aboutsummaryrefslogtreecommitdiff
path: root/engines/sci/engine/object.cpp
blob: 8873812c88087c2d84647adacfc0e16ca56b7e29 (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
/* 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.
 *
 */


#include "sci/engine/kernel.h"
#include "sci/engine/object.h"
#include "sci/engine/script.h"
#include "sci/engine/seg_manager.h"
#ifdef ENABLE_SCI32
#include "sci/engine/features.h"
#endif

namespace Sci {

extern bool relocateBlock(Common::Array<reg_t> &block, int block_location, SegmentId segment, int location, uint32 heapOffset);

void Object::init(const Script &owner, reg_t obj_pos, bool initVariables) {
	const SciSpan<const byte> buf = owner.getSpan(0);
	const SciSpan<const byte> data = owner.getSpan(obj_pos.getOffset());
	_baseObj = data;
	_pos = obj_pos;

	// Calling Object::init more than once will screw up _baseVars/_baseMethod
	// by duplicating data. This could be turned into a soft error by warning
	// instead and clearing arrays, but there does not currently seem to be any
	// reason for an object to be initialized multiple times
	if (_baseVars.size() || _baseMethod.size()) {
		error("Attempt to reinitialize already-initialized object %04x:%04x in script %u", PRINT_REG(obj_pos), owner.getScriptNumber());
	}

	if (getSciVersion() <= SCI_VERSION_1_LATE) {
		const SciSpan<const byte> header = buf.subspan(obj_pos.getOffset() - kOffsetHeaderSize);
		_variables.resize(header.getUint16LEAt(kOffsetHeaderSelectorCounter));

		// Non-class objects do not have a baseVars section
		const uint16 infoSelector = data.getUint16SEAt((_offset + 2) * sizeof(uint16));
		if (infoSelector & kInfoFlagClass) {
			_baseVars.reserve(_variables.size());
			uint baseVarsOffset = _variables.size() * sizeof(uint16);
			for (uint i = 0; i < _variables.size(); ++i) {
				_baseVars.push_back(data.getUint16SEAt(baseVarsOffset));
				baseVarsOffset += sizeof(uint16);
			}
		}

		// method block structure:
		// uint16 count;
		// uint16 selectorNos[count];
		// uint16 zero;
		// uint16 codeOffsets[count];

		const uint16 methodBlockOffset = header.getUint16LEAt(kOffsetHeaderFunctionArea) - 2;
		_methodCount = data.getUint16LEAt(methodBlockOffset);
		const uint32 methodBlockSize = _methodCount * 2 * sizeof(uint16) + /* zero-terminator after selector list */ sizeof(uint16);

		SciSpan<const uint16> methodEntries = data.subspan<const uint16>(methodBlockOffset + /* count */ sizeof(uint16), methodBlockSize);

		// If this happens, then there is either a corrupt script or this code
		// misunderstands the structure of the SCI0/1 method block
		if (methodEntries.getUint16SEAt(_methodCount) != 0) {
			warning("Object %04x:%04x in script %u has a value (0x%04x) in its zero-terminator field", PRINT_REG(obj_pos), owner.getScriptNumber(), methodEntries.getUint16SEAt(_methodCount));
		}

		_baseMethod.reserve(_methodCount * 2);
		for (uint i = 0; i < _methodCount; ++i) {
			_baseMethod.push_back(methodEntries.getUint16SEAt(0));
			_baseMethod.push_back(methodEntries.getUint16SEAt(_methodCount + /* zero-terminator */ 1));
			++methodEntries;
		}
	} else if (getSciVersion() >= SCI_VERSION_1_1 && getSciVersion() <= SCI_VERSION_2_1_LATE) {
		_variables.resize(data.getUint16SEAt(2));

		// Non-class objects do not have a baseVars section
		const uint16 infoSelector = data.getUint16SEAt((_offset + 2) * sizeof(uint16));
		if (infoSelector & kInfoFlagClass) {
			_baseVars.reserve(_variables.size());
			uint baseVarsOffset = data.getUint16SEAt(4);
			for (uint i = 0; i < _variables.size(); ++i) {
				_baseVars.push_back(buf.getUint16SEAt(baseVarsOffset));
				baseVarsOffset += sizeof(uint16);
			}
		}

		// method block structure:
		// uint16 count;
		// struct {
		//   uint16 selectorNo;
		//   uint16 codeOffset;
		// } entries[count];

		const uint16 methodBlockOffset = data.getUint16SEAt(6);
		_methodCount = buf.getUint16SEAt(methodBlockOffset);

