/*

Copyright (C) 1996, 1997, 1998, 1999, 2001, 2002, 2003, 2004, 2005,
              2006, 2007, 2008 John W. Eaton
Copyright (C) 2010 VZLU Prague

This file is part of Octave.

Octave 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 3 of the License, or (at your
option) any later version.

Octave 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 Octave; see the file COPYING.  If not, see
<http://www.gnu.org/licenses/>.

*/

#if !defined (octave_liboctave_mappers_h)
#define octave_liboctave_mappers_h 1

#include <limits>

#include "oct-cmplx.h"
#include "lo-math.h"

// Double Precision 
extern OCTAVE_API double xtrunc (double x);
inline double xcopysign (double x, double y) { return copysign (x, y); }
inline double xceil (double x) { return ceil (x); }
inline double xfloor (double x) { return gnulib::floor (x); }
inline double arg (double x) { return atan2 (0.0, x); }
inline double conj (double x) { return x; }
inline double fix (double x) { return xtrunc (x); }
inline double imag (double) { return 0.0; }
inline double real (double x) { return x; }
extern OCTAVE_API double xround (double x);
extern OCTAVE_API double xroundb (double x);
extern OCTAVE_API double signum (double x);
extern OCTAVE_API double xlog2 (double x); 
extern OCTAVE_API Complex xlog2 (const Complex& x); 
extern OCTAVE_API double xlog2 (double x, int& exp);
extern OCTAVE_API Complex xlog2 (const Complex& x, int& exp);
extern OCTAVE_API double xexp2 (double x);

// These are used by the BOOL_OP macros in mx-op-defs.h.
inline bool xisnan (bool) { return false; }
inline bool xisnan (char) { return false; }

#if defined (HAVE_CMATH_ISNAN)
inline bool xisnan (double x)
{ return std::isnan (x); }
#else
extern OCTAVE_API bool xisnan (double x);
#endif
#if defined (HAVE_CMATH_ISFINITE)
inline bool xfinite (double x)
{ return std::isfinite (x); }
#else
extern OCTAVE_API bool xfinite (double x);
#endif
#if defined (HAVE_CMATH_ISINF)
inline bool xisinf (double x)
{ return std::isinf (x); }
#else
extern OCTAVE_API bool xisinf (double x);
#endif

extern OCTAVE_API bool octave_is_NA (double x);
extern OCTAVE_API bool octave_is_NaN_or_NA (double x) GCC_ATTR_DEPRECATED;

// Generic xmin, xmax definitions
template <class T>
inline T xmin (T x, T y)
{
  return x <= y ? x : y;
}

template <class T>
inline T xmax (T x, T y)
{
  return x >= y ? x : y;
}

// This form is favorable. GCC will translate (x <= y ? x : y) without a
// jump, hence the only conditional jump involved will be the first
// (xisnan), infrequent and hence friendly to branch prediction.
inline double
xmin (double x, double y)
{
  return xisnan (y) ? x : (x <= y ? x : y);
}

inline double
xmax (double x, double y)
{
  return xisnan (y) ? x : (x >= y ? x : y);
}

extern OCTAVE_API Complex acos (const Complex& x);
extern OCTAVE_API Complex acosh (const Complex& x);
extern OCTAVE_API Complex asin (const Complex& x);
extern OCTAVE_API Complex asinh (const Complex& x);
extern OCTAVE_API Complex atan (const Complex& x);
extern OCTAVE_API Complex atanh (const Complex& x);

extern OCTAVE_API bool octave_is_NA (const Complex& x);
extern OCTAVE_API bool octave_is_NaN_or_NA (const Complex& x);

extern OCTAVE_API Complex xmin (const Complex& x, const Complex& y);
extern OCTAVE_API Complex xmax (const Complex& x, const Complex& y);

