public void Inv()
{
double degree = Math.PI / 180;
double lat1 = phi1 / degree, lon1 = lam1 / degree, lat2 = phi2 / degree, lon2 = lam2 / degree;
double azi1, azi2, s12;
GlobalGeodesic.geod_inverse(lat1, lon1, lat2, lon2, out s12, out azi1, out azi2);
azi2 += azi2 >= 0?-180:180; // Compute back azimuth
al12 = azi1 * degree;
al21 = azi2 * degree;
geod_S = s12;
}
// elliptical
XY e_forward(LP lp)
{
XY xy;
xy.x = xy.y = 0;
double coslam = Math.Cos(lp.lam);
double cosphi = Math.Cos(lp.phi);
double sinphi = Math.Sin(lp.phi);
switch (mode)
{
case aeqd_mode.N_POLE: coslam = -coslam; goto case aeqd_mode.S_POLE;
case aeqd_mode.S_POLE:
double rho = Math.Abs(Mp - Proj.pj_mlfn(lp.phi, sinphi, cosphi, en));
xy.x = rho * Math.Sin(lp.lam);
xy.y = rho * coslam;
break;
case aeqd_mode.EQUIT:
case aeqd_mode.OBLIQ:
if (Math.Abs(lp.lam) < EPS10 && Math.Abs(lp.phi - phi0) < EPS10)
{
xy.x = xy.y = 0.0;
break;
}
double phi1 = phi0 * RHO;
double lam1 = lam0 * RHO;
double phi2 = lp.phi * RHO;
double lam2 = (lp.lam + lam0) * RHO;
double azi1, azi2, s12;
g.geod_inverse(phi1, lam1, phi2, lam2, out s12, out azi1, out azi2);
azi1 /= RHO;
xy.x = s12 * Math.Sin(azi1) / a;
xy.y = s12 * Math.Cos(azi1) / a;
break;
}
return(xy);
}