		// Each entry in _baseMethod is actually two values; the first field is
		// a selector number, and the second field is an offset to the method's
		// code in the script
		const uint32 methodBlockSize = _methodCount * 2 * sizeof(uint16);
		_baseMethod.reserve(_methodCount * 2);

		SciSpan<const uint16> methodEntries = buf.subspan<const uint16>(methodBlockOffset + /* count */ sizeof(uint16), methodBlockSize);
		for (uint i = 0; i < _methodCount; ++i) {
			_baseMethod.push_back(methodEntries.getUint16SEAt(0));
			_baseMethod.push_back(methodEntries.getUint16SEAt(1));
			methodEntries += 2;
		}
#ifdef ENABLE_SCI32
	} else if (getSciVersion() == SCI_VERSION_3) {
		initSelectorsSci3(buf, initVariables);
#endif
	}

	// Some objects, like the unnamed LarryTalker instance in LSL6hires script
	// 610, and the File class in Torin script 64993, have a `name` property
	// that is assigned dynamically by game scripts, overriding the static name
	// value that is normally created by the SC compiler. When this happens, the
	// value can be set to anything: in LSL6hires it becomes a Str object; in
	// Torin, it becomes a dynamically allocated string that is disposed before
	// the corresponding File instance is disposed.
	// To ensure `SegManager::getObjectName` works consistently and correctly,
	// without hacks to bypass unexpected/invalid types of dynamic `name` data,
	// the reg_t pointer to the original static name value for the object is
	// stored here, ensuring that it is constant and guaranteed to be either a
	// valid dereferenceable string or NULL_REG.
	if (getSciVersion() != SCI_VERSION_3) {
		const uint32 heapOffset = owner.getHeapOffset();
		const uint32 nameOffset = (obj_pos.getOffset() - heapOffset) + (_offset + 3) * sizeof(uint16);
		const uint32 relocOffset = owner.getRelocationOffset(nameOffset);
		if (relocOffset != kNoRelocation) {
			_name = make_reg(obj_pos.getSegment(), relocOffset + _baseObj.getUint16SEAt((_offset + 3) * sizeof(uint16)));
		}
#ifdef ENABLE_SCI32
	} else if (_propertyOffsetsSci3.size()) {
		const uint32 nameOffset = _propertyOffsetsSci3[0];
		const uint32 relocOffset = owner.getRelocationOffset(nameOffset);
		if (relocOffset != kNoRelocation) {
			_name.setSegment(obj_pos.getSegment());
			_name.setOffset(relocOffset + buf.getUint16SEAt(nameOffset));
		}
#endif
	}

	if (initVariables) {
#ifdef ENABLE_SCI32
		if (getSciVersion() == SCI_VERSION_3) {
			_infoSelectorSci3 = make_reg(0, data.getUint16SEAt(10));
		} else {
#else
		{
#endif
			for (uint i = 0; i < _variables.size(); i++)
				_variables[i] = make_reg(0, data.getUint16SEAt(i * sizeof(uint16)));
		}
	}
}

const Object *Object::getClass(SegManager *segMan) const {
	return isClass() ? this : segMan->getObject(getSuperClassSelector());
}

int Object::locateVarSelector(SegManager *segMan, Selector slc) const {
	const Common::Array<uint16> *buf;
	uint varCount;

#ifdef ENABLE_SCI32
	if (getSciVersion() == SCI_VERSION_3) {
		buf = &_baseVars;
		varCount = getVarCount();
	} else {
#else
	{
#endif
		const Object *obj = getClass(segMan);
		buf = &obj->_baseVars;
		varCount = obj->getVarCount();
	}

	for (uint i = 0; i < varCount; i++)
		if ((*buf)[i] == slc) // Found it?
			return i; // report success

	return -1; // Failed
}

bool Object::relocateSci0Sci21(SegmentId segment, int location, uint32 heapOffset) {
	return relocateBlock(_variables, getPos().getOffset(), segment, location, heapOffset);
}

