GeoJsonLayer

import {GeoJsonLayerDemo} from '@site/src/doc-demos/layers';

The GeoJsonLayer renders GeoJSON formatted data as polygons, lines and points (circles, icons and/or texts).

GeoJsonLayer is a CompositeLayer. See the sub layers that it renders.

import Tabs from '@theme/Tabs'; import TabItem from '@theme/TabItem';

import {Deck} from '@deck.gl/core';
import {GeoJsonLayer} from '@deck.gl/layers';

const layer = new GeoJsonLayer({
  id: 'GeoJsonLayer',
  data: 'https://raw.githubusercontent.com/visgl/deck.gl-data/master/website/bart.geo.json',

  stroked: false,
  filled: true,
  pointType: 'circle+text',
  pickable: true,

  getFillColor: [160, 160, 180, 200],
  getLineColor: f => {
    const hex = f.properties.color;
    // convert to RGB
    return hex ? hex.match(/[0-9a-f]{2}/g).map(x => parseInt(x, 16)) : [0, 0, 0];
  },
  getLineWidth: 20,
  getPointRadius: 4,
  getText: f => f.properties.name,
  getTextSize: 12
});

new Deck({
  initialViewState: {
    longitude: -122.4,
    latitude: 37.74,
    zoom: 11
  },
  controller: true,
  getTooltip: ({object}) => object && object.properties.name,
  layers: [layer]
});

import {Deck, PickingInfo} from '@deck.gl/core';
import {GeoJsonLayer} from '@deck.gl/layers';
import type {Feature, Geometry} from 'geojson';

type PropertiesType = {
  name: string;
  color: string;
};

const layer = new GeoJsonLayer<PropertiesType>({
  id: 'GeoJsonLayer',
  data: 'https://raw.githubusercontent.com/visgl/deck.gl-data/master/website/bart.geo.json',

  stroked: false,
  filled: true,
  pointType: 'circle+text',
  pickable: true,

  getFillColor: [160, 160, 180, 200],
  getLineColor: (f: Feature<Geometry, PropertiesType>) => {
    const hex = f.properties.color;
    // convert to RGB
    return hex ? hex.match(/[0-9a-f]{2}/g).map(x => parseInt(x, 16)) : [0, 0, 0];
  },
  getText: (f: Feature<Geometry, PropertiesType>) => f.properties.name,
  getLineWidth: 20,
  getPointRadius: 4,
  getTextSize: 12
});

new Deck({
  initialViewState: {
    longitude: -122.4,
    latitude: 37.74,
    zoom: 11
  },
  controller: true,
  getTooltip: ({object}: PickingInfo<Feature<Geometry, PropertiesType>>) => object && object.properties.name,
  layers: [layer]
});

import React from 'react';
import {DeckGL} from '@deck.gl/react';
import {GeoJsonLayer} from '@deck.gl/layers';
import type {Feature, Geometry} from 'geojson';
import type {PickingInfo} from '@deck.gl/core';

type PropertiesType = {
  name: string;
  color: string;
};

function App() {
  const layer = new GeoJsonLayer<PropertiesType>({
    id: 'GeoJsonLayer',
    data: 'https://raw.githubusercontent.com/visgl/deck.gl-data/master/website/bart.geo.json',

    stroked: false,
    filled: true,
    pointType: 'circle+text',
    pickable: true,

    getFillColor: [160, 160, 180, 200],
    getLineColor: (f: Feature<Geometry, PropertiesType>) => {
      const hex = f.properties.color;
      // convert to RGB
      return hex ? hex.match(/[0-9a-f]{2}/g).map(x => parseInt(x, 16)) : [0, 0, 0];
    },
    getText: (f: Feature<Geometry, PropertiesType>) => f.properties.name,
    getLineWidth: 20,
    getPointRadius: 4,
    getTextSize: 12
  });

  return <DeckGL
    initialViewState={{
      longitude: -122.4,
      latitude: 37.74,
      zoom: 11
    }}
    controller
    getTooltip={({object}: PickingInfo<Feature<Geometry, PropertiesType>>) => object && object.properties.name}
    layers={[layer]}
  />;
}

