real3d-portalsite/static/js/sunrise-sunset-js/dist/index.js

'use strict';

Object.defineProperty(exports, '__esModule', { value: true });

/**
 * Sunrise/sunset script. By Matt Kane. Adopted for NPM use by Alexey Udivankin.
 *
 * Based loosely and indirectly on Kevin Boone's SunTimes Java implementation
 * of the US Naval Observatory's algorithm.
 *
 * Copyright © 2012 Triggertrap Ltd. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General
 * Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
 * details.
 * You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA,
 * or connect to: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
 */
/**
 * Default zenith
 */
const DEFAULT_ZENITH = 90.8333;
/**
 * Degrees per hour
 */
const DEGREES_PER_HOUR = 360 / 24;
/**
 * Msec in hour
 */
const MSEC_IN_HOUR = 60 * 60 * 1000;
/**
 * Get day of year
 */
function getDayOfYear(date) {
    return Math.ceil((date.getTime() - new Date(date.getFullYear(), 0, 1).getTime()) / 8.64e7);
}
/**
 * Get sin of value in deg
 */
function sinDeg(deg) {
    return Math.sin(deg * 2.0 * Math.PI / 360.0);
}
/**
 * Get acos of value in deg
 */
function acosDeg(x) {
    return Math.acos(x) * 360.0 / (2 * Math.PI);
}
/**
 * Get asin of value in deg
 */
function asinDeg(x) {
    return Math.asin(x) * 360.0 / (2 * Math.PI);
}
/**
 * Get tan of value in deg
 */
function tanDeg(deg) {
    return Math.tan(deg * 2.0 * Math.PI / 360.0);
}
/**
 * Get cos of value in deg
 */
function cosDeg(deg) {
    return Math.cos(deg * 2.0 * Math.PI / 360.0);
}
/**
 * Get ramainder
 */
function mod(a, b) {
    const result = a % b;
    return result < 0
        ? result + b
        : result;
}
/**
 * Calculate Date for either sunrise or sunset
 */
function calculate(latitude, longitude, isSunrise, zenith, date) {
    const dayOfYear = getDayOfYear(date);
    const hoursFromMeridian = longitude / DEGREES_PER_HOUR;
    const approxTimeOfEventInDays = isSunrise
        ? dayOfYear + ((6 - hoursFromMeridian) / 24)
        : dayOfYear + ((18.0 - hoursFromMeridian) / 24);
    const sunMeanAnomaly = (0.9856 * approxTimeOfEventInDays) - 3.289;
    const sunTrueLongitude = mod(sunMeanAnomaly + (1.916 * sinDeg(sunMeanAnomaly)) + (0.020 * sinDeg(2 * sunMeanAnomaly)) + 282.634, 360);
    const ascension = 0.91764 * tanDeg(sunTrueLongitude);
    let rightAscension;
    rightAscension = 360 / (2 * Math.PI) * Math.atan(ascension);
    rightAscension = mod(rightAscension, 360);
    const lQuadrant = Math.floor(sunTrueLongitude / 90) * 90;
    const raQuadrant = Math.floor(rightAscension / 90) * 90;
    rightAscension = rightAscension + (lQuadrant - raQuadrant);
    rightAscension /= DEGREES_PER_HOUR;
    const sinDec = 0.39782 * sinDeg(sunTrueLongitude);
    const cosDec = cosDeg(asinDeg(sinDec));
    const cosLocalHourAngle = ((cosDeg(zenith)) - (sinDec * (sinDeg(latitude)))) / (cosDec * (cosDeg(latitude)));
    const localHourAngle = isSunrise
        ? 360 - acosDeg(cosLocalHourAngle)
        : acosDeg(cosLocalHourAngle);
    const localHour = localHourAngle / DEGREES_PER_HOUR;
    const localMeanTime = localHour + rightAscension - (0.06571 * approxTimeOfEventInDays) - 6.622;
    const time = mod(localMeanTime - (longitude / DEGREES_PER_HOUR), 24);
    const utcMidnight = Date.UTC(date.getFullYear(), date.getMonth(), date.getDate());
    // Created date will be set to local (system) time zone.
    return new Date(utcMidnight + (time * MSEC_IN_HOUR));
}
/**
 * Calculate Sunrise time for given longitude, latitude, zenith and date
 */
function getSunrise(latitude, longitude, date = new Date()) {
    return calculate(latitude, longitude, true, DEFAULT_ZENITH, date);
}
/**
 * Calculate Sunset time for given longitude, latitude, zenith and date
 */
function getSunset(latitude, longitude, date = new Date()) {
    return calculate(latitude, longitude, false, DEFAULT_ZENITH, date);
}

exports.getSunrise = getSunrise;
exports.getSunset = getSunset;