aboutsummaryrefslogtreecommitdiff
path: root/src/PJ_somerc.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/PJ_somerc.c')
-rw-r--r--src/PJ_somerc.c219
1 files changed, 159 insertions, 60 deletions
diff --git a/src/PJ_somerc.c b/src/PJ_somerc.c
index f7d1f119..e7659876 100644
--- a/src/PJ_somerc.c
+++ b/src/PJ_somerc.c
@@ -1,66 +1,165 @@
-#define PROJ_PARMS__ \
- double K, c, hlf_e, kR, cosp0, sinp0;
#define PJ_LIB__
-#include <projects.h>
+#include <projects.h>
+
PROJ_HEAD(somerc, "Swiss. Obl. Mercator") "\n\tCyl, Ell\n\tFor CH1903";
-#define EPS 1.e-10
+
+struct pj_opaque {
+ double K, c, hlf_e, kR, cosp0, sinp0;
+};
+
+#define EPS 1.e-10
#define NITER 6
-FORWARD(e_forward);
- double phip, lamp, phipp, lampp, sp, cp;
-
- sp = P->e * sin(lp.phi);
- phip = 2.* atan( exp( P->c * (
- log(tan(FORTPI + 0.5 * lp.phi)) - P->hlf_e * log((1. + sp)/(1. - sp)))
- + P->K)) - HALFPI;
- lamp = P->c * lp.lam;
- cp = cos(phip);
- phipp = aasin(P->ctx,P->cosp0 * sin(phip) - P->sinp0 * cp * cos(lamp));
- lampp = aasin(P->ctx,cp * sin(lamp) / cos(phipp));
- xy.x = P->kR * lampp;
- xy.y = P->kR * log(tan(FORTPI + 0.5 * phipp));
- return (xy);
+
+
+static XY e_forward (LP lp, PJ *P) { /* Ellipsoidal, forward */
+ XY xy = {0.0, 0.0};
+ double phip, lamp, phipp, lampp, sp, cp;
+ struct pj_opaque *Q = P->opaque;
+
+ sp = P->e * sin (lp.phi);
+ phip = 2.* atan ( exp ( Q->c * (
+ log (tan (FORTPI + 0.5 * lp.phi)) - Q->hlf_e * log ((1. + sp)/(1. - sp)))
+ + Q->K)) - HALFPI;
+ lamp = Q->c * lp.lam;
+ cp = cos(phip);
+ phipp = aasin (P->ctx, Q->cosp0 * sin (phip) - Q->sinp0 * cp * cos (lamp));
+ lampp = aasin (P->ctx, cp * sin (lamp) / cos (phipp));
+ xy.x = Q->kR * lampp;
+ xy.y = Q->kR * log (tan (FORTPI + 0.5 * phipp));
+ return xy;
}
-INVERSE(e_inverse); /* ellipsoid & spheroid */
- double phip, lamp, phipp, lampp, cp, esp, con, delp;
- int i;
-
- phipp = 2. * (atan(exp(xy.y / P->kR)) - FORTPI);
- lampp = xy.x / P->kR;
- cp = cos(phipp);
- phip = aasin(P->ctx,P->cosp0 * sin(phipp) + P->sinp0 * cp * cos(lampp));
- lamp = aasin(P->ctx,cp * sin(lampp) / cos(phip));
- con = (P->K - log(tan(FORTPI + 0.5 * phip)))/P->c;
- for (i = NITER; i ; --i) {
- esp = P->e * sin(phip);
- delp = (con + log(tan(FORTPI + 0.5 * phip)) - P->hlf_e *
- log((1. + esp)/(1. - esp)) ) *
- (1. - esp * esp) * cos(phip) * P->rone_es;
- phip -= delp;
- if (fabs(delp) < EPS)
- break;
- }
- if (i) {
- lp.phi = phip;
- lp.lam = lamp / P->c;
- } else
- I_ERROR
- return (lp);
+
+
+static LP e_inverse (XY xy, PJ *P) { /* Ellipsoidal, inverse */
+ LP lp = {0.0,0.0};
+ struct pj_opaque *Q = P->opaque;
+ double phip, lamp, phipp, lampp, cp, esp, con, delp;
+ int i;
+
+ phipp = 2. * (atan (exp (xy.y / Q->kR)) - FORTPI);
+ lampp = xy.x / Q->kR;
+ cp = cos (phipp);
+ phip = aasin (P->ctx, Q->cosp0 * sin (phipp) + Q->sinp0 * cp * cos (lampp));
+ lamp = aasin (P->ctx, cp * sin (lampp) / cos (phip));
+ con = (Q->K - log (tan (FORTPI + 0.5 * phip)))/Q->c;
+ for (i = NITER; i ; --i) {
+ esp = P->e * sin(phip);
+ delp = (con + log(tan(FORTPI + 0.5 * phip)) - Q->hlf_e *
+ log((1. + esp)/(1. - esp)) ) *
