242 lines
6.3 KiB
JavaScript
242 lines
6.3 KiB
JavaScript
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import tsfnz from '../common/tsfnz';
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import adjust_lon from '../common/adjust_lon';
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import phi2z from '../common/phi2z';
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import { D2R, EPSLN, HALF_PI, TWO_PI, FORTPI } from '../constants/values';
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var TOL = 1e-7;
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function isTypeA(P) {
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var typeAProjections = ['Hotine_Oblique_Mercator','Hotine_Oblique_Mercator_Azimuth_Natural_Origin'];
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var projectionName = typeof P.PROJECTION === "object" ? Object.keys(P.PROJECTION)[0] : P.PROJECTION;
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return 'no_uoff' in P || 'no_off' in P || typeAProjections.indexOf(projectionName) !== -1;
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}
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/* Initialize the Oblique Mercator projection
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------------------------------------------*/
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export function init() {
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var con, com, cosph0, D, F, H, L, sinph0, p, J, gamma = 0,
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gamma0, lamc = 0, lam1 = 0, lam2 = 0, phi1 = 0, phi2 = 0, alpha_c = 0, AB;
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// only Type A uses the no_off or no_uoff property
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// https://github.com/OSGeo/proj.4/issues/104
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this.no_off = isTypeA(this);
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this.no_rot = 'no_rot' in this;
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var alp = false;
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if ("alpha" in this) {
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alp = true;
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}
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var gam = false;
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if ("rectified_grid_angle" in this) {
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gam = true;
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}
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if (alp) {
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alpha_c = this.alpha;
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}
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if (gam) {
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gamma = (this.rectified_grid_angle * D2R);
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}
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if (alp || gam) {
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lamc = this.longc;
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} else {
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lam1 = this.long1;
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phi1 = this.lat1;
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lam2 = this.long2;
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phi2 = this.lat2;
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if (Math.abs(phi1 - phi2) <= TOL || (con = Math.abs(phi1)) <= TOL ||
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Math.abs(con - HALF_PI) <= TOL || Math.abs(Math.abs(this.lat0) - HALF_PI) <= TOL ||
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Math.abs(Math.abs(phi2) - HALF_PI) <= TOL) {
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throw new Error();
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}
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}
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var one_es = 1.0 - this.es;
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com = Math.sqrt(one_es);
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if (Math.abs(this.lat0) > EPSLN) {
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sinph0 = Math.sin(this.lat0);
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cosph0 = Math.cos(this.lat0);
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con = 1 - this.es * sinph0 * sinph0;
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this.B = cosph0 * cosph0;
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this.B = Math.sqrt(1 + this.es * this.B * this.B / one_es);
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this.A = this.B * this.k0 * com / con;
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D = this.B * com / (cosph0 * Math.sqrt(con));
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F = D * D -1;
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if (F <= 0) {
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F = 0;
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} else {
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F = Math.sqrt(F);
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if (this.lat0 < 0) {
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F = -F;
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}
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}
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this.E = F += D;
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this.E *= Math.pow(tsfnz(this.e, this.lat0, sinph0), this.B);
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} else {
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this.B = 1 / com;
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this.A = this.k0;
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this.E = D = F = 1;
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}
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if (alp || gam) {
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if (alp) {
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gamma0 = Math.asin(Math.sin(alpha_c) / D);
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if (!gam) {
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gamma = alpha_c;
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}
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} else {
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gamma0 = gamma;
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alpha_c = Math.asin(D * Math.sin(gamma0));
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}
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this.lam0 = lamc - Math.asin(0.5 * (F - 1 / F) * Math.tan(gamma0)) / this.B;
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} else {
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H = Math.pow(tsfnz(this.e, phi1, Math.sin(phi1)), this.B);
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L = Math.pow(tsfnz(this.e, phi2, Math.sin(phi2)), this.B);
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F = this.E / H;
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p = (L - H) / (L + H);
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J = this.E * this.E;
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J = (J - L * H) / (J + L * H);
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con = lam1 - lam2;
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if (con < -Math.pi) {
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lam2 -=TWO_PI;
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} else if (con > Math.pi) {
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lam2 += TWO_PI;
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}
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this.lam0 = adjust_lon(0.5 * (lam1 + lam2) - Math.atan(J * Math.tan(0.5 * this.B * (lam1 - lam2)) / p) / this.B);
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gamma0 = Math.atan(2 * Math.sin(this.B * adjust_lon(lam1 - this.lam0)) / (F - 1 / F));
