GOB: Use the built-in OPL timer

6 files changed, 50 insertions, 63 deletions

diff --git a/engines/gob/sound/adlib.cpp b/engines/gob/sound/adlib.cpp
index b92e20b42c..20fbced63c 100644
--- a/engines/gob/sound/adlib.cpp
+++ b/engines/gob/sound/adlib.cpp
@@ -93,7 +93,7 @@ const uint16 AdLib::kHihatParams    [kParamCount] = {
 	  0,  1,  0, 15, 11,  0,  7,  5,  0,  0,  0,  0,  0,  0   };
 
 
-AdLib::AdLib(Audio::Mixer &mixer) : _mixer(&mixer), _opl(0),
+AdLib::AdLib(Audio::Mixer &mixer, int callbackFreq) : _mixer(&mixer), _opl(0),
 	_toPoll(0), _repCount(0), _first(true), _playing(false), _ended(true) {
 
 	_rate = _mixer->getOutputRate();
@@ -103,6 +103,7 @@ AdLib::AdLib(Audio::Mixer &mixer) : _mixer(&mixer), _opl(0),
 	createOPL();
 	initOPL();
 
+	_opl->start(new Common::Functor0Mem<void, AdLib>(this, &AdLib::onTimer), callbackFreq);
 	_mixer->playStream(Audio::Mixer::kMusicSoundType, &_handle,
 			this, -1, Audio::Mixer::kMaxChannelVolume, 0, DisposeAfterUse::NO, true);
 }
@@ -144,38 +145,34 @@ void AdLib::createOPL() {
 }
 
 int AdLib::readBuffer(int16 *buffer, const int numSamples) {
+	return _opl->readBuffer(buffer, numSamples);
+}
+
+void AdLib::onTimer() {
 	Common::StackLock slock(_mutex);
 
-	// Nothing to do, fill with silence
-	if (!_playing) {
-		memset(buffer, 0, numSamples * sizeof(int16));
-		return numSamples;
+	// Nothing to do
+	if (!_playing)
+		return;
+
+	// Check if there's anything to do on this step
+	// If not, decrease the poll number and move on
+	if (_toPoll > 0) {
+		_toPoll--;
+		return;
 	}
 
-	// Read samples from the OPL, polling in more music when necessary
-	uint32 samples = numSamples;
-	while (samples && _playing) {
-		if (_toPoll) {
-			const uint32 render = MIN(samples, _toPoll);
-
-			_opl->readBuffer(buffer, render);
-
-			buffer  += render;
-			samples -= render;
-			_toPoll -= render;
-
-		} else {
-			// Song ended, fill the rest with silence
-			if (_ended) {
-				memset(buffer, 0, samples * sizeof(int16));
-				samples = 0;
-				break;
-			}
-
-			// Poll more music
-			_toPoll = pollMusic(_first);
-			_first  = false;
+	// Poll until we have to delay until the next poll
+	while (_toPoll == 0 && _playing) {
+		// Song ended, break out
+		if (_ended) {
+			_toPoll = 0;
+			break;
 		}
+
+		// Poll more music
+		_toPoll = pollMusic(_first);
+		_first  = false;
 	}
 
 	// Song ended, loop if requested
@@ -195,8 +192,6 @@ int AdLib::readBuffer(int16 *buffer, const int numSamples) {
 		} else
 			_playing = false;
 	}
-
-	return numSamples;
 }
 
 bool AdLib::isStereo() const {
@@ -204,7 +199,7 @@ bool AdLib::isStereo() const {
 }
 
 bool AdLib::endOfData() const {
-	return !_playing;
+	return false;
 }
 
 bool AdLib::endOfStream() const {
@@ -231,10 +226,6 @@ void AdLib::setRepeating(int32 repCount) {
 	_repCount = repCount;
 }
 
-uint32 AdLib::getSamplesPerSecond() const {
-	return _rate * (isStereo() ? 2 : 1);
-}
-
 void AdLib::startPlay() {
 	Common::StackLock slock(_mutex);
 
@@ -639,4 +630,8 @@ void AdLib::setFreq(uint8 voice, uint16 note, bool on) {
 	writeOPL(0xB0 + voice, value);
 }
 
+void AdLib::setTimerFrequency(int timerFrequency) {
+	_opl->setCallbackFrequency(timerFrequency);
+}
+
 } // End of namespace Gob
diff --git a/engines/gob/sound/adlib.h b/engines/gob/sound/adlib.h
index 8071249374..6a6215298a 100644
--- a/engines/gob/sound/adlib.h
+++ b/engines/gob/sound/adlib.h
@@ -37,7 +37,7 @@ namespace Gob {
 /** Base class for a player of an AdLib music format. */
 class AdLib : public Audio::AudioStream {
 public:
-	AdLib(Audio::Mixer &mixer);
+	AdLib(Audio::Mixer &mixer, int callbackFrequency);
 	virtual ~AdLib();
 
 	bool isPlaying() const;    ///< Are we currently playing?
@@ -120,8 +120,6 @@ protected:
 	static const int kOPLMidC      = 48; ///< A mid C for the OPL.
 
