TITANIC: Renamings and cleanups for music room handler & audio buffer

6 files changed, 83 insertions, 56 deletions

diff --git a/engines/titanic/sound/audio_buffer.cpp b/engines/titanic/sound/audio_buffer.cpp
index 67a3d67958..6798c8b312 100644
--- a/engines/titanic/sound/audio_buffer.cpp
+++ b/engines/titanic/sound/audio_buffer.cpp
@@ -35,48 +35,48 @@ CAudioBuffer::~CAudioBuffer() {
 
 void CAudioBuffer::reset() {
 	_flag = true;
-	_fieldC = _field10 = _buffer.size() / 2;
+	_fieldC = _writeBytesLeft = _buffer.size() / 2;
 }
 
-byte *CAudioBuffer::getDataPtr1() {
+byte *CAudioBuffer::getBegin() {
 	return _flag ? &_buffer[_buffer.size() / 2] : &_buffer[0];
 }
 
-byte *CAudioBuffer::getDataPtr2() {
+byte *CAudioBuffer::getEnd() {
 	return _flag ? &_buffer[0] : &_buffer[_buffer.size() / 2];
 }
 
 byte *CAudioBuffer::getPtr1() {
-	byte *ptr = getDataPtr1();
+	byte *ptr = getBegin();
 	return ptr + (_buffer.size() / 2 - _fieldC);
 }
 
-uint16 *CAudioBuffer::getPtr2() {
-	byte *ptr = getDataPtr2();
-	return (uint16 *)(ptr + (_buffer.size() / 2 - _field10));
+uint16 *CAudioBuffer::getWritePtr() {
+	byte *ptr = getEnd();
+	return (uint16 *)(ptr + (_buffer.size() / 2 - _writeBytesLeft));
 }
 
 void CAudioBuffer::setC(int val) {
 	_fieldC -= val;
 	if (_fieldC < 0) {
 		_fieldC = 0;
-	} else if (val && !_field10) {
-		update();
+	} else if (val && !_writeBytesLeft) {
+		reverse();
 	}
 }
 
-void CAudioBuffer::set10(int val) {
-	_field10 -= val;
-	if (_field10 < 0) {
-		_field10 = 0;
-	} else if (val && !_field10) {
-		update();
+void CAudioBuffer::advanceWrite(int size) {
+	_writeBytesLeft -= size;
+	if (_writeBytesLeft < 0) {
+		_writeBytesLeft = 0;
+	} else if (size && !_fieldC) {
+		reverse();
 	}
 }
 
-void CAudioBuffer::update() {
+void CAudioBuffer::reverse() {
 	_flag = !_flag;
-	_fieldC = _field10 = _buffer.size() / 2;
+	_fieldC = _writeBytesLeft = _buffer.size() / 2;
 }
 
 void CAudioBuffer::enterCriticalSection() {
diff --git a/engines/titanic/sound/audio_buffer.h b/engines/titanic/sound/audio_buffer.h
index b65f0bb8cc..5b6fb11072 100644
--- a/engines/titanic/sound/audio_buffer.h
+++ b/engines/titanic/sound/audio_buffer.h
@@ -31,10 +31,25 @@ namespace Titanic {
 class CAudioBuffer {
 private:
 	Common::Mutex _mutex;
+private:
+	/**
+	 * Gets the beginning of stored audio data
+	 */
+	byte *getBegin();
+
+	/**
+	 * Gets the end of the stored audio data
+	 */
+	byte *getEnd();
+
+	/**
+	 * Reverses the audio buffer
+	 */
+	void reverse();
 public:
 	Common::Array<byte> _buffer;
 	int _fieldC;
-	int _field10;
+	int _writeBytesLeft;
 	bool _flag;
 	int _field18;
 public:
@@ -42,15 +57,22 @@ public:
 	~CAudioBuffer();
 
 	void reset();
-	byte *getDataPtr1();
-	byte *getDataPtr2();
+
 	byte *getPtr1();
-	uint16 *getPtr2();
+	uint16 *getWritePtr();
 	int getC() const { return _fieldC; }
-	int get10() const { return _field10; }
 	void setC(int val);
-	void set10(int val);
-	void update();
+
+	/**
+	 * Returns how many bytes can be written before hitting the
+	 * end of the audio buffer
+	 */
+	int getWriteBytesLeft() const { return _writeBytesLeft; }
+	
+	/**
+	 * Advances the write pointer by the specified number of bytes
+	 */
+	void advanceWrite(int size);
 
