scummvm/common/iff_container.cpp

126 lines
3.0 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 "common/iff_container.h"
#include "common/substream.h"
#include "common/util.h"
namespace Common {
IFFParser::IFFParser(ReadStream *stream, bool disposeStream) : _stream(stream), _disposeStream(disposeStream) {
setInputStream(stream);
}
IFFParser::~IFFParser() {
if (_disposeStream) {
delete _stream;
}
_stream = nullptr;
}
void IFFParser::setInputStream(ReadStream *stream) {
assert(stream);
_formChunk.setInputStream(stream);
_chunk.setInputStream(stream);
_formChunk.readHeader();
if (_formChunk.id != ID_FORM) {
error("IFFParser input is not a FORM type IFF file");
}
_formSize = _formChunk.size;
_formType = _formChunk.readUint32BE();
}
void IFFParser::parse(IFFCallback &callback) {
bool stop;
do {
_chunk.feed();
_formChunk.incBytesRead(_chunk.size);
if (_formChunk.hasReadAll()) {
break;
}
_formChunk.incBytesRead(8);
_chunk.readHeader();
// invoke the callback
SubReadStream stream(&_chunk, _chunk.size);
IFFChunk chunk(_chunk.id, _chunk.size, &stream);
stop = callback(chunk);
// eats up all the remaining data in the chunk
while (!stream.eos()) {
stream.readByte();
}
} while (!stop);
}
PackBitsReadStream::PackBitsReadStream(Common::ReadStream &input) : _input(&input) {
}
PackBitsReadStream::~PackBitsReadStream() {
}
bool PackBitsReadStream::eos() const {
return _input->eos();
}
uint32 PackBitsReadStream::read(void *dataPtr, uint32 dataSize) {
byte *out = (byte *)dataPtr;
uint32 left = dataSize;
uint32 lenR = 0, lenW = 0;
while (left > 0 && !_input->eos()) {
lenR = _input->readByte();
if (lenR == 128) {
// no-op
lenW = 0;
} else if (lenR <= 127) {
// literal run
lenR++;
lenW = MIN(lenR, left);
for (uint32 j = 0; j < lenW; j++) {
*out++ = _input->readByte();
}
for (; lenR > lenW; lenR--) {
_input->readByte();
}
} else { // len > 128
// expand run
lenW = MIN((256 - lenR) + 1, left);
byte val = _input->readByte();
memset(out, val, lenW);
out += lenW;
}
left -= lenW;
}
return dataSize - left;
}
} // End of namespace Common