112 lines
2.7 KiB
C++
112 lines
2.7 KiB
C++
/* 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 "twine/resources/lzss.h"
|
|
#include "common/textconsole.h"
|
|
|
|
namespace TwinE {
|
|
|
|
LzssReadStream::LzssReadStream(Common::ReadStream *indata, uint32 mode, uint32 realsize) {
|
|
_outLzssBufData = new uint8[realsize];
|
|
memset(_outLzssBufData, 0, realsize);
|
|
decodeLZSS(indata, mode, realsize);
|
|
_size = realsize;
|
|
_pos = 0;
|
|
delete indata;
|
|
}
|
|
|
|
LzssReadStream::~LzssReadStream() {
|
|
delete[] _outLzssBufData;
|
|
}
|
|
|
|
void LzssReadStream::decodeLZSS(Common::ReadStream *in, uint32 mode, uint32 dataSize) {
|
|
if (in->eos() || in->err() || dataSize == 0) {
|
|
_err = dataSize > 0;
|
|
return;
|
|
}
|
|
|
|
uint8 *dst = _outLzssBufData;
|
|
int32 remainingBytes = (int32)dataSize;
|
|
|
|
do {
|
|
uint8 b = in->readByte();
|
|
for (int32 d = 0; d < 8; d++) {
|
|
if (in->eos() || in->err()) {
|
|
_err = dataSize > 0;
|
|
return;
|
|
}
|
|
int32 length;
|
|
if (!(b & (1 << d))) {
|
|
const uint16 offset = in->readUint16LE();
|
|
length = (offset & 0x0F) + (mode + 1);
|
|
const uint8 *ptr = dst - (offset >> 4) - 1;
|
|
if (remainingBytes < length) {
|
|
_err = true;
|
|
return;
|
|
}
|
|
remainingBytes -= length;
|
|
for (int32 i = 0; i < length; i++) {
|
|
*dst++ = *ptr++;
|
|
}
|
|
} else {
|
|
length = 1;
|
|
if (remainingBytes < length) {
|
|
_err = true;
|
|
return;
|
|
}
|
|
remainingBytes -= length;
|
|
*dst++ = in->readByte();
|
|
}
|
|
dataSize -= length;
|
|
if (dataSize <= 0) {
|
|
return;
|
|
}
|
|
}
|
|
} while (dataSize);
|
|
}
|
|
|
|
bool LzssReadStream::eos() const {
|
|
return _pos >= _size;
|
|
}
|
|
|
|
uint32 LzssReadStream::read(void *buf, uint32 dataSize) {
|
|
if (dataSize > _size - _pos) {
|
|
_err = true;
|
|
return 0;
|
|
}
|
|
|
|
memcpy(buf, &_outLzssBufData[_pos], dataSize);
|
|
_pos += dataSize;
|
|
|
|
return dataSize;
|
|
}
|
|
|
|
bool LzssReadStream::seek(int64 offset, int whence) {
|
|
if (whence == SEEK_SET) {
|
|
_pos = offset;
|
|
} else if (whence == SEEK_CUR) {
|
|
_pos += offset;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
} // namespace TwinE
|