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
  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_mus_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 (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_)
 123     {
 124       if (sequential_body_b_ && !beam_)
 125         {
 126           beam_ = new Spanner (get_property ("Beam"));
 127           beam_->set_grob_property ("chord-tremolo", SCM_BOOL_T);
 128
 129           SCM smp = get_property ("measurePosition");
 130           Moment mp
 131             = (unsmob_moment (smp)) ? *unsmob_moment (smp) : Moment (0);
 132           beam_start_location_ = mp;
 133           announce_grob(beam_, repeat_->self_scm());
 134         }
 135       else if (!sequential_body_b_ && !stem_tremolo_)
 136         {
 137           if (flags_)
 138             {
 139               stem_tremolo_ = new Item (get_property ("StemTremolo"));
 140               announce_grob(stem_tremolo_, repeat_->self_scm());
 141               stem_tremolo_->set_grob_property ("flag-count",
 142                                                 scm_int2num (flags_));
 143             }
 144         }
 145     }
 146 }
 147 void
 148 Chord_tremolo_engraver::finalize ()
 149 {
 150   typeset_beam ();
 151   if (beam_)
 152     {
 153       repeat_->origin ()->warning (_ ("unterminated chord tremolo"));
 154       beam_->suicide ();
 155     }
 156 }
 157
 158 void
 159 Chord_tremolo_engraver::typeset_beam ()
 160 {
 161   if (finished_beam_)
 162     {
 163       typeset_grob (finished_beam_);
 164       finished_beam_ = 0;
 165     }
 166 }
 167
 168 void
 169 Chord_tremolo_engraver::acknowledge_grob (Grob_info info)
 170 {
 171   if (beam_ && Stem::has_interface (info.grob_))
 172     {
 173       Grob * s = info.grob_;
 174
 175       if (start_mom_ == now_mom())
 176         Stem::set_beaming (s, flags_, RIGHT);
 177       else
 178         Stem::set_beaming (s, flags_, LEFT);
 179
 180       if (Stem::duration_log (s) != 1)
 181         {
 182           beam_->set_grob_property ("gap-count", gh_int2scm (flags_ - total_duration_flags_));
 183         }
 184
 185       if (info.music_cause ()->is_mus_type ("rhythmic-event"))
 186         {
 187           Beam::add_stem (beam_, s);
 188         }
 189       else
 190         {
 191           String s = _ ("stem must have Rhythmic structure");
 192           if (info.music_cause ())
 193             info.music_cause ()->origin ()->warning (s);
 194           else
 195             ::warning (s);
 196         }
 197     }
 198   else if (stem_tremolo_ && Stem::has_interface (info.grob_))
 199     {
 200        Stem_tremolo::set_stem (stem_tremolo_, info.grob_);
 201        stem_tremolo_->set_parent (info.grob_,X_AXIS);
 202     }
 203 }
 204
 205
 206 void
 207 Chord_tremolo_engraver::start_translation_timestep ()
 208 {
 209   if (beam_ && stop_mom_ == now_mom ())
 210     {
 211       finished_beam_ = beam_;
 212       repeat_ = 0;
 213       beam_ = 0;
 214     }
 215 }
 216
 217
 218 void
 219 Chord_tremolo_engraver::stop_translation_timestep ()
 220 {
 221   typeset_beam ();
 222
 223   if (stem_tremolo_)
 224     {
 225       typeset_grob (stem_tremolo_);
 226       stem_tremolo_ = 0;
 227     }
 228 }
 229
 230
 231
 232 ENTER_DESCRIPTION(Chord_tremolo_engraver,
 233 /* descr */       "Generates beams for  tremolo repeats.",
 234 /* creats*/       "Beam",
 235 /* accepts */     "repeated-music",
 236 /* acks  */      "stem-interface note-head-interface",
 237 /* reads */       "",
 238 /* write */       "");