Allow creating IEditController instances

Now `IPluginFactory::createInstance()` can create multiple (and in our
case, all relevant) different types of objects.

src/common/logging/vst3.cpp

@@ -34,24 +34,29 @@ void Vst3Logger::log_unknown_interface(
 }
 
 void Vst3Logger::log_request(bool is_host_vst,
-                             const Vst3PluginProxy::Construct& args) {
+                             const Vst3PluginProxy::Construct& request) {
     log_request_base(is_host_vst, [&](auto& message) {
-        // TODO: When adding the enum class for instantiating different types,
-        //       make sure to reflect those in the constructor and destructor
-        //       logging
         message << "IPluginFactory::createComponent(cid = "
-                << format_uid(Steinberg::FUID::fromTUID(args.cid.data()))
-                << ", _iid = "
-                   "IComponent::iid, "
-                   "&obj)";
+                << format_uid(Steinberg::FUID::fromTUID(request.cid.data()))
+                << ", _iid = ";
+        switch (request.requested_interface) {
+            case Vst3PluginProxy::Construct::Interface::IComponent:
+                message << "IComponent::iid";
+                break;
+            case Vst3PluginProxy::Construct::Interface::IEditController:
+                message << "IEditController::iid";
+                break;
+        }
+        message << ", &obj)";
     });
 }
 
 void Vst3Logger::log_request(bool is_host_vst,
                              const Vst3PluginProxy::Destruct& request) {
     log_request_base(is_host_vst, [&](auto& message) {
-        message << "<IComponent* #" << request.instance_id
-                << ">::~IComponent()";
+        // We don't know what class this instance was originally instantiated
+        // as, but it also doesn't really matter
+        message << "<FUnknown* #" << request.instance_id << ">::~FUnknown()";
     });
 }
 

src/common/serialization/vst3/plugin-proxy.h

@@ -93,20 +93,29 @@ class Vst3PluginProxy : public YaAudioProcessor,
     /**
      * Message to request the Wine plugin host to instantiate a new IComponent
      * to pass through a call to `IComponent::createInstance(cid,
-     * IComponent::iid, ...)`.
+     * <requested_interface>::iid, ...)`.
      */
     struct Construct {
         using Response = std::variant<ConstructArgs, UniversalTResult>;
 
         ArrayUID cid;
 
-        // TODO: Add an enum class to reify the type of object we want to
-        //       instantiate so we can initialize things other than
-        //       `IComponent`, like `IEditController.`
+        /**
+         * The interface the host was trying to instantiate an object for.
+         * Technically the host can create any kind of object, but these are the
+         * objects that are actually used.
+         */
+        enum class Interface {
+            IComponent,
+            IEditController,
+        };
+
+        Interface requested_interface;
 
         template <typename S>
         void serialize(S& s) {
             s.container1b(cid);
+            s.value4b(requested_interface);
         }
     };
 

src/plugin/bridges/vst3-impls/plugin-factory.cpp

@@ -28,26 +28,16 @@ tresult PLUGIN_API
 YaPluginFactoryImpl::createInstance(Steinberg::FIDString cid,
                                     Steinberg::FIDString _iid,
                                     void** obj) {
-    // TODO: Do the same thing for other types
-
-    // These arw pointers are scary. The idea here is that we return a newly
-    // initialized object (that initializes itself with a reference count of 1),
-    // and then the receiving side will use `Steinberg::owned()` to adopt it to
-    // an `IPtr<T>`.
     ArrayUID cid_array;
     std::copy(cid, cid + sizeof(Steinberg::TUID), cid_array.begin());
+
+    Vst3PluginProxy::Construct::Interface requested_interface;
     if (Steinberg::FIDStringsEqual(_iid, Steinberg::Vst::IComponent::iid)) {
-        std::variant<Vst3PluginProxy::ConstructArgs, UniversalTResult> result =
-            bridge.send_message(Vst3PluginProxy::Construct{.cid = cid_array});
-        return std::visit(
-            overload{
-                [&](Vst3PluginProxy::ConstructArgs&& args) -> tresult {
-                    *obj = static_cast<Steinberg::Vst::IComponent*>(
-                        new Vst3PluginProxyImpl(bridge, std::move(args)));
-                    return Steinberg::kResultOk;
-                },
-                [&](const UniversalTResult& code) -> tresult { return code; }},
-            std::move(result));
+        requested_interface = Vst3PluginProxy::Construct::Interface::IComponent;
+    } else if (Steinberg::FIDStringsEqual(
+                   _iid, Steinberg::Vst::IEditController::iid)) {
+        requested_interface =
+            Vst3PluginProxy::Construct::Interface::IEditController;
     } else {
         // When the host requests an interface we do not (yet) implement, we'll
         // print a recognizable log message. I don't think they include a safe
@@ -65,6 +55,38 @@ YaPluginFactoryImpl::createInstance(Steinberg::FIDString cid,
 
