Implement EPN transmission for the winmidi backend

5 files changed, 88 insertions, 28 deletions

diff --git a/backends/midi.c b/backends/midi.c
index 8a8887a..d581a01 100644
--- a/backends/midi.c
+++ b/backends/midi.c
@@ -109,7 +109,7 @@ static int midi_configure_instance(instance* inst, char* option, char* value){
 		return 0;
 	}
 
-	LOGPF("Unknown instance option %s", option);
+	LOGPF("Unknown instance configuration option %s on instance %s", option, inst->name);
 	return 1;
 }
 
@@ -227,10 +227,10 @@ static int midi_set(instance* inst, size_t num, channel** c, channel_value* v){
 			case rpn:
 			case nrpn:
 				//transmit parameter number
-				midi_tx(data->port, cc, ident.fields.channel, (ident.fields.type == rpn) ? 101 : 99, (ident.fields.control & 0x3F80) >> 7);
+				midi_tx(data->port, cc, ident.fields.channel, (ident.fields.type == rpn) ? 101 : 99, (ident.fields.control >> 7) & 0x7F);
 				midi_tx(data->port, cc, ident.fields.channel, (ident.fields.type == rpn) ? 100 : 98, ident.fields.control & 0x7F);
 				//transmit parameter value
-				midi_tx(data->port, cc, ident.fields.channel, 6, (((uint16_t) (v[u].normalised * 16383.0)) & 0x3F80) >> 7);
+				midi_tx(data->port, cc, ident.fields.channel, 6, (((uint16_t) (v[u].normalised * 16383.0)) >> 7) & 0x7F);
 				midi_tx(data->port, cc, ident.fields.channel, 38, ((uint16_t) (v[u].normalised * 16383.0)) & 0x7F);
 
 				if(!data->epn_tx_short){
diff --git a/backends/midi.md b/backends/midi.md
index 3ac011e..4732452 100644
--- a/backends/midi.md
+++ b/backends/midi.md
@@ -31,8 +31,8 @@ The MIDI backend supports mapping different MIDI events to MIDIMonster channels.
 * `pressure` - Note pressure/aftertouch messages
 * `aftertouch` - Channel-wide aftertouch messages
 * `pitch` - Channel pitchbend messages
-* `rpn` - Registered parameter numbers (14bit extension)
-* `nrpn` - Non-registered parameter numbers (14bit extension)
+* `rpn` - Registered parameter numbers (14-bit extension)
+* `nrpn` - Non-registered parameter numbers (14-bit extension)
 
 A MIDIMonster channel is specified using the syntax `channel<channel>.<type><index>`. The shorthand `ch` may be
 used instead of the word `channel` (Note that `channel` here refers to the MIDI channel number).
@@ -43,7 +43,7 @@ MIDI channels range from `0` to `15`. Each MIDI channel consists of 128 notes (n
 additionally each have a pressure control, 128 CC's (numbered likewise), a channel pressure control (also called
 'channel aftertouch') and a pitch control which may all be mapped to individual MIDIMonster channels.
 
-Every channel also provides `rpn` and `nrpn` controls, which are implemented on top of the MIDI protocol, using
+Every MIDI channel also provides `rpn` and `nrpn` controls, which are implemented on top of the MIDI protocol, using
 the CC controls 101/100/99/98/38/6. Both control types have 14-bit IDs and 14-bit values.
 
 Example mappings:
diff --git a/backends/winmidi.c b/backends/winmidi.c
index 030062d..c89a098 100644
--- a/backends/winmidi.c
+++ b/backends/winmidi.c
@@ -82,7 +82,7 @@ static int winmidi_configure_instance(instance* inst, char* option, char* value)
 		data->read = strdup(value);
 		return 0;
 	}
-	if(!strcmp(option, "write")){
+	else if(!strcmp(option, "write")){
 		if(data->write){
 			LOGPF("Instance %s already connected to an output device", inst->name);
 			return 1;
@@ -90,6 +90,13 @@ static int winmidi_configure_instance(instance* inst, char* option, char* value)
 		data->write = strdup(value);
 		return 0;
 	}
+	else if(!strcmp(option, "epn-tx")){
+		data->epn_tx_short = 0;
+		if(!strcmp(value, "short")){
+			data->epn_tx_short = 1;
+		}
+		return 0;
+	}
 
