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--2009 Han-Wen Nienhuys <hanwen@xs4all.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 MAKE_SCHEME_CALLBACK (Stem_tremolo, calc_slope, 1)
  22 SCM
  23 Stem_tremolo::calc_slope (SCM smob)
  24 {
  25   Grob *me = unsmob_grob (smob);
  26   Grob *stem = unsmob_grob (me->get_object ("stem"));
  27   Spanner *beam = Stem::get_beam (stem);
  28
  29   if (beam)
  30     {
  31       Real dy = 0;
  32       SCM s = beam->get_property ("quantized-positions");
  33       if (is_number_pair (s))
  34         dy = - scm_to_double (scm_car (s)) + scm_to_double (scm_cdr (s));
  35
  36       Grob *s2 = Beam::last_normal_stem (beam);
  37       Grob *s1 = Beam::first_normal_stem (beam);
  38
  39       Grob *common = s1->common_refpoint (s2, X_AXIS);
  40       Real dx = s2->relative_coordinate (common, X_AXIS) -
  41         s1->relative_coordinate (common, X_AXIS);
  42
  43       return scm_from_double (dx ? dy / dx : 0);
  44     }
  45   else
  46     /* down stems with flags should have more sloped trems (helps avoid
  47        flag/stem collisions without making the stem very long) */
  48     return scm_from_double (
  49         (Stem::duration_log (stem) >= 3 && get_grob_direction (stem) == DOWN) ?
  50           0.40 : 0.25);
  51 }
  52
  53 MAKE_SCHEME_CALLBACK (Stem_tremolo, calc_width, 1)
  54 SCM
  55 Stem_tremolo::calc_width (SCM smob)
  56 {
  57   Grob *me = unsmob_grob (smob);
  58   Grob *stem = unsmob_grob (me->get_object ("stem"));
  59   Direction stemdir = get_grob_direction (stem);
  60   bool beam = Stem::get_beam (stem);
  61   bool flag = Stem::duration_log (stem) >= 3 && !beam;
  62
  63   /* beamed stems and up-stems with flags have shorter tremolos */
  64   return scm_from_double (((stemdir == UP && flag) || beam)? 1.0 : 1.5);
  65 }
  66
  67 MAKE_SCHEME_CALLBACK (Stem_tremolo, calc_style, 1)
  68 SCM
  69 Stem_tremolo::calc_style (SCM smob)
  70 {
  71   Grob *me = unsmob_grob (smob);
  72   Grob *stem = unsmob_grob (me->get_object ("stem"));
  73   Direction stemdir = get_grob_direction (stem);
  74   bool beam = Stem::get_beam (stem);
  75   bool flag = Stem::duration_log (stem) >= 3 && !beam;
  76
  77   return ly_symbol2scm (((stemdir == UP && flag) || beam) ? "rectangle" : "default");
  78 }
  79
  80 Real
  81 Stem_tremolo::get_beam_translation (Grob *me)
  82 {
  83   Grob *stem = unsmob_grob (me->get_object ("stem"));
  84   Spanner *beam = Stem::get_beam (stem);
  85
  86   return (beam && beam->is_live ())
  87     ? Beam::get_beam_translation (beam)
  88     : (Staff_symbol_referencer::staff_space (me)
  89        * robust_scm2double (me->get_property ("length-fraction"), 1.0) * 0.81);
  90 }
  91
  92 Stencil
  93 Stem_tremolo::raw_stencil (Grob *me, Real slope, Direction stemdir)
  94 {
  95   Real ss = Staff_symbol_referencer::staff_space (me);
  96   Real thick = robust_scm2double (me->get_property ("beam-thickness"), 1);
  97   Real width = robust_scm2double (me->get_property ("beam-width"), 1);
  98   Real blot = me->layout ()->get_dimension (ly_symbol2scm ("blot-diameter"));
  99   SCM style = me->get_property ("style");
 100   if (!scm_is_symbol (style))
 101     style = ly_symbol2scm ("default");
 102
 103   width *= ss;
 104   thick *= ss;
 105
 106   Stencil a;
 107   if (style == ly_symbol2scm ("rectangle"))
 108     a = Lookup::rotated_box (slope, width, thick, blot);
 109   else
 110     a = Lookup::beam (slope, width, thick, blot);
 111
 112   a.align_to (X_AXIS, CENTER);
 113   a.align_to (Y_AXIS, CENTER);
 114
 115   int tremolo_flags = robust_scm2int (me->get_property ("flag-count"), 0);
 116   if (!tremolo_flags)
 117     {
 118       programming_error ("no tremolo flags");
 119
 120       me->suicide ();
 121       return Stencil ();
 122     }
 123
 124   Real beam_translation = get_beam_translation (me);
 125
 126   Stencil mol;
 127   for (int i = 0; i < tremolo_flags; i++)
 128     {
 129       Stencil b (a);
 130       b.translate_axis (beam_translation * i * stemdir * -1, Y_AXIS);
 131       mol.add_stencil (b);
 132     }
 133   return mol;
