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#define PJ_LIB__
#include <errno.h>
#include <math.h>
#include <stddef.h>
#include <string.h>
#include "proj.h"
#include "projects.h"
namespace { // anonymous namespace
struct pj_opaque {
struct PJconsts *link;
double lamp;
double cphip, sphip;
};
} // anonymous namespace
PROJ_HEAD(ob_tran, "General Oblique Transformation") "\n\tMisc Sph"
"\n\to_proj= plus parameters for projection"
"\n\to_lat_p= o_lon_p= (new pole) or"
"\n\to_alpha= o_lon_c= o_lat_c= or"
"\n\to_lon_1= o_lat_1= o_lon_2= o_lat_2=";
#define TOL 1e-10
static XY o_forward(LP lp, PJ *P) { /* spheroid */
struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque);
double coslam, sinphi, cosphi;
coslam = cos(lp.lam);
sinphi = sin(lp.phi);
cosphi = cos(lp.phi);
lp.lam = adjlon(aatan2(cosphi * sin(lp.lam), Q->sphip * cosphi * coslam +
Q->cphip * sinphi) + Q->lamp);
lp.phi = aasin(P->ctx,Q->sphip * sinphi - Q->cphip * cosphi * coslam);
return Q->link->fwd(lp, Q->link);
}
static XY t_forward(LP lp, PJ *P) { /* spheroid */
struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque);
double cosphi, coslam;
cosphi = cos(lp.phi);
coslam = cos(lp.lam);
lp.lam = adjlon(aatan2(cosphi * sin(lp.lam), sin(lp.phi)) + Q->lamp);
lp.phi = aasin(P->ctx, - cosphi * coslam);
return Q->link->fwd(lp, Q->link);
}
static LP o_inverse(XY xy, PJ *P) { /* spheroid */
struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque);
double coslam, sinphi, cosphi;
LP lp = Q->link->inv(xy, Q->link);
if (lp.lam != HUGE_VAL) {
coslam = cos(lp.lam -= Q->lamp);
sinphi = sin(lp.phi);
cosphi = cos(lp.phi);
lp.phi = aasin(P->ctx,Q->sphip * sinphi + Q->cphip * cosphi * coslam);
lp.lam = aatan2(cosphi * sin(lp.lam), Q->sphip * cosphi * coslam -
Q->cphip * sinphi);
}
return lp;
}
static LP t_inverse(XY xy, PJ *P) { /* spheroid */
struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque);
double cosphi, t;
LP lp = Q->link->inv(xy, Q->link);
if (lp.lam != HUGE_VAL) {
cosphi = cos(lp.phi);
t = lp.lam - Q->lamp;
lp.lam = aatan2(cosphi * sin(t), - sin(lp.phi));
lp.phi = aasin(P->ctx,cosphi * cos(t));
}
return lp;
}
static PJ *destructor(PJ *P, int errlev) {
if (nullptr==P)
return nullptr;
if (nullptr==P->opaque)
return pj_default_destructor (P, errlev);
if (static_cast<struct pj_opaque*>(P->opaque)->link)
static_cast<struct pj_opaque*>(P->opaque)->link->destructor (static_cast<struct pj_opaque*>(P->opaque)->link, errlev);
return pj_default_destructor(P, errlev);
}
/***********************************************************************
These functions are modified versions of the functions "argc_params"
and "argv_params" from PJ_pipeline.c
Basically, they do the somewhat backwards stunt of turning the paralist
representation of the +args back into the original +argv, +argc
representation accepted by pj_init_ctx().
This, however, also begs the question of whether we really need the
paralist linked list representation, or if we could do with a simpler
null-terminated argv style array? This would simplfy some code, and
keep memory allocations more localized.