 
-	/** Return the number of samples per second. */
-	uint32 getSamplesPerSecond() const;
 
 	/** Write a value into an OPL register. */
 	void writeOPL(byte reg, byte val);
@@ -135,7 +133,7 @@ protected:
 	/** The callback function that's called for polling more AdLib commands.
 	 *
 	 *  @param  first Is this the first poll since the start of the song?
-	 *  @return The number of samples until the next poll.
+	 *  @return The number of ticks until the next poll.
 	 */
 	virtual uint32 pollMusic(bool first) = 0;
 
@@ -207,6 +205,11 @@ protected:
 	/** Switch a voice off. */
 	void noteOff(uint8 voice);
 
+	/**
+	 * Set the OPL timer frequency
+	 */
+	void setTimerFrequency(int timerFrequency);
+
 private:
 	static const uint8 kOperatorType  [kOperatorCount];
 	static const uint8 kOperatorOffset[kOperatorCount];
@@ -300,6 +303,11 @@ private:
 	void changePitch(uint8 voice, uint16 pitchBend);
 
 	void setFreq(uint8 voice, uint16 note, bool on);
+
+	/**
+	 * Callback function for OPL
+	 */
+	void onTimer();
 };
 
 } // End of namespace Gob
diff --git a/engines/gob/sound/adlplayer.cpp b/engines/gob/sound/adlplayer.cpp
index 384a928360..e5a276032b 100644
--- a/engines/gob/sound/adlplayer.cpp
+++ b/engines/gob/sound/adlplayer.cpp
@@ -28,7 +28,7 @@
 
 namespace Gob {
 
-ADLPlayer::ADLPlayer(Audio::Mixer &mixer) : AdLib(mixer),
+ADLPlayer::ADLPlayer(Audio::Mixer &mixer) : AdLib(mixer, 1000),
 	_songData(0), _songDataSize(0), _playPos(0) {
 
 }
@@ -135,14 +135,7 @@ uint32 ADLPlayer::pollMusic(bool first) {
 	if (delay & 0x80)
 		delay = ((delay & 3) << 8) | *_playPos++;
 
-	return getSampleDelay(delay);
-}
-
-uint32 ADLPlayer::getSampleDelay(uint16 delay) const {
-	if (delay == 0)
-		return 0;
-
-	return ((uint32)delay * getSamplesPerSecond()) / 1000;
+	return delay;
 }
 
 void ADLPlayer::rewind() {
diff --git a/engines/gob/sound/adlplayer.h b/engines/gob/sound/adlplayer.h
index 3edd238343..bd43cc091c 100644
--- a/engines/gob/sound/adlplayer.h
+++ b/engines/gob/sound/adlplayer.h
@@ -76,8 +76,6 @@ private:
 	bool readHeader  (Common::SeekableReadStream &adl, int &timbreCount);
 	bool readTimbres (Common::SeekableReadStream &adl, int  timbreCount);
 	bool readSongData(Common::SeekableReadStream &adl);
-
-	uint32 getSampleDelay(uint16 delay) const;
 };
 
 } // End of namespace Gob
diff --git a/engines/gob/sound/musplayer.cpp b/engines/gob/sound/musplayer.cpp
index 7001a5724b..bf90d44735 100644
--- a/engines/gob/sound/musplayer.cpp
+++ b/engines/gob/sound/musplayer.cpp
@@ -27,7 +27,7 @@
 
 namespace Gob {
 
-MUSPlayer::MUSPlayer(Audio::Mixer &mixer) : AdLib(mixer),
+MUSPlayer::MUSPlayer(Audio::Mixer &mixer) : AdLib(mixer, 60),
 	_songData(0), _songDataSize(0), _playPos(0), _songID(0) {
 
 }
@@ -43,15 +43,6 @@ void MUSPlayer::unload() {
 	unloadMUS();
 }
 
-uint32 MUSPlayer::getSampleDelay(uint16 delay) const {
-	if (delay == 0)
-		return 0;
-
-	uint32 freq = (_ticksPerBeat * _tempo) / 60;
-
-	return ((uint32)delay * getSamplesPerSecond()) / freq;
-}
-
 void MUSPlayer::skipToTiming() {
 	while (*_playPos < 0x80)
 		_playPos++;
@@ -67,7 +58,7 @@ uint32 MUSPlayer::pollMusic(bool first) {
 	}
 
 	if (first)
-		return getSampleDelay(*_playPos++);
+		return *_playPos++;
 
 	uint16 delay = 0;
 	while (delay == 0) {
@@ -100,6 +91,7 @@ uint32 MUSPlayer::pollMusic(bool first) {
 				uint32 denom = *_playPos++;
 
 				_tempo = _baseTempo * num + ((_baseTempo * denom) >> 7);
+				setTimerFrequency((_ticksPerBeat * _tempo) / 60);
 
 				_playPos++;
 			} else {
@@ -182,7 +174,7 @@ uint32 MUSPlayer::pollMusic(bool first) {
 			delay += *_playPos++;
 	}
 
-	return getSampleDelay(delay);
+	return delay;
 }
 
 void MUSPlayer::rewind() {
@@ -193,6 +185,8 @@ void MUSPlayer::rewind() {
 
 	setPercussionMode(_soundMode != 0);
 	setPitchRange(_pitchBendRange);
+
+	setTimerFrequency((_ticksPerBeat * _tempo) / 60);
 }
 
 bool MUSPlayer::loadSND(Common::SeekableReadStream &snd) {
diff --git a/engines/gob/sound/musplayer.h b/engines/gob/sound/musplayer.h
index c76c5aab38..7c1189b84b 100644
--- a/engines/gob/sound/musplayer.h
+++ b/engines/gob/sound/musplayer.h
@@ -97,7 +97,6 @@ private:
 	bool readMUSHeader(Common::SeekableReadStream &mus);
 	bool readMUSSong  (Common::SeekableReadStream &mus);
 
-	uint32 getSampleDelay(uint16 delay) const;
 	void setInstrument(uint8 voice, uint8 instrument);
 	void skipToTiming();