Initial commit

engines/lastexpress/sound/driver.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 "lastexpress/lastexpress.h"
+
+#include "audio/decoders/raw.h"
+
+namespace LastExpress {
+
+void SoundManager::soundDriverInit() {
+	_stream = Audio::makeQueuingAudioStream(22050, _engine->_mixer->getOutputStereo());
+	memset(_soundMixBuffer, 0, 1470 * sizeof(int16));
+	_mixer->playStream(
+		Audio::Mixer::kPlainSoundType,
+		&_channelHandle,
+		_stream,
+		-1,
+		Audio::Mixer::kMaxChannelVolume
+	);
+
+	// The following is a way to adapt the amount of buffers to the current device capabilities.
+	// Re-adapted from my own code found within the Digital iMUSE subsystem from the SCUMM engine.
+	_maxQueuedStreams = (uint32)ceil((_mixer->getOutputBufSize() / 1470) / ((float)_mixer->getOutputRate() / 44100));
+
+	if (_mixer->getOutputRate() % 44100) {
+		_maxQueuedStreams++;
+	}
+
+	_maxQueuedStreams = MAX<uint32>(4, _maxQueuedStreams);
+}
+
+void SoundManager::soundDriverCopyBuffersToDevice() {
+	_sound30HzCounter++;
+
+	while (_stream->numQueuedStreams() < _maxQueuedStreams) {
+		byte *ptr = (byte *)malloc(1470 * sizeof(int16));
+		assert(ptr);
+
+		mixEngine();
+		memcpy(ptr, _soundMixBuffer, 1470 * sizeof(int16));
+
+		byte flags = Audio::FLAG_16BITS;
+
+		if (_mixer->getOutputStereo()) {
+			flags |= Audio::FLAG_STEREO;
+		}
+
+#ifdef SCUMM_LITTLE_ENDIAN
+		flags |= Audio::FLAG_LITTLE_ENDIAN;
+#endif
+
+		_stream->queueBuffer(ptr, 1470 * sizeof(int16), DisposeAfterUse::YES, flags);
+	}
+}
+
+int SoundManager::soundDriverGetVolume() {
+	// I know, this thing could have been a look-up table :-)
+	// Still, I want this to be completely clear and transparent.
+
+	int scummVMVolume = _mixer->getChannelVolume(_channelHandle);
+
+	// Convert driver volume (0-255) to DirectSound format (-10000 to 0)
+	double dsVolume;
+	if (scummVMVolume == 0) {
+		dsVolume = -10000; // Silence
+	} else {
+		// Convert from linear scale to dB
+		dsVolume = (2000 * log10((double)scummVMVolume / 255.0));
+	}
+
+	// Convert DirectSound scale to game scale (0-7)
+	int engineVolume;
+	if (dsVolume <= -3000) {
+		engineVolume = 0;
+	} else {
+		engineVolume = (int)round((7 * (dsVolume + 3000)) / 3000);
+	}
+
+	return engineVolume;
+}
+
+void SoundManager::soundDriverSetVolume(int volume) {
+	// Convert from game scale (0-7) to DirectSound scale (-10000 to 0)
+	int32 dsVolume;
+	if (volume == 0) {
+		dsVolume = -10000; // Silence
+	} else {
+		dsVolume = 3000 * volume / 7 - 3000;
+	}
+
+	// Convert DirectSound volume to ScummVM volume (0-255)
+	int scummVMVolume = (int)round(pow(10, dsVolume / 2000.0) * 255.0);
+	assert(scummVMVolume >= 0 && scummVMVolume < 256);
+
+	_mixer->setChannelVolume(_channelHandle, (byte)scummVMVolume);
+}
+
+int32 SoundManager::getSoundDriverTicks() {
+	Common::StackLock lock(*_engine->_soundMutex);
+	return _soundDriverTicks;
+}
+
+void SoundManager::setSoundDriverTicks(int32 value) {
+	Common::StackLock lock(*_engine->_soundMutex);
+	_soundDriverTicks = value;
+}
+
+int32 SoundManager::getSoundDriver30HzCounter() {
+	Common::StackLock lock(*_engine->_soundMutex);
+	return _sound30HzCounter;
+}
+
+int32 SoundManager::getSoundDriverFlags() {
+	Common::StackLock lock(*_engine->_soundMutex);
+	return _soundDriverFlags;
+}
+
+void SoundManager::addSoundDriverFlags(int32 flags) {
+	Common::StackLock lock(*_engine->_soundMutex);
+	_soundDriverFlags |= flags;
+}
+
+void SoundManager::removeSoundDriverFlags(int32 flags) {
+	Common::StackLock lock(*_engine->_soundMutex);
+	_soundDriverFlags &= ~flags;
+}
+
+bool SoundManager::isCopyingDataToSoundDriver() {
+	Common::StackLock lock(*_engine->_soundMutex);
+	return _copyingDataToSoundDriver;
+}
+
+} // End of namespace LastExpress