diff options
Diffstat (limited to 'engines/zvision/zork_raw.cpp')
| -rw-r--r-- | engines/zvision/zork_raw.cpp | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/engines/zvision/zork_raw.cpp b/engines/zvision/zork_raw.cpp new file mode 100644 index 0000000000..9332aeb52e --- /dev/null +++ b/engines/zvision/zork_raw.cpp @@ -0,0 +1,186 @@ +/* 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/endian.h"
+#include "common/memstream.h"
+#include "common/textconsole.h"
+#include "common/util.h"
+
+#include "audio/audiostream.h"
+
+#include "engines/zvision/zork_raw.h"
+
+namespace ZVision {
+
+#pragma mark -
+#pragma mark --- RawZorkStream ---
+#pragma mark -
+
+/**
+ * This is a stream, which allows for playing raw PCM data from a stream.
+ */
+class RawZorkStream : public Audio::SeekableAudioStream {
+public:
+ RawZorkStream(int rate, DisposeAfterUse::Flag disposeStream, Common::SeekableReadStream *stream)
+ : _rate(rate), _playtime(0, rate), _stream(stream, disposeStream), _endOfData(false), _buffer(0) {
+ // Setup our buffer for readBuffer
+ _buffer = new byte[kSampleBufferLength];
+ assert(_buffer);
+
+ // Calculate the total playtime of the stream
+ _playtime = Audio::Timestamp(0, _stream->size() / 2 / 1, rate);
+ }
+
+ ~RawZorkStream() {
+ delete[] _buffer;
+ }
+
+ int readBuffer(int16 *buffer, const int numSamples);
+
+ bool isStereo() const { return true; }
+ bool endOfData() const { return _endOfData; }
+
+ int getRate() const { return _rate; }
+ Audio::Timestamp getLength() const { return _playtime; }
+
+ bool seek(const Audio::Timestamp &where);
+private:
+ const int _rate; ///< Sample rate of stream
+ Audio::Timestamp _playtime; ///< Calculated total play time
+ Common::DisposablePtr<Common::SeekableReadStream> _stream; ///< Stream to read data from
+ bool _endOfData; ///< Whether the stream end has been reached
+
+ byte *_buffer; ///< Buffer used in readBuffer
+ enum {
+ /**
+ * How many samples we can buffer at once.
+ *
+ * TODO: Check whether this size suffices
+ * for systems with slow disk I/O.
+ */
+ kSampleBufferLength = 2048
+ };
+
+ /**
+ * Fill the temporary sample buffer used in readBuffer.
+ *
+ * @param maxSamples Maximum samples to read.
+ * @return actual count of samples read.
+ */
+ int fillBuffer(int maxSamples);
+};
+
+int RawZorkStream::readBuffer(int16 *buffer, const int numSamples) {
+ int samplesLeft = numSamples;
+
+ while (samplesLeft > 0) {
+ // Try to read up to "samplesLeft" samples.
+ int len = fillBuffer(samplesLeft);
+
+ // In case we were not able to read any samples
+ // we will stop reading here.
+ if (!len)
+ break;
+
+ // Adjust the samples left to read.
+ samplesLeft -= len;
+
+ // Copy the data to the caller's buffer.
+ const byte *src = _buffer;
+ while (len-- > 0) {
+ if (*src < 128)
+ *buffer++ = ((128 - *src) << 8) ^ 0x8000;
+ else
+ *buffer++ = (*src << 8) ^ 0x8000;
+ src++;
+ }
+ }
+
+ return numSamples - samplesLeft;
+}
+
+int RawZorkStream::fillBuffer(int maxSamples) {
+ int bufferedSamples = 0;
+ byte *dst = _buffer;
+
+ // We can only read up to "kSampleBufferLength" samples
+ // so we take this into consideration, when trying to
+ // read up to maxSamples.
+ maxSamples = MIN<int>(kSampleBufferLength, maxSamples);
+
+ // We will only read up to maxSamples
+ while (maxSamples > 0 && !endOfData()) {
+ // Try to read all the sample data and update the
+ // destination pointer.
+ const int bytesRead = _stream->read(dst, maxSamples);
+ dst += bytesRead;
+
+ // Calculate how many samples we actually read.
+ const int samplesRead = bytesRead;
+
+ // Update all status variables
+ bufferedSamples += samplesRead;
+ maxSamples -= samplesRead;
+
+ // We stop stream playback, when we reached the end of the data stream.
+ // We also stop playback when an error occures.
+ if (_stream->pos() == _stream->size() || _stream->err() || _stream->eos())
+ _endOfData = true;
+ }
+
+ return bufferedSamples;
+}
+
+bool RawZorkStream::seek(const Audio::Timestamp &where) {
+ _endOfData = true;
+
+ if (where > _playtime)
+ return false;
+
+ const uint32 seekSample = convertTimeToStreamPos(where, getRate(), isStereo()).totalNumberOfFrames();
+ _stream->seek(seekSample, SEEK_SET);
+
+ // In case of an error we will not continue stream playback.
+ if (!_stream->err() && !_stream->eos() && _stream->pos() != _stream->size())
+ _endOfData = false;
+
+ return true;
+}
+
+#pragma mark -
+#pragma mark --- Raw stream factories ---
+#pragma mark -
+
+Audio::SeekableAudioStream *makeRawZorkStream(Common::SeekableReadStream *stream,
+ int rate,
+ DisposeAfterUse::Flag disposeAfterUse) {
+ assert(stream->size() % 2 == 0);
+ return new RawZorkStream(rate, disposeAfterUse, stream);
+}
+
+Audio::SeekableAudioStream *makeRawZorkStream(const byte *buffer, uint32 size,
+ int rate,
+ DisposeAfterUse::Flag disposeAfterUse) {
+ return makeRawZorkStream(new Common::MemoryReadStream(buffer, size, disposeAfterUse), rate, DisposeAfterUse::YES);
+}
+
+} // End of namespace Audio
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