include/tdbutil/mathUtilities.h

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/*******************************************************************************
** Copyright (c) 2005 MAK Technologies, Inc.
** All rights reserved.
*******************************************************************************/
/*******************************************************************************
** $RCSfile: mathUtilities.h,v $ $Revision: 1.1 $ $State: Exp $
*******************************************************************************/

#ifndef mathUtilities_H_
#define mathUtilities_H_

#include <limits> // for floating point limits

#ifndef WIN32
#include <math.h>
#endif

#if WIN32
// HACK - these are defined by stdlib.h and windef.h AS MACROS!
// As a result, the walk over the std definition of min below.  So undefine
// them first.
#ifdef min
static const int DtReDefineMin = 1;
#undef min
#else
static const int DtReDefineMin = 0;
#endif

#ifdef max
static const int DtReDefineMax = 1;
#undef max
#else
static const int DtReDefineMax = 0;
#endif

#endif

template <typename T>
inline T DtMinValue()
{
   return (std::numeric_limits<T>::min());
}

template <typename T>
inline T DtMaxValue()
{
   return (std::numeric_limits<T>::max());
}

#if WIN32
// HACK - If we had to undefine it earlier, then redefine it now.
#if DtReDefineMin
#define min(a,b) (((a) < (b)) ? (a) : (b))
#endif

#if DtReDefineMax
#define max(a,b) (((a) > (b)) ? (a) : (b))
#endif

#endif


inline bool DtIsEven(int input)
{
   if ((*reinterpret_cast<int*>(&input) & 0x0001)== 0)
   {
      return true;
   }
   else
   {
      return false;
   }
}

inline bool DtIsOdd(int input)
{
   return !DtIsEven(input);
}


// FLOATING POINT UTILITY ROUTINES (COMPARISON, DIVIDE, ABSOLUTE VALUE...) 

// @returns Result of comparison of input type with 0.  Specialized for
// both single and double precision floating point numbers (float/double).
template <typename T>
inline bool DtIsZero(T input)
{
   return (input == 0);
}

template <>
inline bool DtIsZero<float>(float input)
{
   return (fabs(input) < DtMinValue<float>());
}

template <>
inline bool DtIsZero<double>(double input)
{
   return (fabs(input) < DtMinValue<double>());
}

template <typename T>
inline bool DtIsNotZero(T input)
{
   return !DtIsZero(input);
}


#endif