1 /* MikMod sound library
2 (c) 1998, 1999, 2000, 2001 Miodrag Vallat and others - see file AUTHORS
3 for complete list.
4
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.
9
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.
14
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
18 02111-1307, USA.
19 */
20
21 /*==============================================================================
22
23 $Id$
24
25 All routines dealing with the manipulation of UNITRK streams
26
27 ==============================================================================*/
28
29 #ifdef HAVE_CONFIG_H
30 #include "config.h"
31 #endif
32
33 #include "mikmod_internals.h"
34
35 #include <string.h>
36
37 /* Unibuffer chunk size */
38 #define BUFPAGE 128
39
40 const UWORD unioperands[UNI_LAST] = {
41 0, /* not used */
42 1, /* UNI_NOTE */
43 1, /* UNI_INSTRUMENT */
44 1, /* UNI_PTEFFECT0 */
45 1, /* UNI_PTEFFECT1 */
46 1, /* UNI_PTEFFECT2 */
47 1, /* UNI_PTEFFECT3 */
48 1, /* UNI_PTEFFECT4 */
49 1, /* UNI_PTEFFECT5 */
50 1, /* UNI_PTEFFECT6 */
51 1, /* UNI_PTEFFECT7 */
52 1, /* UNI_PTEFFECT8 */
53 1, /* UNI_PTEFFECT9 */
54 1, /* UNI_PTEFFECTA */
55 1, /* UNI_PTEFFECTB */
56 1, /* UNI_PTEFFECTC */
57 1, /* UNI_PTEFFECTD */
58 1, /* UNI_PTEFFECTE */
59 1, /* UNI_PTEFFECTF */
60 1, /* UNI_S3MEFFECTA */
61 1, /* UNI_S3MEFFECTD */
62 1, /* UNI_S3MEFFECTE */
63 1, /* UNI_S3MEFFECTF */
64 1, /* UNI_S3MEFFECTI */
65 1, /* UNI_S3MEFFECTQ */
66 1, /* UNI_S3MEFFECTR */
67 1, /* UNI_S3MEFFECTT */
68 1, /* UNI_S3MEFFECTU */
69 0, /* UNI_KEYOFF */
70 1, /* UNI_KEYFADE */
71 2, /* UNI_VOLEFFECTS */
72 1, /* UNI_XMEFFECT4 */
73 1, /* UNI_XMEFFECT6 */
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 */
98 2, /* UNI_MEDSPEED */
99 0, /* UNI_MEDEFFECTF1 */
100 0, /* UNI_MEDEFFECTF2 */
101 0, /* UNI_MEDEFFECTF3 */
102 2, /* UNI_OKTARP */
103 };
104
105 /* Sparse description of the internal module format
106 ------------------------------------------------
107
108 A UNITRK stream is an array of bytes representing a single track of a pattern.
109 It's made up of 'repeat/length' bytes, opcodes and operands (sort of a assembly
110 language):
111
112 rrrlllll
113 [REP/LEN][OPCODE][OPERAND][OPCODE][OPERAND] [REP/LEN][OPCODE][OPERAND]..
114 ^ ^ ^
115 |-------ROWS 0 - 0+REP of a track---------| |-------ROWS xx - xx+REP of a track...
116
117 The rep/len byte contains the number of bytes in the current row, _including_
118 the length byte itself (So the LENGTH byte of row 0 in the previous example
119 would have a value of 5). This makes it easy to search through a stream for a
120 particular row. A track is concluded by a 0-value length byte.
121
122 The upper 3 bits of the rep/len byte contain the number of times -1 this row
123 is repeated for this track. (so a value of 7 means this row is repeated 8 times)
124
125 Opcodes can range from 1 to 255 but currently only opcodes 1 to 62 are being
126 used. Each opcode can have a different number of operands. You can find the
127 number of operands to a particular opcode by using the opcode as an index into
128 the 'unioperands' table.
