lily/stem-tremolo.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1997--2010 Han-Wen Nienhuys <hanwen@xs4all.nl>
   5
   6   LilyPond is free software: you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation, either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "stem-tremolo.hh"
  21
  22 #include "spanner.hh"
  23 #include "beam.hh"
  24 #include "directional-element-interface.hh"
  25 #include "item.hh"
  26 #include "lookup.hh"
  27 #include "output-def.hh"
  28 #include "staff-symbol-referencer.hh"
  29 #include "stem.hh"
  30 #include "warn.hh"
  31
  32 MAKE_SCHEME_CALLBACK (Stem_tremolo, calc_slope, 1)
  33 SCM
  34 Stem_tremolo::calc_slope (SCM smob)
  35 {
  36   Grob *me = unsmob_grob (smob);
  37   Grob *stem = unsmob_grob (me->get_object ("stem"));
  38   Spanner *beam = Stem::get_beam (stem);
  39
  40   if (beam)
  41     {
  42       Real dy = 0;
  43       SCM s = beam->get_property ("quantized-positions");
  44       if (is_number_pair (s))
  45         dy = - scm_to_double (scm_car (s)) + scm_to_double (scm_cdr (s));
  46
  47       Grob *s2 = Beam::last_normal_stem (beam);
  48       Grob *s1 = Beam::first_normal_stem (beam);
  49
  50       Grob *common = s1->common_refpoint (s2, X_AXIS);
  51       Real dx = s2->relative_coordinate (common, X_AXIS) -
  52         s1->relative_coordinate (common, X_AXIS);
  53
  54       return scm_from_double (dx ? dy / dx : 0);
  55     }
  56   else
  57     /* down stems with flags should have more sloped trems (helps avoid
  58        flag/stem collisions without making the stem very long) */
  59     return scm_from_double (
  60         (Stem::duration_log (stem) >= 3 && get_grob_direction (stem) == DOWN) ?
  61           0.40 : 0.25);
  62 }
  63
  64 MAKE_SCHEME_CALLBACK (Stem_tremolo, calc_width, 1)
  65 SCM
  66 Stem_tremolo::calc_width (SCM smob)
  67 {
  68   Grob *me = unsmob_grob (smob);
  69   Grob *stem = unsmob_grob (me->get_object ("stem"));
  70   Direction stemdir = get_grob_direction (stem);
  71   bool beam = Stem::get_beam (stem);
  72   bool flag = Stem::duration_log (stem) >= 3 && !beam;
  73
  74   /* beamed stems and up-stems with flags have shorter tremolos */
  75   return scm_from_double (((stemdir == UP && flag) || beam)? 1.0 : 1.5);
  76 }
  77
  78 MAKE_SCHEME_CALLBACK (Stem_tremolo, calc_style, 1)
  79 SCM
  80 Stem_tremolo::calc_style (SCM smob)
  81 {
  82   Grob *me = unsmob_grob (smob);
  83   Grob *stem = unsmob_grob (me->get_object ("stem"));
  84   Direction stemdir = get_grob_direction (stem);
  85   bool beam = Stem::get_beam (stem);
  86   bool flag = Stem::duration_log (stem) >= 3 && !beam;
  87
  88   return ly_symbol2scm (((stemdir == UP && flag) || beam) ? "rectangle" : "default");
  89 }
  90
  91 Real
  92 Stem_tremolo::get_beam_translation (Grob *me)
  93 {
  94   Grob *stem = unsmob_grob (me->get_object ("stem"));
  95   Spanner *beam = Stem::get_beam (stem);
  96
  97   return (beam && beam->is_live ())
  98     ? Beam::get_beam_translation (beam)
  99     : (Staff_symbol_referencer::staff_space (me)
 100        * robust_scm2double (me->get_property ("length-fraction"), 1.0) * 0.81);
 101 }
 102
 103 Stencil
 104 Stem_tremolo::raw_stencil (Grob *me, Real slope, Direction stemdir)
 105 {
 106   Real ss = Staff_symbol_referencer::staff_space (me);
 107   Real thick = robust_scm2double (me->get_property ("beam-thickness"), 1);
 108   Real width = robust_scm2double (me->get_property ("beam-width"), 1);
 109   Real blot = me->layout ()->get_dimension (ly_symbol2scm ("blot-diameter"));
 110   SCM style = me->get_property ("style");
 111   if (!scm_is_symbol (style))
 112     style = ly_symbol2scm ("default");
 113
 114   width *= ss;
 115   thick *= ss;
 116
 117   Stencil a;
 118   if (style == ly_symbol2scm ("rectangle"))
 119     a = Lookup::rotated_box (slope, width, thick, blot);
 120   else
 121     a = Lookup::beam (slope, width, thick, blot);
 122
 123   a.align_to (X_AXIS, CENTER);
 124   a.align_to (Y_AXIS, CENTER);
 125
 126   int tremolo_flags = robust_scm2int (me->get_property ("flag-count"), 0);
 127   if (!tremolo_flags)
 128     {
 129       programming_error ("no tremolo flags");
 130
 131       me->suicide ();
 132       return Stencil ();
 133     }
 134
 135   Real beam_translation = get_beam_translation (me);
 136
 137   Stencil mol;
 138   for (int i = 0; i < tremolo_flags; i++)
 139     {
 140       Stencil b (a);
 141       b.translate_axis (beam_translation * i * stemdir * -1, Y_AXIS);
 142       mol.add_stencil (b);
 143     }
 144   return mol;
