angconversion.h

/*
    SPDX-FileCopyrightText: 2011 Akarsh Simha <akarshsimha@gmail.com>
 
    SPDX-License-Identifier: GPL-2.0-or-later
*/
 
#ifndef ANGCONVERSION_H
#define ANGCONVERSION_H
 
#include <math.h> /* For M_PI */
 
/* Angle conversion macros */
#define RADPERDEG (M_PI / 180.0) /* Number of radians in a degree */
 
/* Basic conversions between Degrees, Hours and Radians */
inline double deg2rad(double x)
{
    return (x * RADPERDEG);
}
inline double rad2deg(double x)
{
    return (x / RADPERDEG);
}
inline double hour2deg(double x)
{
    return (x * 15.0);
}
inline double deg2hour(double x)
{
    return (x / 15.0);
}
inline double hour2rad(double x)
{
    return deg2rad(hour2deg(x));
}
inline double rad2hour(double x)
{
    return deg2hour(rad2deg(x));
}
 
/* Convert degrees to arcminutes or arcseconds and back */
inline double deg2arcsec(double x)
{
    return (x * 3600.0);
}
inline double arcsec2deg(double x)
{
    return (x / 3600.0);
}
inline double deg2arcmin(double x)
{
    return (x * 60.0);
}
inline double arcmin2deg(double x)
{
    return (x / 60.0);
}
 
/* The following are redundant, but anyway */
inline double hour2sec(double x)
{
    return (x * 3600.0);
}
inline double sec2hour(double x)
{
    return (x / 3600.0);
}
inline double hour2min(double x)
{
    return (x * 60.0);
}
inline double min2hour(double x)
{
    return (x / 60.0);
}
 
/* Convert DMS / HMS to Degrees / Hours */
inline double dms2deg(double d, double m, double s)
{
    return (d + m / 60.0 + s / 3600.0);
}
inline double hms2hour(double h, double m, double s)
{
    return (h + m / 60.0 + s / 3600.0);
}
 
void deg2dms(double D, int *d, int *m, float *s)
{
    *d = (int)D;
    *m = (int)((D - *d) * 60);
    *s = (int)((D - *d) * 3600 - (*m * 60));
}
 
void hour2hms(double H, int *h, int *m, float *s) /* Another redundant function */
{
    *h = (int)H;
    *m = (int)((H - *h) * 60);
    *s = (int)((H - *h) * 3600 - (*m * 60));
}
 
#endif