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/*
DDS GIMP plugin
Copyright (C) 2004-2012 Shawn Kirst <skirst@gmail.com>,
with parts (C) 2003 Arne Reuter <homepage@arnereuter.de> where specified.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This program 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING. If not, write to
the Free Software Foundation, 51 Franklin Street, Fifth Floor
Boston, MA 02110-1301, USA.
*/
#ifndef IMATH_H
#define IMATH_H
#ifndef MIN
# ifdef __GNUC__
# define MIN(a, b) ({typeof(a) _a=(a); typeof(b) _b=(b); _a < _b ? _a : _b;})
# else
# define MIN(a, b) ((a) < (b) ? (a) : (b))
# endif
#endif
#ifndef MAX
# ifdef __GNUC__
# define MAX(a, b) ({typeof(a) _a=(a); typeof(b) _b=(b); _a > _b ? _a : _b;})
# else
# define MAX(a, b) ((a) > (b) ? (a) : (b))
# endif
#endif
#define IS_POW2(x) (!((x) & ((x) - 1)))
#define IS_MUL4(x) (((x) & 3) == 0)
/* round integer x up to next multiple of 4 */
#define RND_MUL4(x) ((x) + (4 - ((x) & 3)))
static inline int mul8bit(int a, int b)
{
int t = a * b + 128;
return((t + (t >> 8)) >> 8);
}
static inline int blerp(int a, int b, int x)
{
return(a + mul8bit(b - a, x));
}
static inline int icerp(int a, int b, int c, int d, int x)
{
int p = (d - c) - (a - b);
int q = (a - b) - p;
int r = c - a;
return((x * (x * (x * p + (q << 7)) + (r << 14)) + (b << 21)) >> 21);
}
#endif
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