#ifdef ENABLE_SCI32
bool Object::relocateSci3(SegmentId segment, uint32 location, int offset, uint32 scriptSize) {
	assert(offset >= 0 && (uint)offset < scriptSize);

	for (uint i = 0; i < _variables.size(); ++i) {
		if (location == _propertyOffsetsSci3[i]) {
			_variables[i].setSegment(segment);
			_variables[i].incOffset(offset);
			return true;
		}
	}

	return false;
}
#endif

int Object::propertyOffsetToId(SegManager *segMan, int propertyOffset) const {
	int selectors = getVarCount();

	if (propertyOffset < 0 || (propertyOffset >> 1) >= selectors) {
		error("Applied propertyOffsetToId to invalid property offset %x (property #%d not in [0..%d])",
		          propertyOffset, propertyOffset >> 1, selectors - 1);
		return -1;
	}

	if (getSciVersion() < SCI_VERSION_1_1) {
		const SciSpan<const byte> selectoroffset = _baseObj.subspan(kOffsetSelectorSegment + selectors * 2);
		return selectoroffset.getUint16SEAt(propertyOffset);
	} else {
		const Object *obj = this;
		if (!isClass())
			obj = segMan->getObject(getSuperClassSelector());

		return obj->_baseVars[propertyOffset >> 1];
	}
}

void Object::initSpecies(SegManager *segMan, reg_t addr) {
	uint16 speciesOffset = getSpeciesSelector().getOffset();

	if (speciesOffset == 0xffff)		// -1
		setSpeciesSelector(NULL_REG);	// no species
	else
		setSpeciesSelector(segMan->getClassAddress(speciesOffset, SCRIPT_GET_LOCK, addr.getSegment()));
}

void Object::initSuperClass(SegManager *segMan, reg_t addr) {
	uint16 superClassOffset = getSuperClassSelector().getOffset();

	if (superClassOffset == 0xffff)			// -1
		setSuperClassSelector(NULL_REG);	// no superclass
	else
		setSuperClassSelector(segMan->getClassAddress(superClassOffset, SCRIPT_GET_LOCK, addr.getSegment()));
}

bool Object::initBaseObject(SegManager *segMan, reg_t addr, bool doInitSuperClass) {
	const Object *baseObj = segMan->getObject(getSpeciesSelector());

	if (baseObj) {
		uint originalVarCount = _variables.size();

		if (_variables.size() != baseObj->getVarCount())
			_variables.resize(baseObj->getVarCount());
		// Copy base from species class, as we need its selector IDs
		_baseObj = baseObj->_baseObj;
		assert(_baseObj);
		if (doInitSuperClass)
			initSuperClass(segMan, addr);

		if (_variables.size() != originalVarCount) {
			// These objects are probably broken.
			// An example is 'witchCage' in script 200 in KQ5 (#3034714),
			// but also 'girl' in script 216 and 'door' in script 22.
			// In LSL3 a number of sound objects trigger this right away.
			// SQ4-floppy's bug #3037938 also seems related.

			// The effect is that a number of its method selectors may be
			// treated as variable selectors, causing unpredictable effects.
			int objScript = segMan->getScript(_pos.getSegment())->getScriptNumber();

			// We have to do a little bit of work to get the name of the object
			// before any relocations are done.
			reg_t nameReg = getNameSelector();
			const char *name;
			if (nameReg.isNull()) {
				name = "<no name>";
			} else {
				nameReg.setSegment(_pos.getSegment());
				name = segMan->derefString(nameReg);
				if (!name)
					name = "<invalid name>";
			}

			debugC(kDebugLevelVM, "Object %04x:%04x (name %s, script %d) "
			        "varnum doesn't match baseObj's: obj %d, base %d",
			        PRINT_REG(_pos), name, objScript,
			        originalVarCount, baseObj->getVarCount());

#if 0
			// We enumerate the methods selectors which could be hidden here
			if (getSciVersion() <= SCI_VERSION_2_1) {
				const SegmentRef objRef = segMan->dereference(baseObj->_pos);
				assert(objRef.isRaw);
				uint segBound = objRef.maxSize/2 - baseObj->getVarCount();
				const byte* buf = (const byte *)baseObj->_baseVars;
				if (!buf) {
					// While loading this may happen due to objects being loaded
					// out of order, and we can't proceed then, unfortunately.
					segBound = 0;
				}
				for (uint i = baseObj->getVarCount();
				         i < originalVarCount && i < segBound; ++i) {
					uint16 slc = READ_SCI11ENDIAN_UINT16(buf + 2*i);
					// Skip any numbers which happen to be varselectors too
					bool found = false;
					for (uint j = 0; j < baseObj->getVarCount() && !found; ++j)
						found = READ_SCI11ENDIAN_UINT16(buf + 2*j) == slc;
					if (found) continue;
					// Skip any selectors which aren't method selectors,
					// so couldn't be mistaken for varselectors
					if (lookupSelector(segMan, _pos, slc, 0, 0) != kSelectorMethod) continue;
					warning("    Possibly affected selector: %02x (%s)", slc,
					        g_sci->getKernel()->getSelectorName(slc).c_str());
				}
			}
#endif
		}

