/** Air Navigation Waypoint Intercept Demonstrator
    by Robert J Morton UK-YE572246C */

/*  Provides the navigational essentials of an aircraft - starting position,
    current position, speed. Also the radius of minimum ideal (comfortable)
    turning radius for the type of aircraft concerned. The square of this
    radius is also stored to save on computation time in other classes. */

class aircraft {
  double
    X = 0,   // x co-ord of starting point for waypoint encounter
    Y = 25,  // y co-ord of starting point for waypoint encounter
    x = X,   // current x co-ordinate of aircraft
    y = Y,   // current y co-ordinate of aircraft
    s = .5,  // aircraft's speed: distance travelled every 50 milliseconds
    r = 40;  // radius of aircraft's ideal turning circle

  double R = r * r;  // square of radius

  void reset() { x = X; y = Y; }  // reset aircraft to its stating position

  void advance(double ReqHdg) {  // Advance the aircraft the distance it
    x += s * Math.sin(ReqHdg);   // would travel during the 50 millisecond
    y += s * Math.cos(ReqHdg);   // iteration cycle of the program.
  }
}