source file of the GNU LilyPond music typesetter
- (c) 1997--1999 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+ (c) 1997--2002 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[SMALLER]], positions[slice[BIGGER]]);
+ 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[SMALLER]], positions[slice[BIGGER]]);
-
- if (slice[SMALLER] == slice[BIGGER])
+
+ Real px = frac + positions[0];
+ assert (positions[0] <= px && px <= positions.top ());
+ int i=0;
+ for (; i < positions.size () - 1; i++)
{
- if (slice[SMALLER] == 0)
- iv[SMALLER] = - period + positions.top ();
- else
- iv[BIGGER] = 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;
}