lily/duration-scheme.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 #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   Duration *a = unsmob_duration (p1);
  31   Duration *b = unsmob_duration (p2);
  32
  33   SCM_ASSERT_TYPE (a, p1, SCM_ARG1, __FUNCTION__, "Duration");
  34   SCM_ASSERT_TYPE (b, p2, SCM_ARG2, __FUNCTION__, "Duration");
  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:\n"
  45            "1 is a half note, 2 is a quarter note, 3 is an eighth\n"
  46            "note, etc.  The number of dots after the note is given by\n"
  47            "the optional argument @var{dotcount}.\n"
  48            "\n"
  49            "The duration factor is optionally given by @var{num}\n"
  50            "and @var{den}.\n\n"
  51            "A duration is a musical duration, "
  52            "i.e. a length of time described by a power of two "
  53            "(whole, half, quarter, etc.) and a number of augmentation\n"
  54            "dots. \n")
  55 {
  56   SCM_ASSERT_TYPE (scm_integer_p (length) == SCM_BOOL_T,
  57                    length, SCM_ARG1, __FUNCTION__, "integer");
  58
  59   int dots = 0;
  60   if (dotcount != SCM_UNDEFINED)
  61     {
  62       SCM_ASSERT_TYPE (scm_integer_p (dotcount) == SCM_BOOL_T,
  63                        dotcount, SCM_ARG2, __FUNCTION__, "integer");
  64       dots = scm_to_int (dotcount);
  65     }
  66
  67   bool compress = false;
  68   if (num != SCM_UNDEFINED)
  69     {
  70       SCM_ASSERT_TYPE (scm_is_number (num), num, SCM_ARG3, __FUNCTION__, "integer");
  71       compress = true;
  72     }
  73   else
  74     num = scm_int2num (1);
  75
  76   if (den != SCM_UNDEFINED)
  77     {
  78       SCM_ASSERT_TYPE (scm_is_number (den), den, SCM_ARG4, __FUNCTION__, "integer");
  79       compress = true;
  80     }
  81   else
  82     den = scm_int2num (1);
  83
  84   Duration p (scm_to_int (length), dots);
  85   if (compress)
  86     p = p.compressed (Rational (scm_to_int (num), scm_to_int (den)));
  87
  88   return p.smobbed_copy ();
  89 }
  90
  91 LY_DEFINE (ly_duration_log, "ly:duration-log",
  92            1, 0, 0, (SCM dur),
  93            "Extract the duration log from @var{dur}")
  94 {
  95   SCM_ASSERT_TYPE (unsmob_duration (dur), dur, SCM_ARG1, __FUNCTION__, "duration");
  96   return scm_int2num (unsmob_duration (dur)->duration_log ());
  97 }
  98
  99 LY_DEFINE (ly_duration_dot_count, "ly:duration-dot-count",
 100            1, 0, 0, (SCM dur),
 101            "Extract the dot count from @var{dur}")
 102 {
 103   SCM_ASSERT_TYPE (unsmob_duration (dur), dur, SCM_ARG1, __FUNCTION__, "duration");
 104   return scm_int2num (unsmob_duration (dur)->dot_count ());
 105 }
 106
 107 LY_DEFINE (ly_intlog2, "ly:intlog2",
 108            1, 0, 0, (SCM d),
 109            "The 2-logarithm of 1/@var{d}.")
 110 {
 111   SCM_ASSERT_TYPE (scm_is_number (d), d, SCM_ARG1, __FUNCTION__, "integer");
 112   int log = intlog2 (scm_to_int (d));
 113   return scm_int2num (log);
 114 }
 115
 116 LY_DEFINE (ly_duration_factor, "ly:duration-factor",
 117            1, 0, 0, (SCM dur),
 118            "Extract the compression factor from @var{dur}. Return as a pair.")
 119 {
 120   SCM_ASSERT_TYPE (unsmob_duration (dur), dur, SCM_ARG1, __FUNCTION__, "duration");
 121   Rational r = unsmob_duration (dur)->factor ();
 122   return scm_cons (scm_int2num (r.num ()), scm_int2num (r.den ()));
 123 }