aboutsummaryrefslogtreecommitdiff
path: root/engines/scumm/file.cpp
blob: 6dc31b09efd02d8b51e069830c66c4a134bb49e6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * $URL$
 * $Id$
 *
 */

#include "scumm/file.h"

#include "scumm/scumm.h"

using Common::File;

namespace Scumm {

#pragma mark -
#pragma mark --- ScummFile ---
#pragma mark -

ScummFile::ScummFile() : _encbyte(0), _subFileStart(0), _subFileLen(0) {
}

void ScummFile::setEnc(byte value) {
	_encbyte = value;
}

void ScummFile::setSubfileRange(int32 start, int32 len) {
	// TODO: Add sanity checks
	const int32 fileSize = File::size();
	assert(start <= fileSize);
	assert(start + len <= fileSize);
	_subFileStart = start;
	_subFileLen = len;
	seek(0, SEEK_SET);
}

void ScummFile::resetSubfile() {
	_subFileStart = 0;
	_subFileLen = 0;
	seek(0, SEEK_SET);
}

bool ScummFile::open(const Common::String &filename) {
	if (File::open(filename)) {
		resetSubfile();
		return true;
	} else {
		return false;
	}
}

bool ScummFile::openSubFile(const Common::String &filename) {
	assert(isOpen());

	// Disable the XOR encryption and reset any current subfile range
	setEnc(0);
	resetSubfile();

	// Read in the filename table and look for the specified file

	unsigned long file_off, file_len;
	char file_name[0x20+1];
	unsigned long i;

	// Get the length of the data file to use for consistency checks
	const uint32 data_file_len = size();

	// Read offset and length to the file records */
	const uint32 file_record_off = readUint32BE();
	const uint32 file_record_len = readUint32BE();

	// Do a quick check to make sure the offset and length are good
	if (file_record_off + file_record_len > data_file_len) {
		return false;
	}

	// Do a little consistancy check on file_record_length
	if (file_record_len % 0x28) {
		return false;
	}

	// Scan through the files
	for (i = 0; i < file_record_len; i += 0x28) {
		// read a file record
		seek(file_record_off + i, SEEK_SET);
		file_off = readUint32BE();
		file_len = readUint32BE();
		read(file_name, 0x20);
		file_name[0x20] = 0;

		assert(file_name[0]);
		//debug(7, "  extracting \'%s\'", file_name);

		// Consistency check. make sure the file data is in the file
		if (file_off + file_len > data_file_len) {
			return false;
		}

		if (scumm_stricmp(file_name, filename.c_str()) == 0) {
			// We got a match!
			setSubfileRange(file_off, file_len);
			return true;
		}
	}

	return false;
}


bool ScummFile::eos() const {
	return _subFileLen ? _myEos : File::eos();
}

int32 ScummFile::pos() const {
	return File::pos() - _subFileStart;
}

int32 ScummFile::size() const {
	return _subFileLen ? _subFileLen : File::size();
}

bool ScummFile::seek(int32 offs, int whence) {
	if (_subFileLen) {
		// Constrain the seek to the subfile
		switch (whence) {
		case SEEK_END:
			offs = _subFileStart + _subFileLen + offs;
			break;
		case SEEK_SET:
			offs += _subFileStart;
			break;
		case SEEK_CUR:
			offs += File::pos();
			break;
		}
		assert((int32)_subFileStart <= offs && offs <= (int32)(_subFileStart + _subFileLen));
		whence = SEEK_SET;
	}
	bool ret = File::seek(offs, whence);
	if (ret)
		_myEos = false;
	return ret;
}

uint32 ScummFile::read(void *dataPtr, uint32 dataSize) {
	uint32 realLen;

	if (_subFileLen) {
		// Limit the amount we read by the subfile boundaries.
		const int32 curPos = pos();
		assert(_subFileLen >= curPos);
		int32 newPos = curPos + dataSize;
		if (newPos > _subFileLen) {
			dataSize = _subFileLen - curPos;
			_myEos = true;
		}
	}

	realLen = File::read(dataPtr, dataSize);


	// If an encryption byte was specified, XOR the data we just read by it.
	// This simple kind of "encryption" was used by some of the older SCUMM
	// games.
	if (_encbyte) {
		byte *p = (byte *)dataPtr;
		byte *end = p + realLen;
		while (p < end)
			*p++ ^= _encbyte;
	}

	return realLen;
}

#pragma mark -
#pragma mark --- ScummDiskImage ---
#pragma mark -

static const int maniacResourcesPerFile[55] = {
	 0, 11,  1,  3,  9, 12,  1, 13, 10,  6,
	 4,  1,  7,  1,  1,  2,  7,  8, 19,  9,
	 6,  9,  2,  6,  8,  4, 16,  8,  3,  3,
	12, 12,  2,  8,  1,  1,  2,  1,  9,  1,
	 3,  7,  3,  3, 13,  5,  4,  3,  1,  1,
	 3, 10,  1,  0,  0
};

static const int zakResourcesPerFile[59] = {
	 0, 29, 12, 14, 13,  4,  4, 10,  7,  4,
	14, 19,  5,  4,  7,  6, 11,  9,  4,  4,
	 1,  3,  3,  5,  1,  9,  4, 10, 13,  6,
	 7, 10,  2,  6,  1, 11,  2,  5,  7,  1,
	 7,  1,  4,  2,  8,  6,  6,  6,  4, 13,
	 3,  1,  2,  1,  2,  1, 10,  1,  1
};


static uint16 write_byte(Common::WriteStream *out, byte val) {
	val ^= 0xFF;
	if (out != 0)
		out->writeByte(val);
	return 1;
}

static uint16 write_word(Common::WriteStream *out, uint16 val) {
	val ^= 0xFFFF;
	if (out != 0)
		out->writeUint16LE(val);
	return 2;
}

ScummDiskImage::ScummDiskImage(const char *disk1, const char *disk2, GameSettings game)
	: _stream(0), _buf(0), _game(game),
	_disk1(disk1), _disk2(disk2), _openedDisk(0) {

	if (_game.id == GID_MANIAC) {
		_numGlobalObjects = 256;
		_numRooms = 55;
		_numCostumes = 25;
		_numScripts = 160;
		_numSounds = 70;
		_resourcesPerFile = maniacResourcesPerFile;
	} else {
		_numGlobalObjects = 775;
		_numRooms = 59;
		_numCostumes = 38;
		_numScripts = 155;
		_numSounds = 127;
		_resourcesPerFile = zakResourcesPerFile;
	}
}

void ScummDiskImage::setEnc(byte enc) {
	_stream->setEnc(enc);
}

byte ScummDiskImage::fileReadByte() {
	byte b = 0;
	File::read(&b, 1);
	return b;
}

uint16 ScummDiskImage::fileReadUint16LE() {
	uint16 a = fileReadByte();
	uint16 b = fileReadByte();
	return a | (b << 8);
}

bool ScummDiskImage::openDisk(char num) {
	if (num == '1')
		num = 1;
	if (num == '2')
		num = 2;

	if (_openedDisk != num || !File::isOpen()) {
		if (File::isOpen())
			File::close();

		if (num == 1)
			File::open(_disk1);
		else if (num == 2)
			File::open(_disk2);
		else {
			error("ScummDiskImage::open(): wrong disk (%c)", num);
			return false;
		}

		_openedDisk = num;

		if (!File::isOpen()) {
			error("ScummDiskImage::open(): cannot open disk (%d)", num);
			return false;
		}
	}
	return true;
}

bool ScummDiskImage::open(const Common::String &filename) {
	uint16 signature;

	// check signature
	openDisk(1);

	if (_game.platform == Common::kPlatformApple2GS) {
		File::seek(142080);
	} else {
		File::seek(0);
	}

	signature = fileReadUint16LE();
	if (signature != 0x0A31) {
		error("ScummDiskImage::open(): signature not found in disk 1");
		return false;
	}

	extractIndex(0); // Fill in resource arrays

	openDisk(2);

	if (_game.platform == Common::kPlatformApple2GS) {
		File::seek(143104);
		signature = fileReadUint16LE();
		if (signature != 0x0032)
			error("Error: signature not found in disk 2");
	} else {
		File::seek(0);
		signature = fileReadUint16LE();
		if (signature != 0x0132)
			error("Error: signature not found in disk 2");
	}


	return true;
}


uint16 ScummDiskImage::extractIndex(Common::WriteStream *out) {
	int i;
	uint16 reslen = 0;

	openDisk(1);

	if (_game.platform == Common::kPlatformApple2GS) {
		File::seek(142080);
	} else {
		File::seek(0);
	}

	// skip signature
	fileReadUint16LE();

	// write expected signature
	if (_game.platform == Common::kPlatformApple2GS) {
		reslen += write_word(out, 0x0032);
	} else {
		reslen += write_word(out, 0x0132);
	}

	// copy object flags
	for (i = 0; i < _numGlobalObjects; i++)
		reslen += write_byte(out, fileReadByte());

	// copy room offsets
	for (i = 0; i < _numRooms; i++) {
		_roomDisks[i] = fileReadByte();
		reslen += write_byte(out, _roomDisks[i]);
	}
	for (i = 0; i < _numRooms; i++) {
		_roomSectors[i] = fileReadByte();
		reslen += write_byte(out, _roomSectors[i]);
		_roomTracks[i] = fileReadByte();
		reslen += write_byte(out, _roomTracks[i]);
	}
	for (i = 0; i < _numCostumes; i++)
		reslen += write_byte(out, fileReadByte());
	for (i = 0; i < _numCostumes; i++)
		reslen += write_word(out, fileReadUint16LE());

	for (i = 0; i < _numScripts; i++)
		reslen += write_byte(out, fileReadByte());
	for (i = 0; i < _numScripts; i++)
		reslen += write_word(out, fileReadUint16LE());

	for (i = 0; i < _numSounds; i++)
		reslen += write_byte(out, fileReadByte());
	for (i = 0; i < _numSounds; i++)
		reslen += write_word(out, fileReadUint16LE());

	return reslen;
}

bool ScummDiskImage::generateIndex() {
	int bufsize;

	bufsize = extractIndex(0);

	free(_buf);
	_buf = (byte *)calloc(1, bufsize);

	Common::MemoryWriteStream out(_buf, bufsize);

	extractIndex(&out);

	if (_stream)
		delete _stream;

	_stream = new Common::MemoryReadStream(_buf, bufsize);

	return true;
}

uint16 ScummDiskImage::extractResource(Common::WriteStream *out, int res) {
	const int AppleSectorOffset[36] = {
		0, 16, 32, 48, 64, 80, 96, 112, 128, 144, 160, 176, 192, 208, 224, 240, 256,
		272, 288, 304, 320, 336, 352, 368,
		384, 400, 416, 432, 448, 464,
		480, 496, 512, 528, 544, 560
	};
	const int C64SectorOffset[36] = {
		0,
		0, 21, 42, 63, 84, 105, 126, 147, 168, 189, 210, 231, 252, 273, 294, 315, 336,
		357, 376, 395, 414, 433, 452, 471,
		490, 508, 526, 544, 562, 580,
		598, 615, 632, 649, 666
	};
	int i;
	uint16 reslen = 0;

	openDisk(_roomDisks[res]);

	if (_game.platform == Common::kPlatformApple2GS) {
		File::seek((AppleSectorOffset[_roomTracks[res]] + _roomSectors[res]) * 256);
	} else {
		File::seek((C64SectorOffset[_roomTracks[res]] + _roomSectors[res]) * 256);
	}

	for (i = 0; i < _resourcesPerFile[res]; i++) {
		uint16 len = fileReadUint16LE();
		reslen += write_word(out, len);

		for (len -= 2; len > 0; len--)
			reslen += write_byte(out, fileReadByte());
	}

	return reslen;
}

bool ScummDiskImage::generateResource(int res) {
	int bufsize;

	if (res >= _numRooms)
		return false;

	bufsize = extractResource(0, res);

	free(_buf);
	_buf = (byte *)calloc(1, bufsize);

	Common::MemoryWriteStream out(_buf, bufsize);

	extractResource(&out, res);

	delete _stream;
	_stream = new Common::MemoryReadStream(_buf, bufsize);

	return true;
}

void ScummDiskImage::close() {
	delete _stream;
	_stream = 0;

	free(_buf);
	_buf = 0;

	File::close();
}

bool ScummDiskImage::openSubFile(const Common::String &filename) {
	assert(isOpen());

	const char *ext = strrchr(filename.c_str(), '.');
	char resNum[3];
	int res;

	// We always have file name in form of XX.lfl
	resNum[0] = ext[-2];
	resNum[1] = ext[-1];
	resNum[2] = 0;

	res = atoi(resNum);

	if (res == 0) {
		return generateIndex();
	} else {
		return generateResource(res);
	}

	return true;
}

} // End of namespace Scumm