SCUMM/FM-TOWNS: start rewriting audio code

- Start rewriting audio code for FM-TOWNS versions of Loom, Indy3 and Monkey Island 1 using the recently added code in towns_audio.cpp (Zak should work the same way, but I can't test, since I don't own that one).
- All sound types (pcm, euphony and cd audio) now support volume and balance control (e.g. try walking into/out of the kitchen and opening/closing the door in the Scumm Bar in Monkey Island 1 or walking into/out of the circus tent).
- Pcm sounds now support proper loop start/end and note offsets (e.g. try out the hammer sound in the forge in LOOM for example).
- some other minor improvements
- The FM-Towns versions of Indy 4 and Monkey Island 2 are not affected. I don't have Monkey Island 2, but I presume that it will work like Indy 4. Adding support for these will be a separate task, since they work quite differently.

svn-id: r52198

5 files changed, 46 insertions, 5 deletions

diff --git a/sound/softsynth/fmtowns_pc98/towns_audio.cpp b/sound/softsynth/fmtowns_pc98/towns_audio.cpp
index 46569dd842..bef062b8e6 100644
--- a/sound/softsynth/fmtowns_pc98/towns_audio.cpp
+++ b/sound/softsynth/fmtowns_pc98/towns_audio.cpp
@@ -200,7 +200,7 @@ TownsAudioInterface::TownsAudioInterface(Audio::Mixer *mixer, TownsAudioInterfac
 		INTCB(notImpl),
 		// 72
 		INTCB(notImpl),
-		INTCB(notImpl),
+		INTCB(cdaToggle),
 		INTCB(notImpl),
 		INTCB(notImpl),
 		// 76
@@ -222,9 +222,19 @@ TownsAudioInterface::TownsAudioInterface(Audio::Mixer *mixer, TownsAudioInterfac
 
 	_timerBase = (uint32)(_baserate * 1000000.0f);
 	_tickLength = 2 * _timerBase;
+
+	setTimerCallbackA((ChipTimerProc)&TownsAudioInterface::timerCallbackA);
+	setTimerCallbackB((ChipTimerProc)&TownsAudioInterface::timerCallbackB);
 }
 
 TownsAudioInterface::~TownsAudioInterface() {
+	Common::StackLock lock(_mutex);
+	reset();
+	_ready = false;
+
+	setTimerCallbackA();
+	setTimerCallbackB();
+
 	delete[] _fmSaveReg[0];
 	delete[] _fmSaveReg[1];
 	delete[] _fmInstruments;
@@ -759,6 +769,12 @@ int TownsAudioInterface::intf_updateOutputVolume(va_list &args) {
 	return 0;
 }
 
+int TownsAudioInterface::intf_cdaToggle(va_list &args) {
+	//int mode = va_arg(args, int);
+	//_unkMask = mode ? 0x7f : 0x3f;
+	return 0;
+}
+
 int TownsAudioInterface::intf_pcmUpdateEnvelopeGenerator(va_list &args) {
 	for (int i = 0; i < 8; i++)
 		pcmUpdateEnvelopeGenerator(i);
diff --git a/sound/softsynth/fmtowns_pc98/towns_audio.h b/sound/softsynth/fmtowns_pc98/towns_audio.h
index 950c016b4e..95fb1ded59 100644
--- a/sound/softsynth/fmtowns_pc98/towns_audio.h
+++ b/sound/softsynth/fmtowns_pc98/towns_audio.h
@@ -95,6 +95,7 @@ private:
 	int intf_setOutputVolume(va_list &args);
 	int intf_resetOutputVolume(va_list &args);
 	int intf_updateOutputVolume(va_list &args);
+	int intf_cdaToggle(va_list &args);
 	int intf_pcmUpdateEnvelopeGenerator(va_list &args);
 
 	int intf_notImpl(va_list &args);
diff --git a/sound/softsynth/fmtowns_pc98/towns_pc98_driver.cpp b/sound/softsynth/fmtowns_pc98/towns_pc98_driver.cpp
index 82d0bd0438..6d52937cc6 100644
--- a/sound/softsynth/fmtowns_pc98/towns_pc98_driver.cpp
+++ b/sound/softsynth/fmtowns_pc98/towns_pc98_driver.cpp
@@ -1037,11 +1037,21 @@ TownsPC98_AudioDriver::TownsPC98_AudioDriver(Audio::Mixer *mixer, EmuType type)
 	_musicPlaying(false), _sfxPlaying(false), _fading(false), _looping(0), _ready(false) {
 