129
130 */
131
132 /*========== Reading routines */
133
134 static UBYTE *rowstart; /* startadress of a row */
135 static UBYTE *rowend; /* endaddress of a row (exclusive) */
136 static UBYTE *rowpc; /* current unimod(tm) programcounter */
137
138 static UBYTE lastbyte; /* for UniSkipOpcode() */
139
UniSetRow(UBYTE * t)140 void UniSetRow(UBYTE* t)
141 {
142 rowstart = t;
143 rowpc = rowstart;
144 rowend = t?rowstart+(*(rowpc++)&0x1f):t;
145 }
146
UniGetByte(void)147 UBYTE UniGetByte(void)
148 {
149 return lastbyte = (rowpc<rowend)?*(rowpc++):0;
150 }
151
UniGetWord(void)152 UWORD UniGetWord(void)
153 {
154 return ((UWORD)UniGetByte()<<8)|UniGetByte();
155 }
156
UniSkipOpcode(void)157 void UniSkipOpcode(void)
158 {
159 if (lastbyte < UNI_LAST) {
160 UWORD t = unioperands[lastbyte];
161
162 while (t--)
163 UniGetByte();
164 }
165 }
166
167 /* Finds the address of row number 'row' in the UniMod(tm) stream 't' returns
168 NULL if the row can't be found. */
UniFindRow(UBYTE * t,UWORD row)169 UBYTE *UniFindRow(UBYTE* t,UWORD row)
170 {
171 UBYTE c,l;
172
173 if(t)
174 while(1) {
175 c = *t; /* get rep/len byte */
176 if(!c) return NULL; /* zero ? -> end of track.. */
177 l = (c>>5)+1; /* extract repeat value */
178 if(l>row) break; /* reached wanted row? -> return pointer */
179 row -= l; /* haven't reached row yet.. update row */
180 t += c&0x1f; /* point t to the next row */
181 }
182 return t;
183 }
184
185 /*========== Writing routines */
186
187 static UBYTE *unibuf; /* pointer to the temporary unitrk buffer */
188 static UWORD unimax; /* buffer size */
189
190 static UWORD unipc; /* buffer cursor */
191 static UWORD unitt; /* current row index */
192 static UWORD lastp; /* previous row index */
193
194 /* Resets index-pointers to create a new track. */
UniReset(void)195 void UniReset(void)
196 {
197 unitt = 0; /* reset index to rep/len byte */
198 unipc = 1; /* first opcode will be written to index 1 */
199 lastp = 0; /* no previous row yet */
200 unibuf[0] = 0; /* clear rep/len byte */
201 }
202
203 /* Expands the buffer */
UniExpand(int wanted)204 static BOOL UniExpand(int wanted)
205 {
206 if ((unipc+wanted)>=unimax) {
207 UBYTE *newbuf;
208
209 /* Expand the buffer by BUFPAGE bytes */
210 newbuf=(UBYTE*)MikMod_realloc(unibuf,(unimax+BUFPAGE)*sizeof(UBYTE));
211
212 /* Check if MikMod_realloc succeeded */
213 if(newbuf) {
214 unibuf = newbuf;
215 unimax+=BUFPAGE;
216 return 1;
217 } else
218 return 0;
219 }
220 return 1;
221 }
222
223 /* Appends one byte of data to the current row of a track. */
UniWriteByte(UBYTE data)224 void UniWriteByte(UBYTE data)
225 {
226 if (UniExpand(1))
227 /* write byte to current position and update */
228 unibuf[unipc++]=data;
229 }
230
UniWriteWord(UWORD data)231 void UniWriteWord(UWORD data)
232 {
233 if (UniExpand(2)) {
234 unibuf[unipc++]=data>>8;
235 unibuf[unipc++]=data&0xff;
236 }
237 }
238
MyCmp(const UBYTE * a,const UBYTE * b,UWORD l)239 static BOOL MyCmp(const UBYTE* a,const UBYTE* b,UWORD l)
240 {
241 UWORD t;
242
243 for(t=0;t<l;t++)
244 if(*(a++)!=*(b++)) return 0;
245 return 1;
246 }
247
248 /* Closes the current row of a unitrk stream (updates the rep/len byte) and sets
249 pointers to start a new row. */
UniNewline(void)250 void UniNewline(void)
251 {
252 UWORD n,l,len;
253
254 n = (unibuf[lastp]>>5)+1; /* repeat of previous row */
255 l = (unibuf[lastp]&0x1f); /* length of previous row */
256
257 len = unipc-unitt; /* length of current row */
258
259 /* Now, check if the previous and the current row are identical.. when they
260 are, just increase the repeat field of the previous row */
261 if(n<8 && len==l && MyCmp(&unibuf[lastp+1],&unibuf[unitt+1],len-1)) {
262 unibuf[lastp]+=0x20;
263 unipc = unitt+1;
264 } else {
265 if (UniExpand(unitt-unipc)) {
266 /* current and previous row aren't equal... update the pointers */
267 unibuf[unitt] = len;
268 lastp = unitt;
269 unitt = unipc++;
270 }
271 }
272 }
273
274 /* Terminates the current unitrk stream and returns a pointer to a copy of the
275 stream. */
UniDup(void)276 UBYTE* UniDup(void)
277 {
278 void *d;
279
280 if (!UniExpand(unipc-unitt)) return NULL;
281 unibuf[unitt] = 0;
282
283 if(!(d=MikMod_malloc(unipc))) return NULL;
284 memcpy(d,unibuf,unipc);
285
286 return (UBYTE *)d;
287 }
288
UniInit(void)289 BOOL UniInit(void)
290 {
291 unimax = BUFPAGE;
292
293 if(!(unibuf=(UBYTE*)MikMod_malloc(unimax*sizeof(UBYTE)))) return 0;
294 return 1;
295 }
296
UniCleanup(void)297 void UniCleanup(void)
298 {
299 MikMod_free(unibuf);
300 unibuf = NULL;
301 }
302
303 /* ex:set ts=4: */
304