Using atom:Path to get model to load from DAW

resources/neural_amp_modeler.ttl.in

@@ -9,6 +9,7 @@
 @prefix param: <http://lv2plug.in/ns/ext/parameters#>.
 @prefix patch: <http://lv2plug.in/ns/ext/patch#>.
 @prefix state: <http://lv2plug.in/ns/ext/state#>.
+@prefix work:  <http://lv2plug.in/ns/ext/worker#>.
 
 <@NAM_LV2_ID@>
 	a doap:Project;
@@ -28,8 +29,9 @@
 	lv2:microVersion @PROJECT_VERSION_PATCH@;
 	doap:license <http://opensource.org/licenses/MIT>;
 
-	lv2:requiredFeature urid:map;
+	lv2:requiredFeature urid:map, work:schedule;
 	lv2:optionalFeature lv2:hardRTCapable;
+	lv2:extensionData work:interface;
 
 	rdfs:comment "An LV2 implementation of Neural Amp Modeler";
 

src/nam_lv2.cpp

@@ -9,6 +9,7 @@
 #include <lv2/urid/urid.h>
 #include <lv2/log/log.h>
 #include <lv2/log/logger.h>
+#include <lv2/worker/worker.h>
 
 #include "nam_plugin.hpp"
 
@@ -64,7 +65,36 @@ static void cleanup(LV2_Handle instance) {
 	delete static_cast<NAM::Plugin*>(instance);
 }
 
-static const void* extension_data(const char*) { return nullptr; }
+static LV2_Worker_Status
+work(LV2_Handle                  instance,
+	LV2_Worker_Respond_Function respond,
+	LV2_Worker_Respond_Handle   handle,
+	uint32_t                    size,
+	const void* data)
+{
+
+	return LV2_WORKER_SUCCESS;
+}
+
+static LV2_Worker_Status
+work_response(LV2_Handle  instance,
+	uint32_t    size,
+	const void* data)
+{
+	return LV2_WORKER_SUCCESS;
+}
+
+static const void*
+extension_data(const char* uri)
+{
+	static const LV2_Worker_Interface  worker = { work, work_response, NULL };
+
+	if (!strcmp(uri, LV2_WORKER__interface)) {
+		return &worker;
+	}
+
+	return NULL;
+}
 
 static const LV2_Descriptor descriptor = {
 	"http://github.com/mikeoliphant/neural-amp-modeler-lv2",

src/nam_plugin.cpp

@@ -11,7 +11,6 @@
 namespace NAM {
 	Plugin::Plugin(float rate)
 	{
-		namModel = get_dsp("C:\\Users\\oliph\\AppData\\Roaming\\GuitarSim\\NAM\\AC15Brkup.nam");
 	}
 
 	void Plugin::map_uris(LV2_URID_Map* map) noexcept {
@@ -30,7 +29,46 @@ namespace NAM {
 	}
 
 	void Plugin::process(uint32_t n_samples) noexcept {
-		namModel->process(ports.audio_in, ports.audio_out, n_samples, 1.0, 1.0, mNAMParams);
-		namModel->finalize_(n_samples);
+		if (ports.control) {
+			LV2_ATOM_SEQUENCE_FOREACH(ports.control, event) {
+				if (event->body.type == uris.atom_Object) {
+					const auto obj = reinterpret_cast<LV2_Atom_Object*>(&event->body);
+
+					if (obj->body.otype == uris.patch_Set)
+					{
+						const LV2_Atom* property = NULL;
+						const LV2_Atom* file_path = NULL;
+
+						lv2_atom_object_get(obj, uris.patch_property, &property, 0);
+
+						if (property && (property->type == uris.atom_URID))
+						{
+							if (((const LV2_Atom_URID*)property)->body == uris.model_Path)
+							{
+								lv2_atom_object_get(obj, uris.patch_value, &file_path, 0);
+
+								if (file_path && (file_path->size > 0))
+								{
+									namModel = get_dsp((const char*)LV2_ATOM_BODY_CONST(file_path));
+								}
+							}
+						}
+					}
+				}
+			}
+		}
+
+		if (namModel == nullptr)
+		{
+			for (int i = 0; i < n_samples; i++)
+			{
+				ports.audio_out[i] = ports.audio_in[i];
+			}
+		}
+		else
+		{
+			namModel->process(ports.audio_in, ports.audio_out, n_samples, 1.0, 1.0, mNAMParams);
+			namModel->finalize_(n_samples);
+		}
 	}
 }