AUDIO: Change several fake MidiDrivers to MidiDriver_BASE subclasses

Many engines follow the advice in audio/midiparser.h and create a
"pseudo-MidiDriver" subclass. But MidiParser really only needs a tiny
subset of the MidiDriver capabilities, namely those found in
MidiDriver_BASE. So we try to subclass from that whenever possible; this
allows us to remove many stub methods, and enables further future
simplifications.

2 files changed, 3 insertions, 41 deletions

diff --git a/engines/groovie/music.cpp b/engines/groovie/music.cpp
index 7651576828..1921d65b41 100644
--- a/engines/groovie/music.cpp
+++ b/engines/groovie/music.cpp
@@ -264,12 +264,6 @@ int MusicPlayerMidi::open() {
 	return 0;
 }
 
-bool MusicPlayerMidi::isOpen() const {
-	return _driver && _driver->isOpen();
-}
-
-void MusicPlayerMidi::close() {}
-
 void MusicPlayerMidi::send(uint32 b) {
 	if ((b & 0xFFF0) == 0x07B0) { // Volume change
 		// Save the specific channel volume
@@ -298,32 +292,6 @@ void MusicPlayerMidi::metaEvent(byte type, byte *data, uint16 length) {
 	}
 }
 
-void MusicPlayerMidi::setTimerCallback(void *timer_param, Common::TimerManager::TimerProc timer_proc) {
-	if (_driver)
-		_driver->setTimerCallback(timer_param, timer_proc);
-}
-
-uint32 MusicPlayerMidi::getBaseTempo() {
-	if (_driver)
-		return _driver->getBaseTempo();
-	else
-		return 0;
-}
-
-MidiChannel *MusicPlayerMidi::allocateChannel() {
-	if (_driver)
-		return _driver->allocateChannel();
-	else
-		return 0;
-}
-
-MidiChannel *MusicPlayerMidi::getPercussionChannel() {
-	if (_driver)
-		return _driver->getPercussionChannel();
-	else
-		return 0;
-}
-
 void MusicPlayerMidi::updateChanVolume(byte channel) {
 	// Generate a MIDI Control change message for the volume
 	uint32 b = 0x7B0;
@@ -406,7 +374,7 @@ MusicPlayerXMI::MusicPlayerXMI(GroovieEngine *vm, const Common::String &gtlName)
 
 	// Create the driver
 	MidiDriver::DeviceHandle dev = MidiDriver::detectDevice(MDT_MIDI | MDT_ADLIB | MDT_PREFER_GM);
-	_driver = createMidi(dev);
+	_driver = MidiDriver::createMidi(dev);
 	this->open();
 
 	// Set the parser's driver
@@ -706,7 +674,7 @@ MusicPlayerMac::MusicPlayerMac(GroovieEngine *vm) : MusicPlayerMidi(vm) {
 
 	// Create the driver
 	MidiDriver::DeviceHandle dev = MidiDriver::detectDevice(MDT_MIDI | MDT_ADLIB | MDT_PREFER_GM);
-	_driver = createMidi(dev);
+	_driver = MidiDriver::createMidi(dev);
 	this->open();
 
 	// Set the parser's driver
diff --git a/engines/groovie/music.h b/engines/groovie/music.h
index e45e130a70..870fd10b06 100644
--- a/engines/groovie/music.h
+++ b/engines/groovie/music.h
@@ -88,21 +88,15 @@ protected:
 	virtual void unload();
 };
 
-class MusicPlayerMidi : public MusicPlayer, public MidiDriver {
+class MusicPlayerMidi : public MusicPlayer, public MidiDriver_BASE {
 public:
 	MusicPlayerMidi(GroovieEngine *vm);
 	~MusicPlayerMidi();
 
 	// MidiDriver interface
 	virtual int open();
-	virtual bool isOpen() const;
-	virtual void close();
 	virtual void send(uint32 b);
 	virtual void metaEvent(byte type, byte *data, uint16 length);
-	virtual void setTimerCallback(void *timer_param, Common::TimerManager::TimerProc timer_proc);
-	virtual uint32 getBaseTempo();
-	virtual MidiChannel *allocateChannel();
-	virtual MidiChannel *getPercussionChannel();
 
 private:
 	// Channel volumes