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Diffstat (limited to 'src/projections/omerc.cpp')
| -rw-r--r-- | src/projections/omerc.cpp | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/src/projections/omerc.cpp b/src/projections/omerc.cpp new file mode 100644 index 00000000..ead07128 --- /dev/null +++ b/src/projections/omerc.cpp @@ -0,0 +1,229 @@ +/* +** Copyright (c) 2003, 2006 Gerald I. Evenden +*/ +/* +** Permission is hereby granted, free of charge, to any person obtaining +** a copy of this software and associated documentation files (the +** "Software"), to deal in the Software without restriction, including +** without limitation the rights to use, copy, modify, merge, publish, +** distribute, sublicense, and/or sell copies of the Software, and to +** permit persons to whom the Software is furnished to do so, subject to +** the following conditions: +** +** The above copyright notice and this permission notice shall be +** included in all copies or substantial portions of the Software. +** +** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. +** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY +** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, +** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE +** SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. +*/ +#define PJ_LIB__ + +#include <errno.h> +#include <math.h> + +#include "proj.h" +#include "projects.h" + +PROJ_HEAD(omerc, "Oblique Mercator") + "\n\tCyl, Sph&Ell no_rot\n\t" + "alpha= [gamma=] [no_off] lonc= or\n\t lon_1= lat_1= lon_2= lat_2="; + +namespace { // anonymous namespace +struct pj_opaque { + double A, B, E, AB, ArB, BrA, rB, singam, cosgam, sinrot, cosrot; + double v_pole_n, v_pole_s, u_0; + int no_rot; +}; +} // anonymous namespace + +#define TOL 1.e-7 +#define EPS 1.e-10 + + +static XY e_forward (LP lp, PJ *P) { /* Ellipsoidal, forward */ + XY xy = {0.0,0.0}; + struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque); + double S, T, U, V, W, temp, u, v; + + if (fabs(fabs(lp.phi) - M_HALFPI) > EPS) { + W = Q->E / pow(pj_tsfn(lp.phi, sin(lp.phi), P->e), Q->B); + temp = 1. / W; + S = .5 * (W - temp); + T = .5 * (W + temp); + V = sin(Q->B * lp.lam); + U = (S * Q->singam - V * Q->cosgam) / T; + if (fabs(fabs(U) - 1.0) < EPS) { + proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION); + return xy; + } + v = 0.5 * Q->ArB * log((1. - U)/(1. + U)); + temp = cos(Q->B * lp.lam); + if(fabs(temp) < TOL) { + u = Q->A * lp.lam; + } else { + u = Q->ArB * atan2((S * Q->cosgam + V * Q->singam), temp); + } + } else { + v = lp.phi > 0 ? Q->v_pole_n : Q->v_pole_s; + u = Q->ArB * lp.phi; + } + if (Q->no_rot) { + xy.x = u; + xy.y = v; + } else { + u -= Q->u_0; + xy.x = v * Q->cosrot + u * Q->sinrot; + xy.y = u * Q->cosrot - v * Q->sinrot; + } + return xy; +} + + +static LP e_inverse (XY xy, PJ *P) { /* Ellipsoidal, inverse */ + LP lp = {0.0,0.0}; + struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque); + double u, v, Qp, Sp, Tp, Vp, Up; + + if (Q->no_rot) { + v = xy.y; + u = xy.x; + } else { + v = xy.x * Q->cosrot - xy.y * Q->sinrot; + u = xy.y * Q->cosrot + xy.x * Q->sinrot + Q->u_0; + } + Qp = exp(- Q->BrA * v); + Sp = .5 * (Qp - 1. / Qp); + Tp = .5 * (Qp + 1. / Qp); + Vp = sin(Q->BrA * u); + Up = (Vp * Q->cosgam + Sp * Q->singam) / Tp; + if (fabs(fabs(Up) - 1.) < EPS) { + lp.lam = 0.; + lp.phi = Up < 0. ? -M_HALFPI : M_HALFPI; + } else { + lp.phi = Q->E / sqrt((1. + Up) / (1. - Up)); + if ((lp.phi = pj_phi2(P->ctx, pow(lp.phi, 