lily/chord-tremolo-engraver.cc

   1 /*
   2   chord-tremolo-engraver.cc -- implement Chord_tremolo_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2000--2005 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9 #include "beam.hh"
  10 #include "repeated-music.hh"
  11 #include "stem.hh"
  12 #include "rhythmic-head.hh"
  13 #include "engraver-group-engraver.hh"
  14 #include "warn.hh"
  15 #include "misc.hh"
  16 #include "spanner.hh"
  17 #include "item.hh"
  18 #include "chord-tremolo-iterator.hh"
  19 #include "stem-tremolo.hh"
  20 #include "math.h" // ceil
  21
  22 #include "translator.icc"
  23
  24 /**
  25
  26 This acknowledges repeated music with "tremolo" style.  It typesets
  27 a beam.
  28
  29 TODO:
  30
  31 - perhaps use engraver this to steer other engravers? That would
  32 create dependencies between engravers, which is bad.
  33
  34 - create dots if appropriate.
  35
  36 - create TremoloBeam iso Beam?
  37 */
  38 class Chord_tremolo_engraver : public Engraver
  39 {
  40   void typeset_beam ();
  41   TRANSLATOR_DECLARATIONS (Chord_tremolo_engraver);
  42 protected:
  43   Music *repeat_;
  44
  45   /// moment (global time) where beam started.
  46   Moment start_mom_;
  47   Moment stop_mom_;
  48   int flags_;
  49   int total_duration_flags_;
  50
  51   /// location  within measure where beam started.
  52   Moment beam_start_location_;
  53
  54   bool body_is_sequential_;
  55   Spanner *beam_;
  56   Spanner *finished_beam_;
  57   Item *stem_tremolo_;
  58 protected:
  59   virtual void finalize ();
  60   virtual bool try_music (Music *);
  61   void stop_translation_timestep ();
  62   void start_translation_timestep ();
  63   void process_music ();
  64   DECLARE_ACKNOWLEDGER (stem);
  65 };
  66
  67 Chord_tremolo_engraver::Chord_tremolo_engraver ()
  68 {
  69   beam_ = finished_beam_ = 0;
  70   repeat_ = 0;
  71   flags_ = 0;
  72   stem_tremolo_ = 0;
  73   body_is_sequential_ = false;
  74 }
  75
  76 bool
  77 Chord_tremolo_engraver::try_music (Music *m)
  78 {
  79   if (m->is_mus_type ("repeated-music")
  80       && m->get_property ("iterator-ctor") == Chord_tremolo_iterator::constructor_proc
  81       && !repeat_)
  82     {
  83       Moment l = m->get_length ();
  84       repeat_ = m;
  85       start_mom_ = now_mom ();
  86       stop_mom_ = start_mom_ + l;
  87
  88       Music *body = Repeated_music::body (m);
  89       body_is_sequential_ = body->is_mus_type ("sequential-music");
  90
  91       int elt_count = body_is_sequential_ ? scm_ilength (body->get_property ("elements")) : 1;
  92
  93       if (body_is_sequential_ && elt_count != 2)
  94         m->origin ()->warning (_f ("expect 2 elements for chord tremolo, found %d", elt_count));
  95
  96       if (elt_count <= 0)
  97         elt_count = 1;
  98
  99       Rational total_dur = l.main_part_;
 100       Rational note_dur = total_dur / Rational (elt_count * Repeated_music::repeat_count (repeat_));
 101
 102       total_duration_flags_ = max (0, (intlog2 (total_dur.den ()) - 2));
 103
 104       flags_ = intlog2 (note_dur.den ()) -2;
 105
 106       return true;
 107     }
 108
 109   return false;
 110 }
 111
 112 void
 113 Chord_tremolo_engraver::process_music ()
 114 {
 115   if (repeat_ && body_is_sequential_ && !beam_)
 116     {
 117       beam_ = make_spanner ("Beam", repeat_->self_scm ());
 118       beam_->set_property ("chord-tremolo", SCM_BOOL_T);
 119
 120       beam_start_location_ = robust_scm2moment (get_property ("measurePosition"), Moment (0));
 121     }
 122 }
 123
 124 void
 125 Chord_tremolo_engraver::finalize ()
 126 {
 127   typeset_beam ();
 128   if (beam_)
 129     {
 130       repeat_->origin ()->warning (_ ("unterminated chord tremolo"));
 131       beam_->suicide ();
 132     }
 133 }
 134
 135 void
 136 Chord_tremolo_engraver::typeset_beam ()
 137 {
 138   finished_beam_ = 0;
 139 }
 140
 141 void
 142 Chord_tremolo_engraver::acknowledge_stem (Grob_info info)
 143 {
 144   if (beam_)
 145     {
 146       Grob *s = info.grob ();
 147
 148       if (start_mom_ == now_mom ())
 149         Stem::set_beaming (s, flags_, RIGHT);
 150       else
 151         Stem::set_beaming (s, flags_, LEFT);
 152
 153       if (Stem::duration_log (s) != 1)
 154         beam_->set_property ("gap-count", scm_from_int (flags_ - total_duration_flags_));
 155
 156       if (info.music_cause ()->is_mus_type ("rhythmic-event"))
 157         Beam::add_stem (beam_, s);
 158       else
 159         {
 160           String s = _ ("stem must have Rhythmic structure");
 161           if (info.music_cause ())
 162             info.music_cause ()->origin ()->warning (s);
 163           else
 164             ::warning (s);
 165         }
 166     }
 167   else if (repeat_
 168            && flags_
 169            && !body_is_sequential_)
 170     {
 171       stem_tremolo_ = make_item ("StemTremolo", repeat_->self_scm ());
 172       stem_tremolo_->set_property ("flag-count",
 173                                    scm_from_int (flags_));
 174       stem_tremolo_->set_object ("stem",
 175                                  info.grob ()->self_scm ());
 176       stem_tremolo_->set_parent (info.grob (), X_AXIS);
 177     }
 178 }
 179
 180 void
 181 Chord_tremolo_engraver::start_translation_timestep ()
 182 {
 183   if (beam_ && stop_mom_ == now_mom ())
 184     {
 185       finished_beam_ = beam_;
 186       repeat_ = 0;
 187       beam_ = 0;
 188     }
 189 }
 190
 191 void
 192 Chord_tremolo_engraver::stop_translation_timestep ()
 193 {
 194   if (stem_tremolo_)
 195     {
 196       repeat_ = 0;
 197       if (beam_)
 198         programming_error ("beam and stem tremolo?");
 199       stem_tremolo_ = 0;
 200     }
 201
 202   typeset_beam ();
 203 }
 204
 205 ADD_ACKNOWLEDGER (Chord_tremolo_engraver, stem);
 206 ADD_TRANSLATOR (Chord_tremolo_engraver,
 207                 /* doc */ "Generates beams for  tremolo repeats.",
 208                 /* create */ "Beam",
 209                 /* accept */ "repeated-music",
 210                 /* read */ "",
 211                 /* write */ "");