#include <errno.h>

#include <math.h>

#include "proj.h"

#include "proj_internal.h"

namespace { // anonymous namespace

struct pj_putp5_data {

    double A, B;

};

} // anonymous namespace

PROJ_HEAD(putp5, "Putnins P5") "\n\tPCyl, Sph";

PROJ_HEAD(putp5p, "Putnins P5'") "\n\tPCyl, Sph";

#define C 1.01346

#define D 1.2158542

static PJ_XY putp5_s_forward(PJ_LP lp, PJ *P) { /* Spheroidal, forward */

    PJ_XY xy = {0.0, 0.0};

    struct pj_putp5_data *Q = static_cast<struct pj_putp5_data *>(P->opaque);

    xy.x = C * lp.lam * (Q->A - Q->B * sqrt(1. + D * lp.phi * lp.phi));

    xy.y = C * lp.phi;

    return xy;

}

static PJ_LP putp5_s_inverse(PJ_XY xy, PJ *P) { /* Spheroidal, inverse */

    PJ_LP lp = {0.0, 0.0};

    struct pj_putp5_data *Q = static_cast<struct pj_putp5_data *>(P->opaque);

    lp.phi = xy.y / C;

    lp.lam = xy.x / (C * (Q->A - Q->B * sqrt(1. + D * lp.phi * lp.phi)));

    return lp;

}

PJ *PJ_PROJECTION(putp5) {

    struct pj_putp5_data *Q = static_cast<struct pj_putp5_data *>(

        calloc(1, sizeof(struct pj_putp5_data)));

    if (nullptr == Q)

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

    P->opaque = Q;

    Q->A = 2.;

    Q->B = 1.;

    P->es = 0.;

    P->inv = putp5_s_inverse;

    P->fwd = putp5_s_forward;

    return P;

}

PJ *PJ_PROJECTION(putp5p) {

    struct pj_putp5_data *Q = static_cast<struct pj_putp5_data *>(

        calloc(1, sizeof(struct pj_putp5_data)));

    if (nullptr == Q)

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

    P->opaque = Q;

    Q->A = 1.5;

    Q->B = 0.5;

    P->es = 0.;

    P->inv = putp5_s_inverse;

    P->fwd = putp5_s_forward;

    return P;

}

#undef C

#undef D