// Single Precision 
extern OCTAVE_API float xtrunc (float x);
inline float xcopysign (float x, float y) { return copysignf (x, y); }
inline float xceil (float x) { return ceilf (x); }
inline float xfloor (float x) { return floorf (x); }
inline float arg (float x) { return atan2f (0.0f, x); }
inline float conj (float x) { return x; }
inline float fix (float x) { return xtrunc (x); }
inline float imag (float) { return 0.0f; }
inline float real (float x) { return x; }
extern OCTAVE_API float xround (float x);
extern OCTAVE_API float xroundb (float x);
extern OCTAVE_API float signum (float x);
extern OCTAVE_API float xlog2 (float x); 
extern OCTAVE_API FloatComplex xlog2 (const FloatComplex& x); 
extern OCTAVE_API float xlog2 (float x, int& exp);
extern OCTAVE_API FloatComplex xlog2 (const FloatComplex& x, int& exp);
extern OCTAVE_API float xexp2 (float x);

#if defined (HAVE_CMATH_ISNANF)
inline bool xisnan (float x)
{ return std::isnan (x); }
#else
extern OCTAVE_API bool xisnan (float x);
#endif
#if defined (HAVE_CMATH_ISFINITEF)
inline bool xfinite (float x)
{ return std::isfinite (x); }
#else
extern OCTAVE_API bool xfinite (float x);
#endif
#if defined (HAVE_CMATH_ISINFF)
inline bool xisinf (float x)
{ return std::isinf (x); }
#else
extern OCTAVE_API bool xisinf (float x);
#endif

extern OCTAVE_API bool octave_is_NA (float x);
extern OCTAVE_API bool octave_is_NaN_or_NA (float x) GCC_ATTR_DEPRECATED;

inline float
xmin (float x, float y)
{
  return xisnan (y) ? x : (x <= y ? x : y);
}

inline float
xmax (float x, float y)
{
  return xisnan (y) ? x : (x >= y ? x : y);
}

extern OCTAVE_API FloatComplex acos (const FloatComplex& x);
extern OCTAVE_API FloatComplex acosh (const FloatComplex& x);
extern OCTAVE_API FloatComplex asin (const FloatComplex& x);
extern OCTAVE_API FloatComplex asinh (const FloatComplex& x);
extern OCTAVE_API FloatComplex atan (const FloatComplex& x);
extern OCTAVE_API FloatComplex atanh (const FloatComplex& x);

extern OCTAVE_API bool octave_is_NA (const FloatComplex& x);
extern OCTAVE_API bool octave_is_NaN_or_NA (const FloatComplex& x);

extern OCTAVE_API FloatComplex xmin (const FloatComplex& x, const FloatComplex& y);
extern OCTAVE_API FloatComplex xmax (const FloatComplex& x, const FloatComplex& y);

// These map reals to Complex.

extern OCTAVE_API Complex rc_acos (double);
extern OCTAVE_API FloatComplex rc_acos (float);
extern OCTAVE_API Complex rc_acosh (double);
extern OCTAVE_API FloatComplex rc_acosh (float);
extern OCTAVE_API Complex rc_asin (double);
extern OCTAVE_API FloatComplex rc_asin (float);
extern OCTAVE_API Complex rc_atanh (double);
extern OCTAVE_API FloatComplex rc_atanh (float);
extern OCTAVE_API Complex rc_log (double);
extern OCTAVE_API FloatComplex rc_log (float);
extern OCTAVE_API Complex rc_log2 (double);
extern OCTAVE_API FloatComplex rc_log2 (float);
extern OCTAVE_API Complex rc_log10 (double);
extern OCTAVE_API FloatComplex rc_log10 (float);
extern OCTAVE_API Complex rc_sqrt (double);
extern OCTAVE_API FloatComplex rc_sqrt (float);

// Some useful tests, that are commonly repeated.
// Test for a finite integer.
inline bool
xisinteger (double x)
{
  return xfinite (x) && x == xround (x);
}

inline bool
xisinteger (float x)
{
  return xfinite (x) && x == xround (x);
}

// Test for negative sign. 
extern OCTAVE_API bool xnegative_sign (double x);
extern OCTAVE_API bool xnegative_sign (float x);

