lily/duration.cc

   1 /*
   2   duration.cc -- implement Duration
   3
   4   source file of the LilyPond music typesetter
   5
   6   (c) 1997--2005 Jan Nieuwenhuizen <janneke@gnu.org>
   7   Han-Wen Nienhuys <hanwen@cs.uu.nl>
   8 */
   9
  10 #include "duration.hh"
  11
  12 #include "misc.hh"
  13 #include "lily-proto.hh"
  14
  15 #include "ly-smobs.icc"
  16
  17 int
  18 Duration::compare (Duration const &left, Duration const &right)
  19 {
  20   return Rational::compare (left.get_length (), right.get_length ());
  21 }
  22
  23 Duration::Duration ()
  24 {
  25   durlog_ = 0;
  26   dots_ = 0;
  27   factor_ = Rational (1, 1);
  28 }
  29
  30 Duration::Duration (int log, int d)
  31 {
  32   durlog_ = log;
  33   dots_ = d;
  34   factor_ = Rational (1, 1);
  35 }
  36
  37 Duration
  38 Duration::compressed (Rational m) const
  39 {
  40   Duration d (*this);
  41   d.factor_ *= m;
  42   return d;
  43 }
  44
  45 Rational
  46 Duration::get_length () const
  47 {
  48   Rational mom (1 << abs (durlog_));
  49
  50   if (durlog_ > 0)
  51     mom = Rational (1) / mom;
  52
  53   Rational delta = mom;
  54   for (int i = 0; i < dots_; i++)
  55     {
  56       delta /= Rational (2);
  57       mom += delta;
  58     }
  59
  60   return mom * factor_;
  61 }
  62
  63 String
  64 Duration::to_string () const
  65 {
  66   String s;
  67
  68   if (durlog_ < 0)
  69     s = "log = " + ::to_string (durlog_);
  70   else
  71     s = ::to_string (1 << durlog_);
  72
  73   s += ::to_string ('.', dots_);
  74   if (factor_ != Moment (Rational (1, 1)))
  75     s += "*" + factor_.to_string ();
  76   return s;
  77 }
  78
  79 IMPLEMENT_TYPE_P (Duration, "ly:duration?");
  80
  81 SCM
  82 Duration::mark_smob (SCM)
  83 {
  84   return SCM_EOL;
  85 }
  86
  87 IMPLEMENT_SIMPLE_SMOBS (Duration);
  88 int
  89 Duration::print_smob (SCM s, SCM port, scm_print_state *)
  90 {
  91   Duration *r = (Duration *) SCM_CELL_WORD_1 (s);
  92
  93   scm_puts ("#<Duration ", port);
  94   scm_display (scm_makfrom0str (r->to_string ().to_str0 ()), port);
  95   scm_puts (" >", port);
  96
  97   return 1;
  98 }
  99
 100 SCM
 101 Duration::equal_p (SCM a, SCM b)
 102 {
 103   Duration *p = (Duration *) SCM_CELL_WORD_1 (a);
 104   Duration *q = (Duration *) SCM_CELL_WORD_1 (b);
 105
 106   bool eq = p->dots_ == q->dots_
 107     && p->durlog_ == q->durlog_
 108     && p->factor_ == q->factor_;
 109
 110   return eq ? SCM_BOOL_T : SCM_BOOL_F;
 111 }
 112
 113 int
 114 Duration::duration_log () const
 115 {
 116   return durlog_;
 117 }
 118
 119 int
 120 Duration::dot_count () const
 121 {
 122   return dots_;
 123 }