Revert "side-position-interface: use real positions of cross-staff grobs; issue 3363"

[lilypond.git] / lily / side-position-interface.cc

diff --git a/lily/side-position-interface.cc b/lily/side-position-interface.cc
index 095b8b49c344db5566303b987dd890eea42136a4..dad906f51bf2cef85fcf9ac617d3cdc381a1b28d 100644 (file)
--- a/lily/side-position-interface.cc
+++ b/lily/side-position-interface.cc
@@ -149,29 +149,32 @@ Side_position_interface::calc_cross_staff (SCM smob)
 {
   Grob *me = unsmob_grob (smob);
   extract_grob_set (me, "side-support-elements", elts);
-// Commented out because of cross staff issues
-// Direction for cross staff stems depends on the spacing of staves,
-// which depends on the inclusion of cross-staff side position grobs,
-// which need the direction for positioning.  So the get_grob_direction call
-// may lead to circular dependencies.
-// #if 0
+
   Direction my_dir = get_grob_direction (me) ;
 
-  // if a cross-staff grob is pointing in a different direction than
-  // that of an aligning element, we assume that the alignment
-  // of said element will not be influenced the cross-staffitude
-  // of the grob and thus we do not mark the aligning element
-  // as cross-staff
-  for (vsize i = 0; i < elts.size (); i++)
-    if (to_boolean (elts[i]->get_property ("cross-staff"))
-         && my_dir == get_grob_direction (elts[i]))
-      return SCM_BOOL_T;
-//#endif
-#if 0
   for (vsize i = 0; i < elts.size (); i++)
-    if (to_boolean (elts[i]->get_property ("cross-staff")))
-      return SCM_BOOL_T;
-#endif
+    {
+      /*
+        If 'me' is placed relative to any cross-staff element with a
+        'direction callback defined, the placement of 'me' is likely
+        to depend on staff-spacing, thus 'me' should be considered
+        cross-staff.
+      */
+      if (to_boolean (elts[i]->get_property ("cross-staff"))
+           && !is_direction (elts[i]->get_property_data ("direction")))
+        return SCM_BOOL_T;
+
+      /*
+        If elts[i] is cross-staff and is pointing in the same
+        direction as 'me', we assume that the alignment
+        of 'me' is influenced the cross-staffitude of elts[i]
+        and thus we mark 'me' as cross-staff.
+      */
+      if (to_boolean (elts[i]->get_property ("cross-staff"))
+           && my_dir == get_grob_direction (elts[i]))
+        return SCM_BOOL_T;
+    }
+
   Grob *myvag = Grob::get_vertical_axis_group (me);
   for (vsize i = 0; i < elts.size (); i++)
     if (myvag != Grob::get_vertical_axis_group (elts[i]))
@@ -256,6 +259,18 @@ Side_position_interface::aligned_side (Grob *me, Axis a, bool pure, int start, i
       // In the case of a stem, we will find a note head as well
       // ignoring the stem solves cyclic dependencies if the stem is
       // attached to a cross-staff beam.
+      bool cross_staff = to_boolean (e->get_property ("cross-staff"));
+
+      // avoid cyclic dependency for direction
+      if (a == Y_AXIS
+          && pure
+          && Stem::has_interface (e)
+          && cross_staff
+          && !is_direction (e->get_property_data ("direction")))
+        continue;
+
+      // avoid unnecessary stem look up (if pointing away, it is not
+      // supporting anything)
       if (a == Y_AXIS
           && Stem::has_interface (e)
           && dir == - get_grob_direction (e))
@@ -264,7 +279,6 @@ Side_position_interface::aligned_side (Grob *me, Axis a, bool pure, int start, i
       if (e)
         {
 
-           bool cross_staff = to_boolean (e->get_property ("cross-staff"));
 
            Skyline_pair *sp = Skyline_pair::unsmob
              (e->get_maybe_pure_property (a == X_AXIS
@@ -314,23 +328,27 @@ Side_position_interface::aligned_side (Grob *me, Axis a, bool pure, int start, i
       dim.set_minimum_height (staff_extents[dir]);
     }
 
-  // this seems kinda kludgy, as there is no apparent logic to it
-  // however, it is a holdover from the previous code and
-  // necessary for the InstrumentName grob
-  // TODO: find a better way to deal with this...
+  // Sometimes, we want to side position for grobs but they
+  // don't position against anything.  Some cases where this is true:
+  //   - StanzaNumber if the supporting lyrics are hara-kiri'd
+  //     SystemStartBracket
+  //     InstrumentName
+  // In all these cases, we set the height of the support to 0.
+  // This becomes then like the self-alignment-interface with the
+  // caveat that there is padding added.
+  // TODO: if there is a grob that never has side-support-elements
+  // (like InstrumentName), why are we using this function? Isn't it
+  // overkill? A function like self-alignment-interface with padding
+  // works just fine.
+  // One could even imagine the two interfaces merged, as the only
+  // difference is that in self-alignment-interface we align on the parent
+  // where as here we align on a group of grobs.
   if (dim.is_empty ())
     {
       dim = Skyline (dim.direction ());
       dim.set_minimum_height (0.0);
     }
 
-  // Ditto - seems kludgy, but this time logic of SystemStartBrackets
-  if (my_dim.is_empty ())
-    {
-      my_dim = Skyline (my_dim.direction ());
-      my_dim.set_minimum_height (isinf (max_raise) ? 0.0 : max_raise);
-    }
-
   // Many cross-staff grobs do not have good height estimations.
   // We give the grob the best chance of not colliding by shifting
   // it to the maximum height in the case of cross-staff alignment.