lily/stem-engraver.cc

   1 /*
   2   stem-grav.cc -- implement Stem_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c)  1997--2003 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9 #include "staff-symbol-referencer.hh"
  10 #include "rhythmic-head.hh"
  11 #include "stem.hh"
  12 #include "event.hh"
  13 #include "misc.hh"
  14 #include "stem-tremolo.hh"
  15 #include "item.hh"
  16 #include "translator-group.hh"
  17 #include "engraver.hh"
  18
  19
  20
  21 /**
  22   Make stems upon receiving noteheads.
  23  */
  24 class Stem_engraver : public Engraver
  25 {
  26   TRANSLATOR_DECLARATIONS(Stem_engraver);
  27 protected:
  28   virtual void acknowledge_grob (Grob_info);
  29   virtual void stop_translation_timestep ();
  30   virtual bool try_music (Music*);
  31
  32 private:
  33   Grob  *stem_;
  34   Grob *tremolo_;
  35   Music *rhythmic_req_;
  36   Music* tremolo_req_;
  37 };
  38
  39 Stem_engraver::Stem_engraver ()
  40 {
  41   tremolo_req_ = 0;
  42   stem_ = 0;
  43   tremolo_ = 0;
  44   rhythmic_req_ =0;
  45 }
  46
  47
  48 void
  49 Stem_engraver::acknowledge_grob (Grob_info i)
  50 {
  51   Grob* h = i.grob_;
  52   if (Rhythmic_head::has_interface (h))
  53     {
  54       if (Rhythmic_head::get_stem (h))
  55         return;
  56
  57       /* Reverted to the old method so chord tremolos work again. /MB
  58       */
  59       int duration_log = 0;
  60
  61       Music * m = i.music_cause ();
  62       if (m->is_mus_type ("rhythmic-event"))
  63         duration_log = unsmob_duration (m->get_mus_property ("duration"))-> duration_log ();
  64
  65       if (!stem_)
  66         {
  67           stem_ = new Item (get_property ("Stem"));
  68
  69           stem_->set_grob_property ("duration-log", gh_int2scm (duration_log));
  70
  71           if (tremolo_req_)
  72             {
  73               /*
  74                 Stem tremolo is never applied to a note by default,
  75                 is must me requested.  But there is a default for the
  76                 tremolo value:
  77
  78                    c4:8 c c:
  79
  80                 the first and last (quarter) note bothe get one tremolo flag.
  81                */
  82               int requested_type = gh_scm2int (tremolo_req_->get_mus_property ("tremolo-type"));
  83               SCM f = get_property ("tremoloFlags");
  84               if (!requested_type)
  85                 if (gh_number_p (f))
  86                   requested_type = gh_scm2int (f);
  87                 else
  88                   requested_type = 8;
  89               else
  90                 daddy_trans_->set_property ("tremoloFlags", gh_int2scm (requested_type));
  91
  92               int tremolo_flags = intlog2 (requested_type) - 2
  93                 - (duration_log > 2 ? duration_log - 2 : 0);
  94               if (tremolo_flags <= 0)
  95                 {
  96                   tremolo_req_->origin()->warning (_("tremolo duration is too long"));
  97                   tremolo_flags = 0;
  98                 }
  99
 100               if (tremolo_flags)
 101                 {
 102                   tremolo_ = new Item (get_property ("StemTremolo"));
 103                   announce_grob(tremolo_, tremolo_req_->self_scm());
 104
 105                   /*
 106                     The number of tremolo flags is the number of flags of
 107                     the tremolo-type minus the number of flags of the note
 108                     itself.
 109                    */
 110                           tremolo_->set_grob_property ("flag-count",
 111                                                 gh_int2scm (tremolo_flags));
 112                   tremolo_->set_parent (stem_, X_AXIS);
 113                 }
 114             }
 115
 116           /*
 117             We announce the cause of the head as cause of the stem.
 118             The stem needs a rhythmic structure to fit it into a beam.  */
 119           announce_grob(stem_, i.music_cause ()->self_scm());
 120         }
 121
 122       if (Stem::duration_log (stem_) != duration_log)
 123         {
 124           i.music_cause ()->origin ()->warning (_f ("Adding note head to incompatible stem (type = %d)", 1 <<  Stem::duration_log (stem_))
 125                                                 + _f ("Don't you want polyphonic voices instead?")
 126                                                 );
 127         }
 128
 129       Stem::add_head (stem_,h);
 130     }
 131 }
 132
 133 void
 134 Stem_engraver::stop_translation_timestep ()
 135 {
 136   if (tremolo_)
 137     {
 138       Stem_tremolo::set_stem (tremolo_, stem_);
 139       typeset_grob (tremolo_);
 140       tremolo_ = 0;
 141     }
 142
 143   if (stem_)
 144     {
 145       SCM prop = get_property ("stemLeftBeamCount");
 146       if (gh_number_p (prop))
 147         {
 148           Stem::set_beaming (stem_,gh_scm2int (prop),LEFT);
 149           daddy_trans_->unset_property (ly_symbol2scm ("stemLeftBeamCount"));
 150         }
 151       prop = get_property ("stemRightBeamCount");
 152       if (gh_number_p (prop))
 153         {
 154           Stem::set_beaming (stem_,gh_scm2int (prop), RIGHT);
 155           daddy_trans_->unset_property (ly_symbol2scm ("stemRightBeamCount"));
 156         }
 157
 158       typeset_grob (stem_);
 159       stem_ = 0;
 160     }
 161
 162
 163   tremolo_req_ = 0;
 164 }
 165
 166 bool
 167 Stem_engraver::try_music (Music* r)
 168 {
 169   if (r->is_mus_type ("tremolo-event"))
 170     {
 171       tremolo_req_ = r;
 172       return true;
 173     }
 174   return false;
 175 }
 176
 177 ENTER_DESCRIPTION(Stem_engraver,
 178 /* descr */       "Create stems and single-stem tremolos.  It also works together with "
 179 "the beam engraver for overriding beaming.",
 180 /* creats*/       "Stem StemTremolo",
 181 /* accepts */     "tremolo-event",
 182 /* acks  */      "rhythmic-head-interface",
 183 /* reads */       "tremoloFlags stemLeftBeamCount stemRightBeamCount",
 184 /* write */       "");