#define PJ_LIB__

#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_opaque {
	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_opaque*>(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_opaque*>(P->opaque)->cosphi1 + cos(lp.phi));
	return (lp);
}


PJ *PROJECTION(wink1) {
    struct pj_opaque *Q = static_cast<struct pj_opaque*>(pj_calloc (1, sizeof (struct pj_opaque)));
    if (nullptr==Q)
        return pj_default_destructor(P, ENOMEM);
    P->opaque = Q;

	static_cast<struct pj_opaque*>(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;
}