lily/lyric-extender.cc

   1 /*
   2   lyric-extender.cc -- implement Lyric_extender
   3   source file of the GNU LilyPond music typesetter
   4
   5   (c) 1998--2009 Jan Nieuwenhuizen <janneke@gnu.org>
   6   Han-Wen Nienhuys
   7 */
   8
   9 #include "lyric-extender.hh"
  10
  11 #include "system.hh"
  12 #include "item.hh"
  13 #include "warn.hh"
  14 #include "lookup.hh"
  15 #include "output-def.hh"
  16 #include "note-head.hh"
  17 #include "pointer-group-interface.hh"
  18
  19 MAKE_SCHEME_CALLBACK (Lyric_extender, print, 1);
  20 SCM
  21 Lyric_extender::print (SCM smob)
  22 {
  23   Spanner *me = unsmob_spanner (smob);
  24   Item *left_edge = me->get_bound (LEFT);
  25   Item *right_text = unsmob_item (me->get_object ("next"));
  26
  27   Grob *common = left_edge;
  28
  29   if (right_text)
  30     common = common->common_refpoint (right_text, X_AXIS);
  31
  32   common = common->common_refpoint (me->get_bound (RIGHT), X_AXIS);
  33   common = common->common_refpoint (me->get_system (), X_AXIS);
  34
  35   Real sl = me->layout ()->get_dimension (ly_symbol2scm ("line-thickness"));
  36
  37   extract_grob_set (me, "heads", heads);
  38
  39   if (!heads.size ())
  40     return SCM_EOL;
  41
  42   common = common_refpoint_of_array (heads, common, X_AXIS);
  43
  44   Real left_point = 0.0;
  45   if (left_edge->internal_has_interface (ly_symbol2scm ("lyric-syllable-interface")))
  46     left_point = left_edge->extent (common, X_AXIS)[RIGHT];
  47   else if (heads.size ())
  48     left_point = heads[0]->extent (common, X_AXIS)[LEFT];
  49   else
  50     left_point = left_edge->extent (common, X_AXIS)[RIGHT];
  51
  52   if (isinf (left_point))
  53     return SCM_EOL;
  54
  55   /* It seems that short extenders are even lengthened to go past the
  56      note head, but haven't found a pattern in it yet. --hwn 1/1/04  */
  57   SCM minlen = me->get_property ("minimum-length");
  58   Real right_point
  59     = left_point + (robust_scm2double (minlen, 0));
  60
  61   right_point = min (right_point, me->get_system ()->get_bound (RIGHT)->relative_coordinate (common, X_AXIS));
  62
  63   if (heads.size ())
  64     right_point = max (right_point, heads.back ()->extent (common, X_AXIS)[RIGHT]);
  65
  66   Real h = sl * robust_scm2double (me->get_property ("thickness"), 0);
  67   Drul_array<Real> paddings (robust_scm2double (me->get_property ("left-padding"), h),
  68                              robust_scm2double (me->get_property ("right-padding"), h));
  69
  70   if (right_text)
  71     right_point = min (right_point, (robust_relative_extent (right_text, common, X_AXIS)[LEFT] - paddings[RIGHT]));
  72
  73   /* run to end of line. */
  74   if (me->get_bound (RIGHT)->break_status_dir ())
  75     right_point = max (right_point, (robust_relative_extent (me->get_bound (RIGHT), common, X_AXIS)[LEFT] - paddings[RIGHT]));
  76
  77   left_point += paddings[LEFT];
  78   Real w = right_point - left_point;
  79
  80   if (w < 1.5 * h)
  81     return SCM_EOL;
  82
  83   Stencil mol (Lookup::round_filled_box (Box (Interval (0, w),
  84                                               Interval (0, h)),
  85                                          0.8 * h));
  86   mol.translate_axis (left_point - me->relative_coordinate (common, X_AXIS),
  87                       X_AXIS);
  88   return mol.smobbed_copy ();
  89 }
  90
  91 ADD_INTERFACE (Lyric_extender,
  92                "The extender is a simple line at the baseline of the lyric"
  93                " that helps show the length of a melisma (a tied or slurred"
  94                " note).",
  95
  96                /* properties */
  97                "heads "
  98                "left-padding "
  99                "next "
 100                "right-padding "
 101                "thickness "
 102                );