lily/bend-engraver.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 2006--2010 Han-Wen Nienhuys
   5
   6   LilyPond is free software: you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation, either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "engraver.hh"
  21 #include "item.hh"
  22 #include "moment.hh"
  23 #include "spanner.hh"
  24 #include "stream-event.hh"
  25
  26 #include "translator.icc"
  27
  28 class Bend_engraver : public Engraver
  29 {
  30 public:
  31   TRANSLATOR_DECLARATIONS (Bend_engraver);
  32   DECLARE_ACKNOWLEDGER (note_head);
  33
  34 protected:
  35   DECLARE_TRANSLATOR_LISTENER (bend_after);
  36   void finalize ();
  37   void process_music ();
  38   void stop_translation_timestep ();
  39   void start_translation_timestep ();
  40   void stop_fall ();
  41
  42 private:
  43   Moment stop_moment_;
  44   Stream_event *fall_event_;
  45   Spanner *fall_;
  46   Spanner *last_fall_;
  47   Grob *note_head_;
  48 };
  49
  50 void
  51 Bend_engraver::finalize ()
  52 {
  53   // We shouldn't end a spanner on the last musical column of a piece because then
  54   // it would extend past the last breakable column of the piece.
  55   if (last_fall_)
  56     last_fall_->set_bound (RIGHT, unsmob_grob (get_property ("currentCommandColumn")));
  57 }
  58
  59 void
  60 Bend_engraver::stop_fall ()
  61 {
  62   bool bar = scm_is_string (get_property ("whichBar"));
  63
  64
  65   fall_->set_bound (RIGHT, unsmob_grob (bar
  66                                         ? get_property ("currentCommandColumn")
  67                                         : get_property ("currentMusicalColumn")));
  68   last_fall_ = fall_;
  69   fall_ = 0;
  70   note_head_ = 0;
  71   fall_event_ = 0;
  72 }
  73
  74 void
  75 Bend_engraver::stop_translation_timestep ()
  76 {
  77   if (fall_ && !fall_->get_bound (LEFT))
  78     {
  79       fall_->set_bound (LEFT, note_head_);
  80       fall_->set_parent (note_head_,  Y_AXIS);
  81     }
  82 }
  83
  84 void
  85 Bend_engraver::start_translation_timestep ()
  86 {
  87   last_fall_ = 0;
  88
  89   if (fall_ && now_mom ().main_part_ >= stop_moment_.main_part_)
  90     {
  91       stop_fall ();
  92     }
  93 }
  94
  95 void
  96 Bend_engraver::acknowledge_note_head (Grob_info info)
  97 {
  98   if (!fall_event_)
  99     return;
 100
 101   if (note_head_ && fall_)
 102     {
 103       stop_fall ();
 104     }
 105
 106   note_head_ = info.grob ();
 107   stop_moment_ = now_mom () + get_event_length (info.event_cause (),
 108                                                 now_mom ());
 109 }
 110
 111 Bend_engraver::Bend_engraver ()
 112 {
 113   fall_ = 0;
 114   last_fall_ = 0;
 115   note_head_ = 0;
 116   fall_event_ = 0;
 117 }
 118
 119 IMPLEMENT_TRANSLATOR_LISTENER (Bend_engraver, bend_after);
 120 void
 121 Bend_engraver::listen_bend_after (Stream_event *ev)
 122 {
 123   ASSIGN_EVENT_ONCE (fall_event_, ev);
 124 }
 125
 126 void
 127 Bend_engraver::process_music ()
 128 {
 129   if (fall_event_ && !fall_)
 130     {
 131       fall_ = make_spanner ("BendAfter", fall_event_->self_scm ());
 132       fall_->set_property ("delta-position",
 133                            scm_from_double (robust_scm2double (fall_event_->get_property ("delta-step"), 0)));
 134     }
 135 }
 136
 137 ADD_ACKNOWLEDGER (Bend_engraver, note_head);
 138
 139 ADD_TRANSLATOR (Bend_engraver,
 140                 /* doc */
 141                 "Create fall spanners.",
 142
 143                 /* create */
 144                 "BendAfter ",
 145
 146                 /* read */
 147                 "",
 148
 149                 /* write */
 150                 ""
 151                 );