File indexing completed on 2024-04-21 14:46:53

 /*
     SPDX-FileCopyrightText: 2021 Hy Murveit <hy@murveit.com>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 // Example usage:
 //
 // double az1 = ..., alt1 = ..., az2 = ..., alt2 = ...;
 // GreatCircle gc(az1, alt1, az2, alt2);
 // double az, alt;
 // gc.waypoint(0.75, &az, &alt);
 //
 // az and alt will contain the coordinates for a waypoint 75% of the way
 // between az1,alt1 and az2,alt2 along a great circle path.
 // See https://en.wikipedia.org/wiki/Great-circle_navigation
 
 #pragma once
 
 #include <QObject>
 
 /**
  * @brief A class to compute points along a great circle from one az/alt to another.
  * @author Hy Murveit
  * @version 1.0
  */
 class GreatCircle
 {
     public:
         /**
          * @brief Construct a GreatCircle object for a path between az1,alt1 to az2,alt2
          * @param az1  starting azimuth  value (degrees).
          * @param alt1 starting altitude value (degrees).
          * @param az2    ending azimuth  value (degrees).
          * @param alt2   ending altitude value (degrees).
          */
         GreatCircle(double az1, double alt1, double az2, double alt2);
 
         /**
          * @brief Return the azimuth and altitude for a waypoint
          * @param fraction the desired fraction of the total path
          * @param az the returned azimuth value (degrees)
          * @param alt the returned altitude value (degrees)
          */
         void waypoint(double fraction, double *az, double *alt);
 
     private:
         // These are values computed in the constructor needed by all waypoints.
         double sigma01, sigma02, lambda0;
         double cosAlpha0, sinAlpha0;
 };