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, 12 insertions, 30 deletions

diff --git a/engines/m4/midi.cpp b/engines/m4/midi.cpp
index 36f7f29a2e..b5ae3b90ae 100644
--- a/engines/m4/midi.cpp
+++ b/engines/m4/midi.cpp
@@ -39,14 +39,21 @@ MidiPlayer::MidiPlayer(MadsM4Engine *vm, MidiDriver *driver) : _vm(vm), _midiDat
 	_parser = MidiParser::createParser_SMF();
 	_parser->setMidiDriver(this);
 	_parser->setTimerRate(_driver->getBaseTempo());
-	open();
+
+	int ret = _driver->open();
+	if (ret == 0)
+		_driver->setTimerCallback(this, &onTimer);
 }
 
 MidiPlayer::~MidiPlayer() {
 	_driver->setTimerCallback(NULL, NULL);
 	_parser->setMidiDriver(NULL);
 	stopMusic();
-	close();
+	if (_driver) {
+		_driver->close();
+		delete _driver;
+	}
+	_driver = 0;
 	delete _parser;
 	free(_midiData);
 }
@@ -71,28 +78,6 @@ void MidiPlayer::setVolume(int volume) {
 	}
 }
 
-int MidiPlayer::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);
-	return 0;
-}
-
-void MidiPlayer::close() {
-	stopMusic();
-	if (_driver) {
-		_driver->close();
-		delete _driver;
-	}
-	_driver = 0;
-}
-
 void MidiPlayer::send(uint32 b) {
 	if (_passThrough) {
 		_driver->send(b);
diff --git a/engines/m4/midi.h b/engines/m4/midi.h
index 46dc5efd27..42948e5ff1 100644
--- a/engines/m4/midi.h
+++ b/engines/m4/midi.h
@@ -52,12 +52,9 @@ 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);
 
 protected:
 	static void onTimer(void *data);