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#define PJ_LIB__
#include <projects.h>
struct pj_opaque {
double qp;
double *apa;
};
PROJ_HEAD(cea, "Equal Area Cylindrical") "\n\tCyl, Sph&Ell\n\tlat_ts=";
# define EPS 1e-10
static XY e_forward (LP lp, PJ *P) { /* Ellipsoidal, forward */
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 XY s_forward (LP lp, PJ *P) { /* Spheroidal, forward */
XY xy = {0.0,0.0};
xy.x = P->k0 * lp.lam;
xy.y = sin(lp.phi) / P->k0;
return xy;
}
static LP e_inverse (XY xy, PJ *P) { /* Ellipsoidal, inverse */
LP lp = {0.0,0.0};
lp.phi = pj_authlat(asin( 2. * xy.y * P->k0 / P->opaque->qp), P->opaque->apa);
lp.lam = xy.x / P->k0;
return lp;
}
static LP s_inverse (XY xy, PJ *P) { /* Spheroidal, inverse */
LP lp = {0.0,0.0};
double t;
if ((t = fabs(xy.y *= P->k0)) - 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 I_ERROR;
return (lp);
}
static void *freeup_new (PJ *P) { /* Destructor */
if (0==P)
return 0;
if (0==P->opaque)
return pj_dealloc (P);
pj_dealloc (P->opaque->apa);
pj_dealloc (P->opaque);
return pj_dealloc (P);
}
static void freeup (PJ *P) {
freeup_new (P);
return;
}
PJ *PROJECTION(cea) {
double t = 0.0;
struct pj_opaque *Q = pj_calloc (1, sizeof (struct pj_opaque));
if (0==Q)
return freeup_new (P);
P->opaque = Q;
if (pj_param(P->ctx, P->params, "tlat_ts").i) {
P->k0 = cos(t = pj_param(P->ctx, P->params, "rlat_ts").f);
if (P->k0 < 0.) {
E_ERROR(-24);
}
}
if (P->es != 0.0) {
t = sin(t);
P->k0 /= sqrt(1. - P->es * t * t);
P->e = sqrt(P->es);
if (!(Q->apa = pj_authset(P->es))) E_ERROR_0;
Q->qp = pj_qsfn(1., P->e, P->one_es);
P->inv = e_inverse;
P->fwd = e_forward;
} else {
P->inv = s_inverse;
P->fwd = s_forward;
}
return P;
}
#ifndef PJ_SELFTEST
int pj_cea_selftest (void) {return 0;}
#else
int pj_cea_selftest (void) {
double tolerance_lp = 1e-10;
double tolerance_xy = 1e-7;
char e_args[] = {"+proj=cea +ellps=GRS80 +lat_1=0.5 +lat_2=2"};
char s_args[] = {"+proj=cea +R=6400000 +lat_1=0.5 +lat_2=2"};
LP fwd_in[] = {
{ 2, 1},
{ 2,-1},
{-2, 1},
{-2,-1}
};
XY e_fwd_expect[] = {
{ 222638.981586547132, 110568.812396267356},
{ 222638.981586547132, -110568.812396265886},
{-222638.981586547132, 110568.812396267356},
{-222638.981586547132, -110568.812396265886},
};
XY s_fwd_expect[] = {
{ 223402.144255274179, 111695.401198614476},
{ 223402.144255274179, -111695.401198614476},
{-223402.144255274179, 111695.401198614476},
{-223402.144255274179, -111695.401198614476},
};
XY inv_in[] = {
{ 200, 100},
{ 200,-100},
{-200, 100},
{-200,-100}
};
LP e_inv_expect[] = {
{ 0.00179663056823904264, 0.000904369476105564289},
{ 0.00179663056823904264, -0.000904369476105564289},
{-0.00179663056823904264, 0.000904369476105564289},
{-0.00179663056823904264, -0.000904369476105564289},
};
LP s_inv_expect[] = {
{ 0.00179049310978382265, 0.000895246554928338998},
{ 0.00179049310978382265, -0.000895246554928338998},
{-0.00179049310978382265, 0.000895246554928338998},
{-0.00179049310978382265, -0.000895246554928338998},
};
return pj_generic_selftest (e_args, s_args, tolerance_xy, tolerance_lp, 4, 4, fwd_in, e_fwd_expect, s_fwd_expect, inv_in, e_inv_expect, s_inv_expect);
}
#endif
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