 	/**
 	 * Enters a critical section
diff --git a/engines/titanic/sound/music_room.cpp b/engines/titanic/sound/music_room.cpp
index 4ef3b1dfc7..c2e5b5e380 100644
--- a/engines/titanic/sound/music_room.cpp
+++ b/engines/titanic/sound/music_room.cpp
@@ -85,7 +85,8 @@ void CMusicRoom::setupMusic(int volume) {
 			_musicHandler->setMuteControl(idx, instr._muteControl);
 		}
 
-		_musicHandler->setVolume(volume);
+		// Set up the music handler
+		_musicHandler->setup(volume);
 	}
 }
 
diff --git a/engines/titanic/sound/music_room_handler.cpp b/engines/titanic/sound/music_room_handler.cpp
index d4ae89fa67..e716ebc233 100644
--- a/engines/titanic/sound/music_room_handler.cpp
+++ b/engines/titanic/sound/music_room_handler.cpp
@@ -35,10 +35,10 @@ CMusicRoomHandler::CMusicRoomHandler(CProjectItem *project, CSoundManager *sound
 	_startTicks = _soundStartTicks = 0;
 	Common::fill(&_musicWaves[0], &_musicWaves[4], (CMusicWave *)nullptr);
 	for (int idx = 0; idx < 4; ++idx)
-		_array3[idx] = new CMusicObject(idx);
-	Common::fill(&_array4[0], &_array4[4], 0);
+		_musicObjs[idx] = new CMusicObject(idx);
+	Common::fill(&_startPos[0], &_startPos[4], 0);
 	Common::fill(&_array5[0], &_array5[4], 0.0);
-	Common::fill(&_array6[0], &_array6[4], 0);
+	Common::fill(&_position[0], &_position[4], 0);
 
 	_audioBuffer = new CAudioBuffer(176400);
 }
@@ -46,7 +46,7 @@ CMusicRoomHandler::CMusicRoomHandler(CProjectItem *project, CSoundManager *sound
 CMusicRoomHandler::~CMusicRoomHandler() {
 	stop();
 	for (int idx = 0; idx < 4; ++idx)
-		delete _array3[idx];
+		delete _musicObjs[idx];
 
 	delete _audioBuffer;
 }
@@ -73,7 +73,7 @@ CMusicWave *CMusicRoomHandler::createMusicWave(MusicInstrument instrument, int c
 	return _musicWaves[instrument];
 }
 
-void CMusicRoomHandler::setVolume(int volume) {
+void CMusicRoomHandler::setup(int volume) {
 	_volume = volume;
 	_audioBuffer->reset();
 
@@ -82,12 +82,12 @@ void CMusicRoomHandler::setVolume(int volume) {
 		MusicRoomInstrument &ins2 = _array2[idx];
 
 		if (ins1._directionControl == ins2._directionControl) {
-			_array4[idx] = 0;
+			_startPos[idx] = 0;
 		} else {
-			_array4[idx] = _array3[idx]->size();
+			_startPos[idx] = _musicObjs[idx]->size() - 1;
 		}
 
-		_array6[idx] = _array4[idx];
+		_position[idx] = _startPos[idx];
 		_array5[idx] = 0.0;
 	}
 
@@ -203,30 +203,33 @@ bool CMusicRoomHandler::update() {
 
 void CMusicRoomHandler::updateAudio() {
 	_audioBuffer->enterCriticalSection();
-	int size = _audioBuffer->get10();
+	int size = _audioBuffer->getWriteBytesLeft();
 	int count;
 	uint16 *ptr;
 
 	if (size > 0) {
-		uint16 *audioPtr = _audioBuffer->getPtr2();
-		Common::fill(audioPtr, audioPtr + size, 0);
+		// Null out the destination write area
+		uint16 *audioPtr = _audioBuffer->getWritePtr();
+		Common::fill(audioPtr, audioPtr + size / sizeof(uint16), 0);
 
-		for (int waveIdx = 0; waveIdx < 4; ++waveIdx) {
-			CMusicWave *musicWave = _musicWaves[waveIdx];
+		for (int instrIdx = 0; instrIdx < 4; ++instrIdx) {
+			CMusicWave *musicWave = _musicWaves[instrIdx];
 
+			// Iterate through each of the four instruments and do an additive
+			// read that will merge their data onto the output buffer
 			for (count = size, ptr = audioPtr; count > 0; ) {
 				int amount = musicWave->read(ptr, count);
 				if (amount > 0) {
 					count -= amount;
 					ptr += amount / sizeof(uint16);
-				} else if (!fn2(waveIdx)) {
+				} else if (!fn2(instrIdx)) {
 					--_field108;
 					break;
 				}
 			}
 		}
 		
-		_audioBuffer->set10(size);
+		_audioBuffer->advanceWrite(size);
 	}
 
 	_audioBuffer->leaveCriticalSection();
@@ -240,8 +243,8 @@ void CMusicRoomHandler::fn1() {
 			CMusicWave *musicWave = _musicWaves[idx];
 
