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/****************************************************************************
* mathutil.cpp
*
* This module implements the utility functions for scalar math.
*
* from Persistence of Vision(tm) Ray Tracer version 3.6.
* Copyright 1991-2003 Persistence of Vision Team
* Copyright 2003-2004 Persistence of Vision Raytracer Pty. Ltd.
*---------------------------------------------------------------------------
* NOTICE: This source code file is provided so that users may experiment
* with enhancements to POV-Ray and to port the software to platforms other
* than those supported by the POV-Ray developers. There are strict rules
* regarding how you are permitted to use this file. These rules are contained
* in the distribution and derivative versions licenses which should have been
* provided with this file.
*
* These licences may be found online, linked from the end-user license
* agreement that is located at http://www.povray.org/povlegal.html
*---------------------------------------------------------------------------
* This program is based on the popular DKB raytracer version 2.12.
* DKBTrace was originally written by David K. Buck.
* DKBTrace Ver 2.0-2.12 were written by David K. Buck & Aaron A. Collins.
*---------------------------------------------------------------------------
* $File: //depot/povray/3.6-release/source/mathutil.cpp $
* $Revision: #3 $
* $Change: 3032 $
* $DateTime: 2004/08/02 18:43:41 $
* $Author: chrisc $
* $Log$
*****************************************************************************/
#include <ctype.h>
#include <time.h>
#include <algorithm>
#include <math.h>
#include "frame.h"
#include "mathutil.h"
BEGIN_POV_NAMESPACE
#ifdef NEED_INVHYP
DBL asinh(DBL x)
{
return (x < 0 ? -1 : (x > 0 ? 1 : 0)) * log(fabs(x) + sqrt(1 + x * x));
}
DBL acosh(DBL x)
{
if(x < 1.0)
return 0;
return log(x + sqrt(x * x - 1));
}
DBL atanh(DBL x)
{
if(fabs(x) >= 1)
return 0;
return 0.5 * log((1 + x) / (1 - x));
}
#endif
END_POV_NAMESPACE
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