beginning of midi + fixes

TODO

@@ -12,3 +12,4 @@
 * #if > 0 -> dotjs
 * more mappings, lv2 port props
 * latency mechanism, see https://steinbergmedia.github.io/vst3_dev_portal/pages/Technical+Documentation/Workflow+Diagrams/Get+Latency+Call+Sequence.html, https://steinbergmedia.github.io/vst3_doc/vstinterfaces/classSteinberg_1_1Vst_1_1IAudioProcessor.html#af8884671ccefe68e0a86e72413a0fcf8, https://steinbergmedia.github.io/vst3_dev_portal/pages/Technical+Documentation/Workflow+Diagrams/Audio+Processor+Call+Sequence.html
+* vst3 don't include/link libm if not needed, etc. (reduce to minimum reqs)

notes

@@ -86,7 +86,7 @@ product {
 				LV2: manifest.ttl lv2:port units:unit
 			map:
 				"linear" vs "logarithmic"
-				VST3:
+				VST3: many places (requires libm)
 				LV2: manifest.ttl lv2:port lv2:portProperty pprops:logarithmic
 		}
 	]

templates/lv2/data/manifest.ttl

@@ -54,7 +54,7 @@
 		lv2:portProperty lv2:integer ;
 		lv2:portProperty lv2:reportsLatency ;
 {{??}}
-		a {{?p.type == "control"}}lv2:ControlPort{{??}}{{?p.cv}}lv2:CVPort{{??}}lv2:AudioPort{{?}}{{?}} ,
+		a {{?p.type == "control"}}lv2:ControlPort{{??p.type == "midi"}}atom:AtomPort{{??}}{{?p.cv}}lv2:CVPort{{??}}lv2:AudioPort{{?}}{{?}} ,
 			{{?p.direction == "input"}}lv2:InputPort{{??}}lv2:OutputPort{{?}} ;
 		lv2:name "{{=p.name}}" ;
 {{?"shortName" in p}}
@@ -65,10 +65,16 @@
 		lv2:minimum {{=p.minimum.toExponential()}} ;
 		lv2:maximum {{=p.maximum.toExponential()}} ;
 		lv2:default {{=p.defaultValue.toExponential()}} ;
+{{??p.type == "midi"}}
+		atom:bufferType atom:Sequence ;
+		atom:supports midi:MidiEvent ;
 {{?}}
 {{?p.sidechain}}
 		lv2:portProperty lv2:isSideChain ;
 {{?}}
+{{?p.control}}
+		lv2:designation lv2:control ;
+{{?}}
 {{?p.toggled}}
 		lv2:portProperty lv2:toggled ;
 {{?}}

templates/lv2/src/data.h

@@ -2,6 +2,8 @@
 
 #define DATA_PRODUCT_AUDIO_INPUT_CHANNELS_N	{{=it.product.buses.filter(x => x.type == "audio" && x.direction == "input").reduce((s, x) => s += x.channels == "mono" ? 1 : 2, 0)}}
 #define DATA_PRODUCT_AUDIO_OUTPUT_CHANNELS_N	{{=it.product.buses.filter(x => x.type == "audio" && x.direction == "output").reduce((s, x) => s += x.channels == "mono" ? 1 : 2, 0)}}
+#define DATA_PRODUCT_MIDI_INPUTS_N		{{=it.product.buses.filter(x => x.type == "midi" && x.direction == "input").length}}
+#define DATA_PRODUCT_MIDI_OUTPUTS_N		{{=it.product.buses.filter(x => x.type == "midi" && x.direction == "output").length}}
 #define DATA_PRODUCT_CONTROL_INPUTS_N		{{=it.product.parameters.filter(x => x.direction == "input").length}}
 #define DATA_PRODUCT_CONTROL_OUTPUTS_N		{{=it.product.parameters.filter(x => x.direction == "output").length}}
 

templates/lv2/src/lv2.c

@@ -73,6 +73,20 @@ static void connect_port(LV2_Handle instance, uint32_t port, void * data_locatio
 	}
 	port -= DATA_PRODUCT_AUDIO_OUTPUT_CHANNELS_N;
 #endif
+#if DATA_PRODUCT_MIDI_INPUTS_N > 0
+	if (port < DATA_PRODUCT_MIDI_INPUTS_N) {
+		// TBD
+		return;
+	}
+	port -= DATA_PRODUCT_MIDI_INPUTS_N;
+#endif
+#if DATA_PRODUCT_MIDI_OUTPUTS_N > 0
+	if (port < DATA_PRODUCT_MIDI_OUTPUTS_N) {
+		// TBD
+		return;
+	}
+	port -= DATA_PRODUCT_MIDI_OUTPUTS_N;
+#endif
 #if (DATA_PRODUCT_CONTROL_INPUTS_N + DATA_PRODUCT_CONTROL_OUTPUTS_N) > 0
 	i->c[port] = data_location;
 #endif

templates/lv2/tibia-index.js

@@ -4,9 +4,11 @@ var sep = path.sep;
 module.exports = function (data, api) {
 	data.tibia.lv2 = {
 		prefixes: [
+			{ id: "atom",	uri: "http://lv2plug.in/ns/ext/atom#" },
 			{ id: "doap",	uri: "http://usefulinc.com/ns/doap#" },
 			{ id: "foaf",	uri: "http://xmlns.com/foaf/0.1/" },
 			{ id: "lv2",	uri: "http://lv2plug.in/ns/lv2core#" },
+			{ id: "midi",	uri: "http://lv2plug.in/ns/ext/midi#" },
 			{ id: "pprops",	uri: "http://lv2plug.in/ns/ext/port-props#" },
 			{ id: "rdf",	uri: "http://www.w3.org/1999/02/22-rdf-syntax-ns#" },
 			{ id: "rdfs",	uri: "http://www.w3.org/2000/01/rdf-schema#" },
@@ -56,33 +58,49 @@ module.exports = function (data, api) {
 	for (var id in data.lv2.prefixes)
 		data.tibia.lv2.prefixes.push({ id: id, uri: data.lv2.prefixes[id] });
 
+	var audioBuses = data.product.buses.filter(x => x.type == "audio");
+	var ports = [];
+	var bi = 0;
+	for (; bi < audioBuses.length; bi++) {
+		var b = audioBuses[bi];
+		if (b.channels == "mono") {
+			var e = { type: "audio", direction: b.direction, name: b.name, sidechain: b.sidechain, cv: b.cv, optional: b.optional };
+			e.symbol = data.lv2.busSymbols[bi];
+			ports.push(e);
+		} else {
+			var e = { type: "audio", direction: b.direction, name: b.name + " Left", shortName: b.shortName + " L", sidechain: b.sidechain, cv: b.cv };
+			e.symbol = data.lv2.busSymbols[bi] + "_L";
+			data.tibia.lv2.ports.push(e);
+			var e = { type: "audio", direction: b.direction, name: b.name + " Right", shortName: b.shortName + " R", sidechain: b.sidechain, cv: b.cv };
+			e.symbol = data.lv2.busSymbols[bi] + "_R";
+			ports.push(e);
+		}
+	}
+	ports.sort((a, b) => a.direction != b.direction ? (a.direction == "input" ? -1 : 1) : 0);
+	data.tibia.lv2.ports.push.apply(data.tibia.lv2.ports, ports);
+
+	var midiBuses = data.product.buses.filter(x => x.type == "midi");
+	var ports = [];
+	for (var i = 0; i < midiBuses.length; i++, bi++) {
+		var b = midiBuses[i];
+		var e = { type: "midi", direction: b.direction, name: b.name, sidechain: b.sidechain, control: b.control, optional: b.optional };
+		e.symbol = data.lv2.busSymbols[bi];
+		ports.push(e);
+	}
+	ports.sort((a, b) => a.direction != b.direction ? (a.direction == "input" ? -1 : 1) : 0);
+	data.tibia.lv2.ports.push.apply(data.tibia.lv2.ports, ports);
+
+	var ports = [];
 	for (var i = 0; i < data.product.parameters.length; i++) {
 		var p = data.product.parameters[i];
 		var e = Object.create(p);
 		e.type = "control";
 		e.symbol = data.lv2.parameterSymbols[i];
 		e.paramIndex = i;
-		data.tibia.lv2.ports.push(e);
+		ports.push(e);
 	}
-
+	ports.sort((a, b) => a.direction != b.direction ? (a.direction == "input" ? -1 : 1) : 0);
-	var audioBuses = data.product.buses.filter(x => x.type == "audio");
+	data.tibia.lv2.ports.push.apply(data.tibia.lv2.ports, ports);
-	for (var i = 0; i < audioBuses.length; i++) {
-		var b = audioBuses[i];
-		if (b.channels == "mono") {
-			var e = { type: "audio", direction: b.direction, name: b.name, sidechain: b.sidechain, cv: b.cv };
-			e.symbol = data.lv2.busSymbols[i];
-			data.tibia.lv2.ports.push(e);
-		} else {
-			var e = { type: "audio", direction: b.direction, name: b.name + " Left", shortName: b.shortName + " L", sidechain: b.sidechain, cv: b.cv };
-			e.symbol = data.lv2.busSymbols[i] + "_L";
-			data.tibia.lv2.ports.push(e);
-			var e = { type: "audio", direction: b.direction, name: b.name + " Right", shortName: b.shortName + " R", sidechain: b.sidechain, cv: b.cv };
-			e.symbol = data.lv2.busSymbols[i] + "_R";
-			data.tibia.lv2.ports.push(e);
-		}
-	}
-
-	data.tibia.lv2.ports.sort((a, b) => a.type != b.type ? (a.type == "audio" ? -1 : 1) : (a.direction != b.direction ? (a.direction == "input" ? -1 : 1) : 0));
 
 	api.generateFileFromTemplateFile(`data${sep}manifest.ttl`, `data${sep}manifest.ttl`, data);
 	api.copyFile(`src${sep}lv2.c`, `src${sep}lv2.c`);

templates/vst3/src/data.h

@@ -30,8 +30,8 @@ static const Steinberg_TUID dataControllerCID = SMTG_INLINE_UID(DATA_VST3_CONTRO
 
 #define DATA_PRODUCT_BUSES_AUDIO_INPUT_N	{{=it.product.buses.filter(x => x.type == "audio" && x.direction == "input").length}}
 #define DATA_PRODUCT_BUSES_AUDIO_OUTPUT_N	{{=it.product.buses.filter(x => x.type == "audio" && x.direction == "output").length}}
-#define DATA_PRODUCT_BUSES_EVENT_INPUT_N	{{=it.product.buses.filter(x => x.type == "event" && x.direction == "input").length}}
+#define DATA_PRODUCT_BUSES_MIDI_INPUT_N		{{=it.product.buses.filter(x => x.type == "midi" && x.direction == "input").length}}
-#define DATA_PRODUCT_BUSES_EVENT_OUTPUT_N	{{=it.product.buses.filter(x => x.type == "event" && x.direction == "output").length}}
+#define DATA_PRODUCT_BUSES_MIDI_OUTPUT_N	{{=it.product.buses.filter(x => x.type == "midi" && x.direction == "output").length}}
 
 #define DATA_PRODUCT_CHANNELS_AUDIO_INPUT_N	{{=it.product.buses.filter(x => x.type == "audio" && x.direction == "input").reduce((a, x) => a + (x.channels == "mono" ? 1 : 2), 0)}}
 #define DATA_PRODUCT_CHANNELS_AUDIO_OUTPUT_N	{{=it.product.buses.filter(x => x.type == "audio" && x.direction == "output").reduce((a, x) => a + (x.channels == "mono" ? 1 : 2), 0)}}
@@ -66,30 +66,30 @@ static struct Steinberg_Vst_BusInfo busInfoAudioOutput[DATA_PRODUCT_BUSES_AUDIO_
 };
 #endif
 
-#if DATA_PRODUCT_BUSES_EVENT_INPUT_N > 0
+#if DATA_PRODUCT_BUSES_MIDI_INPUT_N > 0
-static struct Steinberg_Vst_BusInfo busInfoEventInput[DATA_PRODUCT_BUSES_EVENT_INPUT_N] = {
+static struct Steinberg_Vst_BusInfo busInfoMidiInput[DATA_PRODUCT_BUSES_MIDI_INPUT_N] = {
-{{~it.product.buses.filter(x => x.type == "event" && x.direction == "input") :b}}
+{{~it.product.buses.filter(x => x.type == "midi" && x.direction == "input") :b}}
 	{
 		/* .mediaType		= */ Steinberg_Vst_MediaTypes_kEvent,
 		/* .direction		= */ Steinberg_Vst_BusDirections_kInput,
-		/* .channelCount	= */ 1,
+		/* .channelCount	= */ 16,
 		/* .name		= */ { {{~Array.from(b.name) :c}}0x{{=c.charCodeAt(0).toString(16)}}, {{~}}0 },
-		/* .busType		= */ Steinberg_Vst_BusTypes_kMain,
+		/* .busType		= */ {{?b.sidechain}}Steinberg_Vst_BusTypes_kAux{{??}}Steinberg_Vst_BusTypes_kMain{{?}},
 		/* .flags		= */ 0{{?!b.optional}} | Steinberg_Vst_BusInfo_BusFlags_kDefaultActive{{?}}
 	},
 {{~}}
 };
 #endif
 
-#if DATA_PRODUCT_BUSES_EVENT_OUTPUT_N > 0
+#if DATA_PRODUCT_BUSES_MIDI_OUTPUT_N > 0
-static struct Steinberg_Vst_BusInfo busInfoAudioInput[DATA_PRODUCT_BUSES_EVENT_OUTPUT_N] = {
+static struct Steinberg_Vst_BusInfo busInfoMidiOutput[DATA_PRODUCT_BUSES_MIDI_OUTPUT_N] = {
-{{~it.product.buses.filter(x => x.type == "event" && x.direction == "output") :b}}
+{{~it.product.buses.filter(x => x.type == "midi" && x.direction == "output") :b}}
 	{
 		/* .mediaType		= */ Steinberg_Vst_MediaTypes_kEvent,
 		/* .direction		= */ Steinberg_Vst_BusDirections_kOutput,
-		/* .channelCount	= */ 1,
+		/* .channelCount	= */ 16,
 		/* .name		= */ { {{~Array.from(b.name) :c}}0x{{=c.charCodeAt(0).toString(16)}}, {{~}}0 },
-		/* .busType		= */ Steinberg_Vst_BusTypes_kMain,
+		/* .busType		= */ {{?b.sidechain}}Steinberg_Vst_BusTypes_kAux{{??}}Steinberg_Vst_BusTypes_kMain{{?}},
 		/* .flags		= */ 0{{?!b.optional}} | Steinberg_Vst_BusInfo_BusFlags_kDefaultActive{{?}}
 	},
 {{~}}
@@ -98,8 +98,8 @@ static struct Steinberg_Vst_BusInfo busInfoAudioInput[DATA_PRODUCT_BUSES_EVENT_O
 
 #define DATA_PRODUCT_PARAMETERS_N		{{=it.product.parameters.filter(x => !x.isLatency).length}}
 
-#if DATA_PRODUCT_PARAMETERS_N > 0
+#if DATA_PRODUCT_PARAMETERS_N + DATA_PRODUCT_BUSES_MIDI_INPUT_N + DATA_PRODUCT_BUSES_MIDI_OUTPUT_N > 0
-static struct Steinberg_Vst_ParameterInfo parameterInfo[DATA_PRODUCT_PARAMETERS_N] = {
+static struct Steinberg_Vst_ParameterInfo parameterInfo[DATA_PRODUCT_PARAMETERS_N + 2 * (DATA_PRODUCT_BUSES_MIDI_INPUT_N + DATA_PRODUCT_BUSES_MIDI_OUTPUT_N)] = {
 {{~it.product.parameters.filter(x => !x.isLatency) :p:i}}
 	{
 		/* .id				= */ {{=i}},
@@ -122,6 +122,50 @@ static struct Steinberg_Vst_ParameterInfo parameterInfo[DATA_PRODUCT_PARAMETERS_
 {{?}}
 	},
 {{~}}
+{{~it.product.buses.filter(x => x.type == "midi" && x.direction == "input") :b:i}}
+	{
+		/* .id				= */ {{=it.product.parameters.filter(x => !x.isLatency).length + 2 * i}},
+		/* .title			= */ { {{~Array.from(b.name + " CP") :c}}0x{{=c.charCodeAt(0).toString(16)}}, {{~}}0 },
+		/* .shortTitle			= */ { {{~Array.from(b.shortName + " CP") :c}}0x{{=c.charCodeAt(0).toString(16)}}, {{~}}0 },
+		/* .units			= */ { 0 },
+		/* .stepCount			= */ 0,
+		/* .defaultNormalizedValue	= */ 0.0,
+		/* .unitId			= */ 0,
+		/* .flags			= */ Steinberg_Vst_ParameterInfo_ParameterFlags_kIsHidden | Steinberg_Vst_ParameterInfo_ParameterFlags_kIsReadOnly
+	},
+	{
+		/* .id				= */ {{=it.product.parameters.filter(x => !x.isLatency).length + 2 * i + 1}},
+		/* .title			= */ { {{~Array.from(b.name + " PB") :c}}0x{{=c.charCodeAt(0).toString(16)}}, {{~}}0 },
+		/* .shortTitle			= */ { {{~Array.from(b.shortName + " PB") :c}}0x{{=c.charCodeAt(0).toString(16)}}, {{~}}0 },
+		/* .units			= */ { 0 },
+		/* .stepCount			= */ 0,
+		/* .defaultNormalizedValue	= */ 0.0,
+		/* .unitId			= */ 0,
+		/* .flags			= */ Steinberg_Vst_ParameterInfo_ParameterFlags_kIsHidden | Steinberg_Vst_ParameterInfo_ParameterFlags_kIsReadOnly
+	},
+{{~}}
+{{~it.product.buses.filter(x => x.type == "midi" && x.direction == "output") :b:i}}
+	{
+		/* .id				= */ {{=it.product.parameters.filter(x => !x.isLatency).length + 2 * it.product.buses.filter(x => x.type == "midi" && x.direction == "input").length + 2 * i}},
+		/* .title			= */ { {{~Array.from(b.name + " CP") :c}}0x{{=c.charCodeAt(0).toString(16)}}, {{~}}0 },
+		/* .shortTitle			= */ { {{~Array.from(b.shortName + " CP") :c}}0x{{=c.charCodeAt(0).toString(16)}}, {{~}}0 },
+		/* .units			= */ { 0 },
+		/* .stepCount			= */ 0,
+		/* .defaultNormalizedValue	= */ 0.0,
+		/* .unitId			= */ 0,
+		/* .flags			= */ Steinberg_Vst_ParameterInfo_ParameterFlags_kIsHidden | Steinberg_Vst_ParameterInfo_ParameterFlags_kIsReadOnly
+	},
+	{
+		/* .id				= */ {{=it.product.parameters.filter(x => !x.isLatency).length + 2 * it.product.buses.filter(x => x.type == "midi" && x.direction == "input").length + 2 * i + 1}},
+		/* .title			= */ { {{~Array.from(b.name + " PB") :c}}0x{{=c.charCodeAt(0).toString(16)}}, {{~}}0 },
+		/* .shortTitle			= */ { {{~Array.from(b.shortName + " PB") :c}}0x{{=c.charCodeAt(0).toString(16)}}, {{~}}0 },
+		/* .units			= */ { 0 },
+		/* .stepCount			= */ 0,
+		/* .defaultNormalizedValue	= */ 0.0,
+		/* .unitId			= */ 0,
+		/* .flags			= */ Steinberg_Vst_ParameterInfo_ParameterFlags_kIsHidden | Steinberg_Vst_ParameterInfo_ParameterFlags_kIsReadOnly
+	},
+{{~}}
 };
 
 # define DATA_PARAM_BYPASS	1

templates/vst3/src/vst3.c

@@ -168,9 +168,9 @@ static Steinberg_int32 pluginGetBusCount(void *thisInterface, Steinberg_Vst_Medi
 			return DATA_PRODUCT_BUSES_AUDIO_OUTPUT_N;
 	} else if (type == Steinberg_Vst_MediaTypes_kEvent) {
 		if (dir == Steinberg_Vst_BusDirections_kInput)
-			return DATA_PRODUCT_BUSES_EVENT_INPUT_N;
+			return DATA_PRODUCT_BUSES_MIDI_INPUT_N;
 		else if (dir == Steinberg_Vst_BusDirections_kOutput)
-			return DATA_PRODUCT_BUSES_EVENT_OUTPUT_N;
+			return DATA_PRODUCT_BUSES_MIDI_OUTPUT_N;
 	}
 	return 0;
 }
@@ -197,17 +197,17 @@ static Steinberg_tresult pluginGetBusInfo(void* thisInterface, Steinberg_Vst_Med
 		}
 	} else if (type == Steinberg_Vst_MediaTypes_kEvent) {
 		if (dir == Steinberg_Vst_BusDirections_kInput) {
-#if DATA_PRODUCT_BUSES_EVENT_INPUT_N > 0
+#if DATA_PRODUCT_BUSES_MIDI_INPUT_N > 0
-			if (index >= DATA_PRODUCT_BUSES_AUDIO_INPUT_N)
+			if (index >= DATA_PRODUCT_BUSES_MIDI_INPUT_N)
 				return Steinberg_kInvalidArgument;
-			*bus = busInfoEventInput[index];
+			*bus = busInfoMidiInput[index];
 			return Steinberg_kResultTrue;
 #endif
 		} else if (dir == Steinberg_Vst_BusDirections_kOutput) {
-#if DATA_PRODUCT_BUSES_EVENT_OUTPUT_N > 0
+#if DATA_PRODUCT_BUSES_MIDI_OUTPUT_N > 0
-			if (index >= DATA_PRODUCT_BUSES_AUDIO_OUTPUT_N)
+			if (index >= DATA_PRODUCT_BUSES_MIDI_OUTPUT_N)
 				return Steinberg_kInvalidArgument;
-			*bus = busInfoEventOutput[index];
+			*bus = busInfoMidiOutput[index];
 			return Steinberg_kResultTrue;
 #endif
 		}
@@ -240,14 +240,14 @@ static Steinberg_tresult pluginActivateBus(void* thisInterface, Steinberg_Vst_Me
 		}
 	} else if (type == Steinberg_Vst_MediaTypes_kEvent) {
 		if (dir == Steinberg_Vst_BusDirections_kInput) {
-#if DATA_PRODUCT_BUSES_EVENT_INPUT_N > 0
+#if DATA_PRODUCT_BUSES_MIDI_INPUT_N > 0
-			if (index >= DATA_PRODUCT_BUSES_AUDIO_INPUT_N)
+			if (index >= DATA_PRODUCT_BUSES_MIDI_INPUT_N)
 				return Steinberg_kInvalidArgument;
 			return Steinberg_kResultTrue;
 #endif
 		} else if (dir == Steinberg_Vst_BusDirections_kOutput) {
-#if DATA_PRODUCT_BUSES_EVENT_OUTPUT_N > 0
+#if DATA_PRODUCT_BUSES_MIDI_OUTPUT_N > 0
-			if (index >= DATA_PRODUCT_BUSES_AUDIO_OUTPUT_N)
+			if (index >= DATA_PRODUCT_BUSES_MIDI_OUTPUT_N)
 				return Steinberg_kInvalidArgument;
 			return Steinberg_kResultTrue;
 #endif
@@ -704,12 +704,12 @@ static Steinberg_tresult controllerGetState(void* thisInterface, struct Steinber
 
 static Steinberg_int32 controllerGetParameterCount(void* thisInterface) {
 	TRACE("controller get parameter count\n");
-	return DATA_PRODUCT_PARAMETERS_N;
+	return DATA_PRODUCT_PARAMETERS_N + 2 * (DATA_PRODUCT_BUSES_MIDI_INPUT_N + DATA_PRODUCT_BUSES_MIDI_OUTPUT_N);
 }
 
 static Steinberg_tresult controllerGetParameterInfo(void* thisInterface, Steinberg_int32 paramIndex, struct Steinberg_Vst_ParameterInfo* info) {
 	TRACE("controller get parameter info\n");
-	if (paramIndex < 0 || paramIndex >= DATA_PRODUCT_PARAMETERS_N)
+	if (paramIndex < 0 || paramIndex >= DATA_PRODUCT_PARAMETERS_N + 2 * (DATA_PRODUCT_BUSES_MIDI_INPUT_N + DATA_PRODUCT_BUSES_MIDI_OUTPUT_N))
 		return Steinberg_kResultFalse;
 	*info = parameterInfo[paramIndex];
 	return Steinberg_kResultTrue;

