#define PJ_LIB__ #include PROJ_HEAD(nicol, "Nicolosi Globular") "\n\tMisc Sph, no inv."; #define EPS 1e-10 FORWARD(s_forward); /* spheroid */ (void) P; if (fabs(lp.lam) < EPS) { xy.x = 0; xy.y = lp.phi; } else if (fabs(lp.phi) < EPS) { xy.x = lp.lam; xy.y = 0.; } else if (fabs(fabs(lp.lam) - HALFPI) < EPS) { xy.x = lp.lam * cos(lp.phi); xy.y = HALFPI * sin(lp.phi); } else if (fabs(fabs(lp.phi) - HALFPI) < EPS) { xy.x = 0; xy.y = lp.phi; } else { double tb, c, d, m, n, r2, sp; tb = HALFPI / lp.lam - lp.lam / HALFPI; c = lp.phi / HALFPI; d = (1 - c * c)/((sp = sin(lp.phi)) - c); r2 = tb / d; r2 *= r2; m = (tb * sp / d - 0.5 * tb)/(1. + r2); n = (sp / r2 + 0.5 * d)/(1. + 1./r2); xy.x = cos(lp.phi); xy.x = sqrt(m * m + xy.x * xy.x / (1. + r2)); xy.x = HALFPI * ( m + (lp.lam < 0. ? -xy.x : xy.x)); xy.y = sqrt(n * n - (sp * sp / r2 + d * sp - 1.) / (1. + 1./r2)); xy.y = HALFPI * ( n + (lp.phi < 0. ? xy.y : -xy.y )); } return (xy); } FREEUP; if (P) pj_dalloc(P); } ENTRY0(nicol) P->es = 0.; P->fwd = s_forward; ENDENTRY(P)