GROOVIE: Detect if external music exists for the Music Enhancement Pr…

…oject.

T7G's music framework uses either all external or all XMIDI, so assume if one
external song is present, the entire music pack is.

engines/groovie/groovie.cpp

@@ -152,20 +152,26 @@ Common::Error GroovieEngine::run() {
 		break;
 	}
 
-	// Create the music player
-	switch (getPlatform()) {
-	case Common::kPlatformMacintosh:
-		// TODO: The 11th Hour Mac uses QuickTime MIDI files
-		// Right now, since the XMIDI are present and it is still detected as
-		// the DOS version, we don't have to do anything here.
-		_musicPlayer = new MusicPlayerMac(this);
-		break;
-	case Common::kPlatformIOS:
+	// Detect ScummVM Music Enhancement Project presence (T7G only)
+	if (Common::File::exists("gu16.ogg") && _gameDescription->version == kGroovieT7G) {
+		// Load player for external files
 		_musicPlayer = new MusicPlayerIOS(this);
-		break;
-	default:
-		_musicPlayer = new MusicPlayerXMI(this, _gameDescription->version == kGroovieT7G ? "fat" : "sample");
-		break;
+	} else {
+		// Create the music player
+		switch (getPlatform()) {
+		case Common::kPlatformMacintosh:
+			// TODO: The 11th Hour Mac uses QuickTime MIDI files
+			// Right now, since the XMIDI are present and it is still detected as
+			// the DOS version, we don't have to do anything here.
+			_musicPlayer = new MusicPlayerMac(this);
+			break;
+		case Common::kPlatformIOS:
+			_musicPlayer = new MusicPlayerIOS(this);
+			break;
+		default:
+			_musicPlayer = new MusicPlayerXMI(this, _gameDescription->version == kGroovieT7G ? "fat" : "sample");
+			break;
+		}
 	}
 
 	// Load volume levels