lily/chord-tremolo-engraver.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 2000--2010 Han-Wen Nienhuys <hanwen@xs4all.nl>
   5                  Erik Sandberg <mandolaerik@gmail.com>
   6
   7   LilyPond is free software: you can redistribute it and/or modify
   8   it under the terms of the GNU General Public License as published by
   9   the Free Software Foundation, either version 3 of the License, or
  10   (at your option) any later version.
  11
  12   LilyPond is distributed in the hope that it will be useful,
  13   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15   GNU General Public License for more details.
  16
  17   You should have received a copy of the GNU General Public License
  18   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "beam.hh"
  22 #include "engraver-group.hh"
  23 #include "international.hh"
  24 #include "item.hh"
  25 #include "math.h" // ceil
  26 #include "misc.hh"
  27 #include "repeated-music.hh"
  28 #include "rhythmic-head.hh"
  29 #include "spanner.hh"
  30 #include "stem-tremolo.hh"
  31 #include "stem.hh"
  32 #include "stream-event.hh"
  33 #include "warn.hh"
  34
  35 #include "translator.icc"
  36
  37 /**
  38
  39 This acknowledges repeated music with "tremolo" style.  It typesets
  40 a beam.
  41
  42 TODO:
  43
  44 - perhaps use engraver this to steer other engravers? That would
  45 create dependencies between engravers, which is bad.
  46
  47 - create dots if appropriate.
  48
  49 - create TremoloBeam iso Beam?
  50 */
  51 class Chord_tremolo_engraver : public Engraver
  52 {
  53   TRANSLATOR_DECLARATIONS (Chord_tremolo_engraver);
  54 protected:
  55   Stream_event *repeat_;
  56
  57   // current direction of beam (first RIGHT, then LEFT)
  58   Direction beam_dir_;
  59
  60   Spanner *beam_;
  61
  62 protected:
  63   virtual void finalize ();
  64   void process_music ();
  65   DECLARE_TRANSLATOR_LISTENER (tremolo_span);
  66   DECLARE_ACKNOWLEDGER (stem);
  67 };
  68
  69 Chord_tremolo_engraver::Chord_tremolo_engraver ()
  70 {
  71   beam_ = 0;
  72   repeat_ = 0;
  73   beam_dir_ = CENTER;
  74 }
  75
  76 IMPLEMENT_TRANSLATOR_LISTENER (Chord_tremolo_engraver, tremolo_span);
  77 void
  78 Chord_tremolo_engraver::listen_tremolo_span (Stream_event *ev)
  79 {
  80   Direction span_dir = to_dir (ev->get_property ("span-direction"));
  81   if (span_dir == START)
  82     {
  83       if (ASSIGN_EVENT_ONCE (repeat_, ev))
  84         {
  85           beam_dir_ = RIGHT;
  86         }
  87     }
  88   else if (span_dir == STOP)
  89     {
  90       if (!repeat_)
  91         ev->origin ()->warning (_ ("No tremolo to end"));
  92       repeat_ = 0;
  93       beam_ = 0;
  94       beam_dir_ = CENTER;
  95     }
  96 }
  97
  98 void
  99 Chord_tremolo_engraver::process_music ()
 100 {
 101   if (repeat_ && !beam_)
 102     {
 103       beam_ = make_spanner ("Beam", repeat_->self_scm ());
 104     }
 105 }
 106
 107 void
 108 Chord_tremolo_engraver::finalize ()
 109 {
 110   if (beam_)
 111     {
 112       repeat_->origin ()->warning (_ ("unterminated chord tremolo"));
 113       announce_end_grob (beam_, SCM_EOL);
 114       beam_->suicide ();
 115     }
 116 }
 117
 118 void
 119 Chord_tremolo_engraver::acknowledge_stem (Grob_info info)
 120 {
 121   if (beam_)
 122     {
 123       int tremolo_type = robust_scm2int (repeat_->get_property ("tremolo-type"), 1);
 124       int flags = max (0, intlog2 (tremolo_type) - 2);
 125       int repeat_count = robust_scm2int (repeat_->get_property ("repeat-count"), 1);
 126       int gap_count = min (flags, intlog2 (repeat_count) + 1);
 127
 128       Grob *s = info.grob ();
 129       Stem::set_beaming (s, flags, beam_dir_);
 130
 131       if (Stem::duration_log (s) != 1)
 132         beam_->set_property ("gap-count", scm_from_int (gap_count));
 133
 134       if (beam_dir_ == RIGHT)
 135         {
 136           beam_dir_ = LEFT;
 137           announce_end_grob (beam_, s->self_scm ());
 138         }
 139
 140       if (info.ultimate_event_cause ()->in_event_class ("rhythmic-event"))
 141         Beam::add_stem (beam_, s);
 142       else
 143         {
 144           string s = _ ("stem must have Rhythmic structure");
 145           if (info.event_cause ())
 146             info.event_cause ()->origin ()->warning (s);
 147           else
 148             ::warning (s);
 149         }
 150     }
 151 }
 152
 153 ADD_ACKNOWLEDGER (Chord_tremolo_engraver, stem);
 154 ADD_TRANSLATOR (Chord_tremolo_engraver,
 155                 /* doc */
 156                 "Generate beams for tremolo repeats.",
 157
 158                 /* create */
 159                 "Beam ",
 160
 161                 /* read */
 162                 "",
 163
 164                 /* write */
 165                 ""
 166                 );