-Smoothed DSP level metering UI updates

src/dsp/dsp_dbmeter.hxx

@@ -29,11 +29,13 @@ class DBMeter
     {
       // range scale from range = -96 -> +10, to 0 -> 1
       float zeroOneL = (1-(fvbargraph0 / -96.f));
+      fvbargraph0 = -96;
       return pow(zeroOneL, 4);
     }
     float getRightDB()
     {
       float zeroOneR = (1-(fvbargraph1 / -96.f));
+      fvbargraph1 = -96;
       return pow(zeroOneR, 4);
     }
     
@@ -42,10 +44,12 @@ class DBMeter
       for (int i = 0; (i < count); i = (i + 1))
       {
         fRec0[0] = max((fRec0[1] - fConst0), min(10.f, (20.f * log10f(max(1.58489e-05f, fabsf(*inputL))))));
-        fvbargraph0 = fRec0[0];
+        if ( fvbargraph0 < fRec0[0] )
+          fvbargraph0 = fRec0[0];
         
         fRec1[0] = max((fRec1[1] - fConst0), min(10.f, (20.f * log10f(max(1.58489e-05f, fabsf(*inputR))))));
-        fvbargraph1 = fRec1[0];
+        if ( fvbargraph1 < fRec1[0] )
+          fvbargraph1 = fRec1[0];
         
         fRec0[1] = fRec0[0];
         fRec1[1] = fRec1[0];

src/jack.cxx

@@ -19,6 +19,11 @@ Jack::Jack()
   buffers.nframes = jack_get_buffer_size( client );
   buffers.samplerate = jack_get_sample_rate( client );
   
+  // UI update
+  uiUpdateConstant = buffers.samplerate / 30;
+  uiUpdateCounter = buffers.samplerate / 30;
+  
+  
   masterOutput = jack_port_register( client,
                           "master_out",
                           JACK_DEFAULT_AUDIO_TYPE,
@@ -157,13 +162,26 @@ int Jack::process (jack_nframes_t nframes)
   {
     // needs to be setup to handle stereo instead of mono
     dbMeters.at(n).process( nframes, buffers.audio[Buffers::TRACK_0 + n], buffers.audio[Buffers::TRACK_0 + n]);
-    EventTrackSignalLevel e( n, dbMeters.at(n).getLeftDB(), dbMeters.at(n).getRightDB() );
-    writeToGuiRingbuffer( &e );
+    
+    if (uiUpdateCounter > uiUpdateConstant )
+    {
+      EventTrackSignalLevel e( n, dbMeters.at(n).getLeftDB(), dbMeters.at(n).getRightDB() );
+      writeToGuiRingbuffer( &e );
+    }
   }
+
   
   
   metronome.process( nframes, &buffers );
   
+  if (uiUpdateCounter > uiUpdateConstant )
+  {
+    uiUpdateCounter = 0;
+  }
+  
+  uiUpdateCounter += nframes;
+  
+  
   return false;
 }
 

src/jack.hxx

@@ -64,9 +64,13 @@ class Jack
     ControllerUpdater controllerUpdater;
     
     vector<Looper*> loopers;
-    
     vector<DBMeter> dbMeters;
     
+    // UI update variables
+    long uiUpdateCounter;
+    long uiUpdateConstant;
+    
+    
     int nframes;
     int samplerate;