Better pure height approximations of stem tremolos.

Before this patch, stem-tremolo pure heights wer always centered at
the offset of their Y parent (often 0), which means that tremolos
were not being considered correctly in horizontal spacing.  This
patch fixes that.  The regression test stem-tremolo-note-column.ly
now correctly checks for this - before, it only worked because flags
were combined with stems and created a Y-extent that overshot the
flag ending. Making more accurate flag extents broke this regression
test, and this patch rectifies it.

diff --git a/lily/include/stem-tremolo.hh b/lily/include/stem-tremolo.hh
index a7e026a5704d04c0ea67ebfc9dede498466918bd..388dc01388f9a0ce60f5640861b3aba276f9d68b 100644 (file)
--- a/lily/include/stem-tremolo.hh
+++ b/lily/include/stem-tremolo.hh
@@ -30,12 +30,14 @@ public:
   DECLARE_GROB_INTERFACE ();
   DECLARE_SCHEME_CALLBACK (calc_slope, (SCM));
   DECLARE_SCHEME_CALLBACK (calc_width, (SCM));
+  DECLARE_SCHEME_CALLBACK (calc_y_offset, (SCM));
+  DECLARE_SCHEME_CALLBACK (pure_calc_y_offset, (SCM, SCM, SCM));
   DECLARE_SCHEME_CALLBACK (print, (SCM));
   DECLARE_SCHEME_CALLBACK (width, (SCM));
   DECLARE_SCHEME_CALLBACK (calc_style, (SCM));
   DECLARE_SCHEME_CALLBACK (pure_height, (SCM, SCM, SCM));
   static Stencil raw_stencil (Grob *, Real slope, Direction stemdir);
-  static Stencil translated_stencil (Grob *, Real slope);
+  static Real y_offset (Grob *, bool pure);
   static Stencil untranslated_stencil (Grob *, Real slope);
   static Real get_beam_translation (Grob *me);
   static Real vertical_length (Grob *me);

diff --git a/lily/stem-tremolo.cc b/lily/stem-tremolo.cc
index cc4589827e69d13b37da34030d98ca5a5fe1658c..a45ae1182abee4b71c609842cc2c362a1e3f35ee 100644 (file)
--- a/lily/stem-tremolo.cc
+++ b/lily/stem-tremolo.cc
@@ -147,14 +147,35 @@ MAKE_SCHEME_CALLBACK (Stem_tremolo, pure_height, 3);
 SCM
 Stem_tremolo::pure_height (SCM smob, SCM, SCM)
 {
-  Grob *me = unsmob_grob (smob);
+  Item *me = unsmob_item (smob);
 
   /*
     Cannot use the real slope, since it looks at the Beam.
    */
   Stencil s1 (untranslated_stencil (me, 0.35));
+  Item *stem = unsmob_item (me->get_object ("stem"));
+  if (!stem)
+    return ly_interval2scm (s1.extent (Y_AXIS));
+
+  Direction stemdir = get_grob_direction (stem);
+  if (stemdir == 0)
+    stemdir = UP;
+
+  Spanner *beam = Stem::get_beam (stem);
 
-  return ly_interval2scm (s1.extent (Y_AXIS));
+  if (!beam)
+    return ly_interval2scm (s1.extent (Y_AXIS));
+
+  Interval ph = stem->pure_height (stem, 0, INT_MAX);
+  Stem_info si = Stem::get_stem_info (stem);
+  ph[-stemdir] = si.shortest_y_;
+  int beam_count = Stem::beam_multiplicity (stem).length () + 1;
+  Real beam_translation = get_beam_translation (me);
+
+  ph = ph - stemdir * max (beam_count, 1) * beam_translation;
+  ph = ph - ph.center ();
+
+  return ly_interval2scm (ph);
 }
 
 MAKE_SCHEME_CALLBACK (Stem_tremolo, width, 1);
@@ -199,14 +220,30 @@ Stem_tremolo::untranslated_stencil (Grob *me, Real slope)
   return raw_stencil (me, slope, stencil_dir);
 }
 
