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--2006 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
  14 #include "translator.icc"
  15
  16 class Measure_grouping_engraver : public Engraver
  17 {
  18 public:
  19   TRANSLATOR_DECLARATIONS (Measure_grouping_engraver);
  20
  21 protected:
  22   Spanner *grouping_;
  23   Rational stop_grouping_mom_;
  24
  25   void process_music ();
  26   virtual void finalize ();
  27   DECLARE_ACKNOWLEDGER (note_column);
  28 };
  29
  30 void
  31 Measure_grouping_engraver::finalize ()
  32 {
  33   if (grouping_)
  34     {
  35       grouping_->set_bound (RIGHT, unsmob_grob (get_property ("currentCommandColumn")));
  36       grouping_->suicide ();
  37       grouping_ = 0;
  38     }
  39 }
  40
  41 void
  42 Measure_grouping_engraver::acknowledge_note_column (Grob_info gi)
  43 {
  44   if (grouping_)
  45     Side_position_interface::add_support (grouping_, gi.grob ());
  46 }
  47
  48 void
  49 Measure_grouping_engraver::process_music ()
  50 {
  51   Moment now = now_mom ();
  52   if (grouping_ && now.main_part_ >= stop_grouping_mom_ && !now.grace_part_)
  53     {
  54       grouping_->set_bound (RIGHT,
  55                             unsmob_grob (get_property ("currentMusicalColumn")));
  56
  57       grouping_ = 0;
  58     }
  59
  60   if (now.grace_part_)
  61     return;
  62
  63   SCM grouping = get_property ("beatGrouping");
  64   if (scm_is_pair (grouping))
  65     {
  66       Moment *measpos = unsmob_moment (get_property ("measurePosition"));
  67       Rational mp = measpos->main_part_;
  68
  69       Moment *beatlen_mom = unsmob_moment (get_property ("beatLength"));
  70       Rational beat_length = beatlen_mom->main_part_;
  71
  72       Rational where (0);
  73       for (SCM s = grouping; scm_is_pair (s);
  74            where += Rational ((int) scm_to_int (scm_car (s))) * beat_length,
  75              s = scm_cdr (s))
  76         {
  77           int grouplen = scm_to_int (scm_car (s));
  78           if (where == mp)
  79             {
  80               if (grouping_)
  81                 {
  82                   programming_error ("last grouping not finished yet");
  83                   continue;
  84                 }
  85
  86               grouping_ = make_spanner ("MeasureGrouping", SCM_EOL);
  87               grouping_->set_bound (LEFT, unsmob_grob (get_property ("currentMusicalColumn")));
  88
  89               stop_grouping_mom_ = now.main_part_ + Rational (grouplen - 1) * beat_length;
  90               get_global_context ()->add_moment_to_process (Moment (stop_grouping_mom_));
  91
  92               if (grouplen == 3)
  93                 grouping_->set_property ("style", ly_symbol2scm ("triangle"));
  94               else
  95                 grouping_->set_property ("style", ly_symbol2scm ("bracket"));
  96
  97               break;
  98             }
  99         }
 100     }
 101 }
 102
 103 Measure_grouping_engraver::Measure_grouping_engraver ()
 104 {
 105   grouping_ = 0;
 106 }
 107
 108 ADD_ACKNOWLEDGER (Measure_grouping_engraver, note_column);
 109 ADD_TRANSLATOR (Measure_grouping_engraver,
 110                 /* doc */
 111                 "Creates MeasureGrouping to indicate beat subdivision.",
 112                 /* create */
 113                 "MeasureGrouping",
 114                 /* accept */
 115                 "",
 116                 /* read */
 117                 "beatLength "
 118                 "currentMusicalColumn "
 119                 "measurePosition "
 120                 "beatGrouping "
 121                 ,
 122                 /* write */
 123                 "");