Installation

To install the dependencies from NPM:

npm install deck.gl
# or
npm install @deck.gl/core @deck.gl/layers

import {GeoJsonLayer} from '@deck.gl/layers';
import type {GeoJsonLayerProps} from '@deck.gl/layers';

new GeoJsonLayer<FeaturePropertiesT>(...props: GeoJsonLayerProps<FeaturePropertiesT>[]);

To use pre-bundled scripts:

<script src="https://unpkg.com/deck.gl@^9.0.0/dist.min.js"></script>
<!-- or -->
<script src="https://unpkg.com/@deck.gl/core@^9.0.0/dist.min.js"></script>
<script src="https://unpkg.com/@deck.gl/layers@^9.0.0/dist.min.js"></script>

new deck.GeoJsonLayer({});

Properties

Inherits from all Base Layer and CompositeLayer properties.

data {#data}

The GeoJSONLayer accepts any of the following formats passed to the data prop:

• A valid GeoJSON FeatureCollection, Feature, Geometry or GeometryCollection object.
• An array of GeoJSON Feature objects.
• An URL or Promise that resolves to the above formats.
• loaders.gl's flat GeoJSON format.

pointType (string, optional) {#pointtype}

• Default: 'circle'

How to render Point and MultiPoint features in the data. Supported types are:

• circle
• icon
• text

To use more than one type, join the names with +, for example pointType: 'icon+text'.

Fill Options

The following props control the solid fill of Polygon and MultiPolygon features, and the Point and MultiPoint features if pointType is 'circle'.

filled (boolean, optional) {#filled}

• Default: true

Whether to draw filled polygons (solid fill) and points (circles). Note that for each polygon, only the area between the outer polygon and any holes will be filled. This prop is effective only when the polygon is NOT extruded.

getFillColor (Accessor<Color>, optional) {#getfillcolor}

• Default: [0, 0, 0, 255]

The solid color of the polygon and points (circles). Format is [r, g, b, [a]]. Each channel is a number between 0-255 and a is 255 if not supplied.

• If an array is provided, it is used as the fill color for all features.
• If a function is provided, it is called on each feature to retrieve its fill color.

Stroke Options

The following props control the LineString and MultiLineString features, the outline for Polygon and MultiPolygon features, and the outline for Point and MultiPoint features if pointType is 'circle'.

stroked (boolean, optional) {#stroked}

• Default: true

Whether to draw an outline around polygons and points (circles). Note that for complex polygons, both the outer polygon as well the outlines of any holes will be drawn.

getLineColor (Accessor<Color>, optional) {#getlinecolor}

• Default: [0, 0, 0, 255]

The rgba color of a line is in the format of [r, g, b, [a]]. Each channel is a number between 0-255 and a is 255 if not supplied.

• If an array is provided, it is used as the line color for all features.
• If a function is provided, it is called on each feature to retrieve its line color.

getLineWidth (Accessor<number>, optional) {#getlinewidth}

• Default: 1

The width of a line, in units specified by lineWidthUnits (default meters).

• If a number is provided, it is used as the line width for all features.
• If a function is provided, it is called on each feature to retrieve its line width.

lineWidthUnits (string, optional) {#linewidthunits}

• Default: 'meters'

The units of the line width, one of 'meters', 'common', and 'pixels'. See unit system.

lineWidthScale (number, optional) {#linewidthscale}

• Default: 1

A multiplier that is applied to all line widths.

lineWidthMinPixels (number, optional) {#linewidthminpixels}

• Default: 0

The minimum line width in pixels. This prop can be used to prevent the line from getting too thin when zoomed out.

lineWidthMaxPixels (number, optional) {#linewidthmaxpixels}

• Default: Number.MAX_SAFE_INTEGER

The maximum line width in pixels. This prop can be used to prevent the line from getting too thick when zoomed in.

lineCapRounded (boolean, optional) {#linecaprounded}

• Default: false

Type of line caps. If true, draw round caps. Otherwise draw square caps.

lineJointRounded (boolean, optional) {#linejointrounded}

• Default: false

Type of line joint. If true, draw round joints. Otherwise draw miter joints.

lineMiterLimit (number, optional) {#linemiterlimit}

• Default: 4

The maximum extent of a joint in ratio to the stroke width. Only works if lineJointRounded is false.

lineBillboard (boolean, optional) {#linebillboard}

• Default: false

If true, extrude the line in screen space (width always faces the camera). If false, the width always faces up.

