]> git.donarmstrong.com Git - lilypond.git/blobdiff - lily/stem-engraver.cc
new file.
[lilypond.git] / lily / stem-engraver.cc
index 1679e52441275bdab90ca4e37760835274188471..63f8d78843ef4a9eb95b59827e696eb5329c5440 100644 (file)
 /*
-  stem-grav.cc -- implement Stem_engraver
+  stem-engraver.cc -- implement Stem_engraver
 
   source file of the GNU LilyPond music typesetter
 
-  (c)  1997--1999 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+  (c) 1997--2005 Han-Wen Nienhuys <hanwen@cs.uu.nl>
 */
 
-#include "stem-engraver.hh"
-#include "note-head.hh"
-#include "stem.hh"
-#include "musical-request.hh"
-#include "duration-convert.hh"
+#include "context.hh"
+#include "directional-element-interface.hh"
+#include "engraver.hh"
+#include "item.hh"
 #include "misc.hh"
+#include "rhythmic-head.hh"
+#include "script-interface.hh"
+#include "staff-symbol-referencer.hh"
 #include "stem-tremolo.hh"
-#include "staff-info.hh"
-#include "translator-group.hh"
+#include "stem.hh"
 
-Stem_engraver::Stem_engraver()
+/**
+  Make stems upon receiving noteheads.
+ */
+class Stem_engraver : public Engraver
 {
-  abbrev_req_l_ = 0;
-  stem_p_ = 0;
-  abbrev_p_ = 0;
-  default_abbrev_i_ = 16;
-  rhythmic_req_l_ =0;
-}
-
-void
-Stem_engraver::do_creation_processing ()
+  Grob *stem_;
+  Grob *tremolo_;
+  Music *rhythmic_ev_;
+  Music *tremolo_ev_;
+  
+  TRANSLATOR_DECLARATIONS (Stem_engraver);
+
+protected:
+  void make_stem (Grob_info);
+  
+  virtual void acknowledge_grob (Grob_info);
+  virtual void stop_translation_timestep ();
+  virtual bool try_music (Music *);
+};
+
+Stem_engraver::Stem_engraver ()
 {
-  Scalar prop = get_property ("abbrev", 0);
-  if (prop.isnum_b ()) 
-    {
-      default_abbrev_i_  = prop;
-    }
+  tremolo_ev_ = 0;
+  stem_ = 0;
+  tremolo_ = 0;
+  rhythmic_ev_ = 0;
 }
 
 void
-Stem_engraver::acknowledge_element(Score_element_info i)
+Stem_engraver::make_stem (Grob_info gi)
 {
-  if (Rhythmic_head * h = dynamic_cast<Rhythmic_head *> (i.elem_l_))
+  /* Announce the cause of the head as cause of the stem.  The
+     stem needs a rhythmic structure to fit it into a beam.  */
+  stem_ = make_item ("Stem", gi.music_cause ()->self_scm ());
+
+  /*
+    docme: why do we take duration-log from request, not from note
+    head?
+   */
+  int duration_log = gi.music_cause ()->duration_log ();
+  stem_->set_property ("duration-log", scm_int2num (duration_log));
+
+  if (tremolo_ev_)
     {
-      if (h->stem_l_)
-       return;
-      
-      Rhythmic_req * r = dynamic_cast <Rhythmic_req *> (i.req_l_);
-      int duration_log = r->duration_.durlog_i_;      
-      if (!stem_p_) 
+      /* Stem tremolo is never applied to a note by default,
+        is must me requested.  But there is a default for the
+        tremolo value:
+
+        c4:8 c c:
+
+        the first and last (quarter) note bothe get one tremolo flag.  */
+      int requested_type
+       = scm_to_int (tremolo_ev_->get_property ("tremolo-type"));
+      SCM f = get_property ("tremoloFlags");
+      if (!requested_type)
        {
-         stem_p_ = new Stem;
-         stem_p_->flag_i_ = duration_log;
-
-         if (abbrev_req_l_)
-           {
-             /*
-               suggests typing of:
-               c8:16 c: c: c:
-               hmm, which isn't so bad?
-             */
-             int t = abbrev_req_l_->type_i_;
-             if (!t)
-               t = default_abbrev_i_;
-             else
-               default_abbrev_i_ = t;
-
-             if (t)
-               {
-                 abbrev_p_ = new Stem_tremolo;
-                 announce_element (Score_element_info (abbrev_p_, abbrev_req_l_));
-                 abbrev_p_->abbrev_flags_i_ =intlog2 (t) - (duration_log>? 2);
-               }
-           }
-
-         // must give the request, to preserve the rhythmic info.
-         announce_element (Score_element_info (stem_p_, r));
+         if (scm_is_number (f))
+           requested_type = scm_to_int (f);
+         else
+           requested_type = 8;
        }
+      else
+       context ()->set_property ("tremoloFlags", scm_int2num (requested_type));
 
-      if (stem_p_->flag_i_ != duration_log)
+      int tremolo_flags = intlog2 (requested_type) - 2
+       - (duration_log > 2 ? duration_log - 2 : 0);
+      if (tremolo_flags <= 0)
        {
-         r->warning (_f ("Adding note head to incompatible stem (type = %d)", 1 <<  stem_p_->flag_i_));
+         tremolo_ev_->origin ()->warning (_("tremolo duration is too long"));
+         tremolo_flags = 0;
        }
 
