lily/midi-def.cc

   1 /*
   2   midi-def.cc -- implement Midi_def
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c)  1997--2003 Jan Nieuwenhuizen <janneke@gnu.org>
   7
   8 */
   9 #include <math.h>
  10 #include "misc.hh"
  11 #include "midi-def.hh"
  12 #include "performance.hh"
  13 #include "warn.hh"
  14 #include "scm-hash.hh"
  15
  16 Midi_def::Midi_def ()
  17 {
  18   // ugh
  19   set_tempo (Moment (Rational (1, 4)), 60);
  20 }
  21
  22 int
  23 Midi_def::get_tempo (Moment one_beat_mom)
  24 {
  25   SCM wis  = ly_symbol2scm ("whole-in-seconds");
  26   Moment *w = unsmob_moment (lookup_variable (wis));
  27
  28   Moment wholes_per_min = Moment (60);
  29   if (!w)
  30     {
  31       programming_error  ("wholes-in-seconds not set.");
  32       wholes_per_min /= 4;
  33     }
  34   else
  35     {
  36       wholes_per_min /= *w;
  37     }
  38
  39   int beats_per_min =  int ((wholes_per_min / one_beat_mom).main_part_);
  40   return int (beats_per_min);
  41 }
  42
  43 void
  44 Midi_def::set_tempo (Moment one_beat_mom, int beats_per_minute_i)
  45 {
  46   Moment beats_per_second = Moment (beats_per_minute_i) / Moment (60);
  47
  48   Moment m = Moment (1)/Moment (beats_per_second * one_beat_mom);
  49   set_variable (ly_symbol2scm ("whole-in-seconds"), m.smobbed_copy ());
  50 }
  51
  52
  53 int Midi_def::score_count_=0;
  54
  55 int
  56 Midi_def::get_next_score_count () const
  57 {
  58   return score_count_++;
  59 }
  60
  61 void
  62 Midi_def::reset_score_count ()
  63 {
  64   score_count_ = 0;
  65 }