3D Options

The following props control the extrusion of Polygon and MultiPolygon features.

extruded (boolean, optional) {#extruded}

Extrude Polygon and MultiPolygon features along the z-axis if set to true. The height of the drawn features is obtained using the getElevation accessor.

• Default: false

wireframe (boolean, optional) {#wireframe}

• Default: false

Whether to generate a line wireframe of the hexagon. The outline will have "horizontal" lines closing the top and bottom polygons and a vertical line (a "strut") for each vertex on the polygon.

Remarks:

• These lines are rendered with GL.LINE and will thus always be 1 pixel wide.
• Wireframe and solid extrusions are exclusive, you'll need to create two layers with the same data if you want a combined rendering effect.
• This is only effective if the extruded prop is set to true.

getElevation (Accessor<number>, optional) {#getelevation}

• Default: 1000

The elevation of a polygon feature (when extruded is true).

If a cartographic projection mode is used, height will be interpreted as meters, otherwise will be in unit coordinates.

• If a number is provided, it is used as the elevation for all polygon features.
• If a function is provided, it is called on each polygon feature to retrieve its elevation.

elevationScale (number, optional) {#elevationscale}

• Default: 1

Elevation multiplier. The final elevation is calculated by elevationScale * getElevation(d). elevationScale is a handy property to scale all polygon elevation without updating the data.

material (Material, optional) {#material}

• Default: true

This is an object that contains material props for lighting effect applied on extruded polygons. Check the lighting guide for configurable settings.

_full3d (boolean, optional) {#_full3d}

• Default: false

Note: This prop is experimental

When true, polygon tesselation will be performed on the plane with the largest area, instead of the xy plane.

Remarks:

• Only use this if you experience issues rendering features that only change on the z axis.
• This prop is only effective with XYZ data.

pointType:circle Options

The following props are forwarded to a ScatterplotLayer if pointType is 'circle'.

pointType:icon Options

The following props are forwarded to an IconLayer if pointType is 'icon'.

pointType:text Options

The following props are forwarded to a TextLayer if pointType is 'text'.

Sub Layers

The GeoJsonLayer renders the following sublayers:

• polygons-fill - a SolidPolygonLayer rendering all the Polygon and MultiPolygon features.
• polygons-stroke - a PathLayer rendering the outline of all the Polygon and MultiPolygon features. Only rendered if stroked: true and extruded: false.
• linestrings - a PathLayer rendering all the LineString and MultiLineString features.
• points-circle - a ScatterplotLayer rendering all the Point and MultiPoint features if pointType is 'circle'.
• points-icon - an IconLayer rendering all the Point and MultiPoint features if pointType is 'icon'.
• points-text - a TextLayer rendering all the Point and MultiPoint features if pointType is 'text'.

Using binary data

This section is about the special requirements when supplying attributes directly to a GeoJsonLayer.

The most common way to supply binary data is to use the flat GeoJSON format, this is done by default when using the MVTLayer.

Binary format details

In general this format is not intended to be human readable, and rather than being edited by hand should be generated with geojsonToBinary. The purpose of this section is to help explain how this format works.

At the top level the data is grouped by geometry type, into points, lines and polygons:

import type {BinaryFeatureCollection} from '@loaders.gl/schema';

const data: BinaryFeatureCollection = {
  shape: 'binary-feature-collection',
  // points,
  // lines,
  // polygons
};

When the GeoJsonLayer detects this data structure it assumes it is dealing with binary data, rather than standard GeoJSON. Within each geometry type the data is laid out in a format that corresponds to the buffers that will be sent to the GPU.

Point geometries

For GeoJSON features of type Point or MultiPoint, the positions are encoded as a flat interleaved array with associated properties grouped by point:

import type {BinaryPointFeature} from '@loaders.gl/schema';

data.points = {
  type: 'Point',
  positions: {value: new Float32Array([x0, y0, x1, y1, x2, y2, ...]), size: 2}, // Use size=2 for xy and size=3 for xyz
  // featureIds
  // globalFeatureIds
  // numericProps
  // properties
} as BinaryPointFeature

LineString geometries

GeoJSON features of type LineString and MultiLineString are represented in a similar manner, with the addition of a pathIndices array, which contains a series of offsets into the positions array, specifying the vertex index where each line begins.

