+
+Real
+skyline_height (vector<Skyline_entry> const &buildings,
+ Real airplane,
+ Direction sky_dir)
+{
+ Real h = - sky_dir * infinity_f;
+
+ /*
+ Ugh! linear, should be O(log n).
+ */
+ for (vsize i = 0; i < buildings.size (); i++)
+ if (buildings[i].width_.contains (airplane))
+ h = sky_dir * max (sky_dir * h,
+ sky_dir * buildings[i].height_);
+
+ return h;
+}
+