 	_sfxOffsets[0] = _sfxOffsets[1] = 0;
+
+	setTimerCallbackA((ChipTimerProc)&TownsPC98_AudioDriver::timerCallbackA);
+	setTimerCallbackB((ChipTimerProc)&TownsPC98_AudioDriver::timerCallbackB);
 }
 
 TownsPC98_AudioDriver::~TownsPC98_AudioDriver() {
+	Common::StackLock lock(_mutex);
+
 	reset();
 
+	_ready = false;
+
+	setTimerCallbackA();
+	setTimerCallbackB();
+
 	if (_channels) {
 		for (int i = 0; i < _numChan; i++)
 			delete _channels[i];
diff --git a/sound/softsynth/fmtowns_pc98/towns_pc98_fmsynth.cpp b/sound/softsynth/fmtowns_pc98/towns_pc98_fmsynth.cpp
index 241b9bde50..e304537c22 100644
--- a/sound/softsynth/fmtowns_pc98/towns_pc98_fmsynth.cpp
+++ b/sound/softsynth/fmtowns_pc98/towns_pc98_fmsynth.cpp
@@ -835,6 +835,7 @@ TownsPC98_FmSynth::TownsPC98_FmSynth(Audio::Mixer *mixer, EmuType type) :
 
 	memset(&_timers[0], 0, sizeof(ChipTimer));
 	memset(&_timers[1], 0, sizeof(ChipTimer));
+
 	_timers[0].cb = &TownsPC98_FmSynth::timerCallbackA;
 	_timers[1].cb = &TownsPC98_FmSynth::timerCallbackB;
 	_timerbase = (uint32)(_baserate * 1000000.0f);	
@@ -842,6 +843,9 @@ TownsPC98_FmSynth::TownsPC98_FmSynth(Audio::Mixer *mixer, EmuType type) :
 
 TownsPC98_FmSynth::~TownsPC98_FmSynth() {
 	Common::StackLock lock(_mutex);
+	
+	_ready = false;
+
 	_mixer->stopHandle(_soundHandle);
 	delete _ssg;
 	delete _prc;
@@ -1154,6 +1158,14 @@ int TownsPC98_FmSynth::readBuffer(int16 *buffer, const int numSamples) {
 	return numSamples;
 }
 
+void TownsPC98_FmSynth::setTimerCallbackA(ChipTimerProc proc) {
+	_timers[0].cb = proc;
+}
+
+void TownsPC98_FmSynth::setTimerCallbackB(ChipTimerProc proc) {
+	_timers[1].cb = proc;
+}
+
 uint8 TownsPC98_FmSynth::readSSGStatus() {
 	return _ssg->chanEnable();
 }
diff --git a/sound/softsynth/fmtowns_pc98/towns_pc98_fmsynth.h b/sound/softsynth/fmtowns_pc98/towns_pc98_fmsynth.h
index 3072503610..4c2de467d7 100644
--- a/sound/softsynth/fmtowns_pc98/towns_pc98_fmsynth.h
+++ b/sound/softsynth/fmtowns_pc98/towns_pc98_fmsynth.h
@@ -71,6 +71,10 @@ public:
 	}
 
 protected:
+	typedef void (TownsPC98_FmSynth::*ChipTimerProc)();
+	void setTimerCallbackA(ChipTimerProc proc = &TownsPC98_FmSynth::timerCallbackA);
+	void setTimerCallbackB(ChipTimerProc proc = &TownsPC98_FmSynth::timerCallbackB);
+
 	// Implement this in your inherited class if your driver generates
 	// additional output that has to be inserted into the buffer.
 	virtual void nextTickEx(int32 *buffer, uint32 bufferSize) {}
@@ -80,8 +84,8 @@ protected:
 	}
 	uint8 readSSGStatus();
 
-	virtual void timerCallbackA() = 0;
-	virtual void timerCallbackB() = 0;
+	virtual void timerCallbackA() {}
+	virtual void timerCallbackB() {}
 
 	// The audio driver can store and apply two different audio settings
 	// (usually for music and sound effects). The channel mask will determine
@@ -139,8 +143,6 @@ private:
 
 	bool _regProtectionFlag;
 
-	typedef void (TownsPC98_FmSynth::*ChipTimerProc)();
-
 	struct ChipTimer {
 		bool enabled;
 		uint16 value;