X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fduration.cc;h=880b22c46a3575d1fc37bf78943d45992ca1ba8b;hb=a6a51abfd0195a3cf7d6ea095cf69808852f21ce;hp=82f5a506c29b4258a69b2fac5a4af898ad4adfdb;hpb=61bba8a98a53e424054b26d63ead26b0696ea29d;p=lilypond.git

diff --git a/lily/duration.cc b/lily/duration.cc
index 82f5a506c2..880b22c46a 100644
--- a/lily/duration.cc
+++ b/lily/duration.cc
@@ -1,21 +1,27 @@
 /*
-  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
@@ -38,6 +44,56 @@ Duration::Duration (int log, int d)
   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
 {
@@ -51,7 +107,7 @@ Duration::get_length () const
 {
   Rational mom (1 << abs (durlog_));
 
-  if (durlog_> 0)
+  if (durlog_ > 0)
     mom = Rational (1) / mom;
 
   Rational delta = mom;
@@ -64,13 +120,13 @@ Duration::get_length () const
   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_);
 
@@ -80,153 +136,32 @@ Duration::to_string () const
   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
 {