GEOS.js

(WIP) GEOS.js is an easy-to-use geospatial library built on top of GEOS.

The goal of this library is to connect turf-like ease of use with the reliability of GEOS (used by PostGIS, QGIS, GDAL, Shapely and many others).

Try it out

Try out GEOS.js in the interactive playground!

You can also check out API Documentation for live examples!

Project structure

At the core is the C/C++ GEOS library compiled by Emscripten into WebAssembly with a custom ~~slightly over engineered~~ GeoJSON integration. Memory management, pointers and other C/C++/Wasm related stuff are handled by JavaScript wrapper, which by exposing a clean API almost makes Wasm an implementation detail for downstream developers.

Install

npm i geos.js

Quick start

import { initializeFromBase64, fromWKT, toWKT, toWKB, point, area, buffer, union } from 'geos.js';

// GEOS.js needs to be initialized (to compile Wasm code)
await initializeFromBase64();

// GEOS.js can read and write GeoJSON, WKT and WKB
const p1 = buffer(fromWKT('POINT (1 1)'), 10);
const p2 = buffer(point([ 6, 6 ]), 8, { quadrantSegments: 2 });
const u = union(p1, p2);

console.log(area(u)); // 375.3168319264665
console.log(toWKT(u, { precision: 1 })); // 'POLYGON ((10.8 -1, 10.2 -2.8, 9.3 -4.6, 8.1 -6.1, 6...
console.log(u.toJSON()); // { type: 'Feature', geometry: { type: 'Polygon', coordinates: [ [ 10....
console.log(JSON.stringify(u)); // '{"type":"Feature","geometry":{"type":"Polygon","coordinates"...

console.log(toWKB(fromWKT('POINT Z (1 2 3)'), { flavor: 'iso' })); // Uint8Array(29) [1,233,3,0,...

License

GEOS.js is licensed under MIT License. GEOS is available under the terms of GNU Lesser General Public License (LGPL) 2.1.

The inspiration for this library was the geos-wasm library created by Christoph Pahmeyer
Turf - pure JavaScript library with similar functionality
Shapely - Python package build on top of GEOS

geos.js

Package Exports

Readme