Failed attempt at elevations panel

src/viklayerspanel.c

@@ -66,6 +66,8 @@ struct _VikLayersPanel {
   VikAggregateLayer *toplayer;
   GtkTreeIter toplayer_iter;
 
+  GtkWidget *elevation;
+
   VikTreeview *vt;
   VikViewport *vvp; /* reference */
 };
@@ -88,6 +90,7 @@ static void layers_move_item ( VikLayersPanel *vlp, gboolean up );
 static void layers_move_item_up ( VikLayersPanel *vlp );
 static void layers_move_item_down ( VikLayersPanel *vlp );
 static void layers_panel_finalize ( GObject *gob );
+static void vik_layers_panel_elevation_update ( VikLayersPanel *vlp );
 
 G_DEFINE_TYPE (VikLayersPanel, vik_layers_panel, GTK_TYPE_VBOX)
 
@@ -537,10 +540,13 @@ static void vik_layers_panel_init ( VikLayersPanel *vlp )
 
   gtk_calendar_set_detail_func ( GTK_CALENDAR(vlp->calendar), calendar_detail, vlp, NULL );
   vik_layers_panel_set_preferences ( vlp );
-
+
+  vlp->elevation = gtk_vbox_new ( FALSE, 0 );
+
   gtk_box_pack_start ( GTK_BOX(vlp), scrolledwindow, TRUE, TRUE, 0 );
   gtk_box_pack_start ( GTK_BOX(vlp), vlp->calendar, FALSE, FALSE, 0 );
   gtk_box_pack_start ( GTK_BOX(vlp), vlp->hbox, FALSE, FALSE, 0 );
+  gtk_box_pack_start ( GTK_BOX(vlp), vlp->elevation, FALSE, FALSE, 0 );
 }
 
 /**
@@ -847,6 +853,7 @@ void vik_layers_panel_draw_all ( VikLayersPanel *vlp )
 {
   if ( vlp->vvp && VIK_LAYER(vlp->toplayer)->visible )
     vik_aggregate_layer_draw ( vlp->toplayer, vlp->vvp );
+  vik_layers_panel_elevation_update ( vlp );
 }
 
 void vik_layers_panel_cut_selected ( VikLayersPanel *vlp )
@@ -1108,3 +1115,63 @@ void vik_layers_panel_set_preferences ( VikLayersPanel *vlp )
   g_value_set_boolean ( &sd, a_vik_get_calendar_show_day_names() );
   g_object_set_property ( G_OBJECT(vlp->calendar), "show-day-names", &sd );
 }
+
+void vik_layers_panel_elevation_update ( VikLayersPanel *vlp ) {
+  VikWindow *vw = VIK_WINDOW_FROM_WIDGET(vlp);
+
+  // currently only draw directly selected track or route
+  VikTrack *track = (VikTrack*)vik_window_get_selected_track ( vw );
+  if ( track == NULL )
+      return;
+
+  gdouble min_alt, max_alt;
+  GdkPixmap *pix;
+  GtkWidget *image;
+  GtkWidget *eventbox;
+  gint profile_width = 200;
+  gint profile_height = 100;
+
+  // set profile width to 200 for now
+  gdouble *altitudes = vik_track_make_elevation_map ( track, profile_width );
+
+  if (altitudes != NULL ) {
+
+    // Don't use minmax_array(widgets->altitudes), as that is a simplified representative of the points
+    //  thus can miss the highest & lowest values by a few metres
+    if ( !vik_track_get_minmax_alt ( track, &min_alt, &max_alt ) )
+      min_alt = max_alt = NAN;
+
+    pix = gdk_pixmap_new( gtk_widget_get_window(vlp->elevation), profile_width, profile_height, -1 );
+    image = gtk_image_new_from_pixmap ( pix, NULL );
+
+    g_object_unref ( G_OBJECT(pix) );
+
+    eventbox = gtk_event_box_new ();
+    gtk_container_add ( GTK_CONTAINER(eventbox), image );
+
+    gtk_box_pack_start ( GTK_BOX(vlp->elevation), eventbox, TRUE, TRUE, 0 );
+
+    pix = gdk_pixmap_new( gtk_widget_get_window(vlp->elevation), profile_width, profile_height, -1 );
+    gtk_image_set_from_pixmap ( GTK_IMAGE(image), pix, NULL );
+
+    GdkColor color;
+    GdkGC *no_alt_gc = gdk_gc_new ( gtk_widget_get_window( vlp->elevation ) );
+    gdk_color_parse ( "yellow", &color );
+    gdk_gc_set_rgb_fg_color ( no_alt_gc, &color);
+
+    GdkGC *alt_gc = gdk_gc_new ( gtk_widget_get_window( vlp->elevation ) );
+    gdk_color_parse ( "red", &color );
+    gdk_gc_set_rgb_fg_color ( alt_gc, &color);
+
+    /* draw elevations */
+    for ( int i = 0; i < profile_width; i++ ) {
+      if ( isnan(altitudes[i]) ) {
+        gdk_draw_line ( GDK_DRAWABLE(pix), no_alt_gc, i, 0, i, 20);
+      } else {
+        gdk_draw_line ( GDK_DRAWABLE(pix), alt_gc, i, 0, i, 10);
+      }
+    }
+
+    g_object_unref ( G_OBJECT(pix) );
+  }
+}