SCUMM: Handle default instrument set up in iMuse like the original.

2 files changed, 26 insertions, 13 deletions

diff --git a/engines/scumm/imuse/imuse.cpp b/engines/scumm/imuse/imuse.cpp
index 451721cf70..5ad4798578 100644
--- a/engines/scumm/imuse/imuse.cpp
+++ b/engines/scumm/imuse/imuse.cpp
@@ -1682,7 +1682,21 @@ void IMuseInternal::setGlobalInstrument(byte slot, byte *data) {
 void IMuseInternal::copyGlobalInstrument(byte slot, Instrument *dest) {
 	if (slot >= 32)
 		return;
-	_global_instruments[slot].copy_to(dest);
+
+	// Both the AdLib code and the PC Speaker code use an all zero instrument
+	// as default in the original, thus we do the same.
+	// PC Speaker instrument size is 23, while AdLib instrument size is 30.
+	// Thus we just use a 30 byte instrument data array as default.
+	const byte defaultInstr[30] = { 0 };
+
+	if (_global_instruments[slot].isValid()) {
+		// In case we have an valid instrument set up, copy it to the part.
+		_global_instruments[slot].copy_to(dest);
+	} else if (_pcSpeaker) {
+		dest->pcspk(defaultInstr);
+	} else {
+		dest->adlib(defaultInstr);
+	}
 }
 
 
diff --git a/engines/scumm/imuse/sysex_scumm.cpp b/engines/scumm/imuse/sysex_scumm.cpp
index 9f795133be..85ffc86f47 100644
--- a/engines/scumm/imuse/sysex_scumm.cpp
+++ b/engines/scumm/imuse/sysex_scumm.cpp
@@ -81,20 +81,19 @@ void sysexHandler_Scumm(Player *player, const byte *msg, uint16 len) {
 					se->reallocateMidiChannels(player->_midi);
 				}
 			} else {
-				// Even in cases where a program does not seem to be specified,
-				// i.e. bytes 15 and 16 are 0, we send a program change because
-				// 0 is a valid program number. MI2 tests show that in such
-				// cases, a regular program change message always seems to follow
-				// anyway.
 				if (player->_isMIDI) {
+					// Even in cases where a program does not seem to be specified,
+					// i.e. bytes 15 and 16 are 0, we send a program change because
+					// 0 is a valid program number. MI2 tests show that in such
+					// cases, a regular program change message always seems to follow
+					// anyway.
 					part->_instrument.program(buf[8], player->_isMT32);
-				} else if (se->_pcSpeaker) {
-					// FIXME/HACK: This is only needed here, since when we use the following line:
-					// se->copyGlobalInstrument(buf[8], &part->_instrument);
-					// We would not get any instrument for PC Speaker. Because we don't default to an
-					// "empty" instrument in case the global instrument specified is not set up.
-					byte empty[23] = {0};
-					part->_instrument.pcspk(empty);
+				} else {
+					// Like the original we set up the instrument data of the
+					// specified program here too. In case the global
+					// instrument data is not loaded already, this will take
+					// care of setting a default instrument too.
+					se->copyGlobalInstrument(buf[8], &part->_instrument);
 				}
 				part->sendAll();
 			}