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#define PJ_LIB__
#include <errno.h>
#include <math.h>
#include "proj.h"
#include "proj_internal.h"
PROJ_HEAD(urm5, "Urmaev V") "\n\tPCyl, Sph, no inv\n\tn= q= alpha=";
namespace { // anonymous namespace
struct pj_opaque {
double m, rmn, q3, n;
};
} // anonymous namespace
static PJ_XY urm5_s_forward (PJ_LP lp, PJ *P) { /* Spheroidal, forward */
PJ_XY xy = {0.0, 0.0};
struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque);
double t;
t = lp.phi = aasin (P->ctx, Q->n * sin (lp.phi));
xy.x = Q->m * lp.lam * cos (lp.phi);
t *= t;
xy.y = lp.phi * (1. + t * Q->q3) * Q->rmn;
return xy;
}
PJ *PROJECTION(urm5) {
double alpha, t;
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;
if (pj_param(P->ctx, P->params, "tn").i) {
Q->n = pj_param(P->ctx, P->params, "dn").f;
if (Q->n <= 0. || Q->n > 1.)
return pj_default_destructor(P, PJD_ERR_N_OUT_OF_RANGE);
} else {
return pj_default_destructor(P, PJD_ERR_N_OUT_OF_RANGE);
}
Q->q3 = pj_param(P->ctx, P->params, "dq").f / 3.;
alpha = pj_param(P->ctx, P->params, "ralpha").f;
t = Q->n * sin (alpha);
const double denom = sqrt (1. - t * t);
if( denom == 0 ) {
return pj_default_destructor(P, PJD_ERR_LAT_0_OR_ALPHA_EQ_90);
}
Q->m = cos (alpha) / denom;
Q->rmn = 1. / (Q->m * Q->n);
P->es = 0.;
P->inv = nullptr;
P->fwd = urm5_s_forward;
return P;
}
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