1 files changed, 99 insertions, 7 deletions
diff --git a/sound/gmidi.h b/sound/gmidi.h
index 9a63151a58..7e9d7e8db5 100644
--- a/sound/gmidi.h
+++ b/sound/gmidi.h
@@ -6,16 +6,108 @@
 #define SPECIAL_CHANNEL 9
 #define DEVICE_NUM 0
 
-/* Sound output type - MIDI */
+struct MidiEvent {
+	uint32 delta;
+	uint32 event;
+};
+
+/* Lowlevel Abstract Midi Driver Class */
+class MidiDriver {
+	
+public:
+	/* called whenever the midi driver is in streaming mode,
+	 * and more midi commands need to be generated
+	 * return 0 to tell the mididriver that the end of stream was reached
+	 */
+	typedef int StreamCallback(void *param, MidiEvent *ev, int num);
+	
+
+	/* open modes, pass one of those to open() */
+	enum {
+		MO_SIMPLE = 1,
+		MO_STREAMING = 2,
+	};
+
+	/* Special events that can be inserted in a MidiEvent.
+	 * event = (ME_xxx<<24) | <24-bit data associated with event>
+	 */
+	enum {
+		ME_NONE  = 0,
+		ME_TEMPO = 1,
+	};
+
+	/* error codes returned by open.
+	 * can be converted to a string with get_error_name()
+	 */
+	enum {
+		MERR_CANNOT_CONNECT = 1,
+		MERR_STREAMING_NOT_AVAILABLE = 2,
+		MERR_DEVICE_NOT_AVAILABLE = 3,
+		MERR_ALREADY_OPEN = 4,
+	};
+
+	enum {
+		PROP_TIMEDIV = 1,
+	};
+
+	
+	/* destroy the midi object */
+	virtual void destroy() = 0;
+
+	/* open the midi driver.
+	 * returns 0 if successful.
+	 * otherwise an error code. */
+	virtual int open(int mode) = 0;
+
+	/* close the midi driver */
+	virtual void close() = 0;
+
+	/* output a packed midi command to the midi stream
+	 * valid only if mode is MO_SIMPLE
+	 */
+	virtual void send(uint32 b) = 0;
+
+	/* set callback when more streams need to be generated.
+	 * valid only when mode==MO_STREAMING
+	 */
+	virtual void set_stream_callback(void *param, StreamCallback *sc) = 0;
+
+	/* Pause or resume streaming MIDI */
+	virtual void pause(bool pause) = 0;
+
+
+	/* Get or set a property */
+	virtual uint32 property(int prop, uint32 param) = 0;
+
+	/* retrieve a string representation of an error code */
+	static const char *get_error_name(int error_code);
+};
+
+
+
+/* driver types */
 enum {
-	MIDI_NULL = 0,
-	MIDI_WINDOWS = 1,
-	MIDI_TIMIDITY = 2,
-	MIDI_SEQ = 3,
-	MIDI_QTMUSIC = 4,
-	MIDI_AMIDI = 5
+	MD_AUTO = 0,
+	MD_NULL = 1,
+	MD_WINDOWS = 2,
+	MD_TIMIDITY = 3,
+	MD_SEQ = 4,
+	MD_QTMUSIC = 5,
+	MD_AMIDI = 6,
 };
 
+
+/* Factory functions => no need to include the specific classes
+ * in this header => faster compile */
+MidiDriver *MidiDriver_NULL_create();
+MidiDriver *MidiDriver_WIN_create();
+MidiDriver *MidiDriver_TIMIDITY_create();
+MidiDriver *MidiDriver_SEQ_create();
+MidiDriver *MidiDriver_QT_create();
+MidiDriver *MidiDriver_AMIDI_create();
+
+
+
 /* Roland to General Midi patch table. Still needs much work. */
 static const byte mt32_to_gmidi[128] = {
   0,   1,   2,   4,   4,   5,   5,   3,  16,  17,  18,  18,  19,