+LY_DEFINE (make_duration, "ly:make-duration",
+ 1, 3, 0, (SCM length, SCM dotcount, SCM num, SCM den),
+ "@var{length} is the negative logarithm (base 2) of the duration:\n"
+ "1 is a half note, 2 is a quarter note, 3 is an eighth\n"
+ "note, etc. The number of dots after the note is given by\n"
+ "the optional argument @var{dotcount}.\n"
+ "\n"
+ "The duration factor is optionally given by @var{num}\n"
+ "and @var{den}.\n\n"
+ "A duration is a musical duration, "
+ "i.e. a length of time described by a power of two "
+ "(whole, half, quarter, etc.) and a number of augmentation\n"
+ "dots. \n")
+{
+ SCM_ASSERT_TYPE (scm_integer_p (length) == SCM_BOOL_T,
+ length, SCM_ARG1, __FUNCTION__, "integer");
+
+ int dots = 0;
+ if (dotcount != SCM_UNDEFINED)
+ {
+ SCM_ASSERT_TYPE (scm_integer_p (dotcount) == SCM_BOOL_T,
+ dotcount, SCM_ARG2, __FUNCTION__, "integer");
+ dots = ly_scm2int (dotcount);
+ }
+
+ bool compress = false;
+ if (num != SCM_UNDEFINED)
+ {
+ SCM_ASSERT_TYPE (ly_c_number_p (num), length, SCM_ARG3, __FUNCTION__, "integer");
+ compress = true;
+ }
+ else
+ num = scm_int2num (1);
+
+ if (den != SCM_UNDEFINED)
+ {
+ SCM_ASSERT_TYPE (ly_c_number_p (den), length, SCM_ARG4, __FUNCTION__, "integer");
+ compress = true;
+ }
+ else
+ den = scm_int2num (1);
+
+ Duration p (ly_scm2int (length), dots);
+ if (compress)
+ p = p.compressed (Rational (ly_scm2int (num), ly_scm2int (den)));
+
+ return p.smobbed_copy ();
+}
+
+LY_DEFINE (duration_log, "ly:duration-log",
+ 1, 0, 0, (SCM dur),
+ "Extract the duration log from @var{dur}")
+{
+ SCM_ASSERT_TYPE (unsmob_duration (dur), dur, SCM_ARG1, __FUNCTION__, "duration");
+ return scm_int2num (unsmob_duration (dur)->duration_log ());
+}
+
+LY_DEFINE (dot_count_log, "ly:duration-dot-count", 1, 0, 0, (SCM dur),
+ "Extract the dot count from @var{dur}"
+)
+{
+ SCM_ASSERT_TYPE (unsmob_duration (dur), dur, SCM_ARG1, __FUNCTION__, "duration");
+ return scm_int2num (unsmob_duration (dur)->dot_count ());
+}
+
+
+LY_DEFINE (ly_intlog2, "ly:intlog2",
+ 1, 0, 0, (SCM d),
+ "The 2-logarithm of 1/@var{d}.")
+{
+ SCM_ASSERT_TYPE (ly_c_number_p (d), d, SCM_ARG1, __FUNCTION__, "integer");
+ int log = intlog2 (ly_scm2int (d));
+ return scm_int2num (log);
+}
+
+LY_DEFINE (compression_factor, "ly:duration-factor",
+ 1, 0, 0, (SCM dur),
+ "Extract the compression factor from @var{dur}. Return as a pair.")
+{
+ SCM_ASSERT_TYPE (unsmob_duration (dur), dur, SCM_ARG1, __FUNCTION__, "duration");
+ Rational r = unsmob_duration (dur)->factor ();
+ return scm_cons (scm_int2num (r.num ()), scm_int2num (r.den ()));
+}
+
+int
+Duration::duration_log () const
+{
+ return durlog_;
+}
+
+int
+Duration::dot_count () const
+{
+ return dots_;
+}