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#define PJ_LIB__
#include <errno.h>
#include <math.h>
#include "proj.h"
#include "proj_internal.h"
namespace { // anonymous namespace
struct pj_opaque {
double qp;
double *apa;
};
} // anonymous namespace
PROJ_HEAD(cea, "Equal Area Cylindrical") "\n\tCyl, Sph&Ell\n\tlat_ts=";
# define EPS 1e-10
static PJ_XY cea_e_forward (PJ_LP lp, PJ *P) { /* Ellipsoidal, forward */
PJ_XY xy = {0.0,0.0};
xy.x = P->k0 * lp.lam;
xy.y = 0.5 * pj_qsfn (sin (lp.phi), P->e, P->one_es) / P->k0;
return xy;
}
static PJ_XY cea_s_forward (PJ_LP lp, PJ *P) { /* Spheroidal, forward */
PJ_XY xy = {0.0,0.0};
xy.x = P->k0 * lp.lam;
xy.y = sin(lp.phi) / P->k0;
return xy;
}
static PJ_LP cea_e_inverse (PJ_XY xy, PJ *P) { /* Ellipsoidal, inverse */
PJ_LP lp = {0.0,0.0};
lp.phi = pj_authlat(asin( 2. * xy.y * P->k0 / static_cast<struct pj_opaque*>(P->opaque)->qp), static_cast<struct pj_opaque*>(P->opaque)->apa);
lp.lam = xy.x / P->k0;
return lp;
}
static PJ_LP cea_s_inverse (PJ_XY xy, PJ *P) { /* Spheroidal, inverse */
PJ_LP lp = {0.0,0.0};
xy.y *= P->k0;
const double t = fabs(xy.y);
if (t - EPS <= 1.) {
if (t >= 1.)
lp.phi = xy.y < 0. ? -M_HALFPI : M_HALFPI;
else
lp.phi = asin(xy.y);
lp.lam = xy.x / P->k0;
} else {
proj_errno_set(P, PROJ_ERR_COORD_TRANSFM_OUTSIDE_PROJECTION_DOMAIN);
return lp;
}
return (lp);
}
static PJ *destructor (PJ *P, int errlev) { /* Destructor */
if (nullptr==P)
return nullptr;
if (nullptr==P->opaque)
return pj_default_destructor (P, errlev);
free (static_cast<struct pj_opaque*>(P->opaque)->apa);
return pj_default_destructor (P, errlev);
}
PJ *PROJECTION(cea) {
double t = 0.0;
struct pj_opaque *Q = static_cast<struct pj_opaque*>(calloc (1, sizeof (struct pj_opaque)));
if (nullptr==Q)
return pj_default_destructor (P, PROJ_ERR_INVALID_OP /*ENOMEM*/);
P->opaque = Q;
P->destructor = destructor;
if (pj_param(P->ctx, P->params, "tlat_ts").i) {
t = pj_param(P->ctx, P->params, "rlat_ts").f;
P->k0 = cos(t);
if (P->k0 < 0.)
{
proj_log_error(P, _("Invalid value for lat_ts: |lat_ts| should be <= 90°"));
return pj_default_destructor(P, PROJ_ERR_INVALID_OP_ILLEGAL_ARG_VALUE);
}
}
if (P->es != 0.0) {
t = sin(t);
P->k0 /= sqrt(1. - P->es * t * t);
P->e = sqrt(P->es);
Q->apa = pj_authset(P->es);
if (!(Q->apa))
return pj_default_destructor(P, PROJ_ERR_INVALID_OP /*ENOMEM*/);
Q->qp = pj_qsfn(1., P->e, P->one_es);
P->inv = cea_e_inverse;
P->fwd = cea_e_forward;
} else {
P->inv = cea_s_inverse;
P->fwd = cea_s_forward;
}
return P;
}
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