Fix for Bug [775534] 0.5.0 RC SIMON1DOS Random sfx notes during music

Corrected a problem with resource size computation for GMF sound
effect resources. Since GMF resources have no size info, we were
computing sizes with the assumption that each GMF appears in its
own file, so the file size becomes the resource size. This is true
for simon1dos music files but not for SFX files. This fix uses the
resource offset pointers at the beginning of SFX files to properly
compute the size of SFX resources.

svn-id: r9155

1 files changed, 41 insertions, 11 deletions

diff --git a/simon/midi.cpp b/simon/midi.cpp
index dc4ac95cf8..ae562a58a8 100644
--- a/simon/midi.cpp
+++ b/simon/midi.cpp
@@ -129,10 +129,11 @@ void MidiPlayer::send (uint32 b) {
 
 void MidiPlayer::metaEvent (byte type, byte *data, uint16 length) {
 	// Only thing we care about is End of Track.
-	if (!_current || type != 0x2F || _current == &_sfx)
+	if (!_current || type != 0x2F) {
 		return;
-
-	if (_loopTrack) {
+	} else if (_current == &_sfx) {
+		clearConstructs (_sfx);
+	} else if (_loopTrack) {
 		_current->parser->jumpToTick (0);
 	} else if (_queuedTrack != 255) {
 		_currentTrack = 255;
@@ -299,11 +300,19 @@ void MidiPlayer::clearConstructs (MusicInfo &info) {
 	if (info.num_songs > 0) {
 		for (i = 0; i < info.num_songs; ++i)
 			free (info.songs [i]);
+		info.num_songs = 0;
 	}
-	if (info.data)
+
+	if (info.data) {
 		free (info.data);
-	if (info.parser)
+		info.data = 0;
+	} // end if
+
+	if (info.parser) {
 		delete info.parser;
+		info.parser = 0;
+	}
+
 	if (_driver) {
 		for (i = 0; i < 16; ++i) {
 			if (info.channel[i]) {
@@ -327,9 +336,34 @@ void MidiPlayer::loadSMF (File *in, int song, bool sfx) {
 	MusicInfo *p = sfx ? &_sfx : &_music;
 	clearConstructs (*p);
 
+	uint32 startpos = in->pos();
+	byte header[4];
+	in->read (header, 4);
+	bool isGMF = !memcmp (header, "GMF\x1", 4);
+	in->seek (startpos, SEEK_SET);
+
 	uint32 size = in->size() - in->pos();
-	if (size > 64000)
-		size = 64000;
+	if (isGMF) {
+		if (sfx) {
+			// Multiple GMF resources are stored in the SFX files,
+			// but each one is referenced by a pointer at the
+			// beginning of the file. Those pointers can be used
+			// to determine file size.
+			in->seek (0, SEEK_SET);
+			uint16 value = in->readUint16LE() >> 2; // Number of resources
+			if (song != value - 1) {
+				in->seek (song * 2 + 2, SEEK_SET);
+				value = in->readUint16LE();
+				size = value - startpos;
+			}
+			in->seek (startpos, SEEK_SET);
+		} else if (size >= 64000) {
+			// For GMF resources not in separate
+			// files, we're going to have to use
+			// hardcoded size tables.
+			size = simon1_gmf_size [song];
+		}
+	}
 
 	// When allocating space, add 4 bytes in case
 	// this is a GMF and we have to tack on our own
@@ -348,10 +382,6 @@ void MidiPlayer::loadSMF (File *in, int song, bool sfx) {
 		if (!sfx)
 			setLoop (p->data[6] != 0);
 
-		// For GMF files, we're going to have to use
-		// hardcoded size tables.
-		if (size == 64000)
-			size = simon1_gmf_size [song];
 	}
 
 	MidiParser *parser = MidiParser::createParser_SMF();