pj_fwd.c
1.01 KB
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/* general forward projection */
#ifndef lint
static const char SCCSID[]="@(#)pj_fwd.c 4.4 93/06/12 GIE REL";
#endif
#define PJ_LIB__
#include "projects.h"
#include <errno.h>
# define EPS 1.0e-12
XY /* forward projection entry */
pj_fwd(LP lp, PJ *P) {
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;
pj_errno = -14;
} else { /* proceed with projection */
errno = pj_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 = adjlon(lp.lam); /* adjust del longitude */
xy = (*P->fwd)(lp, P); /* project */
if (pj_errno || (pj_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;
}