ENGINES: Further simplify pseudo MidiDrivers; fix some regressions

The regression affected AGOS and maybe some others; specifically,
the real MidiDriver would have been deleted twice -- I previously
missed that the Engine instances takes care of freeing the real
MidiDriver, not the MidiPlayer wrapping it.

This commit should clarify the ownership of the real MidiDriver for
most pseudo MidiDrivers.

2 files changed, 20 insertions, 34 deletions

diff --git a/engines/agi/sound_midi.cpp b/engines/agi/sound_midi.cpp
index 877f6326fa..fe3d97b9c0 100644
--- a/engines/agi/sound_midi.cpp
+++ b/engines/agi/sound_midi.cpp
@@ -74,6 +74,7 @@ MIDISound::MIDISound(uint8 *data, uint32 len, int resnum, SoundMgr &manager) : A
 SoundGenMIDI::SoundGenMIDI(AgiEngine *vm, Audio::Mixer *pMixer) : SoundGen(vm, pMixer), _parser(0), _isPlaying(false), _passThrough(false), _isGM(false) {
 	MidiDriver::DeviceHandle dev = MidiDriver::detectDevice(MDT_MIDI | MDT_ADLIB);
 	_driver = MidiDriver::createMidi(dev);
+	assert(_driver);
 
 	if (ConfMan.getBool("native_mt32") || MidiDriver::getMusicType(dev) == MT_MT32) {
 		_nativeMT32 = true;
@@ -85,7 +86,17 @@ SoundGenMIDI::SoundGenMIDI(AgiEngine *vm, Audio::Mixer *pMixer) : SoundGen(vm, p
 	memset(_channel, 0, sizeof(_channel));
 	memset(_channelVolume, 127, sizeof(_channelVolume));
 	_masterVolume = 0;
-	this->open();
+
+	int ret = _driver->open();
+	if (ret == 0) {
+		if (_nativeMT32)
+			_driver->sendMT32Reset();
+		else
+			_driver->sendGMReset();
+
+		_driver->setTimerCallback(this, &onTimer);
+	}
+
 	_smfParser = MidiParser::createParser_SMF();
 	_midiMusicData = NULL;
 }
@@ -93,7 +104,11 @@ SoundGenMIDI::SoundGenMIDI(AgiEngine *vm, Audio::Mixer *pMixer) : SoundGen(vm, p
 SoundGenMIDI::~SoundGenMIDI() {
 	_driver->setTimerCallback(NULL, NULL);
 	stop();
-	this->close();
+	if (_driver) {
+		_driver->close();
+		delete _driver;
+		_driver = 0;
+	}
 	_smfParser->setMidiDriver(NULL);
 	delete _smfParser;
 	delete[] _midiMusicData;
@@ -119,32 +134,6 @@ void SoundGenMIDI::setVolume(int volume) {
 	}
 }
 
-int SoundGenMIDI::open() {
-	// Don't ever call open without first setting the output driver!
-	if (!_driver)
-		return 255;
-
-	int ret = _driver->open();
-	if (ret)
-		return ret;
-
-	_driver->setTimerCallback(this, &onTimer);
-
-	if (_nativeMT32)
-		_driver->sendMT32Reset();
-	else
-		_driver->sendGMReset();
-
-	return 0;
-}
-
-void SoundGenMIDI::close() {
-	stop();
-	if (_driver)
-		_driver->close();
-	_driver = 0;
-}
-
 void SoundGenMIDI::send(uint32 b) {
 	if (_passThrough) {
 		_driver->send(b);
diff --git a/engines/agi/sound_midi.h b/engines/agi/sound_midi.h
index 2e1bfe2c8a..dc6609c3e7 100644
--- a/engines/agi/sound_midi.h
+++ b/engines/agi/sound_midi.h
@@ -70,12 +70,9 @@ public:
 
 	void setGM(bool isGM) { _isGM = isGM; }
 
-	// MidiDriver interface implementation
-	int open();
-	void close();
-	void send(uint32 b);
-
-	void metaEvent(byte type, byte *data, uint16 length);
+	// MidiDriver_BASE interface implementation
+	virtual void send(uint32 b);
+	virtual void metaEvent(byte type, byte *data, uint16 length);
 
 private: