2 duration.cc -- implement Duration
4 source file of the LilyPond music typesetter
6 (c) 1997--2005 Jan Nieuwenhuizen <janneke@gnu.org>
7 Han-Wen Nienhuys <hanwen@cs.uu.nl>
11 #include "duration.hh"
14 MAKE_SCHEME_CALLBACK (Duration, less_p, 2);
16 Duration::less_p (SCM p1, SCM p2)
18 Duration *a = unsmob_duration (p1);
19 Duration *b = unsmob_duration (p2);
21 if (compare (*a, *b) < 0)
27 LY_DEFINE (ly_duration_less_p, "ly:duration<?",
28 2, 0, 0, (SCM p1, SCM p2),
29 "Is @var{p1} shorter than @var{p2}?")
31 Duration *a = unsmob_duration (p1);
32 Duration *b = unsmob_duration (p2);
34 SCM_ASSERT_TYPE (a, p1, SCM_ARG1, __FUNCTION__, "Duration");
35 SCM_ASSERT_TYPE (b, p2, SCM_ARG2, __FUNCTION__, "Duration");
37 if (Duration::compare (*a, *b) < 0)
43 LY_DEFINE (ly_make_duration, "ly:make-duration",
44 1, 3, 0, (SCM length, SCM dotcount, SCM num, SCM den),
45 "@var{length} is the negative logarithm (base 2) of the duration:\n"
46 "1 is a half note, 2 is a quarter note, 3 is an eighth\n"
47 "note, etc. The number of dots after the note is given by\n"
48 "the optional argument @var{dotcount}.\n"
50 "The duration factor is optionally given by @var{num}\n"
52 "A duration is a musical duration, "
53 "i.e. a length of time described by a power of two "
54 "(whole, half, quarter, etc.) and a number of augmentation\n"
57 SCM_ASSERT_TYPE (scm_integer_p (length) == SCM_BOOL_T,
58 length, SCM_ARG1, __FUNCTION__, "integer");
61 if (dotcount != SCM_UNDEFINED)
63 SCM_ASSERT_TYPE (scm_integer_p (dotcount) == SCM_BOOL_T,
64 dotcount, SCM_ARG2, __FUNCTION__, "integer");
65 dots = scm_to_int (dotcount);
68 bool compress = false;
69 if (num != SCM_UNDEFINED)
71 SCM_ASSERT_TYPE (scm_is_number (num), length, SCM_ARG3, __FUNCTION__, "integer");
75 num = scm_int2num (1);
77 if (den != SCM_UNDEFINED)
79 SCM_ASSERT_TYPE (scm_is_number (den), length, SCM_ARG4, __FUNCTION__, "integer");
83 den = scm_int2num (1);
85 Duration p (scm_to_int (length), dots);
87 p = p.compressed (Rational (scm_to_int (num), scm_to_int (den)));
89 return p.smobbed_copy ();
92 LY_DEFINE (ly_duration_log, "ly:duration-log",
94 "Extract the duration log from @var{dur}")
96 SCM_ASSERT_TYPE (unsmob_duration (dur), dur, SCM_ARG1, __FUNCTION__, "duration");
97 return scm_int2num (unsmob_duration (dur)->duration_log ());
100 LY_DEFINE (ly_duration_dot_count, "ly:duration-dot-count",
102 "Extract the dot count from @var{dur}")
104 SCM_ASSERT_TYPE (unsmob_duration (dur), dur, SCM_ARG1, __FUNCTION__, "duration");
105 return scm_int2num (unsmob_duration (dur)->dot_count ());
108 LY_DEFINE (ly_intlog2, "ly:intlog2",
110 "The 2-logarithm of 1/@var{d}.")
112 SCM_ASSERT_TYPE (scm_is_number (d), d, SCM_ARG1, __FUNCTION__, "integer");
113 int log = intlog2 (scm_to_int (d));
114 return scm_int2num (log);
117 LY_DEFINE (ly_duration_factor, "ly:duration-factor",
119 "Extract the compression factor from @var{dur}. Return as a pair.")
121 SCM_ASSERT_TYPE (unsmob_duration (dur), dur, SCM_ARG1, __FUNCTION__, "duration");
122 Rational r = unsmob_duration (dur)->factor ();
123 return scm_cons (scm_int2num (r.num ()), scm_int2num (r.den ()));