99 lines
2.8 KiB
C++
99 lines
2.8 KiB
C++
/*
|
|
* This program source code file is part of KICAD, a free EDA CAD application.
|
|
*
|
|
* Copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
|
|
* Copyright (C) CERN
|
|
* @author Tomasz Wlostowski <tomasz.wlostowski@cern.ch>
|
|
*
|
|
* 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, you may find one here:
|
|
* http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
|
|
* or you may search the http://www.gnu.org website for the version 2 license,
|
|
* or you may write to the Free Software Foundation, Inc.,
|
|
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
|
|
*/
|
|
|
|
#ifndef __MATH_UTIL_H
|
|
#define __MATH_UTIL_H
|
|
|
|
#include <cmath>
|
|
#include <cstdlib>
|
|
#include <stdint.h>
|
|
|
|
/**
|
|
* Function rescale()
|
|
*
|
|
* Scales a number (value) by rational (numerator/denominator). Numerator must be <= denominator.
|
|
*/
|
|
|
|
template<typename T> static T rescale( T numerator, T value, T denominator )
|
|
{
|
|
return numerator * value / denominator;
|
|
}
|
|
|
|
|
|
// explicit specializations for integer types, taking care of overflow.
|
|
template<> int rescale( int numerator, int value, int denominator )
|
|
{
|
|
return (int) ( (int64_t) numerator * (int64_t) value / (int64_t) denominator );
|
|
}
|
|
|
|
template<> int64_t rescale( int64_t numerator, int64_t value, int64_t denominator )
|
|
{
|
|
int64_t r = 0;
|
|
int64_t sign = ( ( numerator < 0) ? -1 : 1 ) * ( denominator < 0 ? - 1: 1 ) * (value < 0 ? - 1 : 1);
|
|
|
|
int64_t a = std::abs( numerator );
|
|
int64_t b = std::abs( value );
|
|
int64_t c = std::abs( denominator );
|
|
|
|
r = c / 2;
|
|
|
|
if( b <= INT_MAX && c <= INT_MAX )
|
|
{
|
|
if( a <= INT_MAX )
|
|
return sign * ( (a * b + r ) / c );
|
|
else
|
|
return sign * (a / c * b + (a % c * b + r) / c);
|
|
} else {
|
|
uint64_t a0 = a & 0xFFFFFFFF;
|
|
uint64_t a1 = a >> 32;
|
|
uint64_t b0 = b & 0xFFFFFFFF;
|
|
uint64_t b1 = b >> 32;
|
|
uint64_t t1 = a0 * b1 + a1 * b0;
|
|
uint64_t t1a = t1 << 32;
|
|
int i;
|
|
|
|
a0 = a0 * b0 + t1a;
|
|
a1 = a1 * b1 + (t1 >> 32) + (a0 < t1a);
|
|
a0 += r;
|
|
a1 += ((uint64_t)a0) < r;
|
|
|
|
for( i = 63; i >= 0; i-- )
|
|
{
|
|
a1 += a1 + ( (a0 >> i) & 1 );
|
|
t1 += t1;
|
|
|
|
if( (uint64_t)c <= a1 )
|
|
{
|
|
a1 -= c;
|
|
t1++;
|
|
}
|
|
}
|
|
|
|
return t1 * sign;
|
|
}
|
|
};
|
|
|
|
#endif // __MATH_UTIL_H
|