lily/stem-tremolo.cc

   1 /*
   2   stem-tremolo.cc --  implement Stem_tremolo
   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
  10 #include "stem-tremolo.hh"
  11 #include "debug.hh"
  12 #include "beam.hh"
  13 #include "paper-def.hh"
  14 #include "lookup.hh"
  15 #include "stem.hh"
  16 #include "item.hh"
  17 #include "staff-symbol-referencer.hh"
  18 #include "directional-element-interface.hh"
  19
  20 /*
  21   TODO:
  22     lengthen stem if necessary
  23  */
  24
  25 void
  26 Stem_tremolo::set_interface (Grob *me)
  27 {
  28   me->set_interface (ly_symbol2scm ("stem-tremolo"));
  29 }
  30
  31 bool
  32 Stem_tremolo::has_interface (Grob *me)
  33 {
  34   return me->has_interface (ly_symbol2scm ("stem-tremolo"));
  35 }
  36
  37 MAKE_SCHEME_CALLBACK(Stem_tremolo,dim_callback,2);
  38
  39 /*
  40   todo: init with cons.
  41  */
  42 SCM
  43 Stem_tremolo::dim_callback (SCM e, SCM )
  44 {
  45   Grob * se = unsmob_grob (e);
  46
  47   Real space = Staff_symbol_referencer::staff_space (se);
  48   return ly_interval2scm ( Interval (-space, space));
  49 }
  50
  51 /*
  52   ugh ?  --from Slur
  53  */
  54 MAKE_SCHEME_CALLBACK (Stem_tremolo, height, 2);
  55 SCM
  56 Stem_tremolo::height (SCM smob, SCM ax)
  57 {
  58   Axis a = (Axis)gh_scm2int (ax);
  59   Grob * me = unsmob_grob (smob);
  60   assert ( a == Y_AXIS);
  61
  62   SCM mol = me->get_uncached_molecule ();
  63   return ly_interval2scm (unsmob_molecule (mol)->extent (a));
  64 }
  65
  66
  67 MAKE_SCHEME_CALLBACK(Stem_tremolo,brew_molecule,1);
  68 SCM
  69 Stem_tremolo::brew_molecule (SCM smob)
  70 {
  71   Grob *me= unsmob_grob (smob);
  72   Grob * stem = unsmob_grob (me->get_grob_property ("stem"));
  73   Grob * beam = Stem::beam_l (stem);
  74
  75   Real dydx;
  76   if (beam)
  77     {
  78       Real dy = 0;
  79       SCM s = beam->get_grob_property ("height");
  80       if (gh_number_p (s))
  81         dy = gh_scm2double (s);
  82       Real dx = Beam::last_visible_stem (beam)->relative_coordinate (0, X_AXIS)
  83         - Beam::first_visible_stem (beam)->relative_coordinate (0, X_AXIS);
  84       dydx = dx ? dy/dx : 0;
  85     }
  86   else
  87     // urg
  88     dydx = 0.25;
  89
  90   Real ss = Staff_symbol_referencer::staff_space (stem);
  91   Real thick = gh_scm2double (me->get_grob_property ("beam-thickness"));
  92   Real width = gh_scm2double (me->get_grob_property ("beam-width"));
  93   width *= ss;
  94   thick *= ss;
  95
  96   Molecule a (Lookup::beam (dydx, width, thick));
  97   a.translate (Offset (-width/2, width / 2 * dydx));
  98
  99   int tremolo_flags;
 100   SCM s = me->get_grob_property ("tremolo-flags");
 101   if (gh_number_p (s))
 102     tremolo_flags = gh_scm2int (s);
 103   else
 104     // huh?
 105     tremolo_flags = 1;
 106
 107   int mult = beam ? Beam::get_multiplicity (beam) : 0;
 108   SCM space_proc = me->get_grob_property ("beam-space-function");
 109   SCM space = gh_call1 (space_proc, gh_int2scm (mult));
 110   Real interbeam_f = gh_scm2double (space) * ss;
 111
 112
 113   Molecule mol;
 114   for (int i = 0; i < tremolo_flags; i++)
 115     {
 116       Molecule b (a);
 117       b.translate_axis (interbeam_f * i, Y_AXIS);
 118       mol.add_molecule (b);
 119     }
 120   if (tremolo_flags)
 121     mol.translate_axis (-mol.extent (Y_AXIS).center (), Y_AXIS);
 122   if (beam)
 123     {
 124       // ugh, rather calc from Stem_tremolo_req
 125       int beams_i = Stem::beam_count(stem, RIGHT) >? Stem::beam_count (stem, LEFT);
 126       mol.translate (Offset(stem->relative_coordinate (0, X_AXIS) - me->relative_coordinate (0, X_AXIS),
 127                             Stem::stem_end_position (stem ) * ss / 2 -
 128                             Directional_element_interface::get (beam) * beams_i * interbeam_f));
 129     }
 130   else
 131     {
 132       /*
 133         Beams should intersect one beamthickness below stem end
 134       */
 135       Real dy = Stem::stem_end_position (stem ) * ss / 2;
 136       dy -= mol.extent (Y_AXIS).length () / 2 *  Stem::get_direction (stem );
 137
 138       /*
 139         uhg.  Should use relative coords and placement
 140       */
 141       Real whole_note_correction;
 142       if (Stem::invisible_b (stem ))
 143         {
 144           Grob *hed = Stem::support_head (stem );
 145           whole_note_correction = -Stem::get_direction (stem )
 146             *hed->extent (hed, X_AXIS).length () / 2;
 147         }
 148       else
 149         whole_note_correction = 0;
 150
 151       mol.translate (Offset (stem->relative_coordinate (0, X_AXIS) - me->relative_coordinate (0, X_AXIS) +
 152                              whole_note_correction, dy));
 153     }
 154
 155   return mol.smobbed_copy ();
 156 }
 157
 158
 159 void
 160 Stem_tremolo::set_stem (Grob*me,Grob *s)
 161 {
 162   me->set_grob_property ("stem", s->self_scm ());
 163 }
 164