109 lines
4.9 KiB
JavaScript
109 lines
4.9 KiB
JavaScript
/* Generated from Java with JSweet 3.1.0 - http://www.jsweet.org */
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//var btools;
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btools = {};
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(function (btools) {
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var util;
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(function (util) {
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class CheapRuler {
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static __static_initialize() {
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if (!CheapRuler.__static_initialized) {
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CheapRuler.__static_initialized = true;
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CheapRuler.__static_initializer_0();
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}
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}
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static DEG_TO_RAD_$LI$() {
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CheapRuler.__static_initialize();
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if (CheapRuler.DEG_TO_RAD == null) {
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CheapRuler.DEG_TO_RAD = Math.PI / 180.0;
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}
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return CheapRuler.DEG_TO_RAD;
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}
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static SCALE_CACHE_$LI$() {
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CheapRuler.__static_initialize();
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if (CheapRuler.SCALE_CACHE == null) {
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CheapRuler.SCALE_CACHE = ((s) => {
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let a = [];
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while (s-- > 0) a.push(null);
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return a;
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})(CheapRuler.SCALE_CACHE_LENGTH);
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}
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return CheapRuler.SCALE_CACHE;
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}
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static __static_initializer_0() {
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for (let i = 0; i < CheapRuler.SCALE_CACHE_LENGTH; i++) {
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{
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CheapRuler.SCALE_CACHE_$LI$()[i] = CheapRuler.calcKxKyFromILat(
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i * CheapRuler.SCALE_CACHE_INCREMENT + ((CheapRuler.SCALE_CACHE_INCREMENT / 2) | 0)
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);
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}
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}
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}
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/*private*/ static calcKxKyFromILat(ilat) {
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const lat = CheapRuler.DEG_TO_RAD_$LI$() * (ilat * CheapRuler.ILATLNG_TO_LATLNG - 90);
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const cos = Math.cos(lat);
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const cos2 = 2 * cos * cos - 1;
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const cos3 = 2 * cos * cos2 - cos;
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const cos4 = 2 * cos * cos3 - cos2;
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const cos5 = 2 * cos * cos4 - cos3;
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const kxky = [0, 0];
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kxky[0] =
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(111.41513 * cos - 0.09455 * cos3 + 1.2e-4 * cos5) *
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CheapRuler.ILATLNG_TO_LATLNG *
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CheapRuler.KILOMETERS_TO_METERS;
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kxky[1] =
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(111.13209 - 0.56605 * cos2 + 0.0012 * cos4) *
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CheapRuler.ILATLNG_TO_LATLNG *
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CheapRuler.KILOMETERS_TO_METERS;
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return kxky;
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}
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/**
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* Calculate the degree->meter scale for given latitude
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*
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* @return {double[]} [lon->meter,lat->meter]
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* @param {number} ilat
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*/
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static getLonLatToMeterScales(ilat) {
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return CheapRuler.SCALE_CACHE_$LI$()[(ilat / CheapRuler.SCALE_CACHE_INCREMENT) | 0];
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}
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/**
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* Compute the distance (in meters) between two points represented by their
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* (integer) latitude and longitude.
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*
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* @param {number} ilon1 Integer longitude for the start point. this is (longitude in degrees + 180) * 1e6.
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* @param {number} ilat1 Integer latitude for the start point, this is (latitude + 90) * 1e6.
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* @param {number} ilon2 Integer longitude for the end point, this is (longitude + 180) * 1e6.
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* @param {number} ilat2 Integer latitude for the end point, this is (latitude + 90) * 1e6.
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* @return {number} The distance between the two points, in meters.
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*
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* Note:
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* Integer longitude is ((longitude in degrees) + 180) * 1e6.
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* Integer latitude is ((latitude in degrees) + 90) * 1e6.
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*/
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static distance(ilon1, ilat1, ilon2, ilat2) {
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const kxky = CheapRuler.getLonLatToMeterScales((ilat1 + ilat2) >> 1);
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const dlon = (ilon1 - ilon2) * kxky[0];
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const dlat = (ilat1 - ilat2) * kxky[1];
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return Math.sqrt(dlat * dlat + dlon * dlon);
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}
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}
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CheapRuler.__static_initialized = false;
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/**
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* Cheap-Ruler Java implementation
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* See
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* https://blog.mapbox.com/fast-geodesic-approximations-with-cheap-ruler-106f229ad016
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* for more details.
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*
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* Original code is at https://github.com/mapbox/cheap-ruler under ISC license.
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*
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* This is implemented as a Singleton to have a unique cache for the cosine
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* values across all the code.
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*/
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CheapRuler.ILATLNG_TO_LATLNG = 1.0e-6;
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CheapRuler.KILOMETERS_TO_METERS = 1000;
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CheapRuler.SCALE_CACHE_LENGTH = 1800;
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CheapRuler.SCALE_CACHE_INCREMENT = 100000;
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util.CheapRuler = CheapRuler;
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CheapRuler['__class'] = 'btools.util.CheapRuler';
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})((util = btools.util || (btools.util = {})));
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})(btools || (btools = {}));
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btools.util.CheapRuler.__static_initialize();
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