node-red-contrib-tak-registration
Version:
A Node-RED node to register to TAK and to help wrap files as datapackages to send to TAK
72 lines (71 loc) • 2.77 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
// https://en.wikipedia.org/wiki/Rhumb_line
var helpers_1 = require("@turf/helpers");
var invariant_1 = require("@turf/invariant");
/**
* Takes two {@link Point|points} and finds the bearing angle between them along a Rhumb line
* i.e. the angle measured in degrees start the north line (0 degrees)
*
* @name rhumbBearing
* @param {Coord} start starting Point
* @param {Coord} end ending Point
* @param {Object} [options] Optional parameters
* @param {boolean} [options.final=false] calculates the final bearing if true
* @returns {number} bearing from north in decimal degrees, between -180 and 180 degrees (positive clockwise)
* @example
* var point1 = turf.point([-75.343, 39.984], {"marker-color": "#F00"});
* var point2 = turf.point([-75.534, 39.123], {"marker-color": "#00F"});
*
* var bearing = turf.rhumbBearing(point1, point2);
*
* //addToMap
* var addToMap = [point1, point2];
* point1.properties.bearing = bearing;
* point2.properties.bearing = bearing;
*/
function rhumbBearing(start, end, options) {
if (options === void 0) { options = {}; }
var bear360;
if (options.final) {
bear360 = calculateRhumbBearing(invariant_1.getCoord(end), invariant_1.getCoord(start));
}
else {
bear360 = calculateRhumbBearing(invariant_1.getCoord(start), invariant_1.getCoord(end));
}
var bear180 = bear360 > 180 ? -(360 - bear360) : bear360;
return bear180;
}
/**
* Returns the bearing from ‘this’ point to destination point along a rhumb line.
* Adapted from Geodesy: https://github.com/chrisveness/geodesy/blob/master/latlon-spherical.js
*
* @private
* @param {Array<number>} from - origin point.
* @param {Array<number>} to - destination point.
* @returns {number} Bearing in degrees from north.
* @example
* var p1 = new LatLon(51.127, 1.338);
* var p2 = new LatLon(50.964, 1.853);
* var d = p1.rhumbBearingTo(p2); // 116.7 m
*/
function calculateRhumbBearing(from, to) {
// φ => phi
// Δλ => deltaLambda
// Δψ => deltaPsi
// θ => theta
var phi1 = helpers_1.degreesToRadians(from[1]);
var phi2 = helpers_1.degreesToRadians(to[1]);
var deltaLambda = helpers_1.degreesToRadians(to[0] - from[0]);
// if deltaLambdaon over 180° take shorter rhumb line across the anti-meridian:
if (deltaLambda > Math.PI) {
deltaLambda -= 2 * Math.PI;
}
if (deltaLambda < -Math.PI) {
deltaLambda += 2 * Math.PI;
}
var deltaPsi = Math.log(Math.tan(phi2 / 2 + Math.PI / 4) / Math.tan(phi1 / 2 + Math.PI / 4));
var theta = Math.atan2(deltaLambda, deltaPsi);
return (helpers_1.radiansToDegrees(theta) + 360) % 360;
}
exports.default = rhumbBearing;