Fix for Bug [810564] ALL: missing instruments with native MT-32

As defined in Patch [811623] MT-32 patch for Bug 810564

Added a channel mask to MPU-401 devices so that --native-mt32
may force the device to use only the subset of MIDI channels
actually supported by the MT-32. Also added a best-guess
interpretation of iMuse Part priority in the SysEx 0x00 msg,
since part priorities become more of an issue when the
channel count is cramped.

svn-id: r10409

3 files changed, 17 insertions, 3 deletions

diff --git a/sound/mididrv.h b/sound/mididrv.h
index ff8583b0f5..f9164cb3fb 100644
--- a/sound/mididrv.h
+++ b/sound/mididrv.h
@@ -44,7 +44,8 @@ public:
 
 	enum {
 //		PROP_TIMEDIV = 1,
-		PROP_OLD_ADLIB = 2
+		PROP_OLD_ADLIB = 2,
+		PROP_CHANNEL_MASK = 3
 	};
 
 	// Open the midi driver.
diff --git a/sound/mpu401.cpp b/sound/mpu401.cpp
index 5277844426..78845f99a8 100644
--- a/sound/mpu401.cpp
+++ b/sound/mpu401.cpp
@@ -85,7 +85,8 @@ MidiDriver_MPU401::MidiDriver_MPU401() :
 	_started_thread (false),
 	_mutex (0),
 	_timer_proc (0),
-	_timer_param (0)
+	_timer_param (0),
+	_channel_mask (0xFFFF) // Permit all 16 channels by default
 {
 	
 	uint i;
@@ -106,12 +107,22 @@ void MidiDriver_MPU401::close() {
 		send (0x7B << 8 | 0xB0 | i);
 }
 
+uint32 MidiDriver_MPU401::property (int prop, uint32 param) {
+	switch (prop) {
+		case PROP_CHANNEL_MASK:
+			_channel_mask = param & 0xFFFF;
+			return 1;
+	}
+
+	return 0;
+}
+
 MidiChannel *MidiDriver_MPU401::allocateChannel() {
 	MidiChannel_MPU401 *chan;
 	uint i;
 
 	for (i = 0; i < ARRAYSIZE(_midi_channels); ++i) {
-		if (i == 9)
+		if (i == 9 || !(_channel_mask & (1 << i)))
 			continue;
 		chan = &_midi_channels[i];
 		if (!chan->_allocated) {
diff --git a/sound/mpu401.h b/sound/mpu401.h
index 2a7daaea6f..5551fdf48c 100644
--- a/sound/mpu401.h
+++ b/sound/mpu401.h
@@ -85,6 +85,7 @@ private:
 	OSystem::MutexRef _mutex; // Concurrent shutdown barrier
 	volatile TimerCallback _timer_proc;
 	void *_timer_param;
+	uint16 _channel_mask;
 
 	static int midi_driver_thread (void *param);
 
@@ -94,6 +95,7 @@ public:
 	virtual void close();
 	void setTimerCallback(void *timer_param, TimerCallback timer_proc);
 	uint32 getBaseTempo(void) { return 10000; }
+	uint32 property(int prop, uint32 param);
 
 	MidiChannel *allocateChannel();
 	MidiChannel *getPercussionChannel() { return &_midi_channels [9]; }