Implement IUnitInfo::getUnitCount

src/common/logging/vst3.cpp

@@ -430,6 +430,13 @@ bool Vst3Logger::log_request(bool is_host_vst,
     });
 }
 
+bool Vst3Logger::log_request(bool is_host_vst,
+                             const YaUnitInfo::GetUnitCount& request) {
+    return log_request_base(is_host_vst, [&](auto& message) {
+        message << request.instance_id << ": IUnitInfo::getUnitCount()";
+    });
+}
+
 bool Vst3Logger::log_request(
     bool is_host_vst,
     const YaAudioProcessor::SetBusArrangements& request) {

src/common/logging/vst3.h

@@ -108,6 +108,7 @@ class Vst3Logger {
     bool log_request(bool is_host_vst, const YaPluginBase::Terminate&);
     bool log_request(bool is_host_vst, const YaPluginFactory::Construct&);
     bool log_request(bool is_host_vst, const YaPluginFactory::SetHostContext&);
+    bool log_request(bool is_host_vst, const YaUnitInfo::GetUnitCount&);
 
     bool log_request(bool is_host_vst,
                      const YaAudioProcessor::SetBusArrangements&);

src/common/serialization/vst3.h

@@ -99,7 +99,8 @@ using ControlRequest = std::variant<Vst3PlugViewProxy::Destruct,
                                     YaPluginBase::Initialize,
                                     YaPluginBase::Terminate,
                                     YaPluginFactory::Construct,
-                                    YaPluginFactory::SetHostContext>;
+                                    YaPluginFactory::SetHostContext,
+                                    YaUnitInfo::GetUnitCount>;
 
 template <typename S>
 void serialize(S& s, ControlRequest& payload) {

src/common/serialization/vst3/plugin/unit-info.h

@@ -62,6 +62,21 @@ class YaUnitInfo : public Steinberg::Vst::IUnitInfo {
 
     inline bool supported() const { return arguments.supported; }
 
+    /**
+     * Message to pass through a call to `IUnitInfo::getUnitCount()` to the Wine
+     * plugin host.
+     */
+    struct GetUnitCount {
+        using Response = UniversalTResult;
+
+        native_size_t instance_id;
+
+        template <typename S>
+        void serialize(S& s) {
+            s.value8b(instance_id);
+        }
+    };
+
     virtual int32 PLUGIN_API getUnitCount() override = 0;
     virtual tresult PLUGIN_API
     getUnitInfo(int32 unitIndex,

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

@@ -441,9 +441,8 @@ tresult PLUGIN_API Vst3PluginProxyImpl::terminate() {
 }
 
 int32 PLUGIN_API Vst3PluginProxyImpl::getUnitCount() {
-    // TODO: Implement
-    bridge.logger.log("TODO: IUnitInfo::getUnitCount()");
-    return Steinberg::kNotImplemented;
+    return bridge.send_message(
+        YaUnitInfo::GetUnitCount{.instance_id = instance_id()});
 }
 
 tresult PLUGIN_API

src/wine-host/bridges/vst3.cpp

@@ -35,7 +35,8 @@ InstanceInterfaces::InstanceInterfaces(
       connection_point(object),
       edit_controller(object),
       edit_controller_2(object),
-      plugin_base(object) {}
+      plugin_base(object),
+      unit_info(object) {}
 
 Vst3Bridge::Vst3Bridge(MainContext& main_context,
                        std::string plugin_dll_path,
@@ -564,7 +565,13 @@ void Vst3Bridge::run() {
                 assert(factory_3);
 
                 return factory_3->setHostContext(plugin_factory_host_context);
-            }});
+            },
+            [&](const YaUnitInfo::GetUnitCount& request)
+                -> YaUnitInfo::GetUnitCount::Response {
+                return object_instances[request.instance_id]
+                    .unit_info->getUnitCount();
+            },
+        });
 }
 
 void Vst3Bridge::handle_x11_events() {

src/wine-host/bridges/vst3.h

@@ -115,6 +115,7 @@ struct InstanceInterfaces {
     Steinberg::FUnknownPtr<Steinberg::Vst::IEditController> edit_controller;
     Steinberg::FUnknownPtr<Steinberg::Vst::IEditController2> edit_controller_2;
     Steinberg::FUnknownPtr<Steinberg::IPluginBase> plugin_base;
+    Steinberg::FUnknownPtr<Steinberg::Vst::IUnitInfo> unit_info;
 };
 
 /**