lily/duration-scheme.cc

   1 /*
   2   duration.cc -- implement Duration
   3
   4   source file of the LilyPond music typesetter
   5
   6   (c) 1997--2009 Jan Nieuwenhuizen <janneke@gnu.org>
   7   Han-Wen Nienhuys <hanwen@xs4all.nl>
   8 */
   9
  10 #include "duration.hh"
  11 #include "misc.hh"
  12
  13 MAKE_SCHEME_CALLBACK (Duration, less_p, 2);
  14 SCM
  15 Duration::less_p (SCM p1, SCM p2)
  16 {
  17   Duration *a = unsmob_duration (p1);
  18   Duration *b = unsmob_duration (p2);
  19
  20   if (compare (*a, *b) < 0)
  21     return SCM_BOOL_T;
  22   else
  23     return SCM_BOOL_F;
  24 }
  25
  26 LY_DEFINE (ly_duration_less_p, "ly:duration<?",
  27            2, 0, 0, (SCM p1, SCM p2),
  28            "Is @var{p1} shorter than @var{p2}?")
  29 {
  30   LY_ASSERT_SMOB (Duration, p1, 1);
  31   LY_ASSERT_SMOB (Duration, p2, 2);
  32
  33   Duration *a = unsmob_duration (p1);
  34   Duration *b = unsmob_duration (p2);
  35
  36   if (Duration::compare (*a, *b) < 0)
  37     return SCM_BOOL_T;
  38   else
  39     return SCM_BOOL_F;
  40 }
  41
  42 LY_DEFINE (ly_make_duration, "ly:make-duration",
  43            1, 3, 0, (SCM length, SCM dotcount, SCM num, SCM den),
  44            "@var{length} is the negative logarithm (base 2) of the duration:"
  45            " 1@tie{}is a half note, 2@tie{}is a quarter note, 3@tie{}is an"
  46            " eighth note, etc.  The number of dots after the note is given by"
  47            " the optional argument @var{dotcount}.\n"
  48            "\n"
  49            "The duration factor is optionally given by @var{num} and"
  50            " @var{den}.\n"
  51            "\n"
  52            "A duration is a musical duration, i.e., a length of time"
  53            " described by a power of two (whole, half, quarter, etc.) and a"
  54            " number of augmentation dots.")
  55 {
  56   LY_ASSERT_TYPE (scm_is_integer, length, 1);
  57
  58   int dots = 0;
  59   if (dotcount != SCM_UNDEFINED)
  60     {
  61       LY_ASSERT_TYPE (scm_is_integer, dotcount, 2);
  62       dots = scm_to_int (dotcount);
  63     }
  64
  65   bool compress = false;
  66   if (num != SCM_UNDEFINED)
  67     {
  68       LY_ASSERT_TYPE (scm_is_number, num, 3);
  69       compress = true;
  70     }
  71   else
  72     num = scm_from_int (1);
  73
  74   if (den != SCM_UNDEFINED)
  75     {
  76       LY_ASSERT_TYPE (scm_is_number, den, 4);
  77       compress = true;
  78     }
  79   else
  80     den = scm_from_int (1);
  81
  82   Duration p (scm_to_int (length), dots);
  83   if (compress)
  84     p = p.compressed (Rational (scm_to_int (num), scm_to_int (den)));
  85
  86   return p.smobbed_copy ();
  87 }
  88
  89 LY_DEFINE (ly_duration_log, "ly:duration-log",
  90            1, 0, 0, (SCM dur),
  91            "Extract the duration log from @var{dur}.")
  92 {
  93   LY_ASSERT_SMOB (Duration, dur, 1);
  94   return scm_from_int (unsmob_duration (dur)->duration_log ());
  95 }
  96
  97 LY_DEFINE (ly_duration_dot_count, "ly:duration-dot-count",
  98            1, 0, 0, (SCM dur),
  99            "Extract the dot count from @var{dur}.")
 100 {
 101   LY_ASSERT_SMOB (Duration, dur, 1);
 102   return scm_from_int (unsmob_duration (dur)->dot_count ());
 103 }
 104
 105 LY_DEFINE (ly_intlog2, "ly:intlog2",
 106            1, 0, 0, (SCM d),
 107            "The 2-logarithm of 1/@var{d}.")
 108 {
 109   LY_ASSERT_TYPE (scm_is_number, d, 1);
 110   int log = intlog2 (scm_to_int (d));
 111   return scm_from_int (log);
 112 }
 113
 114 LY_DEFINE (ly_duration_length, "ly:duration-length",
 115            1, 0, 0, (SCM dur),
 116            "The length of the duration as a @code{moment}.")
 117 {
 118   LY_ASSERT_SMOB (Duration, dur, 1);
 119   return Moment (unsmob_duration (dur)->get_length ()).smobbed_copy ();
 120 }
 121
 122 LY_DEFINE (ly_duration_2_string, "ly:duration->string",
 123            1, 0, 0, (SCM dur),
 124            "Convert @var{dur} to a string.")
 125 {
 126   LY_ASSERT_SMOB (Duration, dur, 1);
 127   return ly_string2scm (unsmob_duration (dur)->to_string ());
 128 }
 129
 130 LY_DEFINE (ly_duration_factor, "ly:duration-factor",
 131            1, 0, 0, (SCM dur),
 132            "Extract the compression factor from @var{dur}."
 133            "  Return it as a pair.")
 134 {
 135   LY_ASSERT_SMOB (Duration, dur, 1);
 136   Rational r = unsmob_duration (dur)->factor ();
 137   return scm_cons (scm_from_int64 (r.num ()), scm_from_int64 (r.den ()));
 138 }