#define PROJ_PARMS__ \ double cosphi1; #define PJ_LIB__ # include PROJ_HEAD(wink2, "Winkel II") "\n\tPCyl., Sph., no inv.\n\tlat_1="; #define MAX_ITER 10 #define LOOP_TOL 1e-7 #define TWO_D_PI 0.636619772367581343 FORWARD(s_forward); /* spheroid */ double k, V; int i; xy.y = lp.phi * TWO_D_PI; k = PI * sin(lp.phi); lp.phi *= 1.8; for (i = MAX_ITER; i ; --i) { lp.phi -= V = (lp.phi + sin(lp.phi) - k) / (1. + cos(lp.phi)); if (fabs(V) < LOOP_TOL) break; } if (!i) lp.phi = (lp.phi < 0.) ? -HALFPI : HALFPI; else lp.phi *= 0.5; xy.x = 0.5 * lp.lam * (cos(lp.phi) + P->cosphi1); xy.y = FORTPI * (sin(lp.phi) + xy.y); return (xy); } FREEUP; if (P) pj_dalloc(P); } ENTRY0(wink2) P->cosphi1 = cos(pj_param(P->ctx, P->params, "rlat_1").f); P->es = 0.; P->inv = 0; P->fwd = s_forward; ENDENTRY(P)