***********************************************************************/
typedef struct {int argc; char **argv;} ARGS;
/* count the number of args in the linked list <params> */
static size_t paralist_params_argc (paralist *params) {
size_t argc = 0;
for (; params != nullptr; params = params->next)
argc++;
return argc;
}
/* turn paralist into argc/argv style argument list */
static ARGS ob_tran_target_params (paralist *params) {
int i = 0;
ARGS args = {0, nullptr};
size_t argc = paralist_params_argc (params);
if (argc < 2)
return args;
/* all args except the proj_ob_tran */
args.argv = static_cast<char**>(pj_calloc (argc - 1, sizeof (char *)));
if (nullptr==args.argv)
return args;
/* Copy all args *except* the proj=ob_tran arg to the argv array */
for (i = 0; params != nullptr; params = params->next) {
if (0==strcmp (params->param, "proj=ob_tran"))
continue;
args.argv[i++] = params->param;
}
args.argc = i;
/* Then convert the o_proj=xxx element to proj=xxx */
for (i = 0; i < args.argc; i++) {
if (0!=strncmp (args.argv[i], "o_proj=", 7))
continue;
args.argv[i] += 2;
break;
}
return args;
}
PJ *PROJECTION(ob_tran) {
double phip;
char *name;
ARGS args;
PJ *R; /* projection to rotate */
struct pj_opaque *Q = static_cast<struct pj_opaque*>(pj_calloc (1, sizeof (struct pj_opaque)));
if (nullptr==Q)
return destructor(P, ENOMEM);
P->opaque = Q;
P->destructor = destructor;
/* get name of projection to be translated */
if (!(name = pj_param(P->ctx, P->params, "so_proj").s))
return destructor(P, PJD_ERR_NO_ROTATION_PROJ);
/* avoid endless recursion */
if( strcmp(name, "ob_tran") == 0 )
return destructor(P, PJD_ERR_FAILED_TO_FIND_PROJ);
/* Create the target projection object to rotate */
args = ob_tran_target_params (P->params);
R = pj_init_ctx (pj_get_ctx(P), args.argc, args.argv);
pj_dealloc (args.argv);
if (nullptr==R)
return destructor (P, PJD_ERR_UNKNOWN_PROJECTION_ID);
Q->link = R;
if (pj_param(P->ctx, P->params, "to_alpha").i) {
double lamc, phic, alpha;
lamc = pj_param(P->ctx, P->params, "ro_lon_c").f;
phic = pj_param(P->ctx, P->params, "ro_lat_c").f;
alpha = pj_param(P->ctx, P->params, "ro_alpha").f;
if (fabs(fabs(phic) - M_HALFPI) <= TOL)
return destructor(P, PJD_ERR_LAT_0_OR_ALPHA_EQ_90);
Q->lamp = lamc + aatan2(-cos(alpha), -sin(alpha) * sin(phic));
phip = aasin(P->ctx,cos(phic) * sin(alpha));
} else if (pj_param(P->ctx, P->params, "to_lat_p").i) { /* specified new pole */
Q->lamp = pj_param(P->ctx, P->params, "ro_lon_p").f;
phip = pj_param(P->ctx, P->params, "ro_lat_p").f;
} else { /* specified new "equator" points */
double lam1, lam2, phi1, phi2, con;
lam1 = pj_param(P->ctx, P->params, "ro_lon_1").f;
phi1 = pj_param(P->ctx, P->params, "ro_lat_1").f;
lam2 = pj_param(P->ctx, P->params, "ro_lon_2").f;
phi2 = pj_param(P->ctx, P->params, "ro_lat_2").f;
if (fabs(phi1 - phi2) <= TOL || (con = fabs(phi1)) <= TOL ||
fabs(con - M_HALFPI) <= TOL || fabs(fabs(phi2) - M_HALFPI) <= TOL)
return destructor(P, PJD_ERR_LAT_1_OR_2_ZERO_OR_90);
Q->lamp = atan2(cos(phi1) * sin(phi2) * cos(lam1) -
sin(phi1) * cos(phi2) * cos(lam2),
sin(phi1) * cos(phi2) * sin(lam2) -
cos(phi1) * sin(phi2) * sin(lam1));
phip = atan(-cos(Q->lamp - lam1) / tan(phi1));
}
if (fabs(phip) > TOL) { /* oblique */
Q->cphip = cos(phip);
Q->sphip = sin(phip);
P->fwd = Q->link->fwd ? o_forward : nullptr;
P->inv = Q->link->inv ? o_inverse : nullptr;
} else { /* transverse */
P->fwd = Q->link->fwd ? t_forward : nullptr;
P->inv = Q->link->inv ? t_inverse : nullptr;
}
/* Support some rather speculative test cases, where the rotated projection */
/* is actually latlong. We do not want scaling in that case... */
if (Q->link->right==PJ_IO_UNITS_ANGULAR)
P->right = PJ_IO_UNITS_PROJECTED;
return P;
}
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