 134 }
 135
 136
 137
 138 MAKE_SCHEME_CALLBACK (Stem_tremolo, height, 1);
 139 SCM
 140 Stem_tremolo::height (SCM smob)
 141 {
 142   Grob *me = unsmob_grob (smob);
 143
 144   /*
 145     Cannot use the real slope, since it looks at the Beam.
 146    */
 147   Stencil s1 (translated_stencil (me, 0.35));
 148
 149   return ly_interval2scm (s1.extent (Y_AXIS));
 150 }
 151
 152 MAKE_SCHEME_CALLBACK (Stem_tremolo, width, 1);
 153 SCM
 154 Stem_tremolo::width (SCM smob)
 155 {
 156   Grob *me = unsmob_grob (smob);
 157
 158   /*
 159     Cannot use the real slope, since it looks at the Beam.
 160    */
 161   Stencil s1 (untranslated_stencil (me, 0.35));
 162
 163   return ly_interval2scm (s1.extent (X_AXIS));
 164 }
 165
 166 Real
 167 Stem_tremolo::vertical_length (Grob *me)
 168 {
 169   return untranslated_stencil (me, 0.35).extent (Y_AXIS).length ();
 170 }
 171
 172 Stencil
 173 Stem_tremolo::untranslated_stencil (Grob *me, Real slope)
 174 {
 175   Grob *stem = unsmob_grob (me->get_object ("stem"));
 176   if (!stem)
 177     {
 178       programming_error ("no stem for stem-tremolo");
 179       return Stencil ();
 180     }
 181
 182   Direction stemdir = get_grob_direction (stem);
 183   if (!stemdir)
 184     stemdir = UP;
 185
 186   bool whole_note = Stem::duration_log (stem) <= 0;
 187
 188   /* for a whole note, we position relative to the notehead, so we want the
 189      stencil aligned on the flag closest to the head */
 190   Direction stencil_dir = whole_note ? -stemdir : stemdir;
 191   return raw_stencil (me, slope, stencil_dir);
 192 }
 193
 194
 195 Stencil
 196 Stem_tremolo::translated_stencil (Grob *me, Real slope)
 197 {
 198   Stencil mol = untranslated_stencil (me, slope);
 199
 200   Grob *stem = unsmob_grob (me->get_object ("stem"));
 201   if (!stem)
 202     return Stencil ();
 203
 204   Direction stemdir = get_grob_direction (stem);
 205   if (stemdir == 0)
 206     stemdir = UP;
 207
 208   Spanner *beam = Stem::get_beam (stem);
 209   Real beam_translation = get_beam_translation (me);
 210
 211   int beam_count = beam ? (Stem::beam_multiplicity (stem).length () + 1) : 0;
 212   Real ss = Staff_symbol_referencer::staff_space (me);
 213
 214   Real end_y
 215     = Stem::stem_end_position (stem) * ss / 2
 216     - stemdir * max (beam_count, 1) * beam_translation;
 217
 218   if (!beam && Stem::duration_log (stem) >= 3)
 219     {
 220       end_y -= stemdir * (Stem::duration_log (stem) - 2) * beam_translation;
 221       if (stemdir == UP)
 222         end_y -= stemdir * beam_translation * 0.5;
 223     }
 224
 225   bool whole_note = Stem::duration_log (stem) <= 0;
 226   if (whole_note)
 227     {
 228       /* we shouldn't position relative to the end of the stem since the stem
 229          is invisible */
 230       vector<int> nhp = Stem::note_head_positions (stem);
 231       Real note_head = (stemdir == UP ? nhp.back () : nhp[0]) * ss / 2;
 232       end_y = note_head + stemdir * 1.5;
 233     }
 234   mol.translate_axis (end_y, Y_AXIS);
 235
 236   return mol;
 237 }
 238
 239 MAKE_SCHEME_CALLBACK (Stem_tremolo, print, 1);
 240 SCM
 241 Stem_tremolo::print (SCM grob)
 242 {
 243   Grob *me = unsmob_grob (grob);
 244
 245   Stencil s = translated_stencil (me, robust_scm2double (me->get_property ("slope"), 0.25));
 246   return s.smobbed_copy ();
 247 }
 248
 249 ADD_INTERFACE (Stem_tremolo,
 250                "A beam slashing a stem to indicate a tremolo.  The property"
 251                " @code{style} can be @code{default} or @code{rectangle}.",
 252
 253                /* properties */
 254                "beam-thickness "
 255                "beam-width "
 256                "flag-count "
 257                "length-fraction "
 258                "stem "
 259                "style "
 260                "slope "
 261                );