80 lines
2.0 KiB
C++
80 lines
2.0 KiB
C++
/*
|
|
* Copyright (C) 2012-2015 Paul Davis <paul@linuxaudiosystems.com>
|
|
* Copyright (C) 2013 John Emmas <john@creativepost.co.uk>
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
/* Taken from
|
|
* http://www.cygnus-software.com/papers/comparingfloats/comparingfloats.htm
|
|
*
|
|
* Code assumed to be in the public domain.
|
|
*/
|
|
|
|
#ifndef __libpbd__floating_h__
|
|
#define __libpbd__floating_h__
|
|
|
|
#include <stdint.h>
|
|
|
|
#include <cstdlib> // abs(int)
|
|
#include <cmath>
|
|
|
|
#include "pbd/libpbd_visibility.h"
|
|
|
|
namespace PBD {
|
|
|
|
union /*LIBPBD_API*/ Float_t
|
|
{
|
|
Float_t (float num = 0.0f) : f(num) {}
|
|
|
|
// Portable extraction of components.
|
|
bool negative() const { return (i >> 31) != 0; }
|
|
int32_t raw_mantissa() const { return i & ((1 << 23) - 1); }
|
|
int32_t raw_exponent() const { return (i >> 23) & 0xFF; }
|
|
|
|
int32_t i;
|
|
float f;
|
|
};
|
|
|
|
/* Note: ULPS = Units in the Last Place */
|
|
|
|
static inline bool floateq (float a, float b, int max_ulps_diff)
|
|
{
|
|
Float_t ua (a);
|
|
Float_t ub (b);
|
|
|
|
if (a == b) {
|
|
return true;
|
|
}
|
|
|
|
// Different signs means they do not match.
|
|
if (ua.negative() != ub.negative()) {
|
|
return false;
|
|
}
|
|
|
|
// Find the difference in ULPs.
|
|
int ulps_diff = abs (ua.i - ub.i);
|
|
|
|
if (ulps_diff <= max_ulps_diff) {
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
} /* namespace */
|
|
|
|
#endif /* __libpbd__floating_h__ */
|