unitt; /* current row index */
199 static UWORD lastp; /* previous row index */
201 /* Resets index-pointers to create a new track. */
205 unitt = 0; /* reset index to rep/len byte */
206 unipc = 1; /* first opcode will be written to index 1 */
207 lastp = 0; /* no previous row yet */
208 unibuf[0] = 0; /* clear rep/len byte */
211 /* Expands the buffer */
213 UniExpand (int wanted)
215 if ((unipc + wanted) >= unimax)
219 /* Expand the buffer by BUFPAGE bytes */
220 newbuf = (UBYTE *) realloc (unibuf, (unimax + BUFPAGE) * sizeof (UBYTE));
222 /* Check if realloc succeeded */
235 /* Appends one byte of data to the current row of a track. */
237 UniWriteByte (UBYTE data)
240 /* write byte to current position and update */
241 unibuf[unipc++] = data;
245 UniWriteWord (UWORD data)
249 unibuf[unipc++] = data >> 8;
250 unibuf[unipc++] = data & 0xff;
255 MyCmp (UBYTE * a, UBYTE * b, UWORD l)
259 for (t = 0; t < l; t++)
260 if (*(a++) != *(b++))
265 /* Closes the current row of a unitrk stream (updates the rep/len byte) and sets
266 pointers to start a new row. */
272 n = (unibuf[lastp] >> 5) + 1; /* repeat of previous row */
273 l = (unibuf[lastp] & 0x1f); /* length of previous row */
275 len = unipc - unitt; /* length of current row */
277 /* Now, check if the previous and the current row are identical.. when they
278 are, just increase the repeat field of the previous row */
279 if (n < 8 && len == l && MyCmp (&unibuf[lastp + 1], &unibuf[unitt + 1], len - 1))
281 unibuf[lastp] += 0x20;
286 if (UniExpand (unitt - unipc))
288 /* current and previous row aren't equal... update the pointers */
296 /* Terminates the current unitrk stream and returns a pointer to a copy of the
303 if (!UniExpand (unitt - unipc))
307 if (!(d = (UBYTE *) _mm_malloc (unipc)))
309 memcpy (d, unibuf, unipc);
319 if (!(unibuf = (UBYTE *) _mm_malloc (unimax * sizeof (UBYTE))))