vide_public/external/healpix/cxxsupport/pointing.h
2012-10-30 13:56:48 -04:00

106 lines
3.2 KiB
C++

/*
* This file is part of libcxxsupport.
*
* libcxxsupport 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.
*
* libcxxsupport 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 libcxxsupport; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
* libcxxsupport is being developed at the Max-Planck-Institut fuer Astrophysik
* and financially supported by the Deutsches Zentrum fuer Luft- und Raumfahrt
* (DLR).
*/
/*! \file pointing.h
* Class representing a direction in 3D space
*
* Copyright (C) 2003-2010 Max-Planck-Society
* \author Martin Reinecke
*/
#ifndef PLANCK_POINTING_H
#define PLANCK_POINTING_H
#include <cmath>
#include "vec3.h"
#include "cxxutils.h"
/*! \defgroup pointinggroup Pointings */
/*! \{ */
/*! Class representing a direction in 3D space or a location on the
unit sphere. All angles in radians. */
class pointing
{
public:
/*! Colatitude of the pointing (i.e. the North pole is at \a theta=0). */
double theta;
/*! Longitude of the pointing. */
double phi;
/*! Default constructor. \a theta and \a phi are not initialized. */
pointing() {}
/*! Creates a pointing with \a Theta and \a Phi. */
pointing (double Theta, double Phi) : theta(Theta), phi(Phi) {}
// FIXME: should become "explicit" some time
/*! Creates a pointing from the vector \a inp. \a inp need not be
normalized. */
pointing (const vec3 &inp)
{ from_vec3(inp); }
// FIXME: should be removed some time
/*! Returns a normalized vector pointing in the same direction. */
operator vec3() const
{ return to_vec3(); }
/*! Returns a normalized vector pointing in the same direction. */
vec3 to_vec3() const
{
double st=sin(theta);
return vec3 (st*cos(phi), st*sin(phi), cos(theta));
}
/*! Converts \a inp to \a ptg. \a inp need not be normalized. */
void from_vec3 (const vec3 &inp)
{
using namespace std;
const double twopi_=6.283185307179586476925286766559005768394;
theta = atan2(sqrt(inp.x*inp.x+inp.y*inp.y),inp.z);
phi = safe_atan2 (inp.y,inp.x);
if (phi<0.) phi += twopi_;
}
/*! Changes the angles so that \a 0<=theta<=pi and \a 0<=phi<2*pi. */
void normalize()
{
const double pi_=3.141592653589793238462643383279502884197;
const double twopi_=6.283185307179586476925286766559005768394;
theta=fmodulo(theta,twopi_);
if (theta>pi_)
{
phi+=pi_;
theta=twopi_-theta;
}
phi=fmodulo(phi,twopi_);
}
};
/*! Writes \a p to \a os.
\relates pointing */
inline std::ostream &operator<< (std::ostream &os, const pointing &p)
{
os << p.theta << ", " << p.phi << std::endl;
return os;
}
/*! \} */
#endif