gtk2/gtk/fallback-c89.c
Chun-wei Fan 723e50990f gtk/fallback-c89.c: Add C89 fallback for trunc()
Check for trunc() during configure and provide a fallback implementation
for it if it is not found.
2018-08-28 17:43:04 +08:00

117 lines
2.5 KiB
C

/* GTK - The GIMP Toolkit
* Copyright (C) 2011 Chun-wei Fan <fanc999@yahoo.com.tw>
*
* Author: Chun-wei Fan <fanc999@yahoo.com.tw>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <math.h>
/* Workaround for round() for non-GCC/non-C99 compilers */
#ifndef HAVE_ROUND
static inline double
round (double x)
{
if (x >= 0)
return floor (x + 0.5);
else
return ceil (x - 0.5);
}
#endif
/* Workaround for rint() for non-GCC/non-C99 compilers */
#ifndef HAVE_RINT
static inline double
rint (double x)
{
if (ceil (x + 0.5) == floor (x + 0.5))
{
int a;
a = (int) ceil (x);
if (a % 2 == 0)
return ceil (x);
else
return floor (x);
}
else
{
if (x >= 0)
return floor (x + 0.5);
else
return ceil (x - 0.5);
}
}
#endif
#ifndef HAVE_NEARBYINT
/* Workaround for nearbyint() for non-GCC/non-C99 compilers */
/* This is quite similar to rint() in most respects */
static inline double
nearbyint (double x)
{
return floor (x + 0.5);
}
#endif
#ifndef HAVE_DECL_ISINF
/* Unfortunately MSVC does not have finite()
* but it does have _finite() which is the same
* as finite() except when x is a NaN
*/
static inline gboolean
isinf (double x)
{
return (!_finite (x) && !_isnan (x));
}
#endif
#ifndef INFINITY
/* define INFINITY for compilers that lack support for it */
# ifdef HUGE_VALF
# define INFINITY HUGE_VALF
# else
# define INFINITY (float)HUGE_VAL
# endif
#endif
#ifndef HAVE_LOG2
/* Use a simple implementation for log2() for compilers that lack it */
static inline double
log2 (double x)
{
return log (x) / log (2.0);
}
#endif
#ifndef HAVE_EXP2
/* Use a simple implementation for exp2() for compilers that lack it */
static inline double
exp2 (double x)
{
return pow (2.0, x);
}
#endif
#ifndef HAVE_TRUNC
static inline double
trunc (double x)
{
return (x > 0 ? floor (x) : ceil (x));
}
#endif