 145 }
 146
 147
 148
 149 MAKE_SCHEME_CALLBACK (Stem_tremolo, height, 1);
 150 SCM
 151 Stem_tremolo::height (SCM smob)
 152 {
 153   Grob *me = unsmob_grob (smob);
 154
 155   /*
 156     Cannot use the real slope, since it looks at the Beam.
 157    */
 158   Stencil s1 (translated_stencil (me, 0.35));
 159
 160   return ly_interval2scm (s1.extent (Y_AXIS));
 161 }
 162
 163 MAKE_SCHEME_CALLBACK (Stem_tremolo, width, 1);
 164 SCM
 165 Stem_tremolo::width (SCM smob)
 166 {
 167   Grob *me = unsmob_grob (smob);
 168
 169   /*
 170     Cannot use the real slope, since it looks at the Beam.
 171    */
 172   Stencil s1 (untranslated_stencil (me, 0.35));
 173
 174   return ly_interval2scm (s1.extent (X_AXIS));
 175 }
 176
 177 Real
 178 Stem_tremolo::vertical_length (Grob *me)
 179 {
 180   return untranslated_stencil (me, 0.35).extent (Y_AXIS).length ();
 181 }
 182
 183 Stencil
 184 Stem_tremolo::untranslated_stencil (Grob *me, Real slope)
 185 {
 186   Grob *stem = unsmob_grob (me->get_object ("stem"));
 187   if (!stem)
 188     {
 189       programming_error ("no stem for stem-tremolo");
 190       return Stencil ();
 191     }
 192
 193   Direction stemdir = get_grob_direction (stem);
 194   if (!stemdir)
 195     stemdir = UP;
 196
 197   bool whole_note = Stem::duration_log (stem) <= 0;
 198
 199   /* for a whole note, we position relative to the notehead, so we want the
 200      stencil aligned on the flag closest to the head */
 201   Direction stencil_dir = whole_note ? -stemdir : stemdir;
 202   return raw_stencil (me, slope, stencil_dir);
 203 }
 204
 205
 206 Stencil
 207 Stem_tremolo::translated_stencil (Grob *me, Real slope)
 208 {
 209   Stencil mol = untranslated_stencil (me, slope);
 210
 211   Grob *stem = unsmob_grob (me->get_object ("stem"));
 212   if (!stem)
 213     return Stencil ();
 214
 215   Direction stemdir = get_grob_direction (stem);
 216   if (stemdir == 0)
 217     stemdir = UP;
 218
 219   Spanner *beam = Stem::get_beam (stem);
 220   Real beam_translation = get_beam_translation (me);
 221
 222   int beam_count = beam ? (Stem::beam_multiplicity (stem).length () + 1) : 0;
 223   Real ss = Staff_symbol_referencer::staff_space (me);
 224
 225   Real end_y
 226     = Stem::stem_end_position (stem) * ss / 2
 227     - stemdir * max (beam_count, 1) * beam_translation;
 228
 229   if (!beam && Stem::duration_log (stem) >= 3)
 230     {
 231       end_y -= stemdir * (Stem::duration_log (stem) - 2) * beam_translation;
 232       if (stemdir == UP)
 233         end_y -= stemdir * beam_translation * 0.5;
 234     }
 235
 236   bool whole_note = Stem::duration_log (stem) <= 0;
 237   if (whole_note)
 238     {
 239       /* we shouldn't position relative to the end of the stem since the stem
 240          is invisible */
 241       vector<int> nhp = Stem::note_head_positions (stem);
 242       Real note_head = (stemdir == UP ? nhp.back () : nhp[0]) * ss / 2;
 243       end_y = note_head + stemdir * 1.5;
 244     }
 245   mol.translate_axis (end_y, Y_AXIS);
 246
 247   return mol;
 248 }
 249
 250 MAKE_SCHEME_CALLBACK (Stem_tremolo, print, 1);
 251 SCM
 252 Stem_tremolo::print (SCM grob)
 253 {
 254   Grob *me = unsmob_grob (grob);
 255
 256   Stencil s = translated_stencil (me, robust_scm2double (me->get_property ("slope"), 0.25));
 257   return s.smobbed_copy ();
 258 }
 259
 260 ADD_INTERFACE (Stem_tremolo,
 261                "A beam slashing a stem to indicate a tremolo.  The property"
 262                " @code{style} can be @code{default} or @code{rectangle}.",
 263
 264                /* properties */
 265                "beam-thickness "
 266                "beam-width "
 267                "flag-count "
 268                "length-fraction "
 269                "stem "
 270                "style "
 271                "slope "
 272                );