int DecompressorLZW::unpackLZW(Common::ReadStream *src, byte *dest, uint32 nPacked,
uint32 nUnpacked) {
init(src, dest, nPacked, nUnpacked);
uint16 token; // The last received value
uint16 tokenlist[4096]; // pointers to dest[]
uint16 tokenlengthlist[4096]; // char length of each token
uint16 tokenlastlength = 0;
while (!isFinished()) {
token = getBitsLSB(_numbits);
if (token == 0x101)
return 0; // terminator
if (token == 0x100) { // reset command
_numbits = 9;
_endtoken = 0x1FF;
_curtoken = 0x0102;
} else {
if (token > 0xff) {
if (token >= _curtoken) {
warning("unpackLZW: Bad token %x", token);
return SCI_ERROR_DECOMPRESSION_ERROR;
}
tokenlastlength = tokenlengthlist[token] + 1;
if (_dwWrote + tokenlastlength > _szUnpacked) {
// For me this seems a normal situation, It's necessary to handle it
warning("unpackLZW: Trying to write beyond the end of array(len=%d, destctr=%d, tok_len=%d)",
_szUnpacked, _dwWrote, tokenlastlength);
for (int i = 0; _dwWrote < _szUnpacked; i++)
putByte(dest[tokenlist[token] + i]);
} else
for (int i = 0; i < tokenlastlength; i++)
putByte(dest[tokenlist[token] + i]);
} else {
tokenlastlength = 1;
if (_dwWrote >= _szUnpacked)
warning("unpackLZW: Try to write single byte beyond end of array");
else
putByte(token);
}
if (_curtoken > _endtoken && _numbits < 12) {
_numbits++;
_endtoken = (_endtoken << 1) + 1;
}
if (_curtoken <= _endtoken) {
tokenlist[_curtoken] = _dwWrote - tokenlastlength;
tokenlengthlist[_curtoken] = tokenlastlength;
_curtoken++;
}
}
}
return _dwWrote == _szUnpacked ? 0 : SCI_ERROR_DECOMPRESSION_ERROR;
}
byte Decompressor::getByteLSB() {
return getBitsLSB(8);
}