-      stem_p_->add_head (h);
+      if (tremolo_flags)
+       {
+         tremolo_ = make_item ("StemTremolo", tremolo_ev_->self_scm ());
+
+         /* The number of tremolo flags is the number of flags of the
+           tremolo-type minus the number of flags of the note itself.  */
+         tremolo_->set_property ("flag-count", scm_int2num (tremolo_flags));
+         tremolo_->set_parent (stem_, X_AXIS);
+         stem_->set_property ("tremolo-flag", tremolo_->self_scm ());
+         tremolo_->set_property ("stem", stem_->self_scm ());
+       }
     }
 }
 
 void
-Stem_engraver::do_pre_move_processing()
+Stem_engraver::acknowledge_grob (Grob_info gi)
 {
-  if (abbrev_p_)
+  if (Rhythmic_head::has_interface (gi.grob_))
     {
-      abbrev_p_->set_stem (stem_p_);
-      typeset_element (abbrev_p_);
-      abbrev_p_ = 0;
-    }
+      if (Rhythmic_head::get_stem (gi.grob_))
+       return;
 
-  if (stem_p_)
-    {
-      Scalar prop = get_property ("verticalDirection", 0);
-      Direction dir = prop.isnum_b () ? (Direction)int(prop) : CENTER;
-      if (dir)
+      Music * cause = gi.music_cause ();
+      if (!cause)
+       return ;
+      
+      if (!stem_)
+       make_stem (gi);
+      
+      int duration_log = cause->duration_log ();
+      if (Stem::duration_log (stem_) != duration_log)
        {
-         stem_p_->dir_ = dir;
-         stem_p_->set_elt_property (dir_forced_scm_sym, SCM_BOOL_T);
+         // FIXME: 
+         gi.music_cause ()->origin ()->warning (_f ("Adding note head to incompatible stem (type = %d)", 1 << Stem::duration_log (stem_)));
+         
+         gi.music_cause ()->origin ()->warning (_f ("Don't you want polyphonic voices instead?"));
        }
 
-      Translator_group* which;
-      prop = get_property ("stemLeftBeamCount", &which);
-      if (prop.isnum_b ())
-       {
-         stem_p_->beams_i_drul_[LEFT] = prop;
-         ((Translator_group*)which)->set_property ("stemLeftBeamCount", "");
-       }
-      prop = get_property ("stemRightBeamCount", &which);
-      if (prop.isnum_b ())
-       {
-         stem_p_->beams_i_drul_[RIGHT] = prop;
-         ((Translator_group*)which)->set_property ("stemRightBeamCount", "");
-       }
+      Stem::add_head (stem_, gi.grob_);
+    }
+}
 
-      prop = get_property ("stemLength", 0);
-      if (prop.isnum_b ())
+void
+Stem_engraver::stop_translation_timestep ()
+{
+  tremolo_ = 0;
+  if (stem_)
+    {
+      /* FIXME: junk these properties.  */
+      SCM prop = get_property ("stemLeftBeamCount");
+      if (scm_is_number (prop))
        {
-         stem_p_->set_elt_property (length_scm_sym, gh_double2scm (prop.to_f ()));
+         Stem::set_beaming (stem_, scm_to_int (prop), LEFT);
+         context ()->unset_property (ly_symbol2scm ("stemLeftBeamCount"));
        }
-
-      prop = get_property ("stemStyle", 0);
-      if (prop.to_bool ())
+      prop = get_property ("stemRightBeamCount");
+      if (scm_is_number (prop))
        {
-         stem_p_->set_elt_property (style_scm_sym, ly_ch_C_to_scm (prop.ch_C()));
+         Stem::set_beaming (stem_, scm_to_int (prop), RIGHT);
+         context ()->unset_property (ly_symbol2scm ("stemRightBeamCount"));
        }
-      
-      typeset_element(stem_p_);
-      stem_p_ = 0;
+      stem_ = 0;
     }
-  abbrev_req_l_ = 0;
+  tremolo_ev_ = 0;
 }
 
 bool
-Stem_engraver::do_try_music (Music* r)
+Stem_engraver::try_music (Music *m)
 {
-  if (Tremolo_req* a = dynamic_cast <Tremolo_req *> (r))
+  if (m->is_mus_type ("tremolo-event"))
     {
-      abbrev_req_l_ = a;
+      tremolo_ev_ = m;
       return true;
     }
   return false;
 }
 
-
-ADD_THIS_TRANSLATOR(Stem_engraver);
+ADD_TRANSLATOR (Stem_engraver,
+/* descr */       "Create stems and single-stem tremolos.  It also works together with "
+"the beam engraver for overriding beaming.",
+/* creats*/       "Stem StemTremolo",
+/* accepts */     "tremolo-event",
+/* acks  */      "rhythmic-head-interface",
+/* reads */       "tremoloFlags stemLeftBeamCount stemRightBeamCount",
+/* write */       "");