 	LOGPF("Unknown instance configuration option %s on instance %s", option, inst->name);
 	return 1;
@@ -148,6 +155,14 @@ static channel* winmidi_channel(instance* inst, char* spec, uint8_t flags){
 		ident.fields.type = pressure;
 		next_token += 8;
 	}
+	else if(!strncmp(next_token, "rpn", 3)){
+		ident.fields.type = rpn;
+		next_token += 3;
+	}
+	else if(!strncmp(next_token, "nrpn", 4)){
+		ident.fields.type = nrpn;
+		next_token += 4;
+	}
 	else if(!strncmp(next_token, "pitch", 5)){
 		ident.fields.type = pitchbend;
 	}
@@ -167,11 +182,7 @@ static channel* winmidi_channel(instance* inst, char* spec, uint8_t flags){
 	return NULL;
 }
 
-static int winmidi_set(instance* inst, size_t num, channel** c, channel_value* v){
-	winmidi_instance_data* data = (winmidi_instance_data*) inst->impl;
-	winmidi_channel_ident ident = {
-		.label = 0
-	};
+static void winmidi_tx(HMIDIOUT port, uint8_t type, uint8_t channel, uint8_t control, uint16_t value){
 	union {
 		struct {
 			uint8_t status;
@@ -183,6 +194,28 @@ static int winmidi_set(instance* inst, size_t num, channel** c, channel_value* v
 	} output = {
 		.dword = 0
 	};
+
+	output.components.status = type | channel;
+	output.components.data1 = control;
+	output.components.data2 = value;
+
+	if(type == pitchbend){
+		output.components.data1 = value & 0x7F;
+		output.components.data2 = (value >> 7) & 0x7F;
+	}
+	else if(type == aftertouch){
+		output.components.data1 = value;
+		output.components.data2 = 0;
+	}
+
+	midiOutShortMsg(port, output.dword);
+}
+
+static int winmidi_set(instance* inst, size_t num, channel** c, channel_value* v){
+	winmidi_instance_data* data = (winmidi_instance_data*) inst->impl;
+	winmidi_channel_ident ident = {
+		.label = 0
+	};
 	size_t u;
 
 	if(!data->device_out){
@@ -193,20 +226,29 @@ static int winmidi_set(instance* inst, size_t num, channel** c, channel_value* v
 	for(u = 0; u < num; u++){
 		ident.label = c[u]->ident;
 
-		//build output message
-		output.components.status = ident.fields.type | ident.fields.channel;
-		output.components.data1 = ident.fields.control;
-		output.components.data2 = v[u].normalised * 127.0;
-		if(ident.fields.type == pitchbend){
-			output.components.data1 = ((int)(v[u].normalised * 16384.0)) & 0x7F;
-			output.components.data2 = (((int)(v[u].normalised * 16384.0)) >> 7) & 0x7F;
-		}
-		else if(ident.fields.type == aftertouch){
-			output.components.data1 = v[u].normalised * 127.0;
-			output.components.data2 = 0;
+		switch(ident.fields.type){
+			case rpn:
+			case nrpn:
+				//transmit parameter number
+				winmidi_tx(data->device_out, cc, ident.fields.channel, (ident.fields.type == rpn) ? 101 : 99, (ident.fields.control >> 7) & 0x7F);
+				winmidi_tx(data->device_out, cc, ident.fields.channel, (ident.fields.type == rpn) ? 100 : 98, ident.fields.control & 0x7F);
+
+				//transmit parameter value
+				winmidi_tx(data->device_out, cc, ident.fields.channel, 6, (((uint16_t) (v[u].normalised * 16383.0)) >> 7) & 0x7F);
+				winmidi_tx(data->device_out, cc, ident.fields.channel, 38, ((uint16_t) (v[u].normalised * 16383.0)) & 0x7F);
+
+				if(!data->epn_tx_short){
+					//clear active parameter
+					winmidi_tx(data->device_out, cc, ident.fields.channel, 101, 127);
+					winmidi_tx(data->device_out, cc, ident.fields.channel, 100, 127);
+				}
+				break;
+			case pitchbend:
+				winmidi_tx(data->device_out, ident.fields.type, ident.fields.channel, ident.fields.control, v[u].normalised * 16383.0);
+				break;
+			default:
+				winmidi_tx(data->device_out, ident.fields.type, ident.fields.channel, ident.fields.control, v[u].normalised * 127.0);
 		}
-
-		midiOutShortMsg(data->device_out, output.dword);
 	}
 
 	return 0;
@@ -218,6 +260,10 @@ static char* winmidi_type_name(uint8_t typecode){
 			return "note";
 		case cc:
 			return "cc";
+		case rpn:
+			return "rpn";
+		case nrpn:
+			return "nrpn";
 		case pressure:
 			return "pressure";
 		case aftertouch:
@@ -295,6 +341,7 @@ static void CALLBACK winmidi_input_callback(HMIDIIN device, unsigned message, DW
 	//callbacks may run on different threads, so we queue all events and alert the main thread via the feedback socket
 	DBGPF("Input callback on thread %ld", GetCurrentThreadId());
 
