Approximates cross-staff slurs in VerticalAxisGroup vertical-skylines.

lily/grob.cc

Index: lily/grob.cc
diff --git a/lily/grob.cc b/lily/grob.cc
index c515c186169e16402ea38a5476e93f7e1ae5e7a5..79c3f9d795a65a201f89bb6ee5f5aa5c8d53651d 100644
--- a/lily/grob.cc
+++ b/lily/grob.cc
@@ -374,7 +374,7 @@ Grob::pure_relative_y_coordinate (Grob const *refp, int start, int end)
       Real trans = 0;
       if (Align_interface::has_interface (p) && !dim_cache_[Y_AXIS].offset_)
         trans = Align_interface::get_pure_child_y_translation (p, this, start, end);
-
+//printf ("%s O T %4.4f %4.4f\n", name().c_str(), off, trans);
       return off + trans + p->pure_relative_y_coordinate (refp, start, end);
     }
   return off;
@@ -924,6 +924,25 @@ common_refpoint_of_array (set<Grob *> const &arr, Grob *common, Axis a)
 }
 
 Interval
+maybe_pure_robust_relative_extent (Grob *me, Grob *refp, Axis a, bool pure, int start, int end)
+{
+  if (pure && a != Y_AXIS)
+    programming_error ("tried to get pure X-offset");
+  return (pure && a == Y_AXIS) ? pure_robust_relative_extent (me, refp, start, end)
+         : robust_relative_extent (me, refp, a);
+}
+
+Interval
+pure_robust_relative_extent (Grob *me, Grob *refpoint, int start, int end)
+{
+  Interval ext = me->pure_height (refpoint, start, end);
+  if (ext.is_empty ())
+    ext.add_point (me->pure_relative_y_coordinate (refpoint, start, end));
+
+  return ext;
+}
+
+Interval
 robust_relative_extent (Grob *me, Grob *refpoint, Axis a)
 {
   Interval ext = me->extent (refpoint, a);