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--2005 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9 #include "stem-tremolo.hh"
  10
  11 #include "spanner.hh"
  12 #include "beam.hh"
  13 #include "directional-element-interface.hh"
  14 #include "item.hh"
  15 #include "lookup.hh"
  16 #include "output-def.hh"
  17 #include "staff-symbol-referencer.hh"
  18 #include "stem.hh"
  19 #include "warn.hh"
  20
  21 /* TODO: lengthen stem if necessary  */
  22
  23 MAKE_SCHEME_CALLBACK (Stem_tremolo, dim_callback, 2);
  24
  25 /* todo: init with cons.  */
  26 SCM
  27 Stem_tremolo::dim_callback (SCM e, SCM)
  28 {
  29   Grob *se = unsmob_grob (e);
  30
  31   Real space = Staff_symbol_referencer::staff_space (se);
  32   return ly_interval2scm (Interval (-space, space));
  33 }
  34
  35 /* ugh ?  --from Slur   */
  36 MAKE_SCHEME_CALLBACK (Stem_tremolo, height, 2);
  37 SCM
  38 Stem_tremolo::height (SCM smob, SCM ax)
  39 {
  40   Axis a = (Axis)scm_to_int (ax);
  41   Grob *me = unsmob_grob (smob);
  42   assert (a == Y_AXIS);
  43
  44   SCM mol = me->get_uncached_stencil ();
  45
  46   if (Stencil *m = unsmob_stencil (mol))
  47     return ly_interval2scm (m->extent (a));
  48   else
  49     return ly_interval2scm (Interval ());
  50 }
  51
  52 Stencil
  53 Stem_tremolo::raw_stencil (Grob *me)
  54 {
  55   Grob *stem = unsmob_grob (me->get_property ("stem"));
  56   Spanner *beam = Stem::get_beam (stem);
  57   Real dydx;
  58   if (beam)
  59     {
  60       Real dy = 0;
  61       SCM s = beam->get_property ("positions");
  62       if (is_number_pair (s))
  63         dy = -scm_to_double (scm_car (s)) +scm_to_double (scm_cdr (s));
  64
  65       Real dx = Beam::last_visible_stem (beam)->relative_coordinate (0, X_AXIS)
  66         - Beam::first_visible_stem (beam)->relative_coordinate (0, X_AXIS);
  67       dydx = dx ? dy / dx : 0;
  68     }
  69   else
  70     // urg
  71     dydx = 0.25;
  72
  73   Real ss = Staff_symbol_referencer::staff_space (me);
  74   Real thick = robust_scm2double (me->get_property ("beam-thickness"), 1);
  75   Real width = robust_scm2double (me->get_property ("beam-width"), 1);
  76   Real blot = me->get_layout ()->get_dimension (ly_symbol2scm ("blotdiameter"));
  77
  78   width *= ss;
  79   thick *= ss;
  80
  81   Stencil a (Lookup::beam (dydx, width, thick, blot));
  82   a.translate (Offset (-width * 0.5, width * 0.5 * dydx));
  83
  84   int tremolo_flags = 0;
  85   SCM s = me->get_property ("flag-count");
  86   if (scm_is_number (s))
  87     tremolo_flags = scm_to_int (s);
  88
  89   if (!tremolo_flags)
  90     {
  91       programming_error ("no tremolo flags");
  92
  93       me->suicide ();
  94       return Stencil ();
  95     }
  96
  97   /* Who the fuck is 0.81 ? --hwn.   */
  98   Real beam_translation = beam ? Beam::get_beam_translation (beam) : 0.81;
  99
 100   Stencil mol;
 101   for (int i = 0; i < tremolo_flags; i++)
 102     {
 103       Stencil b (a);
 104       b.translate_axis (beam_translation * i, Y_AXIS);
 105       mol.add_stencil (b);
 106     }
 107   return mol;
 108 }
 109
 110 MAKE_SCHEME_CALLBACK (Stem_tremolo, print, 1);
 111 SCM
 112 Stem_tremolo::print (SCM grob)
 113 {
 114   Grob *me = unsmob_grob (grob);
 115   Grob *stem = unsmob_grob (me->get_property ("stem"));
 116   if (!stem)
 117     {
 118       programming_error ("no stem for stem-tremolo");
 119       return SCM_EOL;
 120     }
 121
 122   Spanner *beam = Stem::get_beam (stem);
 123   Direction stemdir = Stem::get_direction (stem);
 124   if (stemdir == 0)
 125     stemdir = UP;
 126
 127   Real beam_translation
 128     = (beam && beam->is_live ())
 129     ? Beam::get_beam_translation (beam)
 130     : 0.81;
 131
 132   Stencil mol = raw_stencil (me);
 133   Interval mol_ext = mol.extent (Y_AXIS);
 134   Real ss = Staff_symbol_referencer::staff_space (me);
 135
 136   // ugh, rather calc from Stem_tremolo_req
 137   int beam_count = beam ? (Stem::beam_multiplicity (stem).length () + 1) : 0;
 138
 139   Real beamthickness = 0.0;
 140   SCM sbt = (beam) ? beam->get_property ("thickness") : SCM_EOL;
 141   if (scm_is_number (sbt))
 142     beamthickness = scm_to_double (sbt) * ss;
 143
 144   Real end_y
 145     = Stem::stem_end_position (stem) * ss / 2
 146     - stemdir * (beam_count * beamthickness
 147                  + (max (beam_count -1, 0) * beam_translation));
 148
 149   /* FIXME: the 0.33 ss is to compensate for the size of the note head.  */
 150   Real chord_start_y = Stem::chord_start_y (stem) + 0.33 * ss * stemdir;
 151
 152   Real padding = beam_translation;
 153
 154   /* if there is a flag, just above/below the notehead.
 155      if there is not enough space, center on remaining space,
 156      else one beamspace away from stem end.  */
 157   if (!beam && Stem::duration_log (stem) >= 3)
 158     {
 159       mol.align_to (Y_AXIS, -stemdir);
 160       mol.translate_axis (chord_start_y + 0.5 * stemdir, Y_AXIS);
 161     }
 162   else if (stemdir * (end_y - chord_start_y) - 2 * padding - mol_ext.length ()
 163            < 0.0)
 164     mol.translate_axis (0.5 * (end_y + chord_start_y) - mol_ext.center (),
 165                         Y_AXIS);
 166   else
 167     mol.translate_axis (end_y - stemdir * beam_translation -mol_ext [stemdir],
 168                         Y_AXIS);
 169
 170   return mol.smobbed_copy ();
 171 }
 172
 173 ADD_INTERFACE (Stem_tremolo, "stem-tremolo-interface",
 174                "A beam slashing a stem to indicate a tremolo.",
 175                "stem beam-width beam-thickness flag-count");