+ (1. - esp * esp) * cos(phip) * P->rone_es;
+ phip -= delp;
+ if (fabs(delp) < EPS)
+ break;
+ }
+ if (i) {
+ lp.phi = phip;
+ lp.lam = lamp / Q->c;
+ } else
+ I_ERROR
+ return (lp);
}
+
+
+#if 0
FREEUP; if (P) pj_dalloc(P); }
-ENTRY0(somerc)
- double cp, phip0, sp;
-
- P->hlf_e = 0.5 * P->e;
- cp = cos(P->phi0);
- cp *= cp;
- P->c = sqrt(1 + P->es * cp * cp * P->rone_es);
- sp = sin(P->phi0);
- P->cosp0 = cos( phip0 = aasin(P->ctx, P->sinp0 = sp / P->c) );
- sp *= P->e;
- P->K = log(tan(FORTPI + 0.5 * phip0)) - P->c * (
- log(tan(FORTPI + 0.5 * P->phi0)) - P->hlf_e *
- log((1. + sp) / (1. - sp)));
- P->kR = P->k0 * sqrt(P->one_es) / (1. - sp * sp);
- P->inv = e_inverse;
- P->fwd = e_forward;
-ENDENTRY(P)
+#endif
+
+
+static void *freeup_new (PJ *P) { /* Destructor */
+ if (0==P)
+ return 0;
+ if (0==P->opaque)
+ return pj_dealloc (P);
+ pj_dealloc (P->opaque);
+ return pj_dealloc(P);
+}
+
+static void freeup (PJ *P) {
+ freeup_new (P);
+ return;
+}
+
+
+PJ *PROJECTION(somerc) {
+ double cp, phip0, sp;
+ struct pj_opaque *Q = pj_calloc (1, sizeof (struct pj_opaque));
+ if (0==Q)
+ return freeup_new (P);
+ P->opaque = Q;
+
+
+ Q->hlf_e = 0.5 * P->e;
+ cp = cos (P->phi0);
+ cp *= cp;
+ Q->c = sqrt (1 + P->es * cp * cp * P->rone_es);
+ sp = sin (P->phi0);
+ Q->cosp0 = cos( phip0 = aasin (P->ctx, Q->sinp0 = sp / Q->c) );
+ sp *= P->e;
+ Q->K = log (tan (FORTPI + 0.5 * phip0)) - Q->c * (
+ log (tan (FORTPI + 0.5 * P->phi0)) - Q->hlf_e *
+ log ((1. + sp) / (1. - sp)));
+ Q->kR = P->k0 * sqrt(P->one_es) / (1. - sp * sp);
+ P->inv = e_inverse;
+ P->fwd = e_forward;
+ return P;
+}
+
+
+#ifdef PJ_OMIT_SELFTEST
+int pj_somerc_selftest (void) {return 0;}
+#else
+
+int pj_somerc_selftest (void) {
+ double tolerance_lp = 1e-10;
+ double tolerance_xy = 1e-7;
+
+ char e_args[] = {"+proj=somerc +ellps=GRS80 +lat_1=0.5 +lat_2=2 +n=0.5"};
+ char s_args[] = {"+proj=somerc +a=6400000 +lat_1=0.5 +lat_2=2 +n=0.5"};
+
+ LP fwd_in[] = {
+ { 2, 1},
+ { 2,-1},
+ {-2, 1},
+ {-2,-1}
+ };
+
+ XY e_fwd_expect[] = {
+ {222638.98158654713, 110579.96521824898},
+ {222638.98158654713, -110579.96521825089},
+ {-222638.98158654713, 110579.96521824898},
+ {-222638.98158654713, -110579.96521825089},
+ };
+
+ XY s_fwd_expect[] = {
+ {223402.14425527418, 111706.74357494408},
+ {223402.14425527418, -111706.74357494518},
+ {-223402.14425527418, 111706.74357494408},
+ {-223402.14425527418, -111706.74357494518},
+ };
+
+ XY inv_in[] = {
+ { 200, 100},
+ { 200,-100},
+ {-200, 100},
+ {-200,-100}
+ };
+
+ LP e_inv_expect[] = {
+ {0.0017966305682390426, 0.00090436947704129484},
+ {0.0017966305682390426, -0.00090436947704377105},
+ {-0.0017966305682390426, 0.00090436947704129484},
+ {-0.0017966305682390426, -0.00090436947704377105},
+ };
+
+ LP s_inv_expect[] = {
+ {0.0017904931097838226, 0.00089524655485801927},
+ {0.0017904931097838226, -0.00089524655484529714},
+ {-0.0017904931097838226, 0.00089524655485801927},
+ {-0.0017904931097838226, -0.00089524655484529714},
+ };
+
+ 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
generated by cgit v1.2.3 (git 2.25.1) at 2026-08-14 11:27:21 +0000