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--2003 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   This acknowledges repeated music with "tremolo" style.  It typesets
  29   a beam.
  30
  31   TODO:
  32
  33   - perhaps use engraver this to steer other engravers? That would
  34   create dependencies between engravers, which is bad.
  35
  36   - create dots if appropriate.
  37
  38   - create  TremoloBeam iso Beam?
  39  */
  40
  41 class Chord_tremolo_engraver : public Engraver
  42 {
  43   void typeset_beam ();
  44 TRANSLATOR_DECLARATIONS(Chord_tremolo_engraver);
  45 protected:
  46   Repeated_music * repeat_;
  47
  48   /// moment (global time) where beam started.
  49   Moment start_mom_;
  50   Moment stop_mom_;
  51   int flags_ ;
  52   /// location  within measure where beam started.
  53   Moment beam_start_location_;
  54
  55   bool sequential_body_b_;
  56   Spanner * beam_;
  57   Spanner * finished_beam_;
  58   Item * stem_tremolo_;
  59 protected:
  60   virtual void finalize ();
  61   virtual bool try_music (Music*);
  62   virtual void acknowledge_grob (Grob_info);
  63   virtual void stop_translation_timestep ();
  64   virtual void start_translation_timestep ();
  65   virtual void process_music ();
  66 };
  67
  68 Chord_tremolo_engraver::Chord_tremolo_engraver ()
  69 {
  70   beam_  = finished_beam_ = 0;
  71   repeat_ =0;
  72   flags_ = 0;
  73   stem_tremolo_ = 0;
  74   sequential_body_b_ = false;
  75 }
  76
  77 bool
  78 Chord_tremolo_engraver::try_music (Music * m)
  79 {
  80   Repeated_music * rp = dynamic_cast<Repeated_music*> (m);
  81   if (rp
  82       && rp->get_mus_property ("iterator-ctor") == Chord_tremolo_iterator::constructor_proc
  83       && !repeat_)
  84     {
  85       Moment l = rp->get_length ();
  86       repeat_ = rp;
  87       start_mom_ = now_mom ();
  88       stop_mom_ = start_mom_ + l;
  89       sequential_body_b_ = dynamic_cast<Sequential_music*> (rp->body ());
  90
  91       Rational total_dur = l.main_part_;
  92       Rational note_dur = (total_dur / Rational (repeat_->repeat_count ()));
  93        flags_ = intlog2 ((total_dur / note_dur).num ());
  94
  95       return true;
  96     }
  97
  98   return false;
  99 }
 100
 101 void
 102 Chord_tremolo_engraver::process_music ()
 103 {
 104   if (repeat_)
 105     {
 106       if (sequential_body_b_ && !beam_)
 107         {
 108           beam_ = new Spanner (get_property ("Beam"));
 109           beam_->set_grob_property ("chord-tremolo", SCM_BOOL_T);
 110
 111           SCM smp = get_property ("measurePosition");
 112           Moment mp
 113             = (unsmob_moment (smp)) ? *unsmob_moment (smp) : Moment (0);
 114           beam_start_location_ = mp;
 115           announce_grob(beam_, repeat_->self_scm());
 116         }
 117       else if (!sequential_body_b_ && !stem_tremolo_)
 118         {
 119
 120           if (flags_)
 121             {
 122               stem_tremolo_ = new Item (get_property ("StemTremolo"));
 123               announce_grob(stem_tremolo_, repeat_->self_scm());
 124               stem_tremolo_->set_grob_property ("flag-count",
 125                                                 scm_int2num (flags_));
 126
 127             }
 128         }
 129     }
 130 }
 131 void
 132 Chord_tremolo_engraver::finalize ()
 133 {
 134   typeset_beam ();
 135   if (beam_)
 136     {
 137       repeat_->origin ()->warning (_ ("unterminated chord tremolo"));
 138       beam_->suicide ();
 139     }
 140 }
 141
 142 void
 143 Chord_tremolo_engraver::typeset_beam ()
 144 {
 145   if (finished_beam_)
 146     {
 147       typeset_grob (finished_beam_);
 148       finished_beam_ = 0;
 149     }
 150 }
 151
 152
 153 void
 154 Chord_tremolo_engraver::acknowledge_grob (Grob_info info)
 155 {
 156   if (beam_ && Stem::has_interface (info.grob_))
 157     {
 158       Grob * s = info.grob_;
 159       Stem::set_beaming (s, flags_, LEFT);
 160       Stem::set_beaming (s, flags_, RIGHT);
 161
 162       SCM d = s->get_grob_property ("direction");
 163       if (Stem::duration_log (s) != 1)
 164         {
 165           beam_->set_grob_property ("gap", gh_double2scm (0.8));
 166         }
 167       s->set_grob_property ("direction", d);
 168
 169       if (info.music_cause ()->is_mus_type ("rhythmic-event"))
 170         {
 171           Beam::add_stem (beam_, s);
 172         }
 173       else
 174         {
 175           String s = _ ("stem must have Rhythmic structure");
 176           if (info.music_cause ())
 177             info.music_cause ()->origin ()->warning (s);
 178           else
 179             ::warning (s);
 180         }
 181     }
 182   else if (stem_tremolo_ && Stem::has_interface (info.grob_))
 183     {
 184        Stem_tremolo::set_stem (stem_tremolo_, info.grob_);
 185        stem_tremolo_->set_parent (info.grob_,X_AXIS);
 186     }
 187 }
 188
 189
 190 void
 191 Chord_tremolo_engraver::start_translation_timestep ()
 192 {
 193   if (beam_ && stop_mom_ == now_mom ())
 194     {
 195       finished_beam_ = beam_;
 196
 197       repeat_ = 0;
 198       beam_ = 0;
 199     }
 200 }
 201
 202
 203 void
 204 Chord_tremolo_engraver::stop_translation_timestep ()
 205 {
 206   typeset_beam ();
 207
 208   if (stem_tremolo_)
 209     {
 210       typeset_grob (stem_tremolo_);
 211       stem_tremolo_ = 0;
 212     }
 213
 214 }
 215
 216
 217
 218 ENTER_DESCRIPTION(Chord_tremolo_engraver,
 219 /* descr */       "Generates beams for  tremolo repeats.",
 220 /* creats*/       "Beam",
 221 /* accepts */     "repeated-music",
 222 /* acks  */      "stem-interface note-head-interface",
 223 /* reads */       "",
 224 /* write */       "");