Fully implement IParameterFinder

With this we're at VST 3.0.2 support.

src/common/serialization/vst3.h

@@ -90,6 +90,7 @@ using ControlRequest =
                  YaNoteExpressionController::GetNoteExpressionInfo,
                  YaNoteExpressionController::GetNoteExpressionStringByValue,
                  YaNoteExpressionController::GetNoteExpressionValueByString,
+                 YaParameterFinder::FindParameter,
                  YaPlugView::IsPlatformTypeSupported,
                  YaPlugView::Attached,
                  YaPlugView::Removed,

src/common/serialization/vst3/plug-view-proxy.cpp

@@ -21,10 +21,13 @@ Vst3PlugViewProxy::ConstructArgs::ConstructArgs() {}
 Vst3PlugViewProxy::ConstructArgs::ConstructArgs(
     Steinberg::IPtr<Steinberg::FUnknown> object,
     size_t owner_instance_id)
-    : owner_instance_id(owner_instance_id), plug_view_args(object) {}
+    : owner_instance_id(owner_instance_id),
+      plug_view_args(object),
+      parameter_finder_args(object) {}
 
 Vst3PlugViewProxy::Vst3PlugViewProxy(const ConstructArgs&& args)
     : YaPlugView(std::move(args.plug_view_args)),
+      YaParameterFinder(std::move(args.parameter_finder_args)),
       arguments(std::move(args)){FUNKNOWN_CTOR}
 
       Vst3PlugViewProxy::~Vst3PlugViewProxy() {
@@ -44,6 +47,10 @@ tresult PLUGIN_API Vst3PlugViewProxy::queryInterface(Steinberg::FIDString _iid,
         QUERY_INTERFACE(_iid, obj, Steinberg::IPlugView::iid,
                         Steinberg::IPlugView)
     }
+    if (YaParameterFinder::supported()) {
+        QUERY_INTERFACE(_iid, obj, Steinberg::Vst::IParameterFinder::iid,
+                        Steinberg::Vst::IParameterFinder)
+    }
 
     *obj = nullptr;
     return Steinberg::kNoInterface;

src/common/serialization/vst3/plug-view-proxy.h

@@ -30,7 +30,7 @@
  * `IEditController::createView()`, and it works exactly the same as
  * `Vst3PluginProxy`.
  */
-class Vst3PlugViewProxy : public YaPlugView {
+class Vst3PlugViewProxy : public YaPlugView, public YaParameterFinder {
    public:
     /**
      * These are the arguments for constructing a
@@ -55,10 +55,13 @@ class Vst3PlugViewProxy : public YaPlugView {
 
         YaPlugView::ConstructArgs plug_view_args;
 
+        YaParameterFinder::ConstructArgs parameter_finder_args;
+
         template <typename S>
         void serialize(S& s) {
             s.value8b(owner_instance_id);
             s.object(plug_view_args);
+            s.object(parameter_finder_args);
         }
     };
 

src/common/serialization/vst3/plug-view/parameter-finder.h

@@ -99,7 +99,7 @@ class YaParameterFinder : public Steinberg::Vst::IParameterFinder {
     virtual tresult PLUGIN_API
     findParameter(int32 xPos,
                   int32 yPos,
-                  Steinberg::Vst::ParamID& resultTag /*out*/) = 0;
+                  Steinberg::Vst::ParamID& resultTag /*out*/) override = 0;
 
    protected:
     ConstructArgs arguments;

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

@@ -157,3 +157,18 @@ Vst3PlugViewProxyImpl::checkSizeConstraint(Steinberg::ViewRect* rect) {
         return Steinberg::kInvalidArgument;
     }
 }
+
+tresult PLUGIN_API Vst3PlugViewProxyImpl::findParameter(
+    int32 xPos,
+    int32 yPos,
+    Steinberg::Vst::ParamID& resultTag /*out*/) {
+    const FindParameterResponse response =
+        bridge.send_message(YaParameterFinder::FindParameter{
+            .owner_instance_id = owner_instance_id(),
+            .x_pos = xPos,
+            .y_pos = yPos});
+
+    resultTag = response.result_tag;
+
+    return response.result;
+}

src/plugin/bridges/vst3-impls/plug-view-proxy.h

@@ -57,6 +57,12 @@ class Vst3PlugViewProxyImpl : public Vst3PlugViewProxy {
     tresult PLUGIN_API canResize() override;
     tresult PLUGIN_API checkSizeConstraint(Steinberg::ViewRect* rect) override;
 
+    // From `IParameterFinder`
+    tresult PLUGIN_API
+    findParameter(int32 xPos,
+                  int32 yPos,
+                  Steinberg::Vst::ParamID& resultTag /*out*/) override;
+
     /**
      * The `IPlugFrame` object passed by the host passed to us in
      * `IPlugView::setFrame()`. When the plugin makes a callback on the

src/wine-host/bridges/vst3.cpp

@@ -449,6 +449,17 @@ void Vst3Bridge::run() {
                                 .result = result,
                                 .value_normalized = value_normalized};
                     },
+            [&](const YaParameterFinder::FindParameter& request)
+                -> YaParameterFinder::FindParameter::Response {
+                Steinberg::Vst::ParamID result_tag;
+                const tresult result =
+                    object_instances[request.owner_instance_id]
+                        .plug_view_instance->parameter_finder->findParameter(
+                            request.x_pos, request.y_pos, result_tag);
+
+                return YaParameterFinder::FindParameterResponse{
+                    .result = result, .result_tag = result_tag};
+            },
             [&](const YaPlugView::IsPlatformTypeSupported& request)
                 -> YaPlugView::IsPlatformTypeSupported::Response {
                 // The host will of course want to pass an X11 window ID for the