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engines/sherlock/scalpel/tsage/resources.cpp

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+/* 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 3 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "common/scummsys.h"
+#include "common/memstream.h"
+#include "common/stack.h"
+#include "sherlock/scalpel/tsage/resources.h"
+
+namespace Sherlock {
+namespace Scalpel {
+namespace TsAGE {
+
+static uint16 bitMasks[4] = {0x1ff, 0x3ff, 0x7ff, 0xfff};
+
+uint16 BitReader::readToken() {
+	assert((numBits >= 9) && (numBits <= 12));
+	uint16 result = _remainder;
+	int bitsLeft = numBits - _bitsLeft;
+	int bitOffset = _bitsLeft;
+	_bitsLeft = 0;
+
+	while (bitsLeft >= 0) {
+		_remainder = readByte();
+		result |= _remainder << bitOffset;
+		bitsLeft -= 8;
+		bitOffset += 8;
+	}
+
+	_bitsLeft = -bitsLeft;
+	_remainder >>= 8 - _bitsLeft;
+	return result & bitMasks[numBits - 9];
+}
+
+/*-------------------------------------------------------------------------*/
+
+TLib::TLib(const Common::Path &filename) : _filename(filename) {
+
+	// If the resource strings list isn't yet loaded, load them
+	if (_resStrings.size() == 0) {
+		Common::File f;
+		if (f.open("tsage.cfg")) {
+			while (!f.eos()) {
+				_resStrings.push_back(f.readLine());
+			}
+			f.close();
+		}
+	}
+
+	if (!_file.open(filename))
+		error("Missing file %s", filename.toString().c_str());
+
+	loadIndex();
+}
+
+TLib::~TLib() {
+	_resStrings.clear();
+}
+
+/**
+ * Load a section index from the given position in the file
+ */
+void TLib::loadSection(uint32 fileOffset) {
+	_resources.clear();
+	_file.seek(fileOffset);
+	_sections.fileOffset = fileOffset;
+
+	loadSection(_file, _resources);
+}
+
+struct DecodeReference {
+	uint16 vWord;
+	uint8 vByte;
+};
+
+/**
+ * Gets a resource from the currently loaded section
+ */
+Common::SeekableReadStream *TLib::getResource(uint16 id, bool suppressErrors) {
+	// Scan for an entry for the given Id
+	ResourceEntry *re = nullptr;
+	ResourceList::iterator iter;
+	for (iter = _resources.begin(); iter != _resources.end(); ++iter) {
+		if ((*iter).id == id) {
+			re = &(*iter);
+			break;
+		}
+	}
+	if (!re) {
+		if (suppressErrors)
+			return nullptr;
+		error("Could not find resource Id #%d", id);
+	}
+
+	if (!re->isCompressed) {
+		// Read in the resource data and return it
+		byte *dataP = (byte *)malloc(re->size);
+		_file.seek(_sections.fileOffset + re->fileOffset);
+		_file.read(dataP, re->size);
+
+		return new Common::MemoryReadStream(dataP, re->size, DisposeAfterUse::YES);
+	}
+
+	/*
+	 * Decompress the data block
+	 */
+
+	_file.seek(_sections.fileOffset + re->fileOffset);
+	Common::ReadStream *compStream = _file.readStream(re->size);
+	BitReader bitReader(*compStream);
+
+	byte *dataOut = (byte *)malloc(re->uncompressedSize);
+	byte *destP = dataOut;
+	uint bytesWritten = 0;
+
+	uint16 ctrCurrent = 0x102, ctrMax = 0x200;
+	uint16 word_48050 = 0, currentToken = 0, word_48054 =0;
+	byte byte_49068 = 0, byte_49069 = 0;
+
+	const uint tableSize = 0x1000;
+	DecodeReference *table = (DecodeReference *)malloc(tableSize * sizeof(DecodeReference));
+	if (!table)