test/lv2.json

@@ -7,7 +7,7 @@
 		"project": "@example:project",
 		"types": [ "@lv2:AmplifierPlugin" ],
 		"version": "1.0",
-		"busSymbols": [ "input", "output" ],
+		"busSymbols": [ "input", "output", "midi_in", "midi_out" ],
-		"parameterSymbols": [ "gain", "enabled" ]
+		"parameterSymbols": [ "gain", "delay", "cutoff", "enabled" ]
 	}
 }

test/plugin.h

@@ -7,10 +7,12 @@ typedef struct plugin {
 
 	float	gain;
 	float	delay;
+	float	cutoff;
 	char	bypass;
 
 	float *	delay_line;
 	size_t	delay_line_cur;
+	float	z1;
 } plugin;
 
 static void plugin_init(plugin *instance) {
@@ -35,6 +37,7 @@ static void plugin_mem_set(plugin *instance, void *mem) {
 static void plugin_reset(plugin *instance) {
 	memset(instance->delay_line, 0, instance->delay_line_length * sizeof(float));
 	instance->delay_line_cur = 0;
+	instance->z1 = 0.f;
 }
 
 static void plugin_set_parameter(plugin *instance, size_t index, float value) {
@@ -46,6 +49,9 @@ static void plugin_set_parameter(plugin *instance, size_t index, float value) {
 		instance->delay = 0.001f * value;
 		break;
 	case 2:
+		instance->cutoff = value;
+		break;
+	case 3:
 		instance->bypass = value >= 0.5f;
 		break;
 	}
@@ -62,12 +68,15 @@ static size_t calc_index(size_t cur, size_t delay, size_t len) {
 
 static void plugin_process(plugin *instance, const float **inputs, float **outputs, size_t n_samples) {
 	size_t delay = roundf(instance->sample_rate * instance->delay);
+	const float mA1 = instance->sample_rate / (instance->sample_rate + 6.283185307179586f * instance->cutoff);
 	for (size_t i = 0; i < n_samples; i++) {
 		instance->delay_line[instance->delay_line_cur] = inputs[0][i];
-		const float y = instance->delay_line[calc_index(instance->delay_line_cur, delay, instance->delay_line_length)];
+		const float x = instance->delay_line[calc_index(instance->delay_line_cur, delay, instance->delay_line_length)];
 		instance->delay_line_cur++;
 		if (instance->delay_line_cur == instance->delay_line_length)
 			instance->delay_line_cur = 0;
+		const float y = x + mA1 * (instance->z1 - x);
+		instance->z1 = y;
 		outputs[0][i] = instance->bypass ? inputs[0][i] : instance->gain * y;
 	}
 }

test/product.json

@@ -24,6 +24,24 @@
 				"sidechain": false,
 				"cv": false,
 				"optional": false
+			},
+			{
+				"type": "midi",
+				"direction": "input",
+				"name": "MIDI input",
+				"shortName": "MIDI input",
+				"sidechain": true,
+				"control": true,
+				"optional": true
+			},
+			{
+				"type": "midi",
+				"direction": "output",
+				"name": "MIDI output",
+				"shortName": "MIDI output",
+				"sidechain": true,
+				"control": true,
+				"optional": true
 			}
 		],
 		"parameters": [
@@ -64,6 +82,22 @@
 				"unit": "ms",
 				"map": "linear"
 			},
+			{
+				"name": "Cutoff",
+				"shortName": "Cutoff",
+				"direction": "input",
+				"isBypass": false,
+				"isLatency": false,
+				"defaultValue": 1000.0,
+				"minimum": 20.0,
+				"maximum": 20e3,
+				"toggled": false,
+				"optional": false,
+				"integer": false,
+				"list": false,
+				"unit": "hz",
+				"map": "logarithmic"
+			},
 			{
 				"name": "Bypass",
 				"shortName": "Bypass",