import type {BinaryLineFeature} from '@loaders.gl/schema';

data.lines = {
  type: 'LineString',
  positions: {value: new Float32Array([x0, y0, x1, y1, x2, y2, ...]), size: 2}, // Use size=2 for xy and size=3 for xyz
  pathIndices: {value: new Uint16Array([0, 5, 7, ...]), size: 1}, // First line contains vertex 0-4, second line contains vertex 5-6, ...
  // featureIds
  // globalFeatureIds
  // numericProps
  // properties
} as BinaryLineFeature

Polygon geometries

Polygons are an extension of the idea introduced with lines, but instead of pathIndices the polygonIndicies array specifies the vertex index where each polygon starts. Because polygons can have holes, the offsets for the outer and inner rings are stored separately in the primitivePolygonIndices array.

import type {BinaryPolygonFeature} from '@loaders.gl/schema';

data.polygons = {
  positions: {value: new Float32Array([x0, y0, x1, y1, x2, y2, ...]), size: 2}, // Use size=2 for xy and size=3 for xyz
  polygonIndices: {value: new Uint16Array([0, 100, ...]), size: 1}, // First polygon contains vertex 0-99
  primitivePolygonIndices: {value: new Uint16Array([0, 60, 80, 100, ...]), size: 1}, // First polygon has 2 holes, made of vertex 60-79 and vertex 80-99
  // featureIds
  // globalFeatureIds
  // numericProps
  // properties
} as BinaryPolygonFeature

Properties and numeric properties

The properties field of each feature is stored in the properties array, for example:

data.points = {
  type: 'Point',
  // positions
  // featureIds
  // globalFeatureIds
  // numericProps
  properties: [{name: 'A'}, {name: 'B'}, ...]
} as BinaryPointFeature

For performance, numeric properties are stored separately in typed arrays:

data.points = {
  type: 'Point',
  // positions
  // featureIds
  // globalFeatureIds
  numericProps: {
    population: {value: new Float32Array([value0, value1, ...]), size: 1}
  },
  // properties
 } as BinaryPointFeature

Both properties and numericProps are specified per-vertex.

Feature IDs and global feature IDs

Both featureIds and globalFeatureIds are specified per-vertex.

Feature ID is used to map each vertex to the corresponding element in the properties array. It increments within the current feature type.

Global feature ID refers to the feature index in the original FeatureCollection, and is unique across all types.

For example, consider a GeoJSON FeatureCollection contains the following features:

data.points = {
  type: 'Point',
  // positions
  featureIds: {value: new Uint16Array([0, 1, 1, 1, 2]), size: 1}, // this vertex belongs to the Nth point-type feature
  globalFeatureIds: {value: new Uint16Array([0, 3, 3, 3, 4]), size: 1}, // this vertex belongs to the Nth feature
  // numericProps
  // properties
 } as BinaryPointFeature

Example comparison

import type {FeatureCollection} from 'geojson';
import type {BinaryPointFeature} from '@loaders.gl/schema';

const geojson: FeatureCollection = {
  type: 'FeatureCollection',
  features: [
    {
      id: 123,
      type: 'Feature',
      properties: {name: 'London', population: 10000000},
      geometry: {coordinates: [1.23, 4.56], type: 'Point'}
    }
  ]
};

const binary: BinaryPointFeature = {
  shape: 'binary-feature-collection',
  points: {
    positions: {value: new Float32Array([1,23, 4.56]), size: 2},
    properties: [{name: 'London'}],
    numericProps: {
      population: {value: new Float32Array([10000000]), size: 1}
    },
    featureIds: {value: new Uint16Array([0]), size: 1},
    globalFeatureIds: {value: new Uint16Array([0]), size: 1},
    fields: [{id: 123}]
  }
};

Overriding attibutes

In order to pass pass attributes directly directly to the sublayers, an optional attributes member can be added to the points, lines or polygons. For example to pass the getWidth attribute to the PathLayer:

{
  lines: {
    // ...
    attributes: {
      getWidth: {value: new Float32Array([1, 2, 3, ....]), size: 1}
    }
  }
}

Remarks

• Geometry transition can be enabled with props.transitions: {geometry: <transition_settings>}.
• Input data must adhere to the GeoJSON specification. Most GIS software support exporting to GeoJSON format. You may validate your data with free tools such as this.
• The GeoJsonLayer renders 3D geometries if each feature's coordinates contain 3D points.

Source

modules/layers/src/geojson-layer