azimuthalequidistantprojector.cpp

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/*
    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>

    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 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.

    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.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

*/

#ifdef _WIN32
#include <windows.h>
#endif

#include "azimuthalequidistantprojector.h"

AzimuthalEquidistantProjector::AzimuthalEquidistantProjector(const ViewParams& p)
    : Projector(p)
{

}

SkyMap::Projection AzimuthalEquidistantProjector::type() const
{
    return SkyMap::AzimuthalEquidistant;
}

double AzimuthalEquidistantProjector::radius() const
{
    return 1.57079633;
}

double AzimuthalEquidistantProjector::projectionK(double x) const
{
    double crad = acos(x);
    return ( (crad != 0 ) ? crad/sin(crad) : 1 ); // This handles the 0/0 case. The limit of x / sin(x) is 1 as x -> 0.
}

double AzimuthalEquidistantProjector::projectionL(double x) const
{
    return x;
}