lily/measure-grouping-engraver.cc

   1 /*
   2   measure-grouping-engraver.cc -- implement Measure_grouping_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2002--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "warn.hh"
  10 #include "side-position-interface.hh"
  11 #include "global-context.hh"
  12 #include "engraver.hh"
  13 #include "spanner.hh"
  14
  15 #include "translator.icc"
  16
  17 class Measure_grouping_engraver : public Engraver
  18 {
  19 public:
  20   TRANSLATOR_DECLARATIONS (Measure_grouping_engraver);
  21
  22 protected:
  23   Spanner *grouping_;
  24   Rational stop_grouping_mom_;
  25
  26   void process_music ();
  27   virtual void finalize ();
  28   DECLARE_ACKNOWLEDGER (note_column);
  29 };
  30
  31 void
  32 Measure_grouping_engraver::finalize ()
  33 {
  34   if (grouping_)
  35     {
  36       grouping_->set_bound (RIGHT, unsmob_grob (get_property ("currentCommandColumn")));
  37       grouping_->suicide ();
  38       grouping_ = 0;
  39     }
  40 }
  41
  42 void
  43 Measure_grouping_engraver::acknowledge_note_column (Grob_info gi)
  44 {
  45   if (grouping_)
  46     Side_position_interface::add_support (grouping_, gi.grob ());
  47 }
  48
  49 void
  50 Measure_grouping_engraver::process_music ()
  51 {
  52   Moment now = now_mom ();
  53   if (grouping_ && now.main_part_ >= stop_grouping_mom_ && !now.grace_part_)
  54     {
  55       grouping_->set_bound (RIGHT,
  56                             unsmob_grob (get_property ("currentMusicalColumn")));
  57
  58       grouping_ = 0;
  59     }
  60
  61   if (now.grace_part_)
  62     return;
  63
  64   SCM grouping = get_property ("beatGrouping");
  65   if (scm_is_pair (grouping))
  66     {
  67       Moment *measpos = unsmob_moment (get_property ("measurePosition"));
  68       Rational mp = measpos->main_part_;
  69
  70       Moment *beatlen_mom = unsmob_moment (get_property ("beatLength"));
  71       Rational beat_length = beatlen_mom->main_part_;
  72
  73       Rational where (0);
  74       for (SCM s = grouping; scm_is_pair (s);
  75            where += Rational ((int) scm_to_int (scm_car (s))) * beat_length,
  76              s = scm_cdr (s))
  77         {
  78           int grouplen = scm_to_int (scm_car (s));
  79           if (where == mp)
  80             {
  81               if (grouping_)
  82                 {
  83                   programming_error ("last grouping not finished yet");
  84                   continue;
  85                 }
  86
  87               grouping_ = make_spanner ("MeasureGrouping", SCM_EOL);
  88               grouping_->set_bound (LEFT, unsmob_grob (get_property ("currentMusicalColumn")));
  89
  90               stop_grouping_mom_ = now.main_part_ + Rational (grouplen - 1) * beat_length;
  91               get_global_context ()->add_moment_to_process (Moment (stop_grouping_mom_));
  92
  93               if (grouplen == 3)
  94                 grouping_->set_property ("style", ly_symbol2scm ("triangle"));
  95               else
  96                 grouping_->set_property ("style", ly_symbol2scm ("bracket"));
  97
  98               break;
  99             }
 100         }
 101     }
 102 }
 103
 104 Measure_grouping_engraver::Measure_grouping_engraver ()
 105 {
 106   grouping_ = 0;
 107 }
 108
 109 ADD_ACKNOWLEDGER (Measure_grouping_engraver, note_column);
 110 ADD_TRANSLATOR (Measure_grouping_engraver,
 111                 /* doc */
 112                 "Create @code{MeasureGrouping} to indicate beat subdivision.",
 113
 114                 /* create */
 115                 "MeasureGrouping ",
 116
 117                 /* read */
 118                 "beatLength "
 119                 "currentMusicalColumn "
 120                 "measurePosition "
 121                 "beatGrouping ",
 122
 123                 /* write */
 124                 ""
 125                 );