Initial commit

common/formats/iff_container.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/formats/iff_container.h"
+#include "common/substream.h"
+#include "common/util.h"
+
+namespace Common {
+
+IFFParser::IFFParser(ReadStream *stream, bool disposeStream, IFF_ID formHeaderID) : _stream(stream), _disposeStream(disposeStream), _formHeaderID(formHeaderID) {
+	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 != _formHeaderID) {
+		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