Remove GetLink(ed) in Normalize effect...

... It's much simpler and should be easy to generalize, but what would be
appropriate messages?

src/effects/Normalize.cpp

@@ -219,10 +219,6 @@ bool EffectNormalize::Process()
    //Iterate over each track
    this->CopyInputTracks(); // Set up mOutputTracks.
    bool bGoodResult = true;
-   SelectedTrackListOfKindIterator iter(Track::Wave, mOutputTracks.get());
-   WaveTrack *track = (WaveTrack *) iter.First();
-   WaveTrack *prevTrack;
-   prevTrack = track;
    double progress = 0;
    wxString topMsg;
    if(mDC && mGain)
@@ -234,8 +230,10 @@ bool EffectNormalize::Process()
    else if(!mDC && !mGain)
       topMsg = _("Not doing anything...\n");   // shouldn't get here
 
-   while (track) {
+   for ( auto track : mOutputTracks->Selected< WaveTrack >()
+            + ( mStereoInd ? &Track::Any : &Track::IsLeader ) ) {
       //Get start and end times from track
+      // PRL:  No accounting for multiple channels?
       double trackStart = track->GetStartTime();
       double trackEnd = track->GetEndTime();
 
@@ -244,121 +242,106 @@ bool EffectNormalize::Process()
       mCurT0 = mT0 < trackStart? trackStart: mT0;
       mCurT1 = mT1 > trackEnd? trackEnd: mT1;
 
+      auto range = mStereoInd
+         ? TrackList::SingletonRange(track)
+         : TrackList::Channels(track);
+
       // Process only if the right marker is to the right of the left marker
       if (mCurT1 > mCurT0) {
-         wxString msg;
+         wxString trackName = track->GetName();
-         auto trackName = track->GetName();
 
-         if(!track->GetLinked() || mStereoInd)
+         float extent;
-            msg =
+#ifdef EXPERIMENTAL_R128_NORM
-               topMsg + wxString::Format( _("Analyzing: %s"), trackName );
+         if (mUseLoudness)
+            // Loudness: use sum of both tracks.
+            // As a result, stereo tracks appear about 3 LUFS louder,
+            // as specified.
+            extent = 0;
          else
-            msg =
+#endif
-               topMsg + wxString::Format( _("Analyzing first track of stereo pair: %s"), trackName );
+            // Will compute a maximum
-         float offset, extent;
+            extent = std::numeric_limits<float>::lowest();
-         bGoodResult = AnalyseTrack(track, msg, progress, offset, extent);
+         std::vector<float> offsets;
-         if (!bGoodResult )
+
-             break;
+         wxString msg;
-         if(!track->GetLinked() || mStereoInd) {
+         if (range.size() == 1)
             // mono or 'stereo tracks independently'
-            if( (extent > 0) && mGain )
+            msg = topMsg +
-            {
+               wxString::Format( _("Analyzing: %s"), trackName );
-               mMult = ratio / extent;
+         else
+            msg = topMsg +
+               // TODO: more-than-two-channels-message
+               wxString::Format( _("Analyzing first track of stereo pair: %s"), trackName);
+         
+         // Analysis loop over channels collects offsets and extent
+         for (auto channel : range) {
+            float offset, extent2;
+            bGoodResult =
+               AnalyseTrack( channel, msg, progress, offset, extent2 );
+            if ( ! bGoodResult )
+               goto break2;
 #ifdef EXPERIMENTAL_R128_NORM
-               if(mUseLoudness) {
+            if (mUseLoudness)
-                  // LUFS is defined as -0.691 dB + 10*log10(sum(channels))
+               extent += extent2;
-                  mMult /= 0.8529037031;
-                  // LUFS are related to square values so the multiplier must be the root.
-                  mMult = sqrt(ratio / extent);
-               }
-#endif
-            }
             else
-               mMult = 1.0;
+#endif
-
+               extent = std::max( extent, extent2 );
-            msg =
+            offsets.push_back(offset);
-               topMsg + wxString::Format( _("Processing: %s"), trackName );
+            // TODO: more-than-two-channels-message
-
+            msg = topMsg +
-            if(track->GetLinked() || prevTrack->GetLinked())  // only get here if there is a linked track but we are processing independently
+               wxString::Format( _("Analyzing second track of stereo pair: %s"), trackName );
-               msg =
-                  topMsg + wxString::Format( _("Processing stereo channels independently: %s"), trackName );
-
-            if (!ProcessOne(track, msg, progress, offset))
-            {
-               bGoodResult = false;
-               break;
-            }
          }
-         else {
-            // we have a linked stereo track
-            // so we need to find it's min, max and offset
-            // as they are needed to calc the multiplier for both tracks
-
-            track = (WaveTrack *) iter.Next();  // get the next one
-            msg =
-               topMsg + wxString::Format( _("Analyzing second track of stereo pair: %s"), trackName );
-
-            float offset2, extent2;
-            bGoodResult = AnalyseTrack(track, msg, progress, offset2, extent2);
-            if ( !bGoodResult )
-                break;
 
