base/consts

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/****************************************************************************
  Copyright (C)2002 David Jung <opensim@pobox.com>

  This program/file 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 2 of the License, or
  (at your option) any later version.
  
  This program 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. (http://www.gnu.org)
  
  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  
  $Id: consts 1029 2004-02-11 20:45:54Z jungd $
  $Revision: 1.2 $
  $Date: 2004-02-11 15:45:54 -0500 (Wed, 11 Feb 2004) $
  $Author: jungd $
 
****************************************************************************/

#ifndef _BASE_CONSTS_
#define _BASE_CONSTS_

#include <base/Object>

#include <limits>

// we make a namespace consts and them alias consts to base::consts
//  so that we can write consts::epsilon, which is more readable than
//  base::epsilon

namespace base {
namespace consts {

  const  Real epsilon = Real(1e-10);  
  const  Real epsilon2 = Real(1e-20);
  const  Real minReal = Real(1.17549435e-38f);
  const  Real maxReal = Real(3.40282347e+38f);
  const  SInt minSInt  = (-2147483647-1);
  const  SInt maxSInt  = 2147483647;
  const  Int  minInt  = 0;
  const  Int  maxInt  = 4294967293U;
  const  Real Pi = Real(3.1415926535897932384626433832795029L);
  const  Real SqrtHalf = Real(0.7071067811865475244008443621048490);
  const  Real TwoPi = Real(Pi*2.0);
  const  Real Infinity = maxReal;

  // unit conversion
  const Real inchesPerMeter = 39.37007874;
  const Real metersPerInch = 0.0254;

} // consts



  // NB: Unfortunately, these are identical to functions in Math, just here 
  //     as they are used in many inline headers before they can include
  //     Math (otherwise they'd have to be not inline and we'd take
  //     a performance hit.

  // equals within eps (i.e. true if |r1-r2| < eps)
  inline bool equals(const Real r1, const Real r2, Real eps = consts::epsilon)
  { return ::fabs(r1-r2) < eps; }

  // absolute value (i.e. |s|)
  inline Real abs(Real s) { return ::fabs(s); }

  // squate root (i.e. n^.5)
  inline Real sqrt(Real n) { return ::sqrt(n); }

  inline Real sin(Real a) { return ::sin(a); }
  inline Real cos(Real a) { return ::cos(a); }


} // base

namespace consts = base::consts;

#endif

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