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--2002 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 "musical-request.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   Rhythmic_req *rhythmic_req_;
  36   Tremolo_req* 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       Rhythmic_req *rhythmic_req = dynamic_cast <Rhythmic_req *> (i.music_cause ());
  61       if (rhythmic_req)
  62         duration_log = unsmob_duration (rhythmic_req->get_mus_property ("duration"))-> duration_log ();
  63
  64       if (!stem_)
  65         {
  66           stem_ = new Item (get_property ("Stem"));
  67
  68           stem_->set_grob_property ("duration-log", gh_int2scm (duration_log));
  69
  70           if (tremolo_req_)
  71             {
  72               /*
  73                 Stem tremolo is never applied to a note by default,
  74                 is must me requested.  But there is a default for the
  75                 tremolo value:
  76
  77                    c4:8 c c:
  78
  79                 the first and last (quarter) note bothe get one tremolo flag.
  80                */
  81               int requested_type = gh_scm2int (tremolo_req_->get_mus_property ("tremolo-type"));
  82               SCM f = get_property ("tremoloFlags");
  83               if (!requested_type && gh_number_p (f))
  84                 requested_type = gh_scm2int (f);
  85               else
  86                 daddy_trans_->set_property ("tremoloFlags", gh_int2scm (requested_type));
  87
  88               int tremolo_flags = intlog2 (requested_type) - 2
  89                 - (duration_log > 2 ? duration_log - 2 : 0);
  90               if (tremolo_flags <= 0)
  91                 {
  92                   tremolo_req_->origin()->warning (_("tremolo duration is too long"));
  93                   tremolo_flags = 0;
  94                 }
  95
  96               if (tremolo_flags)
  97                 {
  98                   tremolo_ = new Item (get_property ("StemTremolo"));
  99                   announce_grob(tremolo_, tremolo_req_->self_scm());
 100
 101                   /*
 102                     The number of tremolo flags is the number of flags of
 103                     the tremolo-type minus the number of flags of the note
 104                     itself.
 105                    */
 106                           tremolo_->set_grob_property ("flag-count",
 107                                                 gh_int2scm (tremolo_flags));
 108                   tremolo_->set_parent (stem_, X_AXIS);
 109                 }
 110             }
 111
 112           /*
 113             We announce the cause of the head as cause of the stem.
 114             The stem needs a rhythmic structure to fit it into a beam.  */
 115           announce_grob(stem_, i.music_cause ()->self_scm());
 116         }
 117
 118       if (Stem::duration_log (stem_) != duration_log)
 119         {
 120           i.music_cause ()->origin ()->warning (_f ("Adding note head to incompatible stem (type = %d)", 1 <<  Stem::duration_log (stem_)));
 121         }
 122
 123       Stem::add_head (stem_,h);
 124     }
 125 }
 126
 127 void
 128 Stem_engraver::stop_translation_timestep ()
 129 {
 130   if (tremolo_)
 131     {
 132       Stem_tremolo::set_stem (tremolo_, stem_);
 133       typeset_grob (tremolo_);
 134       tremolo_ = 0;
 135     }
 136
 137   if (stem_)
 138     {
 139       SCM prop = get_property ("stemLeftBeamCount");
 140       if (gh_number_p (prop))
 141         {
 142           Stem::set_beaming (stem_,gh_scm2int (prop),LEFT);
 143           daddy_trans_->unset_property (ly_symbol2scm ("stemLeftBeamCount"));
 144         }
 145       prop = get_property ("stemRightBeamCount");
 146       if (gh_number_p (prop))
 147         {
 148           Stem::set_beaming (stem_,gh_scm2int (prop), RIGHT);
 149           daddy_trans_->unset_property (ly_symbol2scm ("stemRightBeamCount"));
 150         }
 151
 152       typeset_grob (stem_);
 153       stem_ = 0;
 154     }
 155
 156
 157   tremolo_req_ = 0;
 158 }
 159
 160 bool
 161 Stem_engraver::try_music (Music* r)
 162 {
 163   if (Tremolo_req* a = dynamic_cast <Tremolo_req *> (r))
 164     {
 165       tremolo_req_ = a;
 166       return true;
 167     }
 168   return false;
 169 }
 170
 171 ENTER_DESCRIPTION(Stem_engraver,
 172 /* descr */       "Create stems and single-stem tremolos.  It also works together with
 173 the beam engraver for overriding beaming.",
 174 /* creats*/       "Stem StemTremolo",
 175 /* accepts */     "general-music",
 176 /* acks  */      "rhythmic-head-interface",
 177 /* reads */       "tremoloFlags stemLeftBeamCount stemRightBeamCount",
 178 /* write */       "");