lily/timing-engraver.cc

   1 /*
   2   timing-grav.cc -- implement Timing_engraver
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c)  1997--2001 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8 #include "translator-group.hh"
   9 #include "command-request.hh"
  10 #include "grob-info.hh"
  11 #include "multi-measure-rest.hh"
  12 #include "timing-translator.hh"
  13 #include "engraver.hh"
  14
  15 /**
  16   Do time bookkeeping
  17  */
  18 class Timing_engraver : public Timing_translator, public Engraver
  19 {
  20 protected:
  21   /*
  22     Needed to know whether we're advancing in grace notes, or not.
  23    */
  24   Moment last_moment_;
  25
  26   virtual void start_translation_timestep ();
  27   virtual void stop_translation_timestep ();
  28   virtual void process_music ();
  29
  30 public:
  31   TRANSLATOR_DECLARATIONS(Timing_engraver);
  32 };
  33
  34
  35 Timing_engraver::Timing_engraver ()
  36 {
  37   last_moment_.main_part_ = Rational (-1);
  38 }
  39
  40
  41
  42 void
  43 Timing_engraver::start_translation_timestep ()
  44 {
  45   Timing_translator::start_translation_timestep ();
  46
  47   SCM nonauto = get_property ("barNonAuto");
  48   Moment now = now_mom ();
  49   SCM which = get_property ("whichBar");
  50
  51   /*
  52     Set the first bar of the score?
  53    */
  54   if (!gh_string_p (which))
  55     which
  56       = (now.main_part_ || now.main_part_ == last_moment_.main_part_)
  57       ? SCM_EOL : ly_str02scm ("|");
  58
  59   if (!gh_string_p (which) && !to_boolean (nonauto))
  60     {
  61       SCM always = get_property ("barAlways");
  62       Moment mp = measure_position ();
  63       if ( (last_moment_.main_part_ != now.main_part_
  64             && !mp.main_part_)
  65            || (to_boolean (always)))
  66         {
  67           /* should this work, or be junked?  See input/bugs/no-bars.ly */
  68           which = get_property ("defaultBarType");
  69         }
  70     }
  71
  72   daddy_trans_l_->set_property ("whichBar", which);
  73 }
  74
  75 void
  76 Timing_engraver::stop_translation_timestep ()
  77 {
  78   Timing_translator::stop_translation_timestep ();
  79   daddy_trans_l_->set_property ("whichBar", SCM_EOL);
  80   last_moment_ = now_mom ();
  81 }
  82
  83
  84 /*
  85   ugh. Translator doesn't do process_music ().
  86  */
  87 void
  88 Timing_engraver::process_music ()
  89 {
  90   Timing_translator::process_music ();
  91 }
  92
  93 ENTER_DESCRIPTION(Timing_engraver,
  94 /* descr */       " Responsible for synchronizing timing information from staves.
  95 Normally in @code{Score}.  In order to create polyrhythmic music,
  96 this engraver should be removed from @code{Score} and placed in
  97 @code{Staff}.",
  98 /* creats*/       "",
  99 /* acks  */       "",
 100 /* reads */       "timeSignatureFraction barCheckNoSynchronize barNonAuto whichBar barAlways defaultBarType skipBars timing oneBeat measureLength measurePosition currentBarNumber",
 101 /* write */       "");