Application: gvSIG desktop

#ifndef lint

static const char SCCSID[]="@(#)PJ_wink2.c        4.1 94/02/15     GIE     REL";

#endif

#define PROJ_PARMS__ \

        double        cosphi1;

#define PJ_LIB__

# include        <projects.h>

PROJ_HEAD(wink2, "Winkel II") "\n\tPCyl., Sph., no inv.\n\tlat_1=";

#define MAX_ITER    10

#define LOOP_TOL    1e-7

#define TWO_D_PI 0.636619772367581343

FORWARD(s_forward); /* spheroid */

        double k, V;

        int i;

        xy.y = lp.phi * TWO_D_PI;

        k = PI * sin(lp.phi);

        lp.phi *= 1.8;

        for (i = MAX_ITER; i ; --i) {

                lp.phi -= V = (lp.phi + sin(lp.phi) - k) /

                        (1. + cos(lp.phi));

                if (fabs(V) < LOOP_TOL)

                        break;

        }

        if (!i)

                lp.phi = (lp.phi < 0.) ? -HALFPI : HALFPI;

        else

                lp.phi *= 0.5;

        xy.x = 0.5 * lp.lam * (cos(lp.phi) + P->cosphi1);

        xy.y = FORTPI * (sin(lp.phi) + xy.y);

        return (xy);

}

FREEUP; if (P) pj_dalloc(P); }

ENTRY0(wink2)

        P->cosphi1 = cos(pj_param(P->params, "rlat_1").f);

        P->es = 0.; P->inv = 0; P->fwd = s_forward;

ENDENTRY(P)