-Stencil
-Stem_tremolo::translated_stencil (Grob *me, Real slope)
+MAKE_SCHEME_CALLBACK (Stem_tremolo, calc_y_offset, 1);
+SCM
+Stem_tremolo::calc_y_offset (SCM smob)
 {
-  Stencil mol = untranslated_stencil (me, slope);
+  Grob *me = unsmob_grob (smob);
+  return scm_from_double (y_offset (me, false));
+}
 
-  Grob *stem = unsmob_grob (me->get_object ("stem"));
+MAKE_SCHEME_CALLBACK (Stem_tremolo, pure_calc_y_offset, 3);
+SCM
+Stem_tremolo::pure_calc_y_offset (SCM smob,
+                                  SCM, /* start */
+                                  SCM /* end */)
+{
+  Grob *me = unsmob_grob (smob);
+  return scm_from_double (y_offset (me, true));
+}
+
+Real
+Stem_tremolo::y_offset (Grob *me, bool pure)
+{
+  Item *stem = unsmob_item (me->get_object ("stem"));
   if (!stem)
-    return Stencil ();
+    return 0.0;
 
   Direction stemdir = get_grob_direction (stem);
   if (stemdir == 0)
@@ -217,6 +254,15 @@ Stem_tremolo::translated_stencil (Grob *me, Real slope)
 
   int beam_count = beam ? (Stem::beam_multiplicity (stem).length () + 1) : 0;
 
+  if (pure && beam)
+    {
+      Interval ph = stem->pure_height (stem, 0, INT_MAX);
+      Stem_info si = Stem::get_stem_info (stem);
+      ph[-stemdir] = si.shortest_y_;
+
+      return (ph - stemdir * max (beam_count, 1) * beam_translation)[stemdir] - stemdir * 0.5 * me->pure_height (me, 0, INT_MAX).length ();
+    }
+
   Real end_y
     = stem->extent (stem, Y_AXIS)[stemdir]
       - stemdir * max (beam_count, 1) * beam_translation;
@@ -238,9 +284,8 @@ Stem_tremolo::translated_stencil (Grob *me, Real slope)
       Real note_head = (stemdir == UP ? nhp.back () : nhp[0]) * ss / 2;
       end_y = note_head + stemdir * 1.5;
     }
-  mol.translate_axis (end_y, Y_AXIS);
 
-  return mol;
+  return end_y;
 }
 
 MAKE_SCHEME_CALLBACK (Stem_tremolo, print, 1);
@@ -249,7 +294,7 @@ Stem_tremolo::print (SCM grob)
 {
   Grob *me = unsmob_grob (grob);
 
-  Stencil s = translated_stencil (me, robust_scm2double (me->get_property ("slope"), 0.25));
+  Stencil s = untranslated_stencil (me, robust_scm2double (me->get_property ("slope"), 0.25));
   return s.smobbed_copy ();
 }
 

diff --git a/scm/define-grobs.scm b/scm/define-grobs.scm
index f132b2aa1076f63f1f6ebd754a74a8cef28169ab..4bbe29beb1d90b888d6ae2cc7403b30a43360d27 100644 (file)
--- a/scm/define-grobs.scm
+++ b/scm/define-grobs.scm
@@ -1949,6 +1949,7 @@
        (stencil . ,ly:stem-tremolo::print)
        (style . ,ly:stem-tremolo::calc-style)
        (X-extent . ,ly:stem-tremolo::width)
+       (Y-offset . ,ly:stem-tremolo::calc-y-offset)
        (meta . ((class . Item)
                 (interfaces . (stem-tremolo-interface))))))
 
@@ -2643,6 +2644,7 @@
     (,ly:slur::outside-slur-callback . ,ly:slur::pure-outside-slur-callback)
     (,ly:stem::calc-stem-end-position . ,ly:stem::pure-calc-stem-end-position)
     (,ly:stem::height . ,ly:stem::pure-height)
+    (,ly:stem-tremolo::calc-y-offset . ,ly:stem-tremolo::pure-calc-y-offset)
     (,ly:system::height . ,ly:system::calc-pure-height)))
 
 (define pure-functions