		return true;
	}

	return false;
}

#ifdef ENABLE_SCI32
bool Object::mustSetViewVisible(int index, const bool fromPropertyOp) const {
	if (getSciVersion() == SCI_VERSION_3) {
		// In SCI3, visible flag lookups are based on selectors

		if (!fromPropertyOp) {
			// varindexes must be converted to selectors
			index = getVarSelector(index);
		}

		if (index == -1) {
			error("Selector %d is invalid for object %04x:%04x", index, PRINT_REG(_pos));
		}

		return _mustSetViewVisible[index >> 5];
	} else {
		// In SCI2, visible flag lookups are based on varindexes

		if (fromPropertyOp) {
			// property offsets must be converted to varindexes
			assert((index % 2) == 0);
			index >>= 1;
		}

		int minIndex, maxIndex;
		if (g_sci->_features->usesAlternateSelectors()) {
			minIndex = 24;
			maxIndex = 43;
		} else {
			minIndex = 26;
			maxIndex = 44;
		}

		return index >= minIndex && index <= maxIndex;
	}
}

void Object::initSelectorsSci3(const SciSpan<const byte> &buf, const bool initVariables) {
	enum {
		kExtraGroups = 3,
		kGroupSize   = 32
	};

	const SciSpan<const byte> groupInfo = _baseObj.subspan(16);
	const SciSpan<const byte> selectorBase = groupInfo.subspan(kExtraGroups * kGroupSize * sizeof(uint16));

	int numGroups = g_sci->getKernel()->getSelectorNamesSize() / kGroupSize;
	if (g_sci->getKernel()->getSelectorNamesSize() % kGroupSize)
		++numGroups;

	_mustSetViewVisible.resize(numGroups);

	int numMethods = 0;
	int numProperties = 0;

	// Selectors are divided into groups of 32, of which the first
	// two selectors are always reserved (because their storage
	// space is used by the typeMask).
	// We don't know beforehand how many methods and properties
	// there are, so we count them first.
	for (int groupNr = 0; groupNr < numGroups; ++groupNr) {
		byte groupLocation = groupInfo[groupNr];
		const SciSpan<const byte> seeker = selectorBase.subspan(groupLocation * kGroupSize * sizeof(uint16));

		if (groupLocation != 0)	{
			// This object actually has selectors belonging to this group
			int typeMask = seeker.getUint32SEAt(0);

			_mustSetViewVisible[groupNr] = (typeMask & 1);

			for (int bit = 2; bit < kGroupSize; ++bit) {
				int value = seeker.getUint16SEAt(bit * sizeof(uint16));
				if (typeMask & (1 << bit)) { // Property
					++numProperties;
				} else if (value != 0xffff) { // Method
					++numMethods;
				} else {
					// Undefined selector
				}
			}
		} else
			_mustSetViewVisible[groupNr] = false;
	}

	_methodCount = numMethods;
	_variables.resize(numProperties);
	_baseVars.resize(numProperties);
	_propertyOffsetsSci3.resize(numProperties);

	// Go through the whole thing again to get the property values
	// and method pointers
	int propertyCounter = 0;
	for (int groupNr = 0; groupNr < numGroups; ++groupNr) {
		byte groupLocation = groupInfo[groupNr];
		const SciSpan<const byte> seeker = selectorBase.subspan(groupLocation * kGroupSize * sizeof(uint16));

		if (groupLocation != 0)	{
			// This object actually has selectors belonging to this group
			int typeMask = seeker.getUint32SEAt(0);
			int groupBaseId = groupNr * kGroupSize;

			for (int bit = 2; bit < kGroupSize; ++bit) {
				int value = seeker.getUint16SEAt(bit * sizeof(uint16));
				if (typeMask & (1 << bit)) { // Property
					_baseVars[propertyCounter] = groupBaseId + bit;
					if (initVariables) {
						_variables[propertyCounter] = make_reg(0, value);
					}
					uint32 propertyOffset = (seeker + bit * sizeof(uint16)) - buf;
					_propertyOffsetsSci3[propertyCounter] = propertyOffset;
					++propertyCounter;
				} else if (value != 0xffff) { // Method
					_baseMethod.push_back(groupBaseId + bit);
					const uint32 offset = value + buf.getUint32SEAt(0);
					assert(offset <= kOffsetMask);
					_baseMethod.push_back(offset);
				} else {
					// Undefined selector
				}
			}
		}
	}

	if (initVariables) {
		_speciesSelectorSci3 = make_reg(0, _baseObj.getUint16SEAt(4));
		_superClassPosSci3 = make_reg(0, _baseObj.getUint16SEAt(8));
	}
}
#endif

} // End of namespace Sci