lily/crescendo.cc

   1 /*
   2   crescendo.cc -- implement Crescendo
   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 (Crescendo, brew_molecule, 1);
  19
  20 SCM
  21 Crescendo::brew_molecule (SCM smob)
  22 {
  23   Score_element *me= unsmob_element (smob);
  24   Spanner *span = dynamic_cast<Spanner*>(me);
  25   Real staff_space = me->paper_l ()->get_var ("staffspace");
  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_elt_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
  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   Direction d = LEFT;
  51   do
  52     {
  53       Paper_column* s = dynamic_cast<Paper_column*> (span->get_bound (d)); // UGH
  54       broken[d] = (!s->musical_b ());
  55     }
  56   while (flip (&d) != LEFT);
  57
  58   bool continued = broken[Direction (-grow_dir)];
  59   Real height = staff_space * gh_scm2double (me->get_elt_property ("height"));
  60   Real thick = line * gh_scm2double (me->get_elt_property ("thickness"));
  61
  62   const char* type = (grow_dir < 0) ? "decrescendo" :  "crescendo";
  63   SCM hairpin = gh_list (ly_symbol2scm (type),
  64                     gh_double2scm (thick),
  65                     gh_double2scm (width),
  66                     gh_double2scm (height),
  67                     gh_double2scm (continued ? height/2 : 0.0),
  68                     SCM_UNDEFINED);
  69
  70   Box b (Interval (0, width), Interval (-2*height, 2*height));
  71   Molecule mol (b, hairpin);
  72   mol.translate_axis (broken_left, X_AXIS);
  73
  74   return mol.create_scheme ();
  75 }
  76
  77