PROJ_XY /* forward projection entry */
proj_fwd(PROJ_LP lp, PROJ *P) {
PROJ_XY xy;
double t;
/* check for forward and latitude or longitude overange */
if ((t = fabs(lp.phi)-HALFPI) > EPS || fabs(lp.lam) > 10.) {
xy.x = xy.y = HUGE_VAL;
proj_errno = -14;
} else { /* proceed with projection */
errno = proj_errno = 0;
if (fabs(t) <= EPS)
lp.phi = lp.phi < 0. ? -HALFPI : HALFPI;
else if (P->geoc)
lp.phi = atan(P->rone_es * tan(lp.phi));
lp.lam -= P->lam0; /* compute del lp.lam */
if (!P->over)
lp.lam = proj_adjlon(lp.lam); /* adjust del longitude */
xy = (*P->fwd)(lp, P); /* project */
if (proj_errno || (proj_errno = errno))
xy.x = xy.y = HUGE_VAL;
/* adjust for major axis and easting/northings */
else {
xy.x = P->fr_meter * (P->a * xy.x + P->x0);
xy.y = P->fr_meter * (P->a * xy.y + P->y0);
}
}
return xy;
}
PROJ_LP /* inverse projection entry */
proj_inv(PROJ_XY xy, PROJ *P) {
PROJ_LP lp;
/* can't do as much preliminary checking as with forward */
if (xy.x == HUGE_VAL || xy.y == HUGE_VAL) {
lp.lam = lp.phi = HUGE_VAL;
proj_errno = -15;
}
errno = proj_errno = 0;
xy.x = (xy.x * P->to_meter - P->x0) * P->ra; /* descale and de-offset */
xy.y = (xy.y * P->to_meter - P->y0) * P->ra;
lp = (*P->inv)(xy, P); /* inverse project */
if (proj_errno || (proj_errno = errno))
lp.lam = lp.phi = HUGE_VAL;
else {
lp.lam += P->lam0; /* reduce from del lp.lam */
if (!P->over)
lp.lam = proj_adjlon(lp.lam); /* adjust longitude to CM */
if (P->geoc && fabs(fabs(lp.phi)-HALFPI) > EPS)
lp.phi = atan(P->one_es * tan(lp.phi));
}
return lp;
}
