Ignore unsupported status bytes and messages to other channels

TeslaMidi/MIDI.c

@@ -3,7 +3,7 @@
  *
  * Created: 19.08.2014 23:32:07
  *  Author: Snorre
- */ 
+ */
 
 #include <inttypes.h>
 
@@ -28,45 +28,61 @@ uint8_t midi_current_byte;
 enum {
 	FREE,
 	NOTE_ON,
-	NOTE_OFF
+	NOTE_OFF,
+	IGNORE
 } midi_state;
 
 void midi_init(uint8_t channel, note_t* notes_struct, midi_channel_t* channel_struct)
 {
 	midi_notes = notes_struct;
 	midi_channel = channel_struct;
-	
+
 	midi_channel->active_notes = 0;
 	midi_channel->channel = channel;
-	
+
 	midi_current_byte = 0;
-	
+
 	for(uint8_t i = 0; i << TESLA_MAX_CHANNELS; i++){
 		midi_notes[i].age = 0;
 		midi_notes[i].change = 0;
 		midi_notes[i].update = 0;
 		midi_notes[i].on = 0;
-				
+
 		midi_notes[i].tesla_channel = i;
 	}
-	
+
 }
 
 uint8_t parse_status( char input ) {
-	if( ( input & MIDI_CHANNEL_MASK ) == midi_channel->channel ) {
-		switch ( input & MIDI_STATUS_MASK ) {
-			case MIDI_note_off_gc:
-				midi_state = NOTE_OFF;
-				midi_current_byte = 0;
-				return 1;
-			
-			case MIDI_note_on_gc:
-				midi_state = NOTE_ON;
-				midi_current_byte = 0;
-				return 1;
-		}
-		
-		// No status
+	// Status byte?
+	if( input & MIDI_STATUS_bm ) {
+
+		// Check that they want to speak to us
+		if( ( input & MIDI_CHANNEL_MASK ) == midi_channel->channel ) {
+      switch ( input & MIDI_STATUS_MASK ) {
+			  case MIDI_note_off_gc:
+			  	midi_state = NOTE_OFF;
+			  	midi_current_byte = 0;
+			  	break;
+
+		  	case MIDI_note_on_gc:
+		  		midi_state = NOTE_ON;
+		  		midi_current_byte = 0;
+		  		break;
+
+        default:
+          // Not supported yet
+          midi_state = IGNORE;
+          midi_current_byte = 0;
+          break;
+		  }
+    }
+
+		// Return 1 cause we intercepted a status byte
+		return 1;
+	}
+	else {
+		// Not a status byte
 		return 0;
 	}
 }
@@ -77,25 +93,26 @@ void parse_midi(char input)
 	switch (midi_state)
 	{
 		case FREE:
+		case IGNORE:
 			//check channel
 			parse_status( input );
 			break;
-		
+
 		case NOTE_ON:
 			// Check for status bytes
 			if( parse_status( input ) ) {
 				break;
 			}
-			
+
 			if (!(input & MIDI_STATUS_bm)){
 				if (midi_current_byte == 1){
 					//store note
 					midi_buffer[midi_current_byte++] = input;
-					
+
 				} else if (midi_current_byte == 2) {
 					//store velocity
 					midi_buffer[midi_current_byte++] = input;
-					
+
 					// Zero-velocity input == NOTE_OFF
 					if( input == 0 ) {
 						midi_clear_note( midi_buffer[0], 127 ); // Release with full force
@@ -104,7 +121,7 @@ void parse_midi(char input)
 						//find free channel & update
 						midi_add_note(midi_buffer[0],midi_buffer[1]);
 					}
-					
+
 					// Get ready for next note
 					midi_current_byte = 0;
 				} else {
@@ -113,25 +130,25 @@ void parse_midi(char input)
 			} else {
 				//evaluate if single-byte-interrupting package, else abort
 			}
-		break;
-		
+			break;
+
 		case NOTE_OFF:
 			// Check for status bytes
 			if( parse_status( input ) ) {
 				break;
 			}
-			
+
 			if (!(input & MIDI_STATUS_bm)){
 				if (midi_current_byte == 1){
 					//store note
 					midi_buffer[midi_current_byte++] = input;
-					
+
 				} else if (midi_current_byte == 2) {
 					//store velocity
 					midi_buffer[midi_current_byte++] = input;
-	
+
 					midi_clear_note(midi_buffer[0],midi_buffer[1]);
-					
+
 					// Get ready for next note
 					midi_current_byte = 0;
 				} else {
@@ -139,20 +156,23 @@ void parse_midi(char input)
 				}
 			} else {
 				//check for interrupting frame, panic otherwise
-					
+
 			}
-				
-		break;
-		
+
+			break;
+
+		default:
+			// WTF? Unknown state
+			tesla_panic();
 	}
-	
+
 }
 
 
 
 void midi_add_note(uint8_t note, uint8_t velocity){
 	uint8_t n, result = 0, max_age = 0;
-	
+
 	//check if note already is on
 	for (n = 0; n < TESLA_MAX_CHANNELS; n++){
 		if ((midi_notes[n].note == note) && (midi_notes[n].on)){
@@ -161,7 +181,7 @@ void midi_add_note(uint8_t note, uint8_t velocity){
 			return;
 		}
 	}
-	
+
 	//find free channel
 	for (n = 0; n < TESLA_MAX_CHANNELS; n++){
 		if (!(midi_notes[n].on)){
@@ -172,24 +192,24 @@ void midi_add_note(uint8_t note, uint8_t velocity){
 			return;
 		}
 	}
-	
+
 	//if no free channels, find oldest note and overwrite
 	for (n = 0; n < TESLA_MAX_CHANNELS; n++){
 		if (midi_notes[n].age > max_age){
 			result = n;
 			max_age = midi_notes[n].age;
-		}	
+		}
 	}
 	midi_notes[result].on = 1;
 	midi_notes[result].note = note;
 	midi_notes[result].velocity = velocity;
 	midi_notes[result].change = 1;
-	
+
 }
 
 void midi_clear_note(uint8_t note, uint8_t velocity){
 	uint8_t n;
-		
+
 	//find note
 	for (n = 0; n < TESLA_MAX_CHANNELS; n++){
 		if ((midi_notes[n].note == note) && (midi_notes[n].on)){
@@ -199,5 +219,5 @@ void midi_clear_note(uint8_t note, uint8_t velocity){
 			return;
 		}
 	}
-	
-}
\ No newline at end of file
+
+}