Aligns horizontally-offset fingerings in a column if X distance is small (issue 3269)

Uses a new property snap-radius to "snap" fingerings into alignment if they
look like they naturally belong in a column.

diff --git a/input/regression/fingering-column-snap-radius.ly b/input/regression/fingering-column-snap-radius.ly
new file mode 100644 (file)
index 0000000..bebd1a1
--- /dev/null
+++ b/input/regression/fingering-column-snap-radius.ly
@@ -0,0 +1,13 @@
+\version "2.17.15"
+
+\header {
+  texidoc = "Horizontally-offset @code{Fingerings} align along the Y axis when
+they are within @code{FingeringColumn.snap-radius} of each other.
+"
+}
+
+\relative f'' {
+  \set fingeringOrientations = #'(left)
+  <cis-1 a-1 e-1>4
+  <ceses-1 a-1 e-1>4
+}

diff --git a/lily/fingering-column.cc b/lily/fingering-column.cc
index 1cc6c12b116ca4689d746dedaab149f031712d59..62d7d08db1d7b2dc8f1b0351d2ed2fad992d0e38 100644 (file)
--- a/lily/fingering-column.cc
+++ b/lily/fingering-column.cc
@@ -17,6 +17,7 @@
   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include "directional-element-interface.hh"
 #include "grob.hh"
 #include "fingering-column.hh"
 #include "pointer-group-interface.hh"
@@ -24,6 +25,26 @@
 #include "item.hh"
 #include "paper-column.hh"
 
+#define EPS 1e-5
+
+struct Fingering_and_offset
+{
+  Grob *fingering_;
+  Real offset_;
+  Fingering_and_offset (Grob *fingering, Real offset);
+};
+
+Fingering_and_offset::Fingering_and_offset (Grob *fingering, Real offset) :
+  fingering_ (fingering), offset_ (offset)
+{
+}
+
+bool
+fingering_and_offset_less (Fingering_and_offset fo0, Fingering_and_offset fo1)
+{
+  return fo0.offset_ < fo1.offset_;
+}
+
 MAKE_SCHEME_CALLBACK (Fingering_column, calc_positioning_done, 1);
 SCM
 Fingering_column::calc_positioning_done (SCM smob)
@@ -34,12 +55,21 @@ Fingering_column::calc_positioning_done (SCM smob)
 
   me->set_property ("positioning-done", SCM_BOOL_T);
 
+  do_y_positioning (me);
+  do_x_positioning (me);
+
+  return SCM_BOOL_T;
+}
+
+void
+Fingering_column::do_y_positioning (Grob *me)
+{
   extract_grob_set (me, "fingerings", const_fingerings);
 
   if (const_fingerings.size () < 2)
     {
       me->programming_error ("This FingeringColumn should have never been created.");
-      return SCM_BOOL_T;
+      return;
     }
 
   vector<Grob *> fingerings;
@@ -86,8 +116,40 @@ Fingering_column::calc_positioning_done (SCM smob)
 
   for (vsize i = 0; i < fingerings.size (); i++)
     fingerings[i]->translate_axis(shift[i], Y_AXIS);
+}
+
+void
+Fingering_column::do_x_positioning (Grob *me)
+{
+  extract_grob_set (me, "fingerings", fingerings);
+  if (!fingerings.size ())
+    return;
+
+  Grob *common_x = common_refpoint_of_array (fingerings, me, X_AXIS);
+
+  Real snap = robust_scm2double (me->get_property ("snap-radius"), 0.3);
+  vector<Fingering_and_offset> fos;
+
+  for (vsize i = 0; i < fingerings.size (); i++)
+    fos.push_back (Fingering_and_offset (fingerings[i], fingerings[i]->relative_coordinate (common_x, X_AXIS)));
+
+  vector_sort (fos, fingering_and_offset_less);
+  Direction dir = get_grob_direction (fingerings[0]);
+  if (dir == RIGHT)
+    reverse (fos);
+
+  Real prev = infinity_f * dir;
+  for (vsize i = 0; i < fos.size (); i++)
+    {
+      if ((fabs (fos[i].offset_ - prev) < snap)
+                && (fabs (fos[i].offset_ - prev) > EPS))
+        fos[i].offset_ = prev;
+
+      prev = fos[i].offset_;
+    }
 
- return SCM_BOOL_T;
+  for (vsize i = 0; i < fos.size (); i++)
+    fos[i].fingering_->translate_axis (fos[i].offset_ - fos[i].fingering_->relative_coordinate (common_x, X_AXIS), X_AXIS);
 }
 
 void
@@ -100,9 +162,11 @@ Fingering_column::add_fingering (Grob *fc, Grob *f)
 
 ADD_INTERFACE (Fingering_column,
                "Makes sure that fingerings placed laterally"
-               " do not collide.",
+               " do not collide and that they are flush if"
+               " necessary.",
 
                /* properties */
                "padding "
                "positioning-done "
+               "snap-radius "
               );

diff --git a/lily/include/fingering-column.hh b/lily/include/fingering-column.hh
index 6d6bef2376c9daeb109217a8886ea72efb6e114f..5052322f123c30f61797b4574c945b89cb2c0476 100644 (file)
--- a/lily/include/fingering-column.hh
+++ b/lily/include/fingering-column.hh
@@ -29,6 +29,8 @@ struct Fingering_column
   static void add_fingering (Grob *, Grob *);
   DECLARE_SCHEME_CALLBACK (calc_positioning_done, (SCM));
   DECLARE_GROB_INTERFACE ();
+  static void do_x_positioning (Grob *me);
+  static void do_y_positioning (Grob *me);
 };
 
 #endif /* FINGERING_COLUMN_HH */

diff --git a/scm/define-grob-properties.scm b/scm/define-grob-properties.scm
index 9afb49a0a32e4c3fb471df85f1ad3aea23f06ca4..4c5c404dc78a1c06b6e86ace9020b96f32aeb669 100644 (file)
--- a/scm/define-grob-properties.scm
+++ b/scm/define-grob-properties.scm
@@ -830,6 +830,8 @@ slashes in percent repeat glyphs.  Larger values bring the two
 elements closer together.")
      (slope ,number? "The slope of this object.")
      (slur-padding ,number? "Extra distance between slur and script.")
+     (snap-radius ,number? "The maximum distance between two objects that
+will cause them to snap to alignment along an axis.")
      (space-alist ,list? "A table that specifies distances between
 prefatory items, like clef and time-signature.  The format is an alist
 of spacing tuples: @code{(@var{break-align-symbol} @var{type}

diff --git a/scm/define-grobs.scm b/scm/define-grobs.scm
index 19a767fba5cd980145fa33cd578053e3c606873b..e825cb1ef0a8c4f3192dea85c08d79234c3ee0e3 100644 (file)
--- a/scm/define-grobs.scm
+++ b/scm/define-grobs.scm
@@ -932,6 +932,7 @@
      . (
        (padding . 0.2)
        (positioning-done . ,ly:fingering-column::calc-positioning-done)
+       (snap-radius . 0.3)
        (meta . ((class . Item)
                 (interfaces . (fingering-column-interface))))))