 			// Is this about checking playback position?
-			if (_array6[idx] < 0 || ins1._muteControl || _array6[idx] >= _array3[idx]->size()) {
-				_array6[idx] = -1;
+			if (_position[idx] < 0 || ins1._muteControl || _position[idx] >= _musicObjs[idx]->size()) {
+				_position[idx] = -1;
 				continue;
 			}
 
@@ -249,18 +252,18 @@ void CMusicRoomHandler::fn1() {
 			double val = (double)ticks * 0.001 - 0.6;
 
 			if (val >= musicWave->_floatVal) {
-				_array5[idx] += fn3(idx, _array6[idx]);
+				_array5[idx] += fn3(idx, _position[idx]);
 
-				const CValuePair &vp = (*_array3[idx])[_array6[idx]];
+				const CValuePair &vp = (*_musicObjs[idx])[_position[idx]];
 				if (vp._field0 != 0x7FFFFFFF) {
-					int amount = getPitch(idx, _array6[idx]);
+					int amount = getPitch(idx, _position[idx]);
 					_musicWaves[idx]->start(amount);
 				}
 
 				if (ins1._directionControl == ins2._directionControl) {
-					_array6[idx]++;
+					_position[idx]++;
 				} else {
-					_array6[idx]--;
+					_position[idx]--;
 				}
 			}
 		}
@@ -268,13 +271,13 @@ void CMusicRoomHandler::fn1() {
 }
 
 bool CMusicRoomHandler::fn2(int index) {
-	int &arrIndex = _array4[index];
+	int &arrIndex = _startPos[index];
 	if (arrIndex < 0) {
 		_musicWaves[index]->reset();
 		return false;
 	}
 
-	const CMusicObject &mObj = *_array3[index];
+	const CMusicObject &mObj = *_musicObjs[index];
 	if (arrIndex >= mObj.size()) {
 		arrIndex = -1;
 		_musicWaves[index]->reset();
@@ -299,7 +302,7 @@ bool CMusicRoomHandler::fn2(int index) {
 }
 
 double CMusicRoomHandler::fn3(int index, int arrIndex) {
-	const CValuePair &vp = (*_array3[index])[arrIndex];
+	const CValuePair &vp = (*_musicObjs[index])[arrIndex];
 
 	switch (_array1[index]._speedControl + _array2[index]._speedControl + 3) {
 	case 0:
@@ -320,7 +323,7 @@ double CMusicRoomHandler::fn3(int index, int arrIndex) {
 }
 
 int CMusicRoomHandler::getPitch(int index, int arrIndex) {
-	const CMusicObject &mObj = *_array3[index];
+	const CMusicObject &mObj = *_musicObjs[index];
 	const CValuePair &vp = mObj[arrIndex];
 	int val = vp._field0;
 	const MusicRoomInstrument &ins1 = _array1[index];
diff --git a/engines/titanic/sound/music_room_handler.h b/engines/titanic/sound/music_room_handler.h
index 5f615ccd84..38c1748ab4 100644
--- a/engines/titanic/sound/music_room_handler.h
+++ b/engines/titanic/sound/music_room_handler.h
@@ -52,10 +52,10 @@ private:
 	CMusicWave *_musicWaves[4];
 	MusicRoomInstrument _array1[4];
 	MusicRoomInstrument _array2[4];
-	CMusicObject *_array3[4];
-	int _array4[4];
+	CMusicObject *_musicObjs[4];
+	int _startPos[4];
+	int _position[4];
 	double _array5[4];
-	int _array6[4];
 
 	bool _active;
 	CWaveFile *_waveFile;
@@ -88,9 +88,9 @@ public:
 	CMusicWave *createMusicWave(MusicInstrument instrument, int count);
 
 	/**
-	 * TODO: Verify - this starts the given music?
+	 * Main setup for the music room handler
 	 */
-	void setVolume(int volume);
+	void setup(int volume);
 
 	/**
 	 * Flags whether the music handler is active
diff --git a/engines/titanic/sound/music_wave.cpp b/engines/titanic/sound/music_wave.cpp
index ecf23824b6..2dc7b02c3e 100644
--- a/engines/titanic/sound/music_wave.cpp
+++ b/engines/titanic/sound/music_wave.cpp
@@ -162,6 +162,7 @@ void CMusicWave::start(int val) {
 				_gameObjects[0]->movieSetAudioTiming(true);
 				_gameObjects[0]->playMovie(0, 512, MOVIE_STOP_PREVIOUS);
 				_floatVal = 0.6;
+				break;
 
 			case 62:
 				_gameObjects[0]->playMovie(828, 1023, MOVIE_STOP_PREVIOUS);