// spheroid
LP o_inverse(XY xy)
{
LP lp;
lp.lam = lp.phi = 0;
lp = link.inv(xy);
if (lp.lam != Libc.HUGE_VAL)
{
lp.lam -= lamp;
double coslam = Math.Cos(lp.lam);
double sinphi = Math.Sin(lp.phi);
double cosphi = Math.Cos(lp.phi);
lp.phi = Proj.aasin(ctx, sphip * sinphi + cphip * cosphi * coslam);
lp.lam = Proj.aatan2(cosphi * Math.Sin(lp.lam), sphip * cosphi * coslam - cphip * sinphi);
}
return(lp);
}
// spheroid
LP s_inverse(XY xy)
{
LP lp;
lp.lam = lp.phi = 0;
if (Math.Abs(xy.y) <= PHI_LIM)
{
lp = sinu.inv(xy);
}
else
{
xy.y += (xy.y >= 0.0?Y_COR:-Y_COR);
lp = moll.inv(xy);
}
return(lp);
}