X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fduration.cc;h=755679fd71cf2d84469e69062efd4b7dabd71be9;hb=5b4b0d6e9a197e8f9eb085b7c2ad78b8be3e5cfc;hp=cc44db4def30e2b34e4309be643ca6d4bbd79be5;hpb=c0270765c0df9cceda34a6584f7da324eed5fc2a;p=lilypond.git

diff --git a/lily/duration.cc b/lily/duration.cc
index cc44db4def..755679fd71 100644
--- a/lily/duration.cc
+++ b/lily/duration.cc
@@ -1,41 +1,87 @@
 /*
-  duration.cc -- implement Duration, Plet, 
+  duration.cc -- implement Duration
 
   source file of the LilyPond music typesetter
 
-  (c)  1997--2000 Jan Nieuwenhuizen <janneke@gnu.org>
-           Han-Wen Nienhuys <hanwen@cs.uu.nl>
-
+  (c) 1997--2008 Jan Nieuwenhuizen <janneke@gnu.org>
+  Han-Wen Nienhuys <hanwen@xs4all.nl>
 */
 
-#include <assert.h>
-
-#include "lily-proto.hh"
-#include "string.hh"
-#include "moment.hh"
 #include "duration.hh"
-#include "ly-smobs.icc"
 
+#include "misc.hh"
+#include "lily-proto.hh"
 
+#include "ly-smobs.icc"
 
 int
 Duration::compare (Duration const &left, Duration const &right)
 {
-  return Rational::compare (left.length_mom (), right.length_mom ());
+  return Rational::compare (left.get_length (), right.get_length ());
 }
 
 Duration::Duration ()
 {
-  durlog_i_ = 0;
-  dots_i_ = 0;
-  factor_ = Moment (1,1);
+  durlog_ = 0;
+  dots_ = 0;
+  factor_ = Rational (1, 1);
 }
 
-Duration::Duration (int l, int d)
+Duration::Duration (int log, int d)
 {
-  durlog_i_ = l;
-  dots_i_ = d;
-  factor_ = Moment (1,1);
+  durlog_ = log;
+  dots_ = 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 = r.num ();
+      int q = r.den ();
+      int k = intlog2 (q) - intlog2 (p);
+      if ((p << k) < q)
+	k++;
+
+      assert ((p << k) >= q && (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 = (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
@@ -47,120 +93,81 @@ Duration::compressed (Rational m) const
 }
 
 Rational
-Duration::length_mom () const
+Duration::get_length () const
 {
-  Rational mom (1 << abs (durlog_i_));
+  Rational mom (1 << abs (durlog_));
 
-  if (durlog_i_> 0)
-    mom = Moment (1)/mom;
+  if (durlog_ > 0)
+    mom = Rational (1) / mom;
 
   Rational delta = mom;
-
-  for (int d = dots_i_; d; d--)
+  for (int i = 0; i < dots_; i++)
     {
-      delta /= Moment (2);
+      delta /= Rational (2);
       mom += delta;
     }
 
   return mom * factor_;
 }
 
+string
+Duration::to_string () const
+{
+  string s;
 
+  if (durlog_ < 0)
+    s = "log = " + ::to_string (durlog_);
+  else
+    s = ::to_string (1 << durlog_);
 
-String
-Duration::str () const
-{
-  String s =  to_str (durlog_i_) + to_str ('.', dots_i_);
-  if (factor_ != Moment (1,1))
-    {
-      s += "*" + factor_.str ();
-    }
+  s += ::to_string ('.', dots_);
+  if (factor_ != Moment (Rational (1, 1)))
+    s += "*" + factor_.to_string ();
   return s;
 }
 
-
-IMPLEMENT_TYPE_P(Duration, "duration?");
-IMPLEMENT_UNSMOB(Duration, duration);
+IMPLEMENT_TYPE_P (Duration, "ly:duration?");
 
 SCM
-Duration::mark_smob (SCM )
+Duration::mark_smob (SCM)
 {
   return SCM_EOL;
 }
 
-IMPLEMENT_SIMPLE_SMOBS(Duration);
-
-
+IMPLEMENT_SIMPLE_SMOBS (Duration);
 int
 Duration::print_smob (SCM s, SCM port, scm_print_state *)
 {
-  Duration  *r = (Duration *) gh_cdr (s);
-     
+  Duration *r = (Duration *) SCM_CELL_WORD_1 (s);
+
   scm_puts ("#<Duration ", port);
-  scm_display (ly_str02scm (r->str().ch_C()), port);
+  scm_display (ly_string2scm (r->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 *) gh_cdr (a);
-  Duration  *q = (Duration *) gh_cdr (b);  
+  Duration *p = (Duration *) SCM_CELL_WORD_1 (a);
+  Duration *q = (Duration *) SCM_CELL_WORD_1 (b);
 
-  bool eq = p->dots_i_ == q->dots_i_
-    && p->durlog_i_ == q->durlog_i_
+  bool eq = p->dots_ == q->dots_
+    && 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;
-}
-
-
-static SCM
-make_duration (SCM l, SCM d)
-{
-  Duration p( gh_scm2int (l), gh_scm2int (d));
-  return p.smobbed_copy ();
-}
-
-static void
-add_funcs()
-{
-  scm_make_gsubr ("make-duration", 2, 0, 0, (Scheme_function_unknown)make_duration);
-}
-
-ADD_SCM_INIT_FUNC(duration, add_funcs);
-
-SCM
-Duration::smobbed_copy ()const
-{
-  Duration *  p = new Duration (*this);
-  return p->smobbed_self ();
-}
 
 int
 Duration::duration_log () const
 {
-  return durlog_i_;
+  return durlog_;
 }
 
 int
 Duration::dot_count () const
 {
-  return dots_i_;
+  return dots_;
 }
-