gtk2/gtk/fallback-c89.c
Chun-wei Fan 092cb9e202 GTK: Fix build for pre-C99 compilers
Some compilers we support, such as pre-2013 Visual Studio, does not support
for INIFINITY, log2() and exp2(), so check for exp2() and log2() during
configure, and use fallbacks for them and INIFINTY if they are not found.

https://bugzilla.gnome.org/show_bug.cgi?id=766207
2016-05-10 17:14:07 +08:00

107 lines
2.3 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 <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