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, 85 insertions, 0 deletions

diff --git a/engines/gob/sound/adlplayer.h b/engines/gob/sound/adlplayer.h
new file mode 100644
index 0000000000..9596447bbc
--- /dev/null
+++ b/engines/gob/sound/adlplayer.h
@@ -0,0 +1,85 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifndef GOB_SOUND_ADLPLAYER_H
+#define GOB_SOUND_ADLPLAYER_H
+
+#include "common/array.h"
+
+#include "gob/sound/adlib.h"
+
+namespace Common {
+	class SeekableReadStream;
+}
+
+namespace Gob {
+
+/** A player for Coktel Vision's ADL music format. */
+class ADLPlayer : public AdLib {
+public:
+	ADLPlayer(Audio::Mixer &mixer);
+	~ADLPlayer();
+
+	bool load(Common::SeekableReadStream &adl);
+	bool load(const byte *data, uint32 dataSize, int index = -1);
+	void unload();
+
+	int getIndex() const;
+
+protected:
+	// AdLib interface
+	uint32 pollMusic(bool first);
+	void rewind();
+
+private:
+	struct Timbre {
+		uint16 startParams[kOperatorsPerVoice * kParamCount];
+		uint16 params[kOperatorsPerVoice * kParamCount];
+	};
+
+	uint8 _soundMode;
+
+	Common::Array<Timbre> _timbres;
+
+	byte  *_songData;
+	uint32 _songDataSize;
+
+	const byte *_playPos;
+
+	int _index;
+
+	uint8  _modifyInstrument;
+	uint16 _currentInstruments[kMaxVoiceCount];
+
+
+	void setInstrument(int voice, int instrument);
+
+	bool readHeader  (Common::SeekableReadStream &adl, int &timbreCount);
+	bool readTimbres (Common::SeekableReadStream &adl, int  timbreCount);
+	bool readSongData(Common::SeekableReadStream &adl);
+
+	uint32 getSampleDelay(uint16 delay) const;
+};
+
+} // End of namespace Gob
+
+#endif // GOB_SOUND_ADLPLAYER_H