/*
- duration.cc -- implement Duration
+ This file is part of LilyPond, the GNU music typesetter.
- source file of the LilyPond music typesetter
+ Copyright (C) 1997--2015 Jan Nieuwenhuizen <janneke@gnu.org>
+ Han-Wen Nienhuys <hanwen@xs4all.nl>
- (c) 1997--2004 Jan Nieuwenhuizen <janneke@gnu.org>
- Han-Wen Nienhuys <hanwen@cs.uu.nl>
+ LilyPond is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+ LilyPond is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with LilyPond. If not, see <http://www.gnu.org/licenses/>.
*/
-#include <assert.h>
+#include "duration.hh"
#include "misc.hh"
#include "lily-proto.hh"
-#include "string.hh"
-#include "moment.hh"
-#include "duration.hh"
-#include "ly-smobs.icc"
int
factor_ = Rational (1, 1);
}
+Duration::Duration (Rational r, bool scale)
+{
+ factor_ = Rational (1, 1);
+
+ if (r.num () == 0.0)
+ {
+ durlog_ = 0;
+ dots_ = 0;
+ }
+ else
+ {
+ /* we want to find the integer k for which 2q/p > 2^k >= q/p.
+ It's simple to check that k' = \floor \log q - \floor \log p
+ satisfies the left inequality and is within a factor of 2 of
+ satistying the right one. Therefore either k = k' or k = k'+1 */
+
+ int p = (int) r.num ();
+ int q = (int) r.den ();
+ int k = intlog2 (q) - intlog2 (p);
+ if (shift_left (p, k) < q)
+ k++;
+
+ assert (shift_left (p, k) >= q && shift_left (p, (k - 1)) < q);
+
+ /* If we were to write out log (p/q) in base 2, then the position of the
+ first non-zero bit (ie. k in our notation) would be the durlog
+ and the number of consecutive 1s after that bit would be the number of
+ dots */
+ p = shift_left (p, k) - q;
+ dots_ = 0;
+ while ((p *= 2) >= q)
+ {
+ p -= q;
+ dots_++;
+ }
+
+ /* we only go up to 64th notes */
+ if (k > 6)
+ {
+ durlog_ = 6;
+ dots_ = 0;
+ }
+ else
+ durlog_ = k;
+
+ if (scale || k > 6)
+ factor_ = r / get_length ();
+ }
+}
+
Duration
Duration::compressed (Rational m) const
{
{
Rational mom (1 << abs (durlog_));
- if (durlog_> 0)
+ if (durlog_ > 0)
mom = Rational (1) / mom;
Rational delta = mom;
return mom * factor_;
}
-String
+string
Duration::to_string () const
{
- String s;
+ string s;
- if (durlog_ < 0 )
- s = "log = " + ::to_string (durlog_);
+ if (durlog_ < 0)
+ s = "log = " + ::to_string (durlog_);
else
s = ::to_string (1 << durlog_);
return s;
}
+const char * const Duration::type_p_name_ = "ly:duration?";
-IMPLEMENT_TYPE_P (Duration, "ly:duration?");
-SCM
-Duration::mark_smob (SCM)
-{
- return SCM_EOL;
-}
-
-IMPLEMENT_SIMPLE_SMOBS (Duration);
int
-Duration::print_smob (SCM s, SCM port, scm_print_state *)
+Duration::print_smob (SCM port, scm_print_state *) const
{
- Duration *r = (Duration *) ly_cdr (s);
-
scm_puts ("#<Duration ", port);
- scm_display (scm_makfrom0str (r->to_string ().to_str0 ()), port);
+ scm_display (ly_string2scm (to_string ()), port);
scm_puts (" >", port);
return 1;
}
SCM
-Duration::equal_p (SCM a , SCM b)
+Duration::equal_p (SCM a, SCM b)
{
- Duration *p = (Duration *) ly_cdr (a);
- Duration *q = (Duration *) ly_cdr (b);
+ Duration *p = unsmob<Duration> (a);
+ Duration *q = unsmob<Duration> (b);
bool eq = p->dots_ == q->dots_
- && p->durlog_ == q->durlog_
- && p->factor_ == q->factor_;
+ && p->durlog_ == q->durlog_
+ && p->factor_ == q->factor_;
return eq ? SCM_BOOL_T : SCM_BOOL_F;
}
-MAKE_SCHEME_CALLBACK (Duration, less_p, 2);
-SCM
-Duration::less_p (SCM p1, SCM p2)
-{
- Duration *a = unsmob_duration (p1);
- Duration *b = unsmob_duration (p2);
-
- if (compare (*a, *b) < 0)
- return SCM_BOOL_T;
- else
- return SCM_BOOL_F;
-}
-
-LY_DEFINE (ly_duration_less_p, "ly:duration<?",
- 2, 0, 0, (SCM p1, SCM p2),
- "Is @var{p1} shorter than @var{p2}?")
-{
- Duration *a = unsmob_duration (p1);
- Duration *b = unsmob_duration (p2);
-
- SCM_ASSERT_TYPE (a, p1, SCM_ARG1, __FUNCTION__, "Duration");
- SCM_ASSERT_TYPE (b, p2, SCM_ARG2, __FUNCTION__, "Duration");
-
- if (Duration::compare (*a, *b) < 0)
- return SCM_BOOL_T;
- else
- return SCM_BOOL_F;
-}
-
-LY_DEFINE (ly_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 (ly_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 (ly_duration_dot_count, "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 (ly_duration_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
{
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