SharedMVTLayer

SharedMVTLayer extends SharedTile2DLayer with MVT decoding, tile transforms, clipping, geographic picking and feature-ID highlighting. It accepts MVT URL templates or an externally owned SharedTileset2D containing tile-local GeoJSON features.

Decoded tiles always use normalized local coordinates. Map consumers apply a tile transform; globe consumers reuse a cached WGS84 conversion. Switching views does not invalidate decoded content or fetch a tile again while it remains cached. Each consumer retains its own rendering layers and GPU attributes.

import {SharedMVTLayer, SharedTileset2D} from '@deck.gl-community/geo-layers';

const loader = new SharedMVTLayer({
  data: 'https://example.com/{z}/{x}/{y}.pbf'
});
const tileset = new SharedTileset2D(loader._getTilesetOptions());
const fills = new SharedMVTLayer({id: 'fills', data: tileset, filled: true});
const outlines = new SharedMVTLayer({id: 'outlines', data: tileset, filled: false});

The owner must call tileset.finalize() when all consumers are removed. Finalizing a consumer only detaches its view and subscriptions. Share a tileset only between consumers with the same source, decoder and fetch/load options. Replace it when those inputs change. The cache and request budget apply across all consumers, including consumers added after a request finishes.

The basemap renderer now lives in tangram.gl. Shared tile and MVT adapters remain available here for independent consumers.

This initial adapter uses GeoJSON decoding. Binary MVT data, TileJSON URL resolution and getRenderedFeatures are not supported. Resolve TileJSON to tile templates before creating the layer. For concurrent map and globe rendering, use separate SharedMVTLayer consumers backed by the same tileset. Geometry conversion supports all GeoJSON geometry types, including geometry collections. The adapter preserves buffered geometry on globes; it does not add far-side label occlusion.