spherical-geometry-js

Spherical Geometry Library ·

This library provides classes and functions for the computation of geometric data on the surface of the Earth.

This library ports a small but useful subset of classes from the Google Maps Javascript API version 3, to use as a separate module or in node.

How to use

import * as geometry from 'spherical-geometry-js';

Or import individual modules

import { computeArea } from 'spherical-geometry-js';
import computeArea from 'spherical-geometry-js/compute-area';

Notes:

• The API is nearly identical to the Google Maps Javascript API.
• computeOffsetOrigin has not yet been implemented
• All computed lengths are returned in meters.

API

The full API of the library is described in the typings file.

Classes and libraries ported from the Google Maps Javascript API:

• google.maps.geometry.spherical
• google.maps.LatLng

For convenience, LatLng includes some extra methods.

const latlng = new LatLng(123, 56);
// Alias getters for longitude and latitude

latlng.x === latlng.lng();
latlng.y === latlng.lat();

latlng[0] === latlng.lng();
latlng[1] === latlng.lat();

import { equalLatLngs } from 'spherical-geometry-js';

equalLatLngs(latlng1, latlng2) === latlng1.equals(latlng2);

A function called convertLatLng can be used. It tries to convert an object into a LatLng.

convertLatLng(like) ⇒ LatLng

Converts an object into a LatLng. Tries a few different methods:

1. If instanceof LatLng, clone and return the object

2. If it has 'lat' and 'lng' properties...

   2a. if the properties are functions (like Google LatLngs), use the lat() and lng() values as lat and lng

   2b. otherwise get lat and lng, parse them as floats and try them

3. If it has 'lat' and 'long' properties, parse them as floats and return a LatLng

4. If it has number values for 0 and 1, use 1 as latitude and 0 as longitude.

5. If it has x and y properties, try using y as latitude and x and longitude.