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gamma = alpha_c = Math.asin(D * Math.sin(gamma0));
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}
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this.singam = Math.sin(gamma0);
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this.cosgam = Math.cos(gamma0);
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this.sinrot = Math.sin(gamma);
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this.cosrot = Math.cos(gamma);
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this.rB = 1 / this.B;
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this.ArB = this.A * this.rB;
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this.BrA = 1 / this.ArB;
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AB = this.A * this.B;
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if (this.no_off) {
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this.u_0 = 0;
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} else {
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this.u_0 = Math.abs(this.ArB * Math.atan(Math.sqrt(D * D - 1) / Math.cos(alpha_c)));
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if (this.lat0 < 0) {
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this.u_0 = - this.u_0;
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}
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}
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F = 0.5 * gamma0;
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this.v_pole_n = this.ArB * Math.log(Math.tan(FORTPI - F));
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this.v_pole_s = this.ArB * Math.log(Math.tan(FORTPI + F));
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}
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/* Oblique Mercator forward equations--mapping lat,long to x,y
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----------------------------------------------------------*/
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export function forward(p) {
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var coords = {};
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var S, T, U, V, W, temp, u, v;
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p.x = p.x - this.lam0;
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if (Math.abs(Math.abs(p.y) - HALF_PI) > EPSLN) {
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W = this.E / Math.pow(tsfnz(this.e, p.y, Math.sin(p.y)), this.B);
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temp = 1 / W;
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S = 0.5 * (W - temp);
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T = 0.5 * (W + temp);
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V = Math.sin(this.B * p.x);
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U = (S * this.singam - V * this.cosgam) / T;
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if (Math.abs(Math.abs(U) - 1.0) < EPSLN) {
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throw new Error();
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}
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v = 0.5 * this.ArB * Math.log((1 - U)/(1 + U));
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temp = Math.cos(this.B * p.x);
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if (Math.abs(temp) < TOL) {
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u = this.A * p.x;
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} else {
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u = this.ArB * Math.atan2((S * this.cosgam + V * this.singam), temp);
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}
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} else {
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v = p.y > 0 ? this.v_pole_n : this.v_pole_s;
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u = this.ArB * p.y;
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}
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if (this.no_rot) {
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coords.x = u;
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coords.y = v;
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} else {
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u -= this.u_0;
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coords.x = v * this.cosrot + u * this.sinrot;
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coords.y = u * this.cosrot - v * this.sinrot;
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}
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coords.x = (this.a * coords.x + this.x0);
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coords.y = (this.a * coords.y + this.y0);
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return coords;
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}
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export function inverse(p) {
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var u, v, Qp, Sp, Tp, Vp, Up;
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var coords = {};
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p.x = (p.x - this.x0) * (1.0 / this.a);
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p.y = (p.y - this.y0) * (1.0 / this.a);
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if (this.no_rot) {
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v = p.y;
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u = p.x;
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} else {
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v = p.x * this.cosrot - p.y * this.sinrot;
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u = p.y * this.cosrot + p.x * this.sinrot + this.u_0;
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}
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Qp = Math.exp(-this.BrA * v);
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Sp = 0.5 * (Qp - 1 / Qp);
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Tp = 0.5 * (Qp + 1 / Qp);
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Vp = Math.sin(this.BrA * u);
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Up = (Vp * this.cosgam + Sp * this.singam) / Tp;
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if (Math.abs(Math.abs(Up) - 1) < EPSLN) {
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coords.x = 0;
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coords.y = Up < 0 ? -HALF_PI : HALF_PI;
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} else {
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coords.y = this.E / Math.sqrt((1 + Up) / (1 - Up));
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coords.y = phi2z(this.e, Math.pow(coords.y, 1 / this.B));
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if (coords.y === Infinity) {
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throw new Error();
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}
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coords.x = -this.rB * Math.atan2((Sp * this.cosgam - Vp * this.singam), Math.cos(this.BrA * u));
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}
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coords.x += this.lam0;
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return coords;
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}
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export var names = ["Hotine_Oblique_Mercator", "Hotine Oblique Mercator", "Hotine_Oblique_Mercator_Azimuth_Natural_Origin", "Hotine_Oblique_Mercator_Two_Point_Natural_Origin", "Hotine_Oblique_Mercator_Azimuth_Center", "Oblique_Mercator", "omerc"];
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export default {
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init: init,
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forward: forward,
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inverse: inverse,
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names: names
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};
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