make-tile — Convert geojson to tile

A highly efficient JavaScript library for making vector tile from GeoJSON data on the fly.

Resulting tiles conform to the JSON equivalent of the vector tile specification. To make data rendering and interaction fast, the tiles are simplified, retaining the minimum level of detail appropriate for each zoom level (simplifying shapes, filtering out tiny polygons and polylines).

Usage

// build an tile
const tile = makeTile(geoJSON, options, { x: 149, y: 86, z: 6 });

Options

You can fine-tune the results with an options object, although the defaults are sensible and work well for most use cases.

const tle = makeTile(
    data,
    {
        maxZoom: 14,  // max zoom to preserve detail on; can't be higher than 24
        tolerance: 3, // simplification tolerance (higher means simpler)
        extent: 4096, // tile extent (both width and height)
        buffer: 64,   // tile buffer on each side
        lineMetrics: false, // whether to enable line metrics tracking for LineString/MultiLineString features
        promoteId: null,    // name of a feature property to promote to feature.id. Cannot be used with `generateId`
        generateId: false,  // whether to generate feature ids. Cannot be used with `promoteId`
        indexMaxPoints: 100000 // max number of points per tile in the index
    },
    {
        x: 149,
        y: 86,
        z: 6
    }
);

The promoteId and generateId options ignore existing id values on the feature objects.

Install

Install using NPM (npm install make-tile) or Yarn (yarn add make-tile), then:

// import as a ES module
import makeTile from 'make-tile';

// or require in Node / Browserify
const makeTile = require('make-tile');