SCI: some changes to the way reverb is handled

- "Invalid" SCI reverb values (127) are properly handled now
- SCI kDoSound(reverb) sets the global reverb (renamed it accordingly)
- kDoSound(reverb) can also return the current reverb if no parameter is sent

svn-id: r54457

3 files changed, 21 insertions, 7 deletions

diff --git a/engines/sci/sound/drivers/midi.cpp b/engines/sci/sound/drivers/midi.cpp
index 2b97cdb704..70e1cf2133 100644
--- a/engines/sci/sound/drivers/midi.cpp
+++ b/engines/sci/sound/drivers/midi.cpp
@@ -378,8 +378,10 @@ int MidiPlayer_Midi::getVolume() {
 }
 
 void MidiPlayer_Midi::setReverb(byte reverb) {
-	_reverb = CLIP<byte>(reverb, 0, kReverbConfigNr - 1);
-	if (_hasReverb)
+	assert(reverb < kReverbConfigNr || reverb == 127);
+	_reverb = reverb;
+
+	if (_hasReverb && _reverb != 127)	// 127: SCI invalid, don't send to sound card
 		sendMt32SysEx(0x100001, _reverbConfig[_reverb], 3, true);
 }
 
@@ -469,8 +471,6 @@ void MidiPlayer_Midi::readMt32Patch(const byte *data, int size) {
 	setMt32Volume(volume);
 
 	// Reverb default only used in (roughly) SCI0/SCI01
-	// TODO: we need to send this to the MT-32, if it's available.
-	// Check patch #3117434
 	_reverb = str->readByte();
 	_hasReverb = true;
 
@@ -478,6 +478,8 @@ void MidiPlayer_Midi::readMt32Patch(const byte *data, int size) {
 	str->seek(11, SEEK_CUR);
 
 	// Read reverb data (stored vertically - patch #3117434)
+	// TODO: we need to send this to the MT-32, if it's available,
+	// depending on the SCI version
 	for (int j = 0; j < 3; ++j) {
 		for (int i = 0; i < kReverbConfigNr; i++) {
 			_reverbConfig[i][j] = str->readByte();
diff --git a/engines/sci/sound/soundcmd.cpp b/engines/sci/sound/soundcmd.cpp
index d8cfa672ce..644e2a43d7 100644
--- a/engines/sci/sound/soundcmd.cpp
+++ b/engines/sci/sound/soundcmd.cpp
@@ -491,9 +491,21 @@ reg_t SoundCommandParser::kDoSoundSendMidi(int argc, reg_t *argv, reg_t acc) {
 	return acc;
 }
 
-reg_t SoundCommandParser::kDoSoundReverb(int argc, reg_t *argv, reg_t acc) {
-	debugC(2, kDebugLevelSound, "doSoundReverb: %d", argv[0].toUint16() & 0xF);
+reg_t SoundCommandParser::kDoSoundGlobalReverb(int argc, reg_t *argv, reg_t acc) {
+	if (argc == 0)
+		return make_reg(0, _music->getReverb());
+
+	debugC(2, kDebugLevelSound, "doSoundGlobalReverb: %d", argv[0].toUint16() & 0xF);
+
+	// This is a bit different than SSCI, but the end result should be the same.
+	// SSCI checks the first entry in the playlist for its current reverb value.
+	// If it's 127 (invalid), it sets the reverb parameter of this call to the
+	// driver, otherwise it doesn't, to preserve the song's reverb. When we modify
+	// the global reverb, we send its value to the soundcard, if it isn't 127 (invalid).
+	// This assumes that the currently set reverb in the driver will be the reverb
+	// value sent from the last song, which should be the one at the top of the list.
 	_music->setReverb(argv[0].toUint16() & 0xF);
+
 	return acc;
 }
 
diff --git a/engines/sci/sound/soundcmd.h b/engines/sci/sound/soundcmd.h
index b457ad4618..45b93e9a09 100644
--- a/engines/sci/sound/soundcmd.h
+++ b/engines/sci/sound/soundcmd.h
@@ -94,7 +94,7 @@ public:
 	reg_t kDoSoundUpdate(int argc, reg_t *argv, reg_t acc);
 	reg_t kDoSoundUpdateCues(int argc, reg_t *argv, reg_t acc);
 	reg_t kDoSoundSendMidi(int argc, reg_t *argv, reg_t acc);
-	reg_t kDoSoundReverb(int argc, reg_t *argv, reg_t acc);
+	reg_t kDoSoundGlobalReverb(int argc, reg_t *argv, reg_t acc);
 	reg_t kDoSoundSetHold(int argc, reg_t *argv, reg_t acc);
 	reg_t kDoSoundDummy(int argc, reg_t *argv, reg_t acc);
 	reg_t kDoSoundGetAudioCapability(int argc, reg_t *argv, reg_t acc);