GOB: Rewrite the AdLib players

This is a complete rewrite of the AdLib players for ADL and MDY/TBR
files in the Gob engine.

Major changes
1) The AdLib base class is now completely separated from all file
   format code and can theoretically be used by any OPL2-based
   format (within reason)
2) The new code is far better documented and more readable
3) The MDY player now actually works. The MDY/TBR format is
   in reality the MUS/SND format created by AdLib as a simpler
   alternative to the ROL format
4) Since the MAME emulator is quite buggy and leads to noticable
   wrong percussion in the Gobliins 2 title music, the new AdLib
   player will try to create a DOSBox OPL. If it's not compiled in,
   or if the user configured opl_driver to "mame", it will print
   out appropriate warnings.

1 files changed, 13 insertions, 4 deletions

diff --git a/engines/gob/sound/sound.h b/engines/gob/sound/sound.h
index 585cf36703..ea7d639ffe 100644
--- a/engines/gob/sound/sound.h
+++ b/engines/gob/sound/sound.h
@@ -32,7 +32,7 @@ class GobEngine;
 class PCSpeaker;
 class SoundBlaster;
 class ADLPlayer;
-class MDYPlayer;
+class MUSPlayer;
 class Infogrames;
 class Protracker;
 class CDROM;
@@ -92,7 +92,7 @@ public:
 	bool adlibIsPlaying() const;
 
 	int adlibGetIndex() const;
-	bool adlibGetRepeating() const;
+	int32 adlibGetRepeating() const;
 
 	void adlibSetRepeating(int32 repCount);
 
@@ -145,14 +145,23 @@ private:
 
 	SoundDesc _sounds[kSoundsCount];
 
+	// Speaker
 	PCSpeaker *_pcspeaker;
+
+	// PCM based
 	SoundBlaster *_blaster;
+	BackgroundAtmosphere *_bgatmos;
+
+	// AdLib
+	MUSPlayer *_mdyPlayer;
 	ADLPlayer *_adlPlayer;
-	MDYPlayer *_mdyPlayer;
+
+	// Amiga Paula
 	Infogrames *_infogrames;
 	Protracker *_protracker;
+
+	// Audio CD
 	CDROM *_cdrom;
-	BackgroundAtmosphere *_bgatmos;
 };
 
 } // End of namespace Gob