// Some old rounding functions.

extern OCTAVE_API octave_idx_type NINTbig (double x);
extern OCTAVE_API octave_idx_type NINTbig (float x);

extern OCTAVE_API int NINT (double x);
extern OCTAVE_API int NINT (float x);

template <typename T>
OCTAVE_API
T
X_NINT (T x)
{
  return (xisinf (x) || xisnan (x)) ? x : xfloor (x + 0.5);
}

inline OCTAVE_API double D_NINT (double x) { return X_NINT (x); }
inline OCTAVE_API float F_NINT (float x) { return X_NINT (x); }

// Template functions can have either float or double arguments.

template <typename T>
bool
xisnan (const std::complex<T>& x)
{
  return (xisnan (real (x)) || xisnan (imag (x)));
}

template <typename T>
bool
xfinite (const std::complex<T>& x)
{
  return (xfinite (real (x)) && xfinite (imag (x)));
}

template <typename T>
bool
xisinf (const std::complex<T>& x)
{
  return (xisinf (real (x)) || xisinf (imag (x)));
}

template <typename T>
std::complex<T>
fix (const std::complex<T>& x)
{
  return std::complex<T> (fix (real (x)), fix (imag (x)));
}

template <typename T>
std::complex<T>
ceil (const std::complex<T>& x)
{
  return std::complex<T> (xceil (real (x)), xceil (imag (x)));
}

template <typename T>
std::complex<T>
floor (const std::complex<T>& x)
{
  return std::complex<T> (xfloor (real (x)), xfloor (imag (x)));
}

template <typename T>
std::complex<T>
xround (const std::complex<T>& x)
{
  return std::complex<T> (xround (real (x)), xround (imag (x)));
}

template <typename T>
std::complex<T>
xroundb (const std::complex<T>& x)
{
  return std::complex<T> (xroundb (real (x)), xroundb (imag (x)));
}

template <typename T>
std::complex<T>
signum (const std::complex<T>& x)
{
  T tmp = abs (x);

  return tmp == 0 ? 0.0 : x / tmp;
}

template <typename T>
OCTAVE_API
T
xmod (T x, T y)
{
  T retval;

  if (y == 0)
    retval = x;
  else
    {
      T q = x / y;

      T n = xfloor (q);

      if (X_NINT (y) != y)
        {
          if (X_NINT (q) == q)
            n = q;
          else
            {
              if (x >= -1 && x <= 1)
                {
                  if (std::abs (q - X_NINT (q))
                      < std::numeric_limits<T>::epsilon ())
                    n = X_NINT (q);
                }
              else
                {
                  if (std::abs ((q - X_NINT (q))/ X_NINT (q))
                      < std::numeric_limits<T>::epsilon ())
                    n = X_NINT (q);
                }
            }
        }

      // Prevent use of extra precision.
      volatile T tmp = y * n;

      retval = x - tmp;
    }

  if (x != y && y != 0 && retval != 0)
    retval = xcopysign (retval, y);

  return retval;
}

template <typename T>
OCTAVE_API
T
xrem (T x, T y)
{
  T retval;

  if (y == 0)
    retval = x;
  else
    {
      T q = x / y;

      T n = xtrunc (q);

      if (X_NINT (y) != y)
        {
          if (X_NINT (q) == q)
            n = q;
          else
            {
              if (x >= -1 && x <= 1)
                {
                  if (std::abs (q - X_NINT (q))
                      < std::numeric_limits<T>::epsilon ())
                    n = X_NINT (q);
                }
              else
                {
                  if (std::abs ((q - X_NINT (q))/ X_NINT (q))
                      < std::numeric_limits<T>::epsilon ())
                    n = X_NINT (q);
                }
            }
        }

      // Prevent use of extra precision.
      volatile T tmp = y * n;

      retval = x - tmp;
    }

  if (x != y && y != 0 && retval != 0)
    retval = xcopysign (retval, x);

  return retval;
}

#endif