lib6/spatial-types.js
/**
* Copyright (c) "Neo4j"
* Neo4j Sweden AB [https://neo4j.com]
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import { assertNumber, assertNumberOrInteger } from './internal/util';
const POINT_IDENTIFIER_PROPERTY = '__isPoint__';
/**
* Represents a single two or three-dimensional point in a particular coordinate reference system.
* Created `Point` objects are frozen with `Object.freeze()` in constructor and thus immutable.
*/
export class Point {
/**
* @constructor
* @param {T} srid - The coordinate reference system identifier.
* @param {number} x - The `x` coordinate of the point.
* @param {number} y - The `y` coordinate of the point.
* @param {number} [z=undefined] - The `z` coordinate of the point or `undefined` if point has 2 dimensions.
*/
constructor(srid, x, y, z) {
/**
* The coordinate reference system identifier.
* @type {T}
*/
this.srid = assertNumberOrInteger(srid, 'SRID');
/**
* The `x` coordinate of the point.
* @type {number}
*/
this.x = assertNumber(x, 'X coordinate');
/**
* The `y` coordinate of the point.
* @type {number}
*/
this.y = assertNumber(y, 'Y coordinate');
/**
* The `z` coordinate of the point or `undefined` if point is 2-dimensional.
* @type {number}
*/
this.z = z === null || z === undefined ? z : assertNumber(z, 'Z coordinate');
Object.freeze(this);
}
/**
* @ignore
*/
toString() {
return this.z != null && !isNaN(this.z)
? `Point{srid=${formatAsFloat(this.srid)}, x=${formatAsFloat(this.x)}, y=${formatAsFloat(this.y)}, z=${formatAsFloat(this.z)}}`
: `Point{srid=${formatAsFloat(this.srid)}, x=${formatAsFloat(this.x)}, y=${formatAsFloat(this.y)}}`;
}
}
function formatAsFloat(number) {
return Number.isInteger(number) ? number.toString() + '.0' : number.toString();
}
Object.defineProperty(Point.prototype, POINT_IDENTIFIER_PROPERTY, {
value: true,
enumerable: false,
configurable: false,
writable: false
});
/**
* Test if given object is an instance of {@link Point} class.
* @param {Object} obj the object to test.
* @return {boolean} `true` if given object is a {@link Point}, `false` otherwise.
*/
export function isPoint(obj) {
const anyObj = obj;
return obj != null && anyObj[POINT_IDENTIFIER_PROPERTY] === true;
}