Add a Clock (MIDI slave only for now)

src/main_perkons.cc

@@ -39,6 +39,37 @@ namespace Heck {
         ld::AudioHandle::InterleavingOutputBuffer out,
         size_t size);
 
+    void midi_realtime_handler(ld::MidiEvent& msg);
+
+    struct Clock {
+        void advance()
+        {
+            if (enabled) {
+                time++;
+            }
+        };
+
+        void reset()
+        {
+            time = 0;
+        };
+
+        void enable(bool enabled)
+        {
+            this->enabled = enabled;
+        };
+
+        int gettime()
+        {
+            return time;
+        }
+
+    private:
+        bool enabled{ true };
+        int time{ 0 };
+    };
+
+    Clock clock{};
 
     void init()
     {