+		error("[TLib::getResource] Cannot allocate table buffer");
+
+	for (uint i = 0; i < tableSize; ++i) {
+		table[i].vByte = table[i].vWord = 0;
+	}
+	Common::Stack<uint16> tokenList;
+
+	for (;;) {
+		// Get the next decode token
+		uint16 token = bitReader.readToken();
+
+		// Handle the token
+		if (token == 0x101) {
+			// End of compressed stream
+			break;
+		} else if (token == 0x100) {
+			// Reset bit-rate
+			bitReader.numBits = 9;
+			ctrMax = 0x200;
+			ctrCurrent = 0x102;
+
+			// Set variables with next token
+			currentToken = word_48050 = bitReader.readToken();
+			byte_49069 = byte_49068 = (byte)currentToken;
+
+			++bytesWritten;
+			assert(bytesWritten <= re->uncompressedSize);
+			*destP++ = byte_49069;
+		} else {
+			word_48054 = word_48050 = token;
+
+			if (token >= ctrCurrent) {
+				word_48050 = currentToken;
+				tokenList.push(byte_49068);
+			}
+
+			while (word_48050 >= 0x100) {
+				assert(word_48050 < 0x1000);
+				tokenList.push(table[word_48050].vByte);
+				word_48050 = table[word_48050].vWord;
+			}
+
+			byte_49069 = byte_49068 = (byte)word_48050;
+			tokenList.push(word_48050);
+
+			// Write out any cached tokens
+			while (!tokenList.empty()) {
+				++bytesWritten;
+				assert(bytesWritten <= re->uncompressedSize);
+				*destP++ = tokenList.pop();
+			}
+
+			assert(ctrCurrent < 0x1000);
+			table[ctrCurrent].vByte = byte_49069;
+			table[ctrCurrent].vWord = currentToken;
+			++ctrCurrent;
+
+			currentToken = word_48054;
+			if ((ctrCurrent >= ctrMax) && (bitReader.numBits != 12)) {
+				// Move to the next higher bit-rate
+				++bitReader.numBits;
+				ctrMax <<= 1;
+			}
+		}
+	}
+
+	free(table);
+
+	assert(bytesWritten == re->uncompressedSize);
+	delete compStream;
+	return new Common::MemoryReadStream(dataOut, re->uncompressedSize, DisposeAfterUse::YES);
+}
+
+/**
+ * Finds the correct section and loads the specified resource within it
+ */
+Common::SeekableReadStream *TLib::getResource(ResourceType resType, uint16 resNum, uint16 rlbNum, bool suppressErrors) {
+	SectionList::iterator i = _sections.begin();
+	while ((i != _sections.end()) && ((*i).resType != resType || (*i).resNum != resNum))
+		++i;
+	if (i == _sections.end()) {
+		if (suppressErrors)
+			return nullptr;
+		error("Unknown resource type %d num %d", resType, resNum);
+	}
+
+	loadSection((*i).fileOffset);
+
+	return getResource(rlbNum, suppressErrors);
+}
+
+/**
+ * Gets the offset of the start of a resource in the resource file
+ */
+uint32 TLib::getResourceStart(ResourceType resType, uint16 resNum, uint16 rlbNum, ResourceEntry &entry) {
+	// Find the correct section
+	SectionList::iterator i = _sections.begin();
+	while ((i != _sections.end()) && ((*i).resType != resType || (*i).resNum != resNum))
+		++i;
+	if (i == _sections.end()) {
+		error("Unknown resource type %d num %d", resType, resNum);
+	}
+
+	// Load in the section index
+	loadSection((*i).fileOffset);
+
+	// Scan for an entry for the given Id
+	ResourceEntry *re = nullptr;
+	ResourceList::iterator iter;
+	for (iter = _resources.begin(); iter != _resources.end(); ++iter) {
+		if ((*iter).id == rlbNum) {
+			re = &(*iter);
+			break;
+		}
+	}
+
