* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
- * You should have received a copy of the GNU Library General Public
- * License along with this library; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 02111-1307, USA.
+ * 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.
*
* $Id$
**************************************************************************/
#include <simgear/debug/logstream.hxx>
-#ifdef FG_MATH_EXCEPTION_CLASH
+#ifdef SG_MATH_EXCEPTION_CLASH
# define exception c_exception
#endif
#include <math.h>
actTime = sgCalcActTime(mjd);
// calcualate the angle bewteen ecliptic and equatorial coordinate system
- ecl = DEG_TO_RAD * (23.4393 - 3.563E-7 *actTime);
+ ecl = SGD_DEGREES_TO_RADIANS * (23.4393 - 3.563E-7 *actTime);
eccAnom = sgCalcEccAnom(M, e); //calculate the eccentric anomaly
xv = a * (cos(eccAnom) - e);
ze = yg * sin(ecl) + zg * cos(ecl);
rightAscension = atan2(ye, xe);
declination = atan2(ze, sqrt(xe*xe + ye*ye));
- /* FG_LOG(FG_GENERAL, FG_INFO, "Planet found at : "
+ /* SG_LOG(SG_GENERAL, SG_INFO, "Planet found at : "
<< rightAscension << " (ra), " << declination << " (dec)" ); */
//calculate some variables specific to calculating the magnitude
tmp = -1.0;
}
- FV = RAD_TO_DEG * acos( tmp );
-};
+ FV = SGD_RADIANS_TO_DEGREES * acos( tmp );
+}
/****************************************************************************
* double CelestialBody::sgCalcEccAnom(double M, double e)
diff = fabs(E0 - E1);
E0 = E1;
}
- while (diff > (DEG_TO_RAD * 0.001));
+ while (diff > (SGD_DEGREES_TO_RADIANS * 0.001));
return E0;
}
return eccAnom;
}
+/*****************************************************************************
+ * inline CelestialBody::CelestialBody
+ * public constructor for a generic celestialBody object.
+ * initializes the 6 primary orbital elements. The elements are:
+ * N: longitude of the ascending node
+ * i: inclination to the ecliptic
+ * w: argument of perihelion
+ * a: semi-major axis, or mean distance from the sun
+ * e: eccenticity
+ * M: mean anomaly
+ * Each orbital element consists of a constant part and a variable part that
+ * gradually changes over time.
+ *
+ * Argumetns:
+ * the 13 arguments to the constructor constitute the first, constant
+ * ([NiwaeM]f) and the second variable ([NiwaeM]s) part of the orbital
+ * elements. The 13th argument is the current time. Note that the inclination
+ * is written with a capital (If, Is), because 'if' is a reserved word in the
+ * C/C++ programming language.
+ ***************************************************************************/
+CelestialBody::CelestialBody(double Nf, double Ns,
+ double If, double Is,
+ double wf, double ws,
+ double af, double as,
+ double ef, double es,
+ double Mf, double Ms, double mjd)
+{
+ NFirst = Nf; NSec = Ns;
+ iFirst = If; iSec = Is;
+ wFirst = wf; wSec = ws;
+ aFirst = af; aSec = as;
+ eFirst = ef; eSec = es;
+ MFirst = Mf; MSec = Ms;
+ updateOrbElements(mjd);
+}
+CelestialBody::CelestialBody(double Nf, double Ns,
+ double If, double Is,
+ double wf, double ws,
+ double af, double as,
+ double ef, double es,
+ double Mf, double Ms)
+{
+ NFirst = Nf; NSec = Ns;
+ iFirst = If; iSec = Is;
+ wFirst = wf; wSec = ws;
+ aFirst = af; aSec = as;
+ eFirst = ef; eSec = es;
+ MFirst = Mf; MSec = Ms;
+}
+/****************************************************************************
+ * inline void CelestialBody::updateOrbElements(double mjd)
+ * given the current time, this private member calculates the actual
+ * orbital elements
+ *
+ * Arguments: double mjd: the current modified julian date:
+ *
+ * return value: none
+ ***************************************************************************/
+void CelestialBody::updateOrbElements(double mjd)
+{
+ double actTime = sgCalcActTime(mjd);
+ M = SGD_DEGREES_TO_RADIANS * (MFirst + (MSec * actTime));
+ w = SGD_DEGREES_TO_RADIANS * (wFirst + (wSec * actTime));
+ N = SGD_DEGREES_TO_RADIANS * (NFirst + (NSec * actTime));
+ i = SGD_DEGREES_TO_RADIANS * (iFirst + (iSec * actTime));
+ e = eFirst + (eSec * actTime);
+ a = aFirst + (aSec * actTime);
+}
+/*****************************************************************************
+ * inline double CelestialBody::sgCalcActTime(double mjd)
+ * this private member function returns the offset in days from the epoch for
+ * wich the orbital elements are calculated (Jan, 1st, 2000).
+ *
+ * Argument: the current time
+ *
+ * return value: the (fractional) number of days until Jan 1, 2000.
+ ****************************************************************************/
+double CelestialBody::sgCalcActTime(double mjd)
+{
+ return (mjd - 36523.5);
+}
+/*****************************************************************************
+ * inline void CelestialBody::getPos(double* ra, double* dec)
+ * gives public access to Right Ascension and declination
+ *
+ ****************************************************************************/
+void CelestialBody::getPos(double* ra, double* dec)
+{
+ *ra = rightAscension;
+ *dec = declination;
+}
-
-
-
-
-
-
-
-
-
-
-
-
+/*****************************************************************************
+ * inline void CelestialBody::getPos(double* ra, double* dec, double* magnitude
+ * gives public acces to the current Right ascension, declination, and
+ * magnitude
+ ****************************************************************************/
+void CelestialBody::getPos(double* ra, double* dec, double* magn)
+{
+ *ra = rightAscension;
+ *dec = declination;
+ *magn = magnitude;
+}