lily/chord-tremolo-engraver.cc

   1 /*
   2      new-chord-tremolo-engraver.cc --  implement Chord_tremolo_engraver
   3
   4      source file of the GNU LilyPond music typesetter
   5
   6      (c) 2000--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8 */
   9
  10 #include "engraver.hh"
  11 #include "beam.hh"
  12 #include "repeated-music.hh"
  13 #include "stem.hh"
  14 #include "rhythmic-head.hh"
  15 #include "engraver-group-engraver.hh"
  16 #include "event.hh"
  17 #include "warn.hh"
  18 #include "misc.hh"
  19 #include "note-head.hh"
  20 #include "spanner.hh"
  21 #include "item.hh"
  22 #include "chord-tremolo-iterator.hh"
  23 #include "stem-tremolo.hh"
  24 #include "music-list.hh"
  25 #include "math.h"           // ceil
  26
  27 /**
  28
  29 This acknowledges repeated music with "tremolo" style.  It typesets
  30 a beam.
  31
  32 TODO:
  33
  34 - perhaps use engraver this to steer other engravers? That would
  35 create dependencies between engravers, which is bad.
  36
  37 - create dots if appropriate.
  38
  39 - create TremoloBeam iso Beam?
  40
  41 */
  42 class Chord_tremolo_engraver : public Engraver
  43 {
  44   void typeset_beam ();
  45   TRANSLATOR_DECLARATIONS (Chord_tremolo_engraver);
  46 protected:
  47   Repeated_music * repeat_;
  48
  49   /// moment (global time) where beam started.
  50   Moment start_mom_;
  51   Moment stop_mom_;
  52   int flags_ ;
  53   int total_duration_flags_;
  54
  55   /// location  within measure where beam started.
  56   Moment beam_start_location_;
  57
  58   bool sequential_body_b_;
  59   Spanner * beam_;
  60   Spanner * finished_beam_;
  61   Item * stem_tremolo_;
  62 protected:
  63   virtual void finalize ();
  64   virtual bool try_music (Music*);
  65   virtual void acknowledge_grob (Grob_info);
  66   virtual void stop_translation_timestep ();
  67   virtual void start_translation_timestep ();
  68   virtual void process_music ();
  69 };
  70
  71 Chord_tremolo_engraver::Chord_tremolo_engraver ()
  72 {
  73   beam_  = finished_beam_ = 0;
  74   repeat_ =0;
  75   flags_ = 0;
  76   stem_tremolo_ = 0;
  77   sequential_body_b_ = false;
  78 }
  79
  80 bool
  81 Chord_tremolo_engraver::try_music (Music * m)
  82 {
  83   Repeated_music * rp = dynamic_cast<Repeated_music*> (m);
  84   if (rp
  85       && rp->get_property ("iterator-ctor") == Chord_tremolo_iterator::constructor_proc
  86       && !repeat_)
  87     {
  88       Moment l = rp->get_length ();
  89       repeat_ = rp;
  90       start_mom_ = now_mom ();
  91       stop_mom_ = start_mom_ + l;
  92
  93       Sequential_music * seq = dynamic_cast<Sequential_music*> (rp->body ());
  94       sequential_body_b_ = seq;
  95
  96       int elt_count = seq ? scm_ilength (seq-> music_list ()) : 1;
  97
  98       if (seq && elt_count != 2)
  99         {
 100           rp->origin ()->warning (_f ("Chord tremolo with %d elements. Must have two elements.", elt_count));
 101         }
 102
 103       if (elt_count <= 0)
 104         elt_count = 1;
 105
 106       Rational total_dur = l.main_part_;
 107       Rational note_dur = total_dur / Rational (elt_count * repeat_->repeat_count ());
 108
 109       total_duration_flags_ = 0 >? (intlog2 (total_dur.den ()) - 2);
 110
 111       flags_ = intlog2 (note_dur.den ()) -2 ;
 112
 113       return true;
 114     }
 115
 116   return false;
 117 }
 118
 119 void
 120 Chord_tremolo_engraver::process_music ()
 121 {
 122   if (repeat_ && sequential_body_b_ && !beam_)
 123     {
 124       beam_ = make_spanner ("Beam", repeat_->self_scm ());
 125       beam_->set_property ("chord-tremolo", SCM_BOOL_T);
 126
 127       SCM smp = get_property ("measurePosition");
 128       Moment mp
 129         = (unsmob_moment (smp)) ? *unsmob_moment (smp) : Moment (0);
 130       beam_start_location_ = mp;
 131     }
 132 }
 133
 134 void
 135 Chord_tremolo_engraver::finalize ()
 136 {
 137   typeset_beam ();
 138   if (beam_)
 139     {
 140       repeat_->origin ()->warning (_ ("unterminated chord tremolo"));
 141       beam_->suicide ();
 142     }
 143 }
 144
 145 void
 146 Chord_tremolo_engraver::typeset_beam ()
 147 {
 148   finished_beam_ = 0;
 149 }
 150
 151 void
 152 Chord_tremolo_engraver::acknowledge_grob (Grob_info info)
 153 {
 154   if (beam_ && Stem::has_interface (info.grob_))
 155     {
 156       Grob * s = info.grob_;
 157
 158       if (start_mom_ == now_mom ())
 159         Stem::set_beaming (s, flags_, RIGHT);
 160       else
 161         Stem::set_beaming (s, flags_, LEFT);
 162
 163       if (Stem::duration_log (s) != 1)
 164         {
 165           beam_->set_property ("gap-count", scm_int2num (flags_ - total_duration_flags_));
 166         }
 167
 168       if (info.music_cause ()->is_mus_type ("rhythmic-event"))
 169         {
 170           Beam::add_stem (beam_, s);
 171         }
 172       else
 173         {
 174           String s = _ ("stem must have Rhythmic structure");
 175           if (info.music_cause ())
 176             info.music_cause ()->origin ()->warning (s);
 177           else
 178             ::warning (s);
 179         }
 180     }
 181   else if (repeat_ &&
 182            flags_ && !sequential_body_b_ && Stem::has_interface (info.grob_))
 183     {
 184       stem_tremolo_ = make_item ("StemTremolo", repeat_->self_scm ());
 185       stem_tremolo_->set_property ("flag-count",
 186                                    scm_int2num (flags_));
 187       stem_tremolo_->set_property ("stem",
 188                                    info.grob_->self_scm ());
 189       stem_tremolo_->set_parent (info.grob_, X_AXIS);
 190     }
 191 }
 192
 193
 194 void
 195 Chord_tremolo_engraver::start_translation_timestep ()
 196 {
 197   if (beam_ && stop_mom_ == now_mom ())
 198     {
 199       finished_beam_ = beam_;
 200       repeat_ = 0;
 201       beam_ = 0;
 202     }
 203 }
 204
 205
 206 void
 207 Chord_tremolo_engraver::stop_translation_timestep ()
 208 {
 209   if (stem_tremolo_)
 210     {
 211       repeat_ = 0;
 212       if (beam_)
 213         programming_error ("Huh, beam and stem tremolo?");
 214       stem_tremolo_ = 0;
 215     }
 216
 217   typeset_beam ();
 218 }
 219
 220
 221
 222 ENTER_DESCRIPTION (Chord_tremolo_engraver,
 223 /* descr */       "Generates beams for  tremolo repeats.",
 224 /* creats*/       "Beam",
 225 /* accepts */     "repeated-music",
 226 /* acks  */      "stem-interface note-head-interface",
 227 /* reads */       "",
 228 /* write */       "");