         return Steinberg::kNotImplemented;
     }
+
+    std::variant<Vst3PluginProxy::ConstructArgs, UniversalTResult> result =
+        bridge.send_message(Vst3PluginProxy::Construct{
+            .cid = cid_array, .requested_interface = requested_interface});
+
+    return std::visit(
+        overload{
+            [&](Vst3PluginProxy::ConstructArgs&& args) -> tresult {
+                // These pointers are scary. The idea here is that we return a
+                // newly initialized object (that initializes itself with a
+                // reference count of 1), and then the receiving side will use
+                // `Steinberg::owned()` to adopt it to an `IPtr<T>`.
+                Vst3PluginProxyImpl* proxy_object =
+                    new Vst3PluginProxyImpl(bridge, std::move(args));
+
+                // We return a properly downcasted version of the proxy object
+                // we just created
+                switch (requested_interface) {
+                    case Vst3PluginProxy::Construct::Interface::IComponent:
+                        *obj = static_cast<Steinberg::Vst::IComponent*>(
+                            proxy_object);
+                        break;
+                    case Vst3PluginProxy::Construct::Interface::IEditController:
+                        *obj = static_cast<Steinberg::Vst::IEditController*>(
+                            proxy_object);
+                        break;
+                }
+
+                return Steinberg::kResultOk;
+            },
+            [&](const UniversalTResult& code) -> tresult { return code; }},
+        std::move(result));
 }
 
 tresult PLUGIN_API

src/wine-host/bridges/vst3.cpp

@@ -60,15 +60,29 @@ void Vst3Bridge::run() {
     sockets.host_vst_control.receive_messages(
         std::nullopt,
         overload{
-            [&](const Vst3PluginProxy::Construct& args)
+            [&](const Vst3PluginProxy::Construct& request)
                 -> Vst3PluginProxy::Construct::Response {
                 Steinberg::TUID cid;
-                std::copy(args.cid.begin(), args.cid.end(), cid);
-                // TODO: Change this to allow creating different tyeps of
-                //       objects
-                Steinberg::IPtr<Steinberg::FUnknown> object =
-                    module->getFactory()
-                        .createInstance<Steinberg::Vst::IComponent>(cid);
+                std::copy(request.cid.begin(), request.cid.end(), cid);
+
+                // Even though we're requesting a specific interface (to mimic
+                // what the host is doing), we're immediately upcasting it to an
+                // `FUnknown` so we can create a perfect proxy object.
+                Steinberg::IPtr<Steinberg::FUnknown> object;
+                switch (request.requested_interface) {
+                    case Vst3PluginProxy::Construct::Interface::IComponent:
+                        object =
+                            module->getFactory()
+                                .createInstance<Steinberg::Vst::IComponent>(
+                                    cid);
+                        break;
+                    case Vst3PluginProxy::Construct::Interface::IEditController:
+                        object = module->getFactory()
+                                     .createInstance<
+                                         Steinberg::Vst::IEditController>(cid);
+                        break;
+                }
+
                 if (object) {
                     std::lock_guard lock(object_instances_mutex);