lily/crescendo.cc

   1 /*
   2   crescendo.cc -- implement Hairpin
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c)  1997--2000 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9 #include "molecule.hh"
  10 #include "crescendo.hh"
  11 #include "spanner.hh"
  12 #include "font-interface.hh"
  13 #include "dimensions.hh"
  14 #include "paper-def.hh"
  15 #include "debug.hh"
  16 #include "paper-column.hh"
  17
  18 MAKE_SCHEME_CALLBACK (Hairpin, brew_molecule, 1);
  19
  20 SCM
  21 Hairpin::brew_molecule (SCM smob)
  22 {
  23   Grob *me= unsmob_grob (smob);
  24   Spanner *span = dynamic_cast<Spanner*>(me);
  25
  26   Real line = me->paper_l ()->get_var ("stafflinethickness");
  27
  28   Real broken_left =  span->get_broken_left_end_align ();
  29
  30   SCM s = me->get_grob_property("grow-direction");
  31   if (!isdir_b (s))
  32     {
  33       me->suicide ();
  34       return SCM_EOL;
  35     }
  36
  37   Direction grow_dir = to_dir (s);
  38   Real padding = gh_scm2double (me->get_grob_property ("padding"));
  39   Real width = span->spanner_length ();
  40   width -= span->get_broken_left_end_align ();
  41
  42   if (width < 0)
  43     {
  44       warning (_ ((grow_dir < 0) ? "decrescendo too small"
  45                   : "crescendo too small"));
  46       width = 0;
  47     }
  48
  49   Drul_array<bool> broken;
  50   Drul_array<Real> extra_off;
  51   Direction d = LEFT;
  52   do
  53     {
  54       Item *b = span->get_bound (d);
  55       broken[d] = b->break_status_dir () != CENTER;
  56
  57       if (!broken [d])
  58         {
  59
  60           Interval e =b->extent (b, X_AXIS);
  61           Real r = 0.0;
  62           if (!e.empty_b ())
  63             r = e[-d] + padding;
  64           width += d * r;
  65           extra_off[d] = r;
  66         }
  67     }
  68   while (flip (&d) != LEFT);
  69
  70   bool continued = broken[Direction (-grow_dir)];
  71   Real height = gh_scm2double (me->get_grob_property ("height"));
  72   Real thick = line * gh_scm2double (me->get_grob_property ("thickness"));
  73
  74   const char* type = (grow_dir < 0) ? "decrescendo" :  "crescendo";
  75   SCM hairpin = gh_list (ly_symbol2scm (type),
  76                     gh_double2scm (thick),
  77                     gh_double2scm (width),
  78                     gh_double2scm (height),
  79                     gh_double2scm (continued ? height/2 : 0.0),
  80                     SCM_UNDEFINED);
  81
  82   Box b (Interval (0, width), Interval (-2*height, 2*height));
  83   Molecule mol (b, hairpin);
  84   mol.translate_axis (broken_left + extra_off[LEFT], X_AXIS);
  85
  86   return mol.smobbed_copy ();
  87 }
  88
  89