+         // Compute the multiplier using extent
+         if( (extent > 0) && mGain ) {
+            mMult = ratio / extent;
 #ifdef EXPERIMENTAL_R128_NORM
-            if (mUseLoudness) {
+            if(mUseLoudness) {
-               // Loudness: use sum of both tracks.
+               // PRL:  See commit 9cbb67a for the origin of the next line,
-               // As a result, stereo tracks appear about 3 LUFS louder, as specified.
+               // which has no effect because mMult is again overwritten.  What
-               extent = extent + extent2;
+               // was the intent?
+
                // LUFS is defined as -0.691 dB + 10*log10(sum(channels))
-               extent *= 0.8529037031;
+               mMult /= 0.8529037031;
+               // LUFS are related to square values so the multiplier must be the root.
+               mMult = sqrt(ratio / extent);
             }
-            else {
-               // Peak: use maximum of both tracks.
-               extent = fmax(extent, extent2);
-            }
-#else
-            // Peak: use maximum of both tracks.
-            extent = fmax(extent, extent2);
 #endif
+         }
+         else
+            mMult = 1.0;
 
-            if( (extent > 0) && mGain )
+         if (range.size() == 1) {
-            {
+            if (TrackList::Channels(track).size() == 1)
-               mMult = ratio / extent; // we need to use this for both linked tracks
+               // really mono
-#ifdef EXPERIMENTAL_R128_NORM
+               msg = topMsg +
-               if(mUseLoudness) {
+                  wxString::Format( _("Processing: %s"), trackName );
-                  // LUFS are related to square values so the multiplier must be the root.
-                  mMult = sqrt(mMult);
-               }
-#endif
-            }
             else
-               mMult = 1.0;
+               //'stereo tracks independently'
+               // TODO: more-than-two-channels-message
+               msg = topMsg +
+                  wxString::Format( _("Processing stereo channels independently: %s"), trackName);
+         }
+         else
+            msg = topMsg +
+               // TODO: more-than-two-channels-message
+               wxString::Format( _("Processing first track of stereo pair: %s"), trackName);
 
-            track = (WaveTrack *) iter.Prev();  // go back to the first linked one
+         // Use multiplier in the second, processing loop over channels
-            msg =
+         auto pOffset = offsets.begin();
-               topMsg + wxString::Format( _("Processing first track of stereo pair: %s"), trackName );
+         for (auto channel : range) {
-
+            if (false ==
-            if (!ProcessOne(track, msg, progress, offset))
+                (bGoodResult = ProcessOne(channel, msg, progress, *pOffset++)) )
-            {
+               goto break2;
-               bGoodResult = false;
+            // TODO: more-than-two-channels-message
-               break;
+            msg = topMsg +
-            }
+               wxString::Format( _("Processing second track of stereo pair: %s"), trackName);
-            track = (WaveTrack *) iter.Next();  // go to the second linked one
-            msg =
-               topMsg + wxString::Format( _("Processing second track of stereo pair: %s"), trackName );
-
-            if (!ProcessOne(track, msg, progress, offset2))
-            {
-               bGoodResult = false;
-               break;
-            }
          }
       }
-
-      //Iterate to the next track
-      prevTrack = track;
-      track = (WaveTrack *) iter.Next();
    }
 
+   break2:
+
    this->ReplaceProcessedTracks(bGoodResult);
    return bGoodResult;
 }