/* 
Copyright (C) 1988 Free Software Foundation
    written by Doug Lea (dl@rocky.oswego.edu)

This file is part of GNU CC.

GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY.  No author or distributor
accepts responsibility to anyone for the consequences of using it
or for whether it serves any particular purpose or works at all,
unless he says so in writing.  Refer to the GNU CC General Public
License for full details.

Everyone is granted permission to copy, modify and redistribute
GNU CC, but only under the conditions described in the
GNU CC General Public License.   A copy of this license is
supposed to have been given to you along with GNU CC so you
can know your rights and responsibilities.  It should be in a
file named COPYING.  Among other things, the copyright notice
and this notice must be preserved on all copies.  
*/

#ifdef __GNUG__
#pragma implementation "Complex.h"
#endif
#include <Complex.h>
#include <std.h>

// error handling

void default_Complex_error_handler(const char* msg)
{
  cerr << "Fatal Complex arithmetic error. " << msg << "\n";
  exit(1);
}

one_arg_error_handler_t Complex_error_handler = default_Complex_error_handler;

one_arg_error_handler_t set_Complex_error_handler(one_arg_error_handler_t f)
{
  one_arg_error_handler_t old = Complex_error_handler;
  Complex_error_handler = f;
  return old;
}

void  Complex::error(const char* msg) const
{
  (*Complex_error_handler)(msg);
}

/* from romine@xagsun.epm.ornl.gov */
Complex /* const */ operator / (const Complex& x, const Complex& y)
{
  double den = abs(y.real()) + abs(y.imag());
  if (den == 0.0) x.error ("Attempted division by zero.");
  double xrden = x.real() / den;
  double xiden = x.imag() / den;
  double yrden = y.real() / den;
  double yiden = y.imag() / den;
  double nrm   = yrden * yrden + yiden * yiden;
  return Complex((xrden * yrden + xiden * yiden) / nrm,
                 (xiden * yrden - xrden * yiden) / nrm);
}

Complex& Complex::operator /= (const Complex& y)
{
  double den = abs(y.real()) + abs(y.imag());
  if (den == 0.0) error ("Attempted division by zero.");
  double xrden = re / den;
  double xiden = im / den;
  double yrden = y.real() / den;
  double yiden = y.imag() / den;
  double nrm   = yrden * yrden + yiden * yiden;
  re = (xrden * yrden + xiden * yiden) / nrm;
  im = (xiden * yrden - xrden * yiden) / nrm;
  return *this;
}

Complex /* const */ operator / (double x, const Complex& y)
{
  double den = norm(y);
  if (den == 0.0) y.error ("Attempted division by zero.");
  return Complex((x * y.real()) / den, -(x * y.imag()) / den);
}

Complex /* const */ operator / (const Complex& x, double y)
{
  if (y == 0.0) x.error ("Attempted division by zero.");
  return Complex(x.real() / y, x.imag() / y);
}


Complex& Complex::operator /= (double y)
{
  if (y == 0.0) error ("Attempted division by zero.");
  re /= y;  im /= y;
  return *this;
}


Complex /* const */ exp(const Complex& x)
{
  double r = exp(x.real());
  return Complex(r * cos(x.imag()), 
                 r * sin(x.imag()));
}

Complex /* const */ cosh(const Complex& x)
{
  return Complex(cos(x.imag()) * cosh(x.real()), 
                 sin(x.imag()) * sinh(x.real()));
}

Complex /* const */ sinh(const Complex& x)
{
  return Complex(cos(x.imag()) * sinh(x.real()), 
                 sin(x.imag()) * cosh(x.real()));
}

Complex /* const */ cos(const Complex& x)
{
  return Complex(cos(x.real()) * cosh(x.imag()), 
                 -sin(x.real()) * sinh(x.imag()));
}

Complex /* const */ sin(const Complex& x)
{
  return Complex(sin(x.real()) * cosh(x.imag()), 
                 cos(x.real()) * sinh(x.imag()));
}

Complex /* const */ log(const Complex& x)
{
  double h = hypot(x.real(), x.imag());
  if (h <= 0.0) x.error("attempted log of zero magnitude number.");
  return Complex(log(h), atan2(x.imag(), x.real()));
}

// Corrections based on reports from: thc@cs.brown.edu & saito@sdr.slb.com
Complex /* const */ pow(const Complex& x, const Complex& p)
{
  double h = hypot(x.real(), x.imag());
  if (h <= 0.0) x.error("attempted power of zero magnitude number.");

  double a = atan2(x.imag(), x.real());
  double lr = pow(h, p.real());
  double li = p.real() * a;
  if (p.imag() != 0.0)
  {
    lr /= exp(p.imag() * a);
    li += p.imag() * log(h);
  }
  return Complex(lr * cos(li), lr * sin(li));
}

Complex /* const */ pow(const Complex& x, double p)
{
  double h = hypot(x.real(), x.imag());
  if (h <= 0.0) x.error("attempted power of zero magnitude number.");
  double lr = pow(h, p);
  double a = atan2(x.imag(), x.real());
  double li = p * a;
  return Complex(lr * cos(li), lr * sin(li));
}


Complex /* const */ sqrt(const Complex& x)
{
  if (x.real() == 0.0 && x.imag() == 0.0)
    return Complex(0.0, 0.0);
  else
  {
    double s = sqrt((abs(x.real()) + hypot(x.real(), x.imag())) * 0.5);
    double d = (x.imag() / s) * 0.5;
    if (x.real() > 0.0)
      return Complex(s, d);
    else if (x.imag() >= 0.0)
      return Complex(d, s);
    else
      return Complex(-d, -s);
  }
}


Complex /* const */ pow(const Complex& x, long p)
{
  if (p == 0)
    return Complex(1.0, 0.0);
  else if (x == 0.0)
    return Complex(0.0, 0.0);
  else
  {
    Complex res(1.0, 0.0);
    Complex b = x;
    if (p < 0)
    {
      p = -p;
      b = 1.0 / b;
    }
    for(;;)
    {
      if (p & 1)
        res *= b;
      if ((p >>= 1) == 0)
        return res;
      else
        b *= b;
    }
  }
}

ostream& operator << (ostream& s, const Complex& x)
{
  return s << "(" << x.real() << ", " << x.imag() << ")" ;
}

istream& operator >> (istream& s, Complex& x)
{
  double r, i;
  char ch;
  s >> WS;
  s.get(ch);
  if (ch == '(')
  {
    s >> r;
    s >> WS;
    s.get(ch);
    if (ch == ',')
    {
      s >> i;
      s >> WS;
      s .get(ch);
    }
    else
      i = 0;
    if (ch != ')')
      s.set(_bad);
  }
  else
  {
    s.unget(ch);
    s >> r;
    i = 0;
  }
  x = Complex(r, i);
  return s;
}