static XY e_forward (LP lp, PJ *P) { /* Ellipsoidal, forward */
XY xy = {0.0,0.0};
struct pj_opaque *Q = P->opaque;
double sin_Cn, cos_Cn, cos_Ce, sin_Ce, dCn, dCe;
double Cn = lp.phi, Ce = lp.lam;
/* ell. LAT, LNG -> Gaussian LAT, LNG */
Cn = gatg (Q->cbg, PROJ_ETMERC_ORDER, Cn);
/* Gaussian LAT, LNG -> compl. sph. LAT */
#ifdef _GNU_SOURCE
sincos (Cn, &sin_Cn, &cos_Cn);
sincos (Ce, &sin_Ce, &cos_Ce);
#else
sin_Cn = sin (Cn);
cos_Cn = cos (Cn);
sin_Ce = sin (Ce);
cos_Ce = cos (Ce);
#endif
Cn = atan2 (sin_Cn, cos_Ce*cos_Cn);
Ce = atan2 (sin_Ce*cos_Cn, hypot (sin_Cn, cos_Cn*cos_Ce));
/* compl. sph. N, E -> ell. norm. N, E */
Ce = asinhy ( tan (Ce) ); /* Replaces: Ce = log(tan(FORTPI + Ce*0.5)); */
Cn += clenS (Q->gtu, PROJ_ETMERC_ORDER, 2*Cn, 2*Ce, &dCn, &dCe);
Ce += dCe;
if (fabs (Ce) <= 2.623395162778) {
xy.y = Q->Qn * Cn + Q->Zb; /* Northing */
xy.x = Q->Qn * Ce; /* Easting */
} else
xy.x = xy.y = HUGE_VAL;
return xy;
}
Cn = gatg(P->cbg, PROJ_ETMERC_ORDER, Cn);
/* Gaussian LAT, LNG -> compl. sph. LAT */
#ifdef _GNU_SOURCE
sincos(Cn, &sin_Cn, &cos_Cn);
sincos(Ce, &sin_Ce, &cos_Ce);
#else
sin_Cn = sin(Cn);
cos_Cn = cos(Cn);
sin_Ce = sin(Ce);
cos_Ce = cos(Ce);
#endif
Cn = atan2(sin_Cn, cos_Ce*cos_Cn);
Ce = atan2(sin_Ce*cos_Cn, hypot(sin_Cn, cos_Cn*cos_Ce));
/* compl. sph. N, E -> ell. norm. N, E */
Ce = asinhy(tan(Ce)); /* Replaces: Ce = log(tan(FORTPI + Ce*0.5)); */
Cn += clenS(P->gtu, PROJ_ETMERC_ORDER, 2*Cn, 2*Ce, &dCn, &dCe);
Ce += dCe;
if (fabs(Ce) <= 2.623395162778) {
xy.y = P->Qn * Cn + P->Zb; /* Northing */
xy.x = P->Qn * Ce; /* Easting */
} else
xy.x = xy.y = HUGE_VAL;
return (xy);
}
INVERSE(e_inverse); /* ellipsoid */
double sin_Cn, cos_Cn, cos_Ce, sin_Ce, dCn, dCe;
double Cn = xy.y, Ce = xy.x;
/* normalize N, E */
