itowns/lib/Core/Geographic/Crs.js

A JS/WebGL framework for 3D geospatial data visualization

"use strict";

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports["default"] = void 0;

var _proj = _interopRequireDefault(require("proj4"));

_proj["default"].defs('EPSG:4978', '+proj=geocent +datum=WGS84 +units=m +no_defs');

var TMS = ['WMTS:WGS84', 'WMTS:PM'];
var EPSG = ['EPSG:4326', 'EPSG:3857'];

function formatToTms(crs) {
  if (crs) {
    if (crs.includes('WMTS')) {
      return crs;
    }

    var i = EPSG.indexOf(crs);

    if (i > -1) {
      return TMS[i];
    } else if (crs.includes('EPSG')) {
      return "WMTS:TMS:".concat(crs.replace('EPSG:', ''));
    }
  }
}

function formatToEPSG(crs) {
  if (crs) {
    if (crs.includes('EPSG')) {
      return crs;
    } else if (EPSG[TMS.indexOf(crs)]) {
      return EPSG[TMS.indexOf(crs)];
    } else {
      return "EPSG:".concat(crs.match(/\d+/)[0]);
    }
  }
}

var UNIT = {
  DEGREE: 1,
  METER: 2
};

function is4326(crs) {
  return crs.indexOf('EPSG:4326') == 0;
}

function _unitFromProj4Unit(projunit) {
  if (projunit === 'degrees') {
    return UNIT.DEGREE;
  } else if (projunit === 'm') {
    return UNIT.METER;
  } else {
    return undefined;
  }
}

function toUnit(crs) {
  switch (crs) {
    case 'EPSG:4326':
      return UNIT.DEGREE;

    case 'EPSG:4978':
      return UNIT.METER;

    default:
      {
        var p = _proj["default"].defs(formatToEPSG(crs));

        if (!p) {
          return undefined;
        }

        return _unitFromProj4Unit(p.units);
      }
  }
}

function toUnitWithError(crs) {
  var u = toUnit(crs);

  if (crs === undefined || u === undefined) {
    throw new Error("Invalid crs parameter value '".concat(crs, "'"));
  }

  return u;
}
/**
 * This module provides basic methods to manipulate a CRS (as a string).
 *
 * @module CRS
 */


var _default = {
  /**
   * Units that can be used for a CRS.
   *
   * @enum {number}
   */
  UNIT: UNIT,

  /**
   * Assert that the CRS is valid one.
   *
   * @param {string} crs - The CRS to validate.
   *
   * @throws {Error} if the CRS is not valid.
   */
  isValid: function isValid(crs) {
    toUnitWithError(crs);
  },

  /**
   * Assert that the CRS is geographic.
   *
   * @param {string} crs - The CRS to validate.
   * @return {boolean}
   * @throws {Error} if the CRS is not valid.
   */
  isGeographic: function isGeographic(crs) {
    return toUnitWithError(crs) == UNIT.DEGREE;
  },

  /**
   * Assert that the CRS is using metric units.
   *
   * @param {string} crs - The CRS to validate.
   * @return {boolean}
   * @throws {Error} if the CRS is not valid.
   */
  isMetricUnit: function isMetricUnit(crs) {
    return toUnit(crs) == UNIT.METER;
  },

  /**
   * Get the unit to use with the CRS.
   *
   * @param {string} crs - The CRS to get the unit from.
   * @return {number} Either `UNIT.METER`, `UNIT.DEGREE` or `undefined`.
   */
  toUnit: toUnit,

  /**
   * Is the CRS EPSG:4326 ?
   *
   * @param {string} crs - The CRS to test.
   * @return {boolean}
   */
  is4326: is4326,

  /**
   * Give a reasonnable epsilon to use with this CRS.
   *
   * @param {string} crs - The CRS to use.
   * @return {number} 0.01 if the CRS is EPSG:4326, 0.001 otherwise.
   */
  reasonnableEpsilon: function reasonnableEpsilon(crs) {
    if (is4326(crs)) {
      return 0.01;
    } else {
      return 0.001;
    }
  },

  /**
   * format crs to European Petroleum Survey Group notation : EPSG:XXXX.
   *
   * @param      {string}  crs     The crs to format
   * @return     {string}  formated crs
   */
  formatToEPSG: formatToEPSG,

  /**
   * format crs to tile matrix set notation : WMTS:XXXX.
   *
   * @param      {string}  crs     The crs to format
   * @return     {string}  formated crs
   */
  formatToTms: formatToTms
};
exports["default"] = _default;