Implement CLAP plugin initialization

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

@@ -25,7 +25,6 @@ clap_plugin_proxy::clap_plugin_proxy(ClapPluginBridge& bridge,
     : bridge_(bridge),
       instance_id_(instance_id),
       descriptor_(std::move(descriptor)),
-      host_(host),
       plugin_vtable_(clap_plugin_t{
           .desc = descriptor_.get(),
           .plugin_data = this,
@@ -39,14 +38,23 @@ clap_plugin_proxy::clap_plugin_proxy(ClapPluginBridge& bridge,
           .process = plugin_process,
           .get_extension = plugin_get_extension,
           .on_main_thread = plugin_on_main_thread,
-      }) {}
+      }),
+      host_(host) {}
 
 bool CLAP_ABI clap_plugin_proxy::plugin_init(const struct clap_plugin* plugin) {
     assert(plugin && plugin->plugin_data);
-    auto self = static_cast<const clap_plugin_proxy*>(plugin->plugin_data);
+    auto self = static_cast<clap_plugin_proxy*>(plugin->plugin_data);
 
-    // TODO: Implement
-    return false;
+    const clap::plugin::InitResponse response =
+        self->bridge_.send_main_thread_message(
+            clap::plugin::Init{.instance_id = self->instance_id(),
+                               .supported_host_extensions = *self->host_});
+
+    // This determines which extensions the host is allowed to query in
+    // `clap_plugin::get_extension()`
+    self->supported_extensions_ = response.supported_plugin_extensions;
+
+    return response.result;
 }
 
 void CLAP_ABI

src/plugin/bridges/clap-impls/plugin-proxy.h

@@ -83,16 +83,23 @@ class clap_plugin_proxy {
     size_t instance_id_;
     clap::plugin::Descriptor descriptor_;
 
-    /**
-     * The `clap_host_t*` passed when creating the instance. Any callbacks made
-     * by the proxied plugin instance must go through ere.
-     */
-    const clap_host_t* host_;
-
     /**
      * The vtable for `clap_plugin`, requires that this object is never moved or
      * copied. We'll use the host data pointer instead of placing this vtable at
      * the start of the struct and directly casting the `clap_plugin_t*`.
      */
     const clap_plugin_t plugin_vtable_;
+
+    /**
+     * The extensions supported by the bridged plugin. Set after a successful
+     * `clap_plugin::init()` call. We'll allow the host to query these same
+     * extensions from our plugin proxy.
+     */
+    clap::plugin::SupportedPluginExtensions supported_extensions_;
+
+    /**
+     * The `clap_host_t*` passed when creating the instance. Any callbacks made
+     * by the proxied plugin instance must go through ere.
+     */
+    const clap_host_t* host_;
 };