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; }