LV2: add support for (de)activate in plugin wrapper.

The `activate` callback is called _before_ any audio processing begins.
This is a good place to initialize the plugin to a known good state.

The `deactivate` callback is called _after_ all audio processing is
finished. If any cleanup is needed, this is a good place to do so.

2 files changed, 10 insertions, 1 deletions

diff --git a/plugins/LV2/include/lv2plugin.h b/plugins/LV2/include/lv2plugin.h
index 46464a3..77b3996 100644
--- a/plugins/LV2/include/lv2plugin.h
+++ b/plugins/LV2/include/lv2plugin.h
@@ -12,6 +12,8 @@ public:
         : rate(frame_rate)
     {}
 
+    virtual ~LV2Plugin() {}
+
     void connect_port(uint32_t port, void * data)
     {
         if (port < nparams) {
@@ -33,6 +35,9 @@ public:
         return rate;
     }
 
+    virtual void activate() {}
+    virtual void deactivate() {}
+
     const float * params[nparams];
     const float * in[ninputs];
     float * out[noutputs];
diff --git a/plugins/LV2/include/lv2wrapper.h b/plugins/LV2/include/lv2wrapper.h
index 26531cb..e92c690 100644
--- a/plugins/LV2/include/lv2wrapper.h
+++ b/plugins/LV2/include/lv2wrapper.h
@@ -42,6 +42,8 @@ private:
 
     static void activate(LV2_Handle instance)
     {
+        auto accel = static_cast<Plugin *>(instance);
+        accel->activate();
     }
 
     static void run(LV2_Handle instance, uint32_t num_samples)
@@ -50,8 +52,10 @@ private:
         accel->run(num_samples);
     }
 
-    static void deactivate(LV2_Handle)
+    static void deactivate(LV2_Handle instance)
     {
+        auto accel = static_cast<Plugin *>(instance);
+        accel->deactivate();
     }
 
     static void destroy(LV2_Handle instance)