// $Id: fgl_routines.h $
// =================================================================
//  This code is distributed under the terms and conditions of the
//  CCP4 Program Suite Licence Agreement as 'Part 2' (Annex 2)
//  software. A copy of the CCP4 licence can be obtained by writing
//  to CCP4, Research Complex at Harwell, Rutherford Appleton
//  Laboratory, Didcot OX11 0FA, UK, or from
//  http://www.ccp4.ac.uk/ccp4license.php.
// =================================================================
//
//    29.08.13   <--  Date of Last Modification.
//                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//  ----------------------------------------------------------------
//
//  **** Module  :  fgl_routines <interface>
//       ~~~~~~~~~
//  **** Project :  QtLibs/FGL - plotting in Qt
//       ~~~~~~~~~
//  **** Classes :  fgl::Range
//       ~~~~~~~~~  various functions
//
//  (C) E. Krissinel 2012-2013
//
// =================================================================
//

#ifndef FGL_ROUTINES_H
#define FGL_ROUTINES_H

#include <math.h>
#include <QRectF>

namespace fgl  {

  const qreal _minReal     = 1.7e-307;
  const qreal _sqrtMinReal = 4.123e-154;
  const qreal _maxReal     = 1.7e+308;
  const qreal _ln10        = log(10.0);
  const qreal _pi          = 3.14159265;

  qreal _machinEps();

  qreal _pow     ( qreal X, int   Y );
  qreal _pow1    ( qreal X, qreal Y );
  qreal _sign    ( qreal q );
  qreal _exp     ( qreal X );
  qreal _order   ( qreal q );

  inline qreal _exp10   ( qreal x ) { return  _exp ( x*_ln10 ); }
  inline qreal _log10   ( qreal q ) { return log10 ( qMax(fabs(q),_minReal) ); }
  inline qreal _round   ( qreal q ) { return floor(q+0.499999999); }
  inline int   _iround  ( qreal q ) { return (int)floor(q+0.499999999); }
  inline int   _ifloor  ( qreal q ) { return (int)floor(q);  }
  inline bool  _isround ( qreal q ) { return (fabs(q-_round(q))<1.0e-8); }

  class Range  {

    public:
      qreal q1,q2;
      qreal stretch;

      Range ( qreal v1, qreal v2, qreal s )
             { q1 = v1;  q2 = v2;  stretch = s; }
      ~Range() {}

  };

}

#endif // FGL_ROUTINES_H