+	// Throw an error if no resource was found, or the resource is compressed
+	if (!re || re->isCompressed)
+		error("Invalid resource Id #%d", rlbNum);
+
+	// Return the resource entry as well as the file offset
+	entry = *re;
+	return _sections.fileOffset + entry.fileOffset;
+}
+
+void TLib::loadIndex() {
+	uint16 resNum, configId, fileOffset;
+
+	// Load the root resources section
+	loadSection(0);
+
+	// Get the single resource from it
+	Common::SeekableReadStream *stream = getResource(0);
+
+	_sections.clear();
+
+	// Loop through reading the entries
+	while ((resNum = stream->readUint16LE()) != 0xffff) {
+		configId = stream->readUint16LE();
+		fileOffset = stream->readUint16LE();
+
+		SectionEntry se;
+		se.resNum = resNum;
+		se.resType = (ResourceType)(configId & 0x1f);
+		se.fileOffset = (((configId >> 5) & 0x7ff) << 16) | fileOffset;
+
+		_sections.push_back(se);
+	}
+
+	delete stream;
+}
+
+/**
+ * Retrieves the specified palette resource and returns it's data
+ *
+ * @paletteNum Specefies the palette number
+ */
+void TLib::getPalette(byte palette[Graphics::PALETTE_SIZE], int paletteNum) {
+	// Get the specified palette
+	Common::SeekableReadStream *stream = getResource(RES_PALETTE, paletteNum, 0, true);
+	if (!stream)
+		return;
+
+	int startNum = stream->readUint16LE();
+	int numEntries = stream->readUint16LE();
+	assert((startNum < 256) && ((startNum + numEntries) <= 256));
+	stream->skip(2);
+
+	// Copy over the data
+	stream->read(&palette[startNum * 3], numEntries * 3);
+
+	delete stream;
+}
+
+/**
+ * Open up the given resource file using a passed file object. If the desired entry is found
+ * in the index, return the index entry for it, and move the file to the start of the resource
+ */
+bool TLib::scanIndex(Common::File &f, ResourceType resType, int rlbNum, int resNum,
+									  ResourceEntry &resEntry) {
+	// Load the root section index
+	ResourceList resList;
+	loadSection(f, resList);
+
+	// Loop through the index for the desired entry
+	ResourceList::iterator iter;
+	for (iter = resList.begin(); iter != resList.end(); ++iter) {
+		ResourceEntry &re = *iter;
+		if (re.id == resNum) {
+			// Found it, so exit
+			resEntry = re;
+			f.seek(re.fileOffset);
+			return true;
+		}
+	}
+
+	// No matching entry found
+	return false;
+}
+
+/**
+ * Inner logic for decoding a section index into a passed resource list object
+ */
+void TLib::loadSection(Common::File &f, ResourceList &resources) {
+	if (f.readUint32BE() != 0x544D492D)
+		error("Data block is not valid Rlb data");
+
+	/*uint8 unknown1 = */f.readByte();
+	uint16 numEntries = f.readByte();
+
+	for (uint i = 0; i < numEntries; ++i) {
+		uint16 id = f.readUint16LE();
+		uint16 size = f.readUint16LE();
+		uint16 uncSize = f.readUint16LE();
+		uint8 sizeHi = f.readByte();
+		uint8 type = f.readByte() >> 5;
+		assert(type <= 1);
+		uint32 offset = f.readUint32LE();
+
+		ResourceEntry re;
+		re.id = id;
+		re.fileOffset = offset;
+		re.isCompressed = type != 0;
+		re.size = ((sizeHi & 0xF) << 16) | size;
+		re.uncompressedSize = ((sizeHi & 0xF0) << 12) | uncSize;
+
+		resources.push_back(re);
+	}
+}
+
+} // end of namespace TsAGE
+} // end of namespace Scalpel
+} // end of namespace Sherlock