https://github.com/geoarrow/geoarrow-js
TypeScript implementation of GeoArrow
https://github.com/geoarrow/geoarrow-js
apache-arrow geoarrow typescript
Last synced: 5 months ago
JSON representation
TypeScript implementation of GeoArrow
- Host: GitHub
- URL: https://github.com/geoarrow/geoarrow-js
- Owner: geoarrow
- License: mit
- Created: 2023-11-21T18:44:34.000Z (almost 2 years ago)
- Default Branch: main
- Last Pushed: 2025-02-10T19:21:39.000Z (8 months ago)
- Last Synced: 2025-04-15T04:18:56.418Z (6 months ago)
- Topics: apache-arrow, geoarrow, typescript
- Language: TypeScript
- Homepage: http://geoarrow.org/geoarrow-js/
- Size: 308 KB
- Stars: 28
- Watchers: 4
- Forks: 6
- Open Issues: 5
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
README
# `geoarrow-js`
A minimal TypeScript implementation of [GeoArrow](https://geoarrow.org/) building on top of [Arrow JS](https://arrow.apache.org/docs/js/index.html).
It complements the work-in-progress [`geoarrow-wasm`](https://github.com/geoarrow/geoarrow-rs/tree/main/js), which will provide Rust-based operations on GeoArrow memory.
## Features
- Performant spatial operations.
- Rich static typing of geometry arrays.
- Tree shakeable.
- Utilities for sharing Arrow data across Web Workers (not specific to GeoArrow)
## Spatial operations
Only spatial operations that are implemented on binary representations of geometry will be added to this repo.
This means that `geoarrow-js` will not, say, use algorithms from [Turf](https://turfjs.org/), because that would require conversions to and from GeoJSON for the operation.
### Implemented algorithms:
Refer to the [`algorithm` namespace](https://geoarrow.github.io/geoarrow-js/modules/algorithm.html) in the docs.
- Polygon area and signed area (via [`@math.gl/polygon`](https://github.com/visgl/math.gl))
- Polygon winding order (via [`@math.gl/polygon`](https://github.com/visgl/math.gl))
- Polygon triangulation (via [`@math.gl/polygon`](https://github.com/visgl/math.gl), a fork of [`earcut`](https://github.com/mapbox/earcut).)
- Coordinate reprojection (via [`proj4`](https://github.com/proj4js/proj4js))
- Total bounds (the bounding box of an array of geometries).
## Web Worker utilities
Refer to the [`worker` namespace](https://geoarrow.github.io/geoarrow-js/modules/worker.html). Use `preparePostMessage` to obtain references to all underlying `ArrayBuffer` objects, so they can be transfered instead of copied.
```ts
import * as arrow from "apache-arrow";
import {
preparePostMessage,
rehydrateVector,
} from "@geoarrow/geoarrow-js/worker";
const originalVector = arrow.makeVector(new Int32Array([1, 2, 3]));
const [preparedVector, arrayBuffers] = preparePostMessage(originalVector);
// Here we use structuredClone to simulate a postMessage but on the main thread
const receivedVector = structuredClone(preparedVector, {
transfer: arrayBuffers,
});
const rehydratedVector = rehydrateVector(receivedVector);
```
## Ecosystem
`geoarrow-js` is designed to be used seamlessly with WebAssembly-based GeoArrow operations, such as those in the JavaScript bindings of the Rust GeoArrow implementation, and with rendering libraries, such as [deck.gl](https://deck.gl/), with the help of [`@geoarrow/deck.gl-layers`](https://github.com/geoarrow/deck.gl-layers).
For more background on my plans for GeoArrow ecosystem in JS and WebAssembly, refer to [this thread](https://github.com/geoarrow/geoarrow-rs/issues/283).