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--2003 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9
  10 #include "stem-tremolo.hh"
  11 #include "warn.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 MAKE_SCHEME_CALLBACK (Stem_tremolo,dim_callback,2);
  25
  26 /*
  27   todo: init with cons.
  28  */
  29 SCM
  30 Stem_tremolo::dim_callback (SCM e, SCM)
  31 {
  32   Grob * se = unsmob_grob (e);
  33
  34   Real space = Staff_symbol_referencer::staff_space (se);
  35   return ly_interval2scm (Interval (-space, space));
  36 }
  37
  38 /*
  39   ugh ?  --from Slur
  40  */
  41 MAKE_SCHEME_CALLBACK (Stem_tremolo, height, 2);
  42 SCM
  43 Stem_tremolo::height (SCM smob, SCM ax)
  44 {
  45   Axis a = (Axis)gh_scm2int (ax);
  46   Grob * me = unsmob_grob (smob);
  47   assert (a == Y_AXIS);
  48
  49   SCM mol = me->get_uncached_molecule ();
  50
  51   if (Molecule *m = unsmob_molecule (mol))
  52     return ly_interval2scm (m->extent (a));
  53   else
  54     return ly_interval2scm (Interval());
  55 }
  56
  57
  58 Molecule
  59 Stem_tremolo::raw_molecule (Grob *me)
  60 {
  61   Grob *stem = unsmob_grob (me->get_grob_property ("stem"));
  62   Grob *beam = Stem::get_beam (stem);
  63
  64   Real dydx;
  65   if (beam)
  66     {
  67       Real dy = 0;
  68       SCM s = beam->get_grob_property ("positions");
  69       if (is_number_pair (s))
  70         {
  71           dy = -gh_scm2double (gh_car (s)) +gh_scm2double (gh_cdr (s));
  72         }
  73
  74       Real dx = Beam::last_visible_stem (beam)->relative_coordinate (0, X_AXIS)
  75         - Beam::first_visible_stem (beam)->relative_coordinate (0, X_AXIS);
  76       dydx = dx ? dy/dx : 0;
  77     }
  78   else
  79     // urg
  80     dydx = 0.25;
  81
  82   Real ss = Staff_symbol_referencer::staff_space (me);
  83   Real thick = gh_scm2double (me->get_grob_property ("beam-thickness"));
  84   Real width = gh_scm2double (me->get_grob_property ("beam-width"));
  85   width *= ss;
  86   thick *= ss;
  87
  88   Molecule a (Lookup::beam (dydx, width, thick));
  89   a.translate (Offset (-width/2, width / 2 * dydx));
  90
  91   int tremolo_flags = 0;
  92   SCM s = me->get_grob_property ("flag-count");
  93   if (gh_number_p (s))
  94     tremolo_flags = gh_scm2int (s);
  95
  96   if (!tremolo_flags)
  97     {
  98       programming_error ("No tremolo flags?");
  99
 100       me->suicide();
 101       return Molecule ();
 102     }
 103
 104   /*
 105     Who the fuck is 0.81 ?
 106
 107     --hwn.
 108    */
 109   Real beam_translation = beam ? Beam::get_beam_translation (beam) : 0.81;
 110
 111   Molecule mol;
 112   for (int i = 0; i < tremolo_flags; i++)
 113     {
 114       Molecule b (a);
 115       b.translate_axis (beam_translation * i, Y_AXIS);
 116       mol.add_molecule (b);
 117     }
 118   return mol;
 119 }
 120
 121
 122 MAKE_SCHEME_CALLBACK (Stem_tremolo,brew_molecule,1);
 123 SCM
 124 Stem_tremolo::brew_molecule (SCM grob)
 125 {
 126   Grob *me = unsmob_grob (grob);
 127   Grob *stem = unsmob_grob (me->get_grob_property ("stem"));
 128   Grob *beam = Stem::get_beam (stem);
 129   Direction stemdir = Stem::get_direction (stem);
 130   Real beam_translation = beam ? Beam::get_beam_translation (beam) : 0.81;
 131
 132   Molecule mol = raw_molecule (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   /*
 140     TODO.
 141    */
 142
 143
 144   Real beamthickness = 0.0;
 145   SCM sbt = (beam) ? beam->get_grob_property ("thickness") : SCM_EOL ;
 146   if (gh_number_p (sbt))
 147     {
 148       beamthickness = gh_scm2double (sbt) * ss;
 149     }
 150
 151   Real end_y
 152     = Stem::stem_end_position (stem) *ss/2
 153     - stemdir * (beam_count * beamthickness
 154                  + ((beam_count -1) >? 0) * beam_translation);
 155
 156   /*
 157     the 0.33 ss is to compensate for the size of the note head
 158    */
 159   Real chord_start_y = Stem::chord_start_y (stem) +
 160     0.33 * ss * stemdir;
 161
 162   Real padding = beam_translation;
 163
 164   /*
 165     if there is a flag, just above/below the notehead.
 166     if there is not enough space, center on remaining space,
 167     else one beamspace away from stem end.
 168    */
 169   if (!beam && Stem::duration_log (stem) >= 3)
 170     {
 171       mol.align_to (Y_AXIS, -stemdir);
 172       mol.translate_axis (chord_start_y + .5 * stemdir, Y_AXIS);
 173     }
 174   else if (stemdir * (end_y - chord_start_y) - 2*padding - mol_ext.length ()  < 0.0)
 175     {
 176       mol.translate_axis (0.5 * (end_y + chord_start_y)  - mol_ext.center (),Y_AXIS);
 177     }
 178   else
 179     {
 180       mol.translate_axis (end_y - stemdir * beam_translation
 181                           -mol_ext [stemdir]
 182                           , Y_AXIS);
 183     }
 184
 185   return mol.smobbed_copy ();
 186 }
 187
 188
 189 void
 190 Stem_tremolo::set_stem (Grob*me,Grob *s)
 191 {
 192   me->set_grob_property ("stem", s->self_scm ());
 193 }
 194
 195
 196 ADD_INTERFACE (Stem_tremolo,"stem-tremolo-interface",
 197   "",
 198   "stem beam-width beam-thickness flag-count");