diff options
Diffstat (limited to 'src/3rdparty/proj/PJ_cea.c')
-rw-r--r-- | src/3rdparty/proj/PJ_cea.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/src/3rdparty/proj/PJ_cea.c b/src/3rdparty/proj/PJ_cea.c new file mode 100644 index 00000000..97e4f3aa --- /dev/null +++ b/src/3rdparty/proj/PJ_cea.c @@ -0,0 +1,61 @@ +#define PROJ_PARMS__ \ + double qp; \ + double *apa; +#define PJ_LIB__ +# include <projects.h> +PROJ_HEAD(cea, "Equal Area Cylindrical") "\n\tCyl, Sph&Ell\n\tlat_ts="; +# define EPS 1e-10 +FORWARD(e_forward); /* spheroid */ + xy.x = P->k0 * lp.lam; + xy.y = .5 * pj_qsfn(sin(lp.phi), P->e, P->one_es) / P->k0; + return (xy); +} +FORWARD(s_forward); /* spheroid */ + xy.x = P->k0 * lp.lam; + xy.y = sin(lp.phi) / P->k0; + return (xy); +} +INVERSE(e_inverse); /* spheroid */ + lp.phi = pj_authlat(asin( 2. * xy.y * P->k0 / P->qp), P->apa); + lp.lam = xy.x / P->k0; + return (lp); +} +INVERSE(s_inverse); /* spheroid */ + double t; + + if ((t = fabs(xy.y *= P->k0)) - EPS <= 1.) { + if (t >= 1.) + lp.phi = xy.y < 0. ? -HALFPI : HALFPI; + else + lp.phi = asin(xy.y); + lp.lam = xy.x / P->k0; + } else I_ERROR; + return (lp); +} +FREEUP; + if (P) { + if (P->apa) + pj_dalloc(P->apa); + pj_dalloc(P); + } +} +ENTRY1(cea, apa) + double t; + + if (pj_param(P->params, "tlat_ts").i && + (P->k0 = cos(t = pj_param(P->params, "rlat_ts").f)) < 0.) E_ERROR(-24) + else + t = 0.; + if (P->es) { + t = sin(t); + P->k0 /= sqrt(1. - P->es * t * t); + P->e = sqrt(P->es); + if (!(P->apa = pj_authset(P->es))) E_ERROR_0; + P->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; + } +ENDENTRY(P) |