zarr-gl

Custom WebGL Zarr layer for Mapbox and Maplibre.

This library allows you to load Zarr data into a Mapbox GL JS or Maplibre GL JS map.

Takes inspiration from carbonplan/maps, but with two differences:
1. A library, rather than a framework, so you can use it how you like.
2. Adds a Custom Layer to Mapbox's GL context, rather than creating a whole separate one. Allows you to mix and match with Map styles, adjust layer ordering etc.

You can see a demo at: rainy.rdrn.me.

Quickstart

``bash
npm install zarr-gl
`

You'll need to prepare the data using carbonplan/ndpyramid.
Hoping to make that unnecessary at least for use-cases where a narrow zoom-range works.
There's a basic data preparation example at example/prep.py.

`js
import { ZarrLayer } from "zarr-gl";
// or skip the npm install and just do this:
// import { ZarrLayer } from "https://cdn.jsdelivr.net/npm/zarr-gl@0.2.0/+esm";

const map = new mapboxgl.Map({
container: "map",
style: "mapbox://styles/mapbox/standard",
projection: "mercator",
});

const layer = new ZarrLayer({
id: "myZarrLayer",
source: "https://example.com/path/to/my.zarr",
variable: "precip",
colormap: [[200, 10, 50], [30, 40, 30], [50, 10, 200]],
vmin: 0,
vmax: 100,
opacity: 0.8,
map,
});
map.addLayer(layer);
`

Roadmap


- [x] Support a selector` option to index into additional dimensions. Currently only 2D datasets are supported.
- [ ] Reproject from lon/lat to EPSG:3857 on the fly
- [x] Handle chunk sizes other than 128x128.
- [ ] Appropriately handle non-float32 data.
- [ ] Add more lifecycle events.

Examples

1. There is a very basic example (including data prep) in the example directory.
2. There's also a more complex React app inside demo and viewable at rainy.rdrn.me.

Contributing

I'd love input on use-cases, ideas, missing features etc.
Even better if they come with code.

See CONTRIBUTING.md for details on how to contribute.

$3

When you open a pull request, a preview build is automatically created and deployed. A Github action will autmatically provide the link and the code snippet to use in a comment on the PR.