+	//TODO handle (n)rpn RX
 	switch(message){
 		case MIM_MOREDATA:
 			//processing too slow, do not immediately alert the main loop
diff --git a/backends/winmidi.h b/backends/winmidi.h
index 4c740ea..fbb2c94 100644
--- a/backends/winmidi.h
+++ b/backends/winmidi.h
@@ -13,6 +13,7 @@ static int winmidi_shutdown(size_t n, instance** inst);
 typedef struct /*_winmidi_instance_data*/ {
 	char* read;
 	char* write;
+	uint8_t epn_tx_short;
 	HMIDIIN device_in;
 	HMIDIOUT device_out;
 } winmidi_instance_data;
@@ -23,15 +24,17 @@ enum /*_winmidi_channel_type*/ {
 	cc = 0xB0,
 	pressure = 0xA0,
 	aftertouch = 0xD0,
-	pitchbend = 0xE0
+	pitchbend = 0xE0,
+	rpn = 0xF0,
+	nrpn = 0xF1
 };
 
 typedef union {
 	struct {
-		uint8_t pad[5];
+		uint8_t pad[4];
 		uint8_t type;
 		uint8_t channel;
-		uint8_t control;
+		uint16_t control;
 	} fields;
 	uint64_t label;
 } winmidi_channel_ident;
diff --git a/backends/winmidi.md b/backends/winmidi.md
index 25a6378..6b0fa98 100644
--- a/backends/winmidi.md
+++ b/backends/winmidi.md
@@ -19,6 +19,7 @@ some deviations may still be present.
 |---------------|-----------------------|-----------------------|-----------------------|
 | `read`	| `2`			| none			| MIDI device to connect for input |
 | `write`	| `DeviceName`		| none			| MIDI device to connect for output |
+| `epn-tx`	| `short`		| `full`		| Configure whether to clear the active parameter number after transmitting an `nrpn` or `rpn` parameter. |
 
 Input/output device names may either be prefixes of MIDI device names or numeric indices corresponding
 to the listing shown at startup when using the global `list` option.
@@ -32,6 +33,8 @@ The `winmidi` backend supports mapping different MIDI events as MIDIMonster chan
 * `pressure` - Note pressure/aftertouch messages
 * `aftertouch` - Channel-wide aftertouch messages
 * `pitch` - Channel pitchbend messages
+* `rpn` - Registered parameter numbers (14-bit extension)
+* `nrpn` - Non-registered parameter numbers (14-bit extension)
 
 A MIDIMonster channel is specified using the syntax `channel<channel>.<type><index>`. The shorthand `ch` may be
 used instead of the word `channel` (Note that `channel` here refers to the MIDI channel number).
@@ -42,16 +45,23 @@ MIDI channels range from `0` to `15`. Each MIDI channel consists of 128 notes (n
 additionally each have a pressure control, 128 CC's (numbered likewise), a channel pressure control (also called
 'channel aftertouch') and a pitch control which may all be mapped to individual MIDIMonster channels.
 
+Every MIDI channel also provides `rpn` and `nrpn` controls, which are implemented on top of the MIDI protocol, using
+the CC controls 101/100/99/98/38/6. Both control types have 14-bit IDs and 14-bit values.
+
 Example mappings:
 ```
 midi1.ch0.note9 > midi2.channel1.cc4
 midi1.channel15.pressure1 > midi1.channel0.note0
 midi1.ch1.aftertouch > midi2.ch2.cc0
 midi1.ch0.pitch > midi2.ch1.pitch
+midi2.ch0.nrpn900 > midi1.ch1.rpn1
 ```
 
 #### Known bugs / problems
 
+Extended parameter numbers (`rpn` and `nrpn` control types) can currently only be transmitted, not properly
+received as such. Support for this functionality is planned.
+
 Currently, no Note Off messages are sent (instead, Note On messages with a velocity of 0 are
 generated, which amount to the same thing according to the spec). This may be implemented as
 a configuration option at a later time.