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Diffstat (limited to 'engines/macventure/container.cpp')
| -rw-r--r-- | engines/macventure/container.cpp | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/engines/macventure/container.cpp b/engines/macventure/container.cpp new file mode 100644 index 0000000000..dbbc7ebaa2 --- /dev/null +++ b/engines/macventure/container.cpp @@ -0,0 +1,195 @@ +/* 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. + * + */ + +/* + * Based on + * WebVenture (c) 2010, Sean Kasun + * https://github.com/mrkite/webventure, http://seancode.com/webventure/ + * + * Used with explicit permission from the author + */ + +#include "macventure/container.h" + +namespace MacVenture { + +Container::Container(Common::String filename) { + _filename = filename; + + if (!_file.open(_filename)) { + error("CONTAINER: Could not open %s", _filename.c_str()); + } + + _res = _file.readStream(_file.size()); + _header = _res->readUint32BE(); + _simplified = false; + + for (uint i = 0; i < 16; ++i) { + _huff.push_back(0); + } + + for (uint i = 0; i < 16; ++i) { + _lens.push_back(0); + } + + if (!(_header & 0x80000000)) { + // Is simplified container + _simplified = true; + int dataLen = _res->size() - sizeof(_header); + _lenObjs = _header; + _numObjs = dataLen / _lenObjs; + } else { + _header &= 0x7fffffff; + _res->seek(_header, SEEK_SET); + _numObjs = _res->readUint16BE(); + + for (uint i = 0; i < 15; ++i) { + _huff[i] = _res->readUint16BE(); + } + + for (uint i = 0; i < 16; ++i) { + _lens[i] = _res->readByte(); + } + + // Read groups + uint numGroups = _numObjs / 64; + if ((_numObjs % 64) > 0) { + numGroups++; + } + + for (uint i = 0; i < numGroups; ++i) { + ItemGroup group; + + // Place myself in the correct position to read group + _res->seek(_header + (i * 6) + 0x30, SEEK_SET); + byte b1, b2, b3; + b1 = _res->readByte(); + b2 = _res->readByte(); + b3 = _res->readByte(); + group.bitOffset = (b1 << 16) + (b2 << 8) + (b3 << 0); + + b1 = _res->readByte(); + b2 = _res->readByte(); + b3 = _res->readByte(); + group.offset = (b1 << 16) + (b2 << 8) + (b3 << 0); + + // Place the bit reader in the correct position + // group.bitOffset indicates the offset from the start of the subHeader + _res->seek(_header + (group.bitOffset >> 3), SEEK_SET); + uint32 bits = group.bitOffset & 7; + + for (uint j = 0; j < 64; ++j) { + uint32 length = 0; + uint32 mask = 0; + mask = _res->readUint32BE(); + mask >>= (16 - bits); + mask &= 0xFFFF; + debugC(4, kMVDebugContainer, "Load mask of object &%d:%d is %x", i, j, mask); + _res->seek(-4, SEEK_CUR); + // Look in the Huffman table + int x = 0; + for (x = 0; x < 16; x++) { + if (_huff[x] > mask) { + break; + } + } + + // I will opt to copy the code from webventure, + // But according to the docs, this call should suffice: + // length = bitStream.getBits(_lens[x]); + // The problem is that _lens[] usually contains values larger + // Than 32, so we have to read them with the method below + + //This code below, taken from the implementation, seems to give the same results. + + uint32 bitSize = _lens[x]; + bits += bitSize & 0xF; + if (bits & 0x10) { + bits &= 0xF; + _res->seek(2, SEEK_CUR); + } + bitSize >>= 4; + if (bitSize) { + length = _res->readUint32BE(); + _res->seek(-4, SEEK_CUR); + bitSize--; + if (bitSize == 0) { + length = 0; + } else { + length >>= (32 - bitSize) - bits; + } + length &= (1 << bitSize) - 1; + length |= 1 << bitSize; + bits += bitSize; + if (bits & 0x10) { + bits &= 0xF; + _res->seek(2, SEEK_CUR); + } + } + group.lengths[j] = length; + debugC(4, kMVDebugContainer, "Load legth of object %d:%d is %d", i, j, length); + } + _groups.push_back(group); + } + } +} + +Container::~Container() { + + if (_file.isOpen()) + _file.close(); + + if (_res) + delete _res; +} + +uint32 Container::getItemByteSize(uint32 id) { + if (_simplified) { + return _lenObjs; + } else { + uint32 groupID = (id >> 6); + uint32 objectIndex = id & 0x3f; // Index within the group + return _groups[groupID].lengths[objectIndex]; + } +} + +Common::SeekableReadStream *Container::getItem(uint32 id) { + if (_simplified) { + _res->seek((id * _lenObjs) + sizeof(_header), SEEK_SET); + } else { + uint32 groupID = (id >> 6); + uint32 objectIndex = id & 0x3f; // Index within the group + + uint32 offset = 0; + for (uint i = 0; i < objectIndex; i++) { + offset += _groups[groupID].lengths[i]; + } + _res->seek(_groups[groupID].offset + offset + sizeof(_header), SEEK_SET); + } + + // HACK Should Limit the size of the stream returned + Common::SeekableReadStream *res = _res->readStream(_res->size() - _res->pos() + 1); + return res; +} + + +} // End of namespace MacVenture |