1. / Q->B), P->e)) == HUGE_VAL) { + proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION); + return lp; + } + lp.lam = - Q->rB * atan2((Sp * Q->cosgam - + Vp * Q->singam), cos(Q->BrA * u)); + } + return lp; +} + + +PJ *PROJECTION(omerc) { + double con, com, cosph0, D, F, H, L, sinph0, p, J, gamma=0, + gamma0, lamc=0, lam1=0, lam2=0, phi1=0, phi2=0, alpha_c=0; + int alp, gam, no_off = 0; + + struct pj_opaque *Q = static_cast<struct pj_opaque*>(pj_calloc (1, sizeof (struct pj_opaque))); + if (nullptr==Q) + return pj_default_destructor (P, ENOMEM); + P->opaque = Q; + + Q->no_rot = pj_param(P->ctx, P->params, "bno_rot").i; + if ((alp = pj_param(P->ctx, P->params, "talpha").i) != 0) + alpha_c = pj_param(P->ctx, P->params, "ralpha").f; + if ((gam = pj_param(P->ctx, P->params, "tgamma").i) != 0) + gamma = pj_param(P->ctx, P->params, "rgamma").f; + if (alp || gam) { + lamc = pj_param(P->ctx, P->params, "rlonc").f; + no_off = + /* For libproj4 compatibility */ + pj_param(P->ctx, P->params, "tno_off").i + /* for backward compatibility */ + || pj_param(P->ctx, P->params, "tno_uoff").i; + if( no_off ) + { + /* Mark the parameter as used, so that the pj_get_def() return them */ + pj_param(P->ctx, P->params, "sno_uoff"); + pj_param(P->ctx, P->params, "sno_off"); + } + } else { + lam1 = pj_param(P->ctx, P->params, "rlon_1").f; + phi1 = pj_param(P->ctx, P->params, "rlat_1").f; + lam2 = pj_param(P->ctx, P->params, "rlon_2").f; + phi2 = pj_param(P->ctx, P->params, "rlat_2").f; + if (fabs(phi1 - phi2) <= TOL || + (con = fabs(phi1)) <= TOL || + fabs(con - M_HALFPI) <= TOL || + fabs(fabs(P->phi0) - M_HALFPI) <= TOL || + fabs(fabs(phi2) - M_HALFPI) <= TOL) + return pj_default_destructor(P, PJD_ERR_LAT_0_OR_ALPHA_EQ_90); + } + com = sqrt(P->one_es); + if (fabs(P->phi0) > EPS) { + sinph0 = sin(P->phi0); + cosph0 = cos(P->phi0); + con = 1. - P->es * sinph0 * sinph0; + Q->B = cosph0 * cosph0; + Q->B = sqrt(1. + P->es * Q->B * Q->B / P->one_es); + Q->A = Q->B * P->k0 * com / con; + D = Q->B * com / (cosph0 * sqrt(con)); + if ((F = D * D - 1.) <= 0.) + F = 0.; + else { + F = sqrt(F); + if (P->phi0 < 0.) + F = -F; + } + Q->E = F += D; + Q->E *= pow(pj_tsfn(P->phi0, sinph0, P->e), Q->B); + } else { + Q->B = 1. / com; + Q->A = P->k0; + Q->E = D = F = 1.; + } + if (alp || gam) { + if (alp) { + gamma0 = aasin(P->ctx, sin(alpha_c) / D); + if (!gam) + gamma = alpha_c; + } else + alpha_c = aasin(P->ctx, D*sin(gamma0 = gamma)); + P->lam0 = lamc - aasin(P->ctx, .5 * (F - 1. / F) * + tan(gamma0)) / Q->B; + } else { + H = pow(pj_tsfn(phi1, sin(phi1), P->e), Q->B); + L = pow(pj_tsfn(phi2, sin(phi2), P->e), Q->B); + F = Q->E / H; + p = (L - H) / (L + H); + J = Q->E * Q->E; + J = (J - L * H) / (J + L * H); + if ((con = lam1 - lam2) < -M_PI) + lam2 -= M_TWOPI; + else if (con > M_PI) + lam2 += M_TWOPI; + P->lam0 = adjlon(.5 * (lam1 + lam2) - atan( + J * tan(.5 * Q->B * (lam1 - lam2)) / p) / Q->B); + gamma0 = atan(2. * sin(Q->B * adjlon(lam1 - P->lam0)) / + (F - 1. / F)); + gamma = alpha_c = aasin(P->ctx, D * sin(gamma0)); + } + Q->singam = sin(gamma0); + Q->cosgam = cos(gamma0); + Q->sinrot = sin(gamma); + Q->cosrot = cos(gamma); + Q->BrA = 1. / (Q->ArB = Q->A * (Q->rB = 1. / Q->B)); + Q->AB = Q->A * Q->B; + if (no_off) + Q->u_0 = 0; + else { + Q->u_0 = fabs(Q->ArB * atan(sqrt(D * D - 1.) / cos(alpha_c))); + if (P->phi0 < 0.) + Q->u_0 = - Q->u_0; + } + F = 0.5 * gamma0; + Q->v_pole_n = Q->ArB * log(tan(M_FORTPI - F)); + Q->v_pole_s = Q->ArB * log(tan(M_FORTPI + F)); + P->inv = e_inverse; + P->fwd = e_forward; + + return P; +} |