#include <errno.h>

#include <math.h>

#include "proj.h"

#include "proj_internal.h"

PROJ_HEAD(wink1, "Winkel I") "\n\tPCyl, Sph\n\tlat_ts=";

namespace { // anonymous namespace

struct pj_wink1_data {

    double cosphi1;

};

} // anonymous namespace

static PJ_XY wink1_s_forward(PJ_LP lp, PJ *P) { /* Spheroidal, forward */

    PJ_XY xy = {0.0, 0.0};

    xy.x =

        .5 * lp.lam *

        (static_cast<struct pj_wink1_data *>(P->opaque)->cosphi1 + cos(lp.phi));

    xy.y = lp.phi;

    return (xy);

}

static PJ_LP wink1_s_inverse(PJ_XY xy, PJ *P) { /* Spheroidal, inverse */

    PJ_LP lp = {0.0, 0.0};

    lp.phi = xy.y;

    lp.lam =

        2. * xy.x /

        (static_cast<struct pj_wink1_data *>(P->opaque)->cosphi1 + cos(lp.phi));

    return (lp);

}

PJ *PJ_PROJECTION(wink1) {

    struct pj_wink1_data *Q = static_cast<struct pj_wink1_data *>(

        calloc(1, sizeof(struct pj_wink1_data)));

    if (nullptr == Q)

        return pj_default_destructor(P, PROJ_ERR_OTHER /*ENOMEM*/);

    P->opaque = Q;

    static_cast<struct pj_wink1_data *>(P->opaque)->cosphi1 =

        cos(pj_param(P->ctx, P->params, "rlat_ts").f);

    P->es = 0.;

    P->inv = wink1_s_inverse;

    P->fwd = wink1_s_forward;

    return P;

}