#include <math.h>

#include "proj.h"

#include "proj_internal.h"

PROJ_HEAD(cc, "Central Cylindrical") "\n\tCyl, Sph";

#define EPS10 1.e-10

static PJ_XY cc_s_forward(PJ_LP lp, PJ *P) { /* Spheroidal, forward */

    PJ_XY xy = {0.0, 0.0};

    if (fabs(fabs(lp.phi) - M_HALFPI) <= EPS10) {

        proj_errno_set(P, PROJ_ERR_COORD_TRANSFM_OUTSIDE_PROJECTION_DOMAIN);

        return xy;

    }

    xy.x = lp.lam;

    xy.y = tan(lp.phi);

    return xy;

}

static PJ_LP cc_s_inverse(PJ_XY xy, PJ *P) { /* Spheroidal, inverse */

    PJ_LP lp = {0.0, 0.0};

    (void)P;

    lp.phi = atan(xy.y);

    lp.lam = xy.x;

    return lp;

}

PJ *PJ_PROJECTION(cc) {

    P->es = 0.;

    P->inv = cc_s_inverse;

    P->fwd = cc_s_forward;

    return P;

}