lily/chord-tremolo-iterator.cc

   1 /*
   2   chord-tremolo-iterator.cc -- implement Chord_tremolo_iterator
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2000--2006 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7                  Erik Sandberg <mandolaerik@gmail.com>
   8 */
   9
  10 #include "chord-tremolo-iterator.hh"
  11
  12 #include "input.hh"
  13 #include "international.hh"
  14 #include "misc.hh"
  15 #include "repeated-music.hh"
  16
  17 Chord_tremolo_iterator::Chord_tremolo_iterator ()
  18 {
  19 }
  20
  21 SCM
  22 Chord_tremolo_iterator::get_music_list () const
  23 {
  24   Music *mus = get_music ();
  25   Input *origin = mus->origin ();
  26   Moment l = mus->get_length ();
  27   Music *body = Repeated_music::body (mus);
  28   bool body_is_sequential = body->is_mus_type ("sequential-music");
  29
  30   int elt_count = body_is_sequential ? scm_ilength (body->get_property ("elements")) : 1;
  31
  32   if (body_is_sequential && elt_count != 2)
  33     mus->origin ()->warning (_f ("expect 2 elements for chord tremolo, found %d", elt_count));
  34
  35   if (elt_count <= 0)
  36     elt_count = 1;
  37
  38   Rational total_dur = l.main_part_;
  39   Rational note_dur = total_dur / Rational (elt_count * Repeated_music::repeat_count (mus));
  40
  41   SCM tremolo_type = scm_int2num (note_dur.den ());
  42   int expected_beaming_ = max (0, (intlog2 (total_dur.den ()) - 2));
  43
  44   if (elt_count == 1)
  45     {
  46       Music *ev = make_music_by_name (ly_symbol2scm ("TremoloEvent"));
  47       ev->set_spot (*origin);
  48       ev->set_property ("tremolo-type", tremolo_type);
  49       return scm_list_2 (ev->unprotect (), body->self_scm ());
  50     }
  51   else
  52     {
  53       SCM tremolo_symbol = ly_symbol2scm ("TremoloSpanEvent");
  54       SCM start_event_scm = scm_call_2 (ly_lily_module_constant ("make-span-event"), tremolo_symbol, scm_from_int (START));
  55       unsmob_music (start_event_scm)->set_spot (*origin);
  56       SCM stop_event_scm = scm_call_2 (ly_lily_module_constant ("make-span-event"), tremolo_symbol, scm_from_int (STOP));
  57
  58       Music *start_event = unsmob_music (start_event_scm);
  59       Music *stop_event = unsmob_music (stop_event_scm);
  60       start_event->set_spot (*origin);
  61       stop_event->set_spot (*origin);
  62       start_event->set_property ("tremolo-type", tremolo_type);
  63       start_event->set_property ("expected-beam-count", scm_int2num (expected_beaming_));
  64
  65       return scm_list_3 (start_event_scm, body->self_scm (), stop_event_scm);
  66     }
  67 }
  68
  69 IMPLEMENT_CTOR_CALLBACK (Chord_tremolo_iterator);