Application: gvSIG desktop

#ifndef lint

static const char SCCSID[]="@(#)PJ_tmerc.c        4.2        94/06/02        GIE        REL";

#endif

#define PROJ_PARMS__ \

        double        esp; \

        double        ml0; \

        double        *en;

#define PJ_LIB__

#include        <projects.h>

PROJ_HEAD(tmerc, "Transverse Mercator") "\n\tCyl, Sph&Ell";

PROJ_HEAD(utm, "Universal Transverse Mercator (UTM)")

        "\n\tCyl, Sph\n\tzone= south";

#define EPS10        1.e-10

#define aks0        P->esp

#define aks5        P->ml0

#define FC1 1.

#define FC2 .5

#define FC3 .16666666666666666666

#define FC4 .08333333333333333333

#define FC5 .05

#define FC6 .03333333333333333333

#define FC7 .02380952380952380952

#define FC8 .01785714285714285714

FORWARD(e_forward); /* ellipse */

        double al, als, n, cosphi, sinphi, t;

        sinphi = sin(lp.phi); cosphi = cos(lp.phi);

        t = fabs(cosphi) > 1e-10 ? sinphi/cosphi : 0.;

        t *= t;

        al = cosphi * lp.lam;

        als = al * al;

        al /= sqrt(1. - P->es * sinphi * sinphi);

        n = P->esp * cosphi * cosphi;

        xy.x = P->k0 * al * (FC1 +

                FC3 * als * (1. - t + n +

                FC5 * als * (5. + t * (t - 18.) + n * (14. - 58. * t)

                + FC7 * als * (61. + t * ( t * (179. - t) - 479. ) )

                )));

        xy.y = P->k0 * (pj_mlfn(lp.phi, sinphi, cosphi, P->en) - P->ml0 +

                sinphi * al * lp.lam * FC2 * ( 1. +

                FC4 * als * (5. - t + n * (9. + 4. * n) +

                FC6 * als * (61. + t * (t - 58.) + n * (270. - 330 * t)

                + FC8 * als * (1385. + t * ( t * (543. - t) - 3111.) )

                ))));

        return (xy);

}

FORWARD(s_forward); /* sphere */

        double b, cosphi;

        b = (cosphi = cos(lp.phi)) * sin(lp.lam);

        if (fabs(fabs(b) - 1.) <= EPS10) F_ERROR;

        xy.x = aks5 * log((1. + b) / (1. - b));

        if ((b = fabs( xy.y = cosphi * cos(lp.lam) / sqrt(1. - b * b) )) >= 1.) {

                if ((b - 1.) > EPS10) F_ERROR

                else xy.y = 0.;

        } else

                xy.y = acos(xy.y);

        if (lp.phi < 0.) xy.y = -xy.y;

        xy.y = aks0 * (xy.y - P->phi0);

        return (xy);

}

INVERSE(e_inverse); /* ellipsoid */

        double n, con, cosphi, d, ds, sinphi, t;

        lp.phi = pj_inv_mlfn(P->ml0 + xy.y / P->k0, P->es, P->en);

        if (fabs(lp.phi) >= HALFPI) {

                lp.phi = xy.y < 0. ? -HALFPI : HALFPI;

                lp.lam = 0.;

        } else {

                sinphi = sin(lp.phi);

                cosphi = cos(lp.phi);

                t = fabs(cosphi) > 1e-10 ? sinphi/cosphi : 0.;

                n = P->esp * cosphi * cosphi;

                d = xy.x * sqrt(con = 1. - P->es * sinphi * sinphi) / P->k0;

                con *= t;

                t *= t;

                ds = d * d;

                lp.phi -= (con * ds / (1.-P->es)) * FC2 * (1. -

                        ds * FC4 * (5. + t * (3. - 9. *  n) + n * (1. - 4 * n) -

                        ds * FC6 * (61. + t * (90. - 252. * n +

                                45. * t) + 46. * n

                   - ds * FC8 * (1385. + t * (3633. + t * (4095. + 1574. * t)) )

                        )));

                lp.lam = d*(FC1 -

                        ds*FC3*( 1. + 2.*t + n -

                        ds*FC5*(5. + t*(28. + 24.*t + 8.*n) + 6.*n

                   - ds * FC7 * (61. + t * (662. + t * (1320. + 720. * t)) )

                ))) / cosphi;

        }

        return (lp);

}

INVERSE(s_inverse); /* sphere */

        double h, g;

        h = exp(xy.x / aks0);

        g = .5 * (h - 1. / h);

        h = cos(P->phi0 + xy.y / aks0);

        lp.phi = asin(sqrt((1. - h * h) / (1. + g * g)));

        if (xy.y < 0.) lp.phi = -lp.phi;

        lp.lam = (g || h) ? atan2(g, h) : 0.;

        return (lp);

}

FREEUP;

        if (P) {

                if (P->en)

                        pj_dalloc(P->en);

                pj_dalloc(P);

        }

}

        static PJ *

setup(PJ *P) { /* general initialization */

        if (P->es) {

                if (!(P->en = pj_enfn(P->es)))

                        E_ERROR_0;

                P->ml0 = pj_mlfn(P->phi0, sin(P->phi0), cos(P->phi0), P->en);

                P->esp = P->es / (1. - P->es);

                P->inv = e_inverse;

                P->fwd = e_forward;

        } else {

                aks0 = P->k0;

                aks5 = .5 * aks0;

                P->inv = s_inverse;

                P->fwd = s_forward;

        }

        return P;

}

ENTRY1(tmerc, en)

ENDENTRY(setup(P))

ENTRY1(utm, en)

        int zone;

        if (!P->es) E_ERROR(-34);

        P->y0 = pj_param(P->params, "bsouth").i ? 10000000. : 0.;

        P->x0 = 500000.;

        if (pj_param(P->params, "tzone").i) /* zone input ? */

                if ((zone = pj_param(P->params, "izone").i) > 0 && zone <= 60)

                        --zone;

                else

                        E_ERROR(-35)

        else /* nearest central meridian input */

                if ((zone = floor((adjlon(P->lam0) + PI) * 30. / PI)) < 0)

                        zone = 0;

                else if (zone >= 60)

                        zone = 59;

        P->lam0 = (zone + .5) * PI / 30. - PI;

        P->k0 = 0.9996;

        P->phi0 = 0.;

ENDENTRY(setup(P))