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engines/ultima/nuvie/sound/mididrv_m_mt32.h

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+/* 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 3 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef NUVIE_SOUND_MIDIDRV_M_MT32_H
+#define NUVIE_SOUND_MIDIDRV_M_MT32_H
+
+#include "audio/mt32gm.h"
+
+namespace Ultima {
+namespace Nuvie {
+
+// An assignment of a MIDI instrument to a MIDI output channel. M data channels
+// using this instrument will be mapped to the specified MIDI channel.
+struct MInstrumentAssignment {
+	int8 midiChannel;
+	uint8 midiInstrument;
+};
+
+/**
+ * M driver for the Roland MT-32.
+ * The M format is focused on OPL2 and conversion to MIDI is rudimentary. Only
+ * note on/off, channel volume (using note velocity) and program change are
+ * implemented by the original driver.
+ * A mapping of M instruments to MIDI instruments must be set using
+ * setInstrumentAssignments before starting playback of a track.
+ */
+class MidiDriver_M_MT32 : public MidiDriver_MT32GM {
+protected:
+	/**
+	 * Playback status information for an M channel.
+	 * Note that although this data applies to an M data channel, the values
+	 * are MIDI note and velocity values.
+	 */
+	struct MChannelData {
+		// The MIDI note currently played on this channel.
+		int8 activeNote = -1;
+		// The MIDI note velocity currently used on this channel.
+		uint8 velocity = 0;
+		// The MIDI note queued for playback on this channel.
+		int8 queuedNote = -1;
+	};
+
+	// Converts M note values to MIDI notes.
+	static const uint8 MIDI_NOTE_MAP[24];
+
+public:
+	MidiDriver_M_MT32();
+	~MidiDriver_M_MT32();
+
+	using MidiDriver_MT32GM::open;
+	int open(MidiDriver *driver, bool nativeMT32) override;
+
+	using MidiDriver_MT32GM::send;
+	void send(int8 source, uint32 b) override;
+	void metaEvent(int8 source, byte type, const byte *data, uint16 length) override;
+
+	/**
+	 * Sets the assignments of the 16 M instruments to the MIDI instruments and
+	 * MIDI output channels they should use.
+	 * 
+	 * @param assignments An instrument assignment array of length 16
+	 */
+	void setInstrumentAssignments(const MInstrumentAssignment *assignments);
+
+	void stopAllNotes(bool stopSustainedNotes) override;
+
+protected:
+	void onTimer() override;
+
+	MChannelData _mChannelData[9];
+	// Mapping of M instrument numbers to MIDI output channels
+	int8 _mInstrumentMidiChannels[16];
+	// Mapping of M instrument numbers to MIDI instrument numbers
+	uint8 _mInstrumentMapping[16];
+};
+
+} // End of namespace Nuvie
+} // End of namespace Ultima
+
+#endif