Describe how createInstance() is going to work

src/plugin/bridges/vst3-impls.cpp

@@ -20,9 +20,33 @@ YaPluginFactoryPluginImpl::YaPluginFactoryPluginImpl(Vst3PluginBridge& bridge)
     : bridge(bridge) {}
 
 tresult PLUGIN_API
-YaPluginFactoryPluginImpl::createInstance(Steinberg::FIDString /*cid*/,
-                                          Steinberg::FIDString /*_iid*/,
-                                          void** /*obj*/) {
+YaPluginFactoryPluginImpl::createInstance(Steinberg::FIDString cid,
+                                          Steinberg::FIDString _iid,
+                                          void** obj) {
+    // TODO: This should:
+    //       1. Check which interface `_iid` belongs to. Let's call this
+    //          interface `T`. If we do not (yet) support it, then we should log
+    //          it and return `Steinberg::kNotImplemented`.
+    //       2. Send a control message to the Wine plugin host to instantiate a
+    //          new object of type `T` with `cid` and `_iid` as parameters.
+    //       3. On the Wine side this calls `createIntance()` on the module's
+    //          factory with thsoe same `cid` and `_iid` arguments.
+    //       4. It this was successful, we'll assign this object a unique number
+    //          (by just doing a fetch-and-add on an atomic size_t) so we can
+    //          refer to it and add it to an `std::map<size_t, IPtr<T>` (could
+    //          also throw everything in a single map with `FUnknown`s, but
+    //          while more verbose this sounds much less prone to breakage).
+    //       5. We'll serialize any payload data into a `YaT` **which includes
+    //          that unique identifier we generated** and send it back to the
+    //          plugin.
+    //       6. The plugin then converts it to the correct smart pointer format
+    //          and writes it to `obj`. We don't have to keep track of these
+    //          objects on the plugin side and the reference counting pointers
+    //          will cause everything to clean up after itself.
+    //       7. Since those `YaT` objects we'll return from `createInstance()`
+    //          will have a reference to `Vst3PluginBridge`, they can also send
+    //          control messages themselves.
+
     // TODO: Send a control message
     return Steinberg::kNotImplemented;
 }