lily/arpeggio.cc

   1 /*
   2   arpegggio.cc -- implement Arpeggio
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2000--2001 Jan Nieuwenhuizen <janneke@gnu.org>
   7  */
   8
   9 #include "molecule.hh"
  10 #include "paper-def.hh"
  11 #include "arpeggio.hh"
  12 #include "grob.hh"
  13 #include "stem.hh"
  14 #include "staff-symbol-referencer.hh"
  15 #include "staff-symbol.hh"
  16 #include "warn.hh"
  17 #include "font-interface.hh"
  18
  19 bool
  20 Arpeggio::has_interface (Grob* me)
  21 {
  22   return me && me->has_interface (ly_symbol2scm ("arpeggio-interface"));
  23 }
  24
  25 MAKE_SCHEME_CALLBACK (Arpeggio, brew_molecule, 1);
  26 SCM
  27 Arpeggio::brew_molecule (SCM smob)
  28 {
  29   Grob *me = unsmob_grob (smob);
  30
  31   Grob * common = me;
  32   for (SCM s = me->get_grob_property ("stems"); gh_pair_p (s); s = gh_cdr (s))
  33     {
  34       Grob * stem =  unsmob_grob (gh_car (s));
  35       common =  common->common_refpoint (Staff_symbol_referencer::staff_symbol_l (stem),
  36                                  Y_AXIS);
  37     }
  38
  39   /*
  40     TODO:
  41
  42     Using stems here is not very convenient; should store noteheads
  43     instead, and also put them into the support. Now we will mess up
  44     in vicinity of a collision.
  45
  46   */
  47   Interval heads;
  48   Real my_y = me->relative_coordinate (common, Y_AXIS);
  49
  50   for (SCM s = me->get_grob_property ("stems"); gh_pair_p (s); s = gh_cdr (s))
  51     {
  52       Grob * stem = unsmob_grob (gh_car (s));
  53       Grob * ss = Staff_symbol_referencer::staff_symbol_l (stem);
  54       Interval iv =Stem::head_positions (stem);
  55       iv *= Staff_symbol::staff_space (ss)/2.0;
  56
  57       heads.unite (iv + ss->relative_coordinate (common, Y_AXIS)
  58                    - my_y);
  59     }
  60
  61   if (heads.empty_b ())
  62     {
  63       programming_error ("Huh? Dumb blonde encountered?");
  64       /*
  65         Nee Valerie, jij bent _niet_ dom.
  66        */
  67       return SCM_EOL;
  68     }
  69
  70   Molecule mol;
  71   Molecule arpeggio = Font_interface::get_default_font (me)->find_by_name ("scripts-arpeggio");
  72
  73   Real y = heads[LEFT];
  74   while (y < heads[RIGHT])
  75     {
  76       mol.add_at_edge (Y_AXIS, UP,arpeggio, 0.0);
  77       y+= arpeggio. extent (Y_AXIS).length ();
  78     }
  79   mol.translate_axis (heads[LEFT], Y_AXIS);
  80
  81   return mol.smobbed_copy () ;
  82 }
  83
  84 /*
  85   We have to do a callback, because brew_molecule () triggers a
  86   vertical alignment if it is cross-staff.
  87   This callback also adds padding.
  88 */
  89 MAKE_SCHEME_CALLBACK (Arpeggio, width_callback,2);
  90 SCM
  91 Arpeggio::width_callback (SCM smob, SCM axis)
  92 {
  93   Grob * me = unsmob_grob (smob);
  94   Axis a = (Axis)gh_scm2int (axis);
  95   assert (a == X_AXIS);
  96   Molecule arpeggio = Font_interface::get_default_font (me)->find_by_name ("scripts-arpeggio");
  97
  98   return ly_interval2scm (arpeggio.extent (X_AXIS) * 1.5);
  99 }