Improve smoothing a little.

diff --git a/src/wx/audio_plot.cc b/src/wx/audio_plot.cc
index 2098adb40d04e2a7f7801b35d1de99d676f60400..068b74ffdf57c4c81d09d3d0dd04ebbd8f9fbe83 100644 (file)
--- a/src/wx/audio_plot.cc
+++ b/src/wx/audio_plot.cc
@@ -213,14 +213,39 @@ AudioPlot::plot_rms (wxGraphicsPath& path, int channel) const
        path.MoveToPoint (_db_label_width, y_for_linear (_analysis->get_point(channel, 0)[AudioPoint::RMS]));
 
        list<float> smoothing;
+
        int const N = _analysis->points(channel);
+
+       float const first = _analysis->get_point(channel, 0)[AudioPoint::RMS];
+       float const last = _analysis->get_point(channel, N - 1)[AudioPoint::RMS];
+
+       int const before = _smoothing / 2;
+       int const after = _smoothing - before;
+       
+       /* Pre-load the smoothing list */
+       for (int i = 0; i < before; ++i) {
+               smoothing.push_back (first);
+       }
+       for (int i = 0; i < after; ++i) {
+               if (i < N) {
+                       smoothing.push_back (_analysis->get_point(channel, i)[AudioPoint::RMS]);
+               } else {
+                       smoothing.push_back (last);
+               }
+       }
+       
        for (int i = 0; i < N; ++i) {
 
-               smoothing.push_back (_analysis->get_point(channel, i)[AudioPoint::RMS]);
-               if (int(smoothing.size()) > _smoothing) {
-                       smoothing.pop_front ();
+               int const next_for_window = i + after;
+
+               if (next_for_window < N) {
+                       smoothing.push_back (_analysis->get_point(channel, i)[AudioPoint::RMS]);
+               } else {
+                       smoothing.push_back (last);
                }
 
+               smoothing.pop_front ();
+
                float p = 0;
                for (list<float>::const_iterator j = smoothing.begin(); j != smoothing.end(); ++j) {
                        p += pow (*j, 2);
@@ -228,8 +253,7 @@ AudioPlot::plot_rms (wxGraphicsPath& path, int channel) const
 
                p = sqrt (p / smoothing.size ());
 
-               int const ind = max (0, i - int(smoothing.size() / 2));
-               path.AddLineToPoint (_db_label_width + ind * _x_scale, y_for_linear (p));
+               path.AddLineToPoint (_db_label_width + i * _x_scale, y_for_linear (p));
        }
 }