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/*
* ***** BEGIN GPL LICENSE BLOCK *****
*
* 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; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
* All rights reserved.
*
* The Original Code is: some of this file.
*
* ***** END GPL LICENSE BLOCK *****
* */
/** \file blender/blenlib/intern/math_base.c
* \ingroup bli
*/
#include "BLI_math.h"
#include "BLI_strict_flags.h"
int pow_i(int base, int exp)
{
int result = 1;
BLI_assert(exp >= 0);
while (exp) {
if (exp & 1) {
result *= base;
}
exp >>= 1;
base *= base;
}
return result;
}
/* from python 3.1 floatobject.c
* ndigits must be between 0 and 21 */
double double_round(double x, int ndigits)
{
double pow1, pow2, y, z;
if (ndigits >= 0) {
pow1 = pow(10.0, (double)ndigits);
pow2 = 1.0;
y = (x * pow1) * pow2;
/* if y overflows, then rounded value is exactly x */
if (!isfinite(y))
return x;
}
else {
pow1 = pow(10.0, (double)-ndigits);
pow2 = 1.0; /* unused; silences a gcc compiler warning */
y = x / pow1;
}
z = round(y);
if (fabs(y - z) == 0.5)
/* halfway between two integers; use round-half-even */
z = 2.0 * round(y / 2.0);
if (ndigits >= 0)
z = (z / pow2) / pow1;
else
z *= pow1;
/* if computation resulted in overflow, raise OverflowError */
return z;
}
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