Application: gvSIG desktop

#ifndef lint

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

#endif

#define PROJ_PARMS__ \

        double        phi1; \

        double        fxa; \

        double        fxb; \

        int                mode;

#define EPS        1e-9

#define PJ_LIB__

#include        <projects.h>

PROJ_HEAD(rpoly, "Rectangular Polyconic")

        "\n\tConic, Sph., no inv.\n\tlat_ts=";

FORWARD(s_forward); /* spheroid */

        double fa;

        if (P->mode)

                fa = tan(lp.lam * P->fxb) * P->fxa;

        else

                fa = 0.5 * lp.lam;

        if (fabs(lp.phi) < EPS) {

                xy.x = fa + fa;

                xy.y = - P->phi0;

        } else {

                xy.y = 1. / tan(lp.phi);

                xy.x = sin(fa = 2. * atan(fa * sin(lp.phi))) * xy.y;

                xy.y = lp.phi - P->phi0 + (1. - cos(fa)) * xy.y;

        }

        return (xy);

}

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

ENTRY0(rpoly)

        if ((P->mode = (P->phi1 = fabs(pj_param(P->params, "rlat_ts").f)) > EPS)) {

                P->fxb = 0.5 * sin(P->phi1);

                P->fxa = 0.5 / P->fxb;

        }

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

ENDENTRY(P)