lily/stem-engraver.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 "engraver.hh"
  21
  22 #include "context.hh"
  23 #include "directional-element-interface.hh"
  24 #include "duration.hh"
  25 #include "international.hh"
  26 #include "item.hh"
  27 #include "misc.hh"
  28 #include "rhythmic-head.hh"
  29 #include "script-interface.hh"
  30 #include "staff-symbol-referencer.hh"
  31 #include "stem-tremolo.hh"
  32 #include "stem.hh"
  33 #include "stream-event.hh"
  34
  35 #include "translator.icc"
  36
  37 class Stem_engraver : public Engraver
  38 {
  39   Grob *stem_;
  40   Grob *tremolo_;
  41   Stream_event *rhythmic_ev_;
  42   Stream_event *tremolo_ev_;
  43
  44   TRANSLATOR_DECLARATIONS (Stem_engraver);
  45
  46 protected:
  47   void make_stem (Grob_info);
  48
  49   DECLARE_TRANSLATOR_LISTENER (tremolo);
  50   DECLARE_ACKNOWLEDGER (rhythmic_head);
  51   void stop_translation_timestep ();
  52 };
  53
  54 Stem_engraver::Stem_engraver ()
  55 {
  56   tremolo_ev_ = 0;
  57   stem_ = 0;
  58   tremolo_ = 0;
  59   rhythmic_ev_ = 0;
  60 }
  61
  62 void
  63 Stem_engraver::make_stem (Grob_info gi)
  64 {
  65   /* Announce the cause of the head as cause of the stem.  The
  66      stem needs a rhythmic structure to fit it into a beam.  */
  67   stem_ = make_item ("Stem", gi.grob ()->self_scm ());
  68
  69   if (tremolo_ev_)
  70     {
  71       /* Stem tremolo is never applied to a note by default,
  72          is must me requested.  But there is a default for the
  73          tremolo value:
  74
  75          c4:8 c c:
  76
  77          the first and last (quarter) note bothe get one tremolo flag.  */
  78       int requested_type
  79         = scm_to_int (tremolo_ev_->get_property ("tremolo-type"));
  80       SCM f = get_property ("tremoloFlags");
  81       if (!requested_type)
  82         {
  83           if (scm_is_number (f))
  84             requested_type = scm_to_int (f);
  85           else
  86             requested_type = 8;
  87         }
  88       else
  89         context ()->set_property ("tremoloFlags", scm_from_int (requested_type));
  90
  91
  92       /*
  93         we take the duration log from the Event, since the duration-log
  94         for a note head is always <= 2.
  95       */
  96       Stream_event *ev = gi.event_cause ();
  97       Duration *dur = unsmob_duration (ev->get_property ("duration"));
  98
  99       int tremolo_flags = intlog2 (requested_type) - 2
 100         - (dur->duration_log () > 2 ? dur->duration_log () - 2 : 0);
 101       if (tremolo_flags <= 0)
 102         {
 103           tremolo_ev_->origin ()->warning (_ ("tremolo duration is too long"));
 104           tremolo_flags = 0;
 105         }
 106
 107       if (tremolo_flags)
 108         {
 109           tremolo_ = make_item ("StemTremolo", tremolo_ev_->self_scm ());
 110
 111           /* The number of tremolo flags is the number of flags of the
 112              tremolo-type minus the number of flags of the note itself.  */
 113           tremolo_->set_property ("flag-count", scm_from_int (tremolo_flags));
 114           tremolo_->set_parent (stem_, X_AXIS);
 115           stem_->set_object ("tremolo-flag", tremolo_->self_scm ());
 116           tremolo_->set_object ("stem", stem_->self_scm ());
 117         }
 118     }
 119 }
 120
 121 void
 122 Stem_engraver::acknowledge_rhythmic_head (Grob_info gi)
 123 {
 124   if (Rhythmic_head::get_stem (gi.grob ()))
 125     return;
 126
 127   Stream_event *cause = gi.event_cause ();
 128   if (!cause)
 129     return;
 130   Duration *d = unsmob_duration (cause->get_property ("duration"));
 131   if (!d)
 132     return;
 133
 134   if (!stem_)
 135     make_stem (gi);
 136
 137   if (Stem::duration_log (stem_) != d->duration_log ())
 138     {
 139       // FIXME:
 140       gi.event_cause ()->origin ()->warning (_f ("adding note head to incompatible stem (type = %d)",
 141                                                  1 << Stem::duration_log (stem_)));
 142       gi.event_cause ()->origin ()->warning (_ ("maybe input should specify polyphonic voices"));
 143     }
 144
 145   Stem::add_head (stem_, gi.grob ());
 146 }
 147
 148 void
 149 Stem_engraver::stop_translation_timestep ()
 150 {
 151   tremolo_ = 0;
 152   if (stem_)
 153     {
 154       /* FIXME: junk these properties.  */
 155       SCM prop = get_property ("stemLeftBeamCount");
 156       if (scm_is_number (prop))
 157         {
 158           Stem::set_beaming (stem_, scm_to_int (prop), LEFT);
 159           context ()->unset_property (ly_symbol2scm ("stemLeftBeamCount"));
 160         }
 161       prop = get_property ("stemRightBeamCount");
 162       if (scm_is_number (prop))
 163         {
 164           Stem::set_beaming (stem_, scm_to_int (prop), RIGHT);
 165           context ()->unset_property (ly_symbol2scm ("stemRightBeamCount"));
 166         }
 167       stem_ = 0;
 168     }
 169   tremolo_ev_ = 0;
 170 }
 171
 172 IMPLEMENT_TRANSLATOR_LISTENER (Stem_engraver, tremolo);
 173 void
 174 Stem_engraver::listen_tremolo (Stream_event *ev)
 175 {
 176   ASSIGN_EVENT_ONCE (tremolo_ev_, ev);
 177 }
 178
 179 ADD_ACKNOWLEDGER (Stem_engraver, rhythmic_head);
 180
 181 ADD_TRANSLATOR (Stem_engraver,
 182                 /* doc */
 183                 "Create stems and single-stem tremolos.  It also works"
 184                 " together with the beam engraver for overriding beaming.",
 185
 186                 /* create */
 187                 "Stem "
 188                 "StemTremolo ",
 189
 190                 /* read */
 191                 "tremoloFlags "
 192                 "stemLeftBeamCount "
 193                 "stemRightBeamCount ",
 194
 195                 /* write */
 196                 ""
 197                 );