// Compute the topocentric place of a solar system body.
func (p *Body) Topo(t Time, geo *Place, refr RefractType) BodyTopoData {
t.update()
data := BodyTopoData{}
var ra, dec, dis C.double
switch p.class {
case clPLANET:
if err := C.topo_planet(C.double(t.jd_tt), &p.object, C.double(t.delta_t), &geo.place, C.short(Accuracy), &ra, &dec, &dis); err != 0 {
log.Fatalf("Error %d from app_planet (%s)\n", int(err), p.name)
}
data.Dis = float64(dis)
case clSTAR:
if err := C.topo_star(C.double(t.jd_tt), C.double(t.delta_t), &p.cat_entry, &geo.place, C.short(Accuracy), &ra, &dec); err != 0 {
log.Fatalf("Error %d from app_planet (%s)\n", int(err), p.name)
}
data.Dis = math.NaN()
}
var elon, elat C.double
C.equ2ecl(C.double(t.jd_tt), 0, C.short(Accuracy), ra, dec, &elon, &elat)
var zd, az, rar, decr C.double
C.equ2hor(C.double(t.jd_ut1), C.double(t.delta_t), C.short(Accuracy), 0, 0, &geo.place, ra, dec, C.short(refr), &zd, &az, &rar, &decr)
data.Alt = 90 - float64(zd)
data.Az = float64(az)
return data
}
// Compute the apparent place of an object.
func (p *Body) App(t Time) BodyData {
t.update()
data := BodyData{}
var ra, dec, dis C.double
switch p.class {
case clPLANET:
if err := C.app_planet(C.double(t.jd_tt), &p.object, C.short(Accuracy), &ra, &dec, &dis); err != 0 {
log.Fatalf("Error %d from app_planet (%s)\n", int(err), p.name)
}
data.Dis = float64(dis)
case clSTAR:
if err := C.app_star(C.double(t.jd_tt), &p.cat_entry, C.short(Accuracy), &ra, &dec); err != 0 {
log.Fatalf("Error %d from app_star (%s)\n", int(err), p.name)
}
data.Dis = math.NaN()
}
data.RA = float64(ra)
data.Dec = float64(dec)
var elon, elat C.double
C.equ2ecl(C.double(t.jd_tt), 0, C.short(Accuracy), ra, dec, &elon, &elat)
data.ELon = float64(elon)
data.ELat = float64(elat)
return data
}