patch::: 1.4.0.jcn4

[lilypond.git] / lily / misc.cc

diff --git a/lily/misc.cc b/lily/misc.cc
index e63ac8cab11dbfd2d59a076b7cc13e6a3197213a..45a055f8a6bb4841b2028da33e4309683573dd7f 100644 (file)
--- a/lily/misc.cc
+++ b/lily/misc.cc
@@ -3,118 +3,67 @@
 
   source file of the GNU LilyPond music typesetter
 
-  (c)  1997--1999, 1998 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+  (c)  1997--2001 Han-Wen Nienhuys <hanwen@cs.uu.nl>
     Jan Nieuwenhuizen <janneke@gnu.org>
 */
 
 #include <math.h>
-
 #include "misc.hh"
 
-#ifndef STANDALONE
-#include "item.hh"
-#endif
-
+/*
+  Return the 2-log, rounded down 
+ */
 int
-intlog2(int d) {
+intlog2 (int d)
+{
+  assert (d);
   int i=0;
-  while (!(d&1)) 
+  while ((d != 1)) 
     {
-       d/= 2;
-       i++;
+      d/= 2;
+      i++;
     }
-  assert (!(d/2));
+  
+  assert (! (d/2));
   return i;
 }
 
 double
-log_2(double x) {
-  return log (x)  /log (2.0);
-}
-
-#ifndef STANDALONE
-Interval
-itemlist_width (const Array<Item*> &its)
-{
-  Interval iv ;
-  iv.set_empty();
-   
-  for (int j =0; j < its.size(); j++)
-    {
-       iv.unite (its[j]->extent (X_AXIS));
-
-    }
-  return iv;
-}
-
-#endif
-
-
-/*
-  TODO
-    group in some Array_*
-    make more generic / templatise
- */
-int
-get_lower_bound (Array<Real> const& positions, Real x)
+log_2 (double x)
 {
-  if (x < positions[0])
-    return 0;
-  for (int i = 1; i < positions.size (); i++)
-    if (x < positions[i])
-      return i - 1;
-  return positions.size () - 1;
+  return log (x)  /log (2.0);
 }
 
-Slice
-get_bounds_slice (Array<Real> const& positions, Real x)
-{
-  int l = get_lower_bound (positions, x);
-  int u = positions.size () - 1 <? l + 1;
-  if (x < positions[l])
-    u = l;
-  return Slice (l, u);
-}
 
-Interval
-get_bounds_iv (Array<Real> const& positions, Real x)
+static int
+comp (Real const &a, Real const &b)
 {
-  Slice slice = get_bounds_slice (positions, x);
-  return Interval (positions[slice.min ()], positions[slice.max ()]);
+  return sign (a-b);
 }
 
-// silly name
 Interval
-quantise_iv (Array<Real> const& positions, Real period, Real x)
+quantise_iv (Array<Real> positions, Real x)
 {
-  /*
-    ugh
-    assume that 
-      * positions are sorted, 
-      * positions are nonnegative
-      * period starts at zero
-   */
+  positions.sort (comp);
+  Real period = positions.top () - positions[0];
+  
+  int n =  int ((x - positions[0]) / period);
+  Real frac = (x - positions[0]) -  n * period;
 
-  int n = (int)(x / period);
-  Real frac = (x / period - n) * period;
-  if (frac < 0)
+  while (frac < 0)
     {
       frac += period;
-      n--;
+      n --;
     }
-
-  Slice slice = get_bounds_slice (positions, frac);
-  Interval iv(positions[slice.min ()], positions[slice.max ()]);
-
-  if (slice.min () == slice.max ())
+  
+  Real px = frac + positions[0];
+  assert (positions[0] <= px && px <= positions.top ());
+  int i=0;
+  for (; i < positions.size () - 1; i++)
     {
-      if (slice.min () == 0)
-       iv.min () = - period + positions.top ();
-      else
-       iv.max () = period + positions[0];
+      if (positions[i] <= px && px <= positions[i+1])
+       break; 
     }
 
-  iv += period * n;
-
-  return iv;
+  return Interval (positions[i] , positions[i+1]) + period * n;
 }