Sort audio timeline views in order of DCP audio channel mappings (#1279).

diff --git a/src/wx/timeline.cc b/src/wx/timeline.cc
index 5babcfea14547c4eefb9aea87dbbc7598e7f98ab..2e90b3a81c4ea0f8326cb8f2b09bdf0f2ea8b370 100644 (file)
--- a/src/wx/timeline.cc
+++ b/src/wx/timeline.cc
@@ -306,6 +306,27 @@ place (TimelineViewList& views, int& tracks)
        return tracks - base;
 }
 
+/** Compare the mapped output channels of two TimelineViews, so we can into
+ *  order of first mapped DCP channel.
+ */
+struct AudioMappingComparator {
+       bool operator()(shared_ptr<TimelineView> a, shared_ptr<TimelineView> b) {
+               int la = -1;
+               shared_ptr<TimelineAudioContentView> cva = dynamic_pointer_cast<TimelineAudioContentView>(a);
+               if (cva) {
+                       list<int> oc = cva->content()->audio->mapping().mapped_output_channels();
+                       la = *min_element(begin(oc), end(oc));
+               }
+               int lb = -1;
+               shared_ptr<TimelineAudioContentView> cvb = dynamic_pointer_cast<TimelineAudioContentView>(b);
+               if (cvb) {
+                       list<int> oc = cvb->content()->audio->mapping().mapped_output_channels();
+                       lb = *min_element(begin(oc), end(oc));
+               }
+               return la < lb;
+       }
+};
+
 void
 Timeline::assign_tracks ()
 {
@@ -373,9 +394,13 @@ Timeline::assign_tracks ()
                ++_tracks;
        }
 
-       /* Audio */
+       /* Audio.  We're sorting the views so that we get the audio views in order of increasing
+          DCP channel index.
+       */
 
-       int const audio_tracks = place<TimelineAudioContentView> (_views, _tracks);
+       TimelineViewList views = _views;
+       sort(views.begin(), views.end(), AudioMappingComparator());
+       int const audio_tracks = place<TimelineAudioContentView> (views, _tracks);
 
        _labels_view->set_3d (have_3d);
        _labels_view->set_audio_tracks (audio_tracks);