GeoJsonLayer
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.
- JavaScript
- TypeScript
- React
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
The GeoJSONLayer
accepts any of the following formats passed to the data
prop:
- A valid GeoJSON
FeatureCollection
,Feature
,Geometry
orGeometryCollection
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)
- 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)
- 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)
- 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)
- 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)
- 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)
- 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)
- Default:
'meters'
The units of the line width, one of 'meters'
, 'common'
, and 'pixels'
. See unit system.
lineWidthScale
(number, optional)
- Default:
1
A multiplier that is applied to all line widths.
lineWidthMinPixels
(number, optional)
- 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)
- 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)
- Default:
false
Type of line caps. If true
, draw round caps. Otherwise draw square caps.
lineJointRounded
(boolean, optional)
- Default:
false
Type of line joint. If true
, draw round joints. Otherwise draw miter joints.
lineMiterLimit
(number, optional)
- Default:
4
The maximum extent of a joint in ratio to the stroke width.
Only works if lineJointRounded
is false
.
lineBillboard
(boolean, optional)
- 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)
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)
- 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)
- 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)
- 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)
- 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)
- 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'
.
Prop name | Default value | ScatterplotLayer equivalent |
---|---|---|
getPointRadius | 1 | getRadius |
pointRadiusUnits | 'meters' | radiusUnits |
pointRadiusScale | 1 | radiusScale |
pointRadiusMinPixels | 0 | radiusMinPixels |
pointRadiusMaxPixels | Number.MAX_SAFE_INTEGER | radiusMaxPixels |
pointAntialiasing | true | antialiasing |
pointBillboard | false | billboard |
pointType:icon Options
The following props are forwarded to an IconLayer
if pointType
is 'icon'
.
Prop name | Default value | IconLayer equivalent |
---|---|---|
iconAtlas | null | iconAtlas |
iconMapping | {} | iconMapping |
getIcon | f => f.properties.icon | getIcon |
getIconSize | 1 | getSize |
getIconColor | [0, 0, 0, 255] | getColor |
getIconAngle | 0 | getAngle |
getIconPixelOffset | [0, 0] | getPixelOffset |
iconSizeUnits | 'pixels' | sizeUnits |
iconSizeScale | 1 | sizeScale |
iconSizeMinPixels | 0 | sizeMinPixels |
iconSizeMaxPixels | Number.MAX_SAFE_INTEGER | sizeMaxPixels |
iconBillboard | true | billboard |
iconAlphaCutoff | 0.05 | alphaCutoff |
pointType:text Options
The following props are forwarded to a TextLayer
if pointType
is 'text'
.
Prop name | Default value | TextLayer equivalent |
---|---|---|
getText | f => f.properties.text | getText |
getTextColor | [0, 0, 0, 255] | getColor |
getTextAngle | 0 | getAngle |
getTextSize | 32 | getSize |
getTextAnchor | 'middle' | getTextAnchor |
getTextAlignmentBaseline | 'center' | getAlignmentBaseline |
getTextPixelOffset | [0, 0] | getPixelOffset |
getTextBackgroundColor | [255, 255, 255, 255] | getBackgroundColor |
getTextBorderColor | [0, 0, 0, 255] | getBorderColor |
getTextBorderWidth | 0 | getBorderWidth |
textSizeUnits | 'pixels' | sizeUnits |
textSizeScale | 1 | sizeScale |
textSizeMinPixels | 0 | sizeMinPixels |
textSizeMaxPixels | Number.MAX_SAFE_INTEGER | sizeMaxPixels |
textCharacterSet | ASCII chars 32-128 | characterSet |
textFontFamily | 'Monaco, monospace' | fontFamily |
textFontWeight | 'normal' | fontWeight |
textLineHeight | 1 | lineHeight |
textMaxWidth | -1 | maxWidth |
textWordBreak | 'break-word' | wordBreak |
textBackground | false | background |
textBackgroundPadding | [0, 0] | backgroundPadding |
textOutlineColor | [0, 0, 0, 255] | outlineColor |
textOutlineWidth | 0 | outlineWidth |
textBillboard | true | billboard |
textFontSettings | {} | fontSettings |
Sub Layers
The GeoJsonLayer renders the following sublayers:
polygons-fill
- a SolidPolygonLayer rendering all thePolygon
andMultiPolygon
features.polygons-stroke
- a PathLayer rendering the outline of all thePolygon
andMultiPolygon
features. Only rendered ifstroked: true
andextruded: false
.linestrings
- a PathLayer rendering all theLineString
andMultiLineString
features.points-circle
- a ScatterplotLayer rendering all thePoint
andMultiPoint
features ifpointType
is'circle'
.points-icon
- an IconLayer rendering all thePoint
andMultiPoint
features ifpointType
is'icon'
.points-text
- a TextLayer rendering all thePoint
andMultiPoint
features ifpointType
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: 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: Float32Array([x0, y0, x1, y1, x2, y2, ...]), size: 2}, // Use size=2 for xy and size=3 for xyz
pathIndices: {value: 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: Float32Array([x0, y0, x1, y1, x2, y2, ...]), size: 2}, // Use size=2