From 177cfe4c92085991867fe82ad750e51620f55f6e Mon Sep 17 00:00:00 2001
From: Filippos Karapetis
Date: Fri, 15 Jan 2010 07:40:07 +0000
Subject: When unloading a song, only reset the channels that it actually used,
 not all channels

svn-id: r47304
---
 engines/sci/sound/midiparser_sci.cpp | 15 ++++++++++-----
 engines/sci/sound/midiparser_sci.h   |  4 ++++
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/engines/sci/sound/midiparser_sci.cpp b/engines/sci/sound/midiparser_sci.cpp
index 00b954c43f..0bf3a09101 100644
--- a/engines/sci/sound/midiparser_sci.cpp
+++ b/engines/sci/sound/midiparser_sci.cpp
@@ -80,6 +80,8 @@ bool MidiParser_SCI::loadMusic(SoundResource::Track *track, MusicEntry *psnd, in
 	_tracks[0] = _mixedData;
 	setTrack(0);
 	_loopTick = 0;
+	_channelsUsed = 0;
+
 	return true;
 }
 
@@ -95,17 +97,20 @@ void MidiParser_SCI::unloadMusic() {
 	}
 
 	// Center the pitch wheels and hold pedal in preparation for the next piece of music
-	// TODO: We should monitor what channels are used by each song, and only
-	// reset these channels, not all of them!
 	if (_driver) {
 		for (int i = 0; i < 16; ++i) {
-			_driver->send(0xE0 | i, 0, 0x40);	// Reset pitch wheel
-			_driver->send(0xB0 | i, 0x40, 0);	// Reset hold pedal
+			if (_channelsUsed & (1 << i)) {
+				_driver->send(0xE0 | i, 0, 0x40);	// Reset pitch wheel
+				_driver->send(0xB0 | i, 0x40, 0);	// Reset hold pedal
+			}
 		}
 	}
 }
 
 void MidiParser_SCI::parseNextEvent(EventInfo &info) {
+	// Monitor which channels are used by this song
+	_channelsUsed |= (1 << info.channel());
+
 	// Set signal AFTER waiting for delta, otherwise we would set signal too soon resulting in all sorts of bugs
 	if (_signalSet) {
 		_signalSet = false;
@@ -186,7 +191,7 @@ void MidiParser_SCI::parseNextEvent(EventInfo &info) {
 			case 0x46: // LSL3 - binoculars
 			case 0x61: // Iceman (Adlib?)
 			case 0x73: // Hoyle
-			case 0xd1: // KQ4, when riding the unicorn
+			case 0xD1: // KQ4, when riding the unicorn
 				// Obscure SCI commands - ignored
 				break;
 			// Standard MIDI commands
diff --git a/engines/sci/sound/midiparser_sci.h b/engines/sci/sound/midiparser_sci.h
index 5e62e2d7c3..cc97466e37 100644
--- a/engines/sci/sound/midiparser_sci.h
+++ b/engines/sci/sound/midiparser_sci.h
@@ -84,6 +84,10 @@ protected:
 
 	bool _signalSet;
 	int16 _signalToSet;
+
+	// A 16-bit mask, containing the channels used
+	// by the currently parsed song
+	uint16 _channelsUsed;
 };
 
 } // End of namespace Sci
-- 
cgit v1.2.3