Angle.h

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/*
 * This file is part of sphgeom.
 *
 * Developed for the LSST Data Management System.
 * This product includes software developed by the LSST Project
 * (http://www.lsst.org).
 * See the COPYRIGHT file at the top-level directory of this distribution
 * for details of code ownership.
 *
 * This software is dual licensed under the GNU General Public License and also
 * under a 3-clause BSD license. Recipients may choose which of these licenses
 * to use; please see the files gpl-3.0.txt and/or bsd_license.txt,
 * respectively.  If you choose the GPL option then the following text applies
 * (but note that there is still no warranty even if you opt for BSD instead):
 *
 * This program 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.
 *
 * 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
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 * You should have received a copy of the GNU General Public License
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 */
 
#ifndef LSST_SPHGEOM_ANGLE_H_
#define LSST_SPHGEOM_ANGLE_H_

 
#include <cmath>
#include <algorithm>
#include <iosfwd>
#include <limits>
 
#include "constants.h"
 
 
namespace lsst {
namespace sphgeom {

class Angle {
public:
    static Angle nan() {
        return Angle(std::numeric_limits<double>::quiet_NaN());
    }
 
    static Angle fromDegrees(double a) { return Angle(a * RAD_PER_DEG); }
 
    static Angle fromRadians(double a) { return Angle(a); }

    Angle() : _rad(0.0) {}

    explicit Angle(double a) : _rad(a) {}
 
    // Comparison operators
    bool operator==(Angle const & a) const { return _rad == a._rad; }
    bool operator!=(Angle const & a) const { return _rad != a._rad; }
    bool operator<(Angle const & a) const { return _rad < a._rad; }
    bool operator>(Angle const & a) const { return _rad > a._rad; }
    bool operator<=(Angle const & a) const { return _rad <= a._rad; }
    bool operator>=(Angle const & a) const { return _rad >= a._rad; }
 
    // Arithmetic operators
    Angle operator-() const { return Angle(-_rad); }
    Angle operator+(Angle const & a) const { return Angle(_rad + a._rad); }
    Angle operator-(Angle const & a) const { return Angle(_rad - a._rad); }
    Angle operator*(double a) const { return Angle(_rad * a); }
    Angle operator/(double a) const { return Angle(_rad / a); }
    double operator/(Angle const & a) const { return _rad / a._rad; }
 
    // In-place arithmetic operators
    Angle & operator+=(Angle const & a) { *this = *this + a; return *this; }
    Angle & operator-=(Angle const & a) { *this = *this - a; return *this; }
    Angle & operator*=(double a) { *this = *this * a; return *this; }
    Angle & operator/=(double a) { *this = *this / a; return *this; }

    double asDegrees() const { return _rad * DEG_PER_RAD; }

    double asRadians() const { return _rad; }

    bool isNormalized() const { return _rad >= 0.0 && _rad <= 2.0 * PI; }

    bool isNan() const { return std::isnan(_rad); }
 
private:
    double _rad;
};
 
 
inline Angle operator*(double a, Angle const & b) { return b * a; }
 
std::ostream & operator<<(std::ostream &, Angle const &);
 
inline double sin(Angle const & a) { return std::sin(a.asRadians()); }
inline double cos(Angle const & a) { return std::cos(a.asRadians()); }
inline double tan(Angle const & a) { return std::tan(a.asRadians()); }
 
inline Angle abs(Angle const & a) { return Angle(std::fabs(a.asRadians())); }
 
}} // namespace lsst::sphgeom
 
#endif // LSST_SPHGEOM_ANGLE_H_