"use strict"; Object.defineProperty(exports, "__esModule", { value: true }); // http://en.wikipedia.org/wiki/Haversine_formula // http://www.movable-type.co.uk/scripts/latlong.html var helpers_1 = require("@turf/helpers"); var invariant_1 = require("@turf/invariant"); /** * Takes a {@link Point} and calculates the location of a destination point given a distance in * degrees, radians, miles, or kilometers; and bearing in degrees. * This uses the [Haversine formula](http://en.wikipedia.org/wiki/Haversine_formula) to account for global curvature. * * @name destination * @param {Coord} origin starting point * @param {number} distance distance from the origin point * @param {number} bearing ranging from -180 to 180 * @param {Object} [options={}] Optional parameters * @param {string} [options.units='kilometers'] miles, kilometers, degrees, or radians * @param {Object} [options.properties={}] Translate properties to Point * @returns {Feature} destination point * @example * var point = turf.point([-75.343, 39.984]); * var distance = 50; * var bearing = 90; * var options = {units: 'miles'}; * * var destination = turf.destination(point, distance, bearing, options); * * //addToMap * var addToMap = [point, destination] * destination.properties['marker-color'] = '#f00'; * point.properties['marker-color'] = '#0f0'; */ function destination(origin, distance, bearing, options) { if (options === void 0) { options = {}; } // Handle input var coordinates1 = invariant_1.getCoord(origin); var longitude1 = helpers_1.degreesToRadians(coordinates1[0]); var latitude1 = helpers_1.degreesToRadians(coordinates1[1]); var bearingRad = helpers_1.degreesToRadians(bearing); var radians = helpers_1.lengthToRadians(distance, options.units); // Main var latitude2 = Math.asin(Math.sin(latitude1) * Math.cos(radians) + Math.cos(latitude1) * Math.sin(radians) * Math.cos(bearingRad)); var longitude2 = longitude1 + Math.atan2(Math.sin(bearingRad) * Math.sin(radians) * Math.cos(latitude1), Math.cos(radians) - Math.sin(latitude1) * Math.sin(latitude2)); var lng = helpers_1.radiansToDegrees(longitude2); var lat = helpers_1.radiansToDegrees(latitude2); return helpers_1.point([lng, lat], options.properties); } exports.default = destination;