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//
// libavg - Media Playback Engine.
// Copyright (C) 2003-2014 Ulrich von Zadow
//
// 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, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
// Current versions can be found at www.libavg.de
//
#include "MathHelper.h"
#include <math.h>
#include <iostream>
using namespace std;
namespace avg {
bool ispow2(int n)
{
return ((n & (n-1)) == 0);
}
int nextpow2(int n)
{
n--;
n |= n >> 1; // handle 2 bit numbers
n |= n >> 2; // handle 4 bit numbers
n |= n >> 4; // handle 8 bit numbers
n |= n >> 8; // handle 16 bit numbers
n |= n >> 16; // handle 32 bit numbers
n++;
return n;
}
int safeCeil(float d)
{
if (fabs(d-int(d)) < EPSILON) {
return int(d);
} else {
return int(d)+1;
}
}
float invSqrt(float x)
{
#if 0
// TODO: This gives incorrect results on Athlon X2, gcc 4.2.
float xhalf = 0.5f*x;
int i = *(int*)&x; // get bits for floating value
i = 0x5f3759d5 - (i>>1); // give initial guess y0
x = *(float*)&i; // convert bits back to float
x *= 1.5f - xhalf*x*x; // newton step, repeating this step
// increases accuracy
x *= 1.5f - xhalf*x*x;
return x;
#endif
return 1/sqrt(x);
}
bool almostEqual(float d1, float d2, float epsilon)
{
return (fabs(d1-d2)<epsilon);
}
}
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