aboutsummaryrefslogtreecommitdiff
path: root/engines/kyra/script.cpp
blob: ef3e259cfa747d66f634cc07968f929bc7f2aff4 (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
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
/* 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 "common/endian.h"
#include "common/stream.h"
#include "common/util.h"
#include "common/system.h"
#include "kyra/kyra_v1.h"
#include "kyra/resource.h"
#include "kyra/script.h"

namespace Kyra {
EMCInterpreter::EMCInterpreter(KyraEngine_v1 *vm) : _vm(vm) {
#define COMMAND(x) { &EMCInterpreter::x, #x }
	static CommandEntry commandProcs[] = {
		// 0x00
		COMMAND(cmd_jmpTo),
		COMMAND(cmd_setRetValue),
		COMMAND(cmd_pushRetOrPos),
		COMMAND(cmd_push),
		// 0x04
		COMMAND(cmd_push),
		COMMAND(cmd_pushReg),
		COMMAND(cmd_pushBPNeg),
		COMMAND(cmd_pushBPAdd),
		// 0x08
		COMMAND(cmd_popRetOrPos),
		COMMAND(cmd_popReg),
		COMMAND(cmd_popBPNeg),
		COMMAND(cmd_popBPAdd),
		// 0x0C
		COMMAND(cmd_addSP),
		COMMAND(cmd_subSP),
		COMMAND(cmd_execOpcode),
		COMMAND(cmd_ifNotJmp),
		// 0x10
		COMMAND(cmd_negate),
		COMMAND(cmd_eval),
		COMMAND(cmd_setRetAndJmp)
	};
	_commands = commandProcs;
#undef COMMAND
}

bool EMCInterpreter::load(const char *filename, EMCData *scriptData, const Common::Array<const Opcode*> *opcodes) {
	ScriptFileParser file(filename, _vm->resource());
	if (!file) {
		error("Couldn't open script file '%s'", filename);
		return false;
	}

	memset(scriptData, 0, sizeof(EMCData));

	uint32 formBlockSize = file.getFORMBlockSize();
	if (formBlockSize == (uint32)-1) {
		error("No FORM chunk found in file: '%s'", filename);
		return false;
	}

	uint32 chunkSize = file.getIFFBlockSize(TEXT_CHUNK);
	if (chunkSize != (uint32)-1) {
		scriptData->text = new byte[chunkSize];

		if (!file.loadIFFBlock(TEXT_CHUNK, scriptData->text, chunkSize)) {
			unload(scriptData);
			error("Couldn't load TEXT chunk from file: '%s'", filename);
			return false;
		}
	}

	chunkSize = file.getIFFBlockSize(ORDR_CHUNK);
	if (chunkSize == (uint32)-1) {
		unload(scriptData);
		error("No ORDR chunk found in file: '%s'", filename);
		return false;
	}
	chunkSize >>= 1;

	scriptData->ordr = new uint16[chunkSize];

	if (!file.loadIFFBlock(ORDR_CHUNK, scriptData->ordr, chunkSize << 1)) {
		unload(scriptData);
		error("Couldn't load ORDR chunk from file: '%s'", filename);
		return false;
	}

	while (chunkSize--)
		scriptData->ordr[chunkSize] = READ_BE_UINT16(&scriptData->ordr[chunkSize]);

	chunkSize = file.getIFFBlockSize(DATA_CHUNK);
	if (chunkSize == (uint32)-1) {
		unload(scriptData);
		error("No DATA chunk found in file: '%s'", filename);
		return false;
	}
	chunkSize >>= 1;

	scriptData->data = new uint16[chunkSize];

	if (!file.loadIFFBlock(DATA_CHUNK, scriptData->data, chunkSize << 1)) {
		unload(scriptData);
		error("Couldn't load DATA chunk from file: '%s'", filename);
		return false;
	}
	scriptData->dataSize = chunkSize;

	while (chunkSize--)
		scriptData->data[chunkSize] = READ_BE_UINT16(&scriptData->data[chunkSize]);

	scriptData->opcodes = opcodes;

	return true;
}

void EMCInterpreter::unload(EMCData *data) {
	if (!data)
		return;

	delete[] data->text;
	delete[] data->ordr;
	delete[] data->data;

	data->text = 0;
	data->ordr = data->data = 0;
}

void EMCInterpreter::init(EMCState *scriptStat, const EMCData *data) {
	scriptStat->dataPtr = data;
	scriptStat->ip = 0;
	scriptStat->stack[60] = 0;
	scriptStat->bp = 62;
	scriptStat->sp = 60;
}

bool EMCInterpreter::start(EMCState *script, int function) {
	if (!script->dataPtr)
		return false;

	uint16 functionOffset = script->dataPtr->ordr[function];
	if (functionOffset == 0xFFFF)
		return false;

	if (_vm->game() == GI_KYRA1) {
		if (_vm->gameFlags().platform == Common::kPlatformFMTowns || _vm->gameFlags().platform == Common::kPlatformPC98)
			script->ip = &script->dataPtr->data[functionOffset+1];
		else
			script->ip = &script->dataPtr->data[functionOffset];
	} else {
		script->ip = &script->dataPtr->data[functionOffset+1];
	}

	return true;
}

bool EMCInterpreter::isValid(EMCState *script) {
	if (!script->ip || !script->dataPtr || _vm->quit())
		return false;
	return true;
}

bool EMCInterpreter::run(EMCState *script) {
	_parameter = 0;

	if (!script->ip)
		return false;

	// Should be no Problem at all to cast to uint32 here, since that's the biggest ptrdiff the original
	// would allow, of course that's not realistic to happen to be somewhere near the limit of uint32 anyway.
	const uint32 instOffset = (uint32)((const byte*)script->ip - (const byte*)script->dataPtr->data);
	int16 code = *script->ip++;
	int16 opcode = (code >> 8) & 0x1F;

	if (code & 0x8000) {
		opcode = 0;
		_parameter = code & 0x7FFF;
	} else if (code & 0x4000) {
		_parameter = (int8)(code);
	} else if (code & 0x2000) {
		_parameter = *script->ip++;
	} else {
		_parameter = 0;
	}

	if (opcode > 18) {
		error("Script unknown command: %d", opcode);
	} else {
		debugC(5, kDebugLevelScript, "[0x%.08X] EMCInterpreter::%s([%d/%u])", instOffset, _commands[opcode].desc, _parameter, (uint)_parameter);
		(this->*(_commands[opcode].proc))(script);
	}

	return (script->ip != 0);
}

#pragma mark -
#pragma mark - ScriptFileParser implementation
#pragma mark -

void ScriptFileParser::setFile(const char *filename, Resource *res) {
	destroy();

	res->exists(filename, true);
	_stream = res->getFileStream(filename);
	assert(_stream);
	_startOffset = 0;
	_endOffset = _stream->size();
}

void ScriptFileParser::destroy() {
	delete _stream;
	_stream = 0;
	_startOffset = _endOffset = 0;
}

uint32 ScriptFileParser::getFORMBlockSize() {
	uint32 oldOffset = _stream->pos();

	uint32 data = _stream->readUint32LE();

	if (data != FORM_CHUNK) {
		_stream->seek(oldOffset);
		return (uint32)-1;
	}

	data = _stream->readUint32BE();
	return data;
}

uint32 ScriptFileParser::getIFFBlockSize(const uint32 chunkName) {
	uint32 size = (uint32)-1;

	_stream->seek(_startOffset + 0x0C);

	while (_stream->pos() < _endOffset) {
		uint32 chunk = _stream->readUint32LE();
		uint32 size_temp = _stream->readUint32BE();

		if (chunk != chunkName) {
			_stream->seek((size_temp + 1) & (~1), SEEK_CUR);
			assert(_stream->pos() <= _endOffset);
		} else {
			size = size_temp;
			break;
		}
	}

	return size;
}

bool ScriptFileParser::loadIFFBlock(const uint32 chunkName, void *loadTo, uint32 ptrSize) {
	_stream->seek(_startOffset + 0x0C);

	while (_stream->pos() < _endOffset) {
		uint32 chunk = _stream->readUint32LE();
		uint32 chunkSize = _stream->readUint32BE();

		if (chunk != chunkName) {
			_stream->seek((chunkSize + 1) & (~1), SEEK_CUR);
			assert(_stream->pos() <= _endOffset);
		} else {
			uint32 loadSize = 0;

			loadSize = MIN(ptrSize, chunkSize);
			_stream->read(loadTo, loadSize);
			return true;
		}
	}

	return false;
}

#pragma mark -
#pragma mark - Command implementations
#pragma mark -

void EMCInterpreter::cmd_jmpTo(EMCState* script) {
	script->ip = script->dataPtr->data + _parameter;
}

void EMCInterpreter::cmd_setRetValue(EMCState* script) {
	script->retValue = _parameter;
}

void EMCInterpreter::cmd_pushRetOrPos(EMCState* script) {
	switch (_parameter) {
	case 0:
		script->stack[--script->sp] = script->retValue;
		break;

	case 1:
		script->stack[--script->sp] = script->ip - script->dataPtr->data + 1;
		script->stack[--script->sp] = script->bp;
		script->bp = script->sp + 2;
		break;

	default:
		script->ip = 0;
		break;
	}
}

void EMCInterpreter::cmd_push(EMCState* script) {
	script->stack[--script->sp] = _parameter;
}

void EMCInterpreter::cmd_pushReg(EMCState* script) {
	script->stack[--script->sp] = script->regs[_parameter];
}

void EMCInterpreter::cmd_pushBPNeg(EMCState* script) {
	script->stack[--script->sp] = script->stack[(-(int32)(_parameter + 2)) + script->bp];
}

void EMCInterpreter::cmd_pushBPAdd(EMCState* script) {
	script->stack[--script->sp] = script->stack[(_parameter - 1) + script->bp];
}

void EMCInterpreter::cmd_popRetOrPos(EMCState* script) {
	switch (_parameter) {
	case 0:
		script->retValue = script->stack[script->sp++];
		break;

	case 1:
		if (script->sp >= 60) {
			script->ip = 0;
		} else {
			script->bp = script->stack[script->sp++];
			script->ip = script->dataPtr->data + script->stack[script->sp++];
		}
		break;

	default:
		script->ip = 0;
		break;
	}
}

void EMCInterpreter::cmd_popReg(EMCState* script) {
	script->regs[_parameter] = script->stack[script->sp++];
}

void EMCInterpreter::cmd_popBPNeg(EMCState* script) {
	script->stack[(-(int32)(_parameter + 2)) + script->bp] = script->stack[script->sp++];
}

void EMCInterpreter::cmd_popBPAdd(EMCState* script) {
	script->stack[(_parameter - 1) + script->bp] = script->stack[script->sp++];
}

void EMCInterpreter::cmd_addSP(EMCState* script) {
	script->sp += _parameter;
}

void EMCInterpreter::cmd_subSP(EMCState* script) {
	script->sp -= _parameter;
}

void EMCInterpreter::cmd_execOpcode(EMCState* script) {
	uint8 opcode = _parameter;

	assert(script->dataPtr->opcodes);
	assert(opcode < script->dataPtr->opcodes->size());

	if ((*script->dataPtr->opcodes)[opcode] && ((*script->dataPtr->opcodes)[opcode])->isValid()) {
		script->retValue = (*(*script->dataPtr->opcodes)[opcode])(script);
	} else {
		script->retValue = 0;
		warning("calling unimplemented opcode(0x%.02X/%d)", opcode, opcode);
	}
}

void EMCInterpreter::cmd_ifNotJmp(EMCState* script) {
	if (!script->stack[script->sp++]) {
		_parameter &= 0x7FFF;
		script->ip = script->dataPtr->data + _parameter;
	}
}

void EMCInterpreter::cmd_negate(EMCState* script) {
	int16 value = script->stack[script->sp];
	switch (_parameter) {
	case 0:
		if (!value)
			script->stack[script->sp] = 1;
		else
			script->stack[script->sp] = 0;
		break;

	case 1:
		script->stack[script->sp] = -value;
		break;

	case 2:
		script->stack[script->sp] = ~value;
		break;

	default:
		warning("Unknown negation func: %d", _parameter);
		script->ip = 0;
		break;
	}
}

void EMCInterpreter::cmd_eval(EMCState* script) {
	int16 ret = 0;
	bool error = false;

	int16 val1 = script->stack[script->sp++];
	int16 val2 = script->stack[script->sp++];

	switch (_parameter) {
	case 0:
		if (!val2 || !val1)
			ret = 0;
		else
			ret = 1;
		break;

	case 1:
		if (val2 || val1)
			ret = 1;
		else
			ret = 0;
		break;

	case 2:
		if (val1 == val2)
			ret = 1;
		else
			ret = 0;
		break;

	case 3:
		if (val1 != val2)
			ret = 1;
		else
			ret = 0;
		break;

	case 4:
		if (val1 > val2)
			ret = 1;
		else
			ret = 0;
		break;

	case 5:
		if (val1 >= val2)
			ret = 1;
		else
			ret = 0;
		break;

	case 6:
		if (val1 < val2)
			ret = 1;
		else
			ret = 0;
		break;

	case 7:
		if (val1 <= val2)
			ret = 1;
		else
			ret = 0;
		break;

	case 8:
		ret = val1 + val2;
		break;

	case 9:
		ret = val2 - val1;
		break;

	case 10:
		ret = val1 * val2;
		break;

	case 11:
		ret = val2 / val1;
		break;

	case 12:
		ret = val2 >> val1;
		break;

	case 13:
		ret = val2 << val1;
		break;

	case 14:
		ret = val1 & val2;
		break;

	case 15:
		ret = val1 | val2;
		break;

	case 16:
		ret = val2 % val1;
		break;

	case 17:
		ret = val1 ^ val2;
		break;

	default:
		warning("Unknown evaluate func: %d", _parameter);
		error = true;
		break;
	}

	if (error)
		script->ip = 0;
	else
		script->stack[--script->sp] = ret;
}

void EMCInterpreter::cmd_setRetAndJmp(EMCState* script) {
	if (script->sp >= 60) {
		script->ip = 0;
	} else {
		script->retValue = script->stack[script->sp++];
		uint16 temp = script->stack[script->sp++];
		script->stack[60] = 0;
		script->ip = &script->dataPtr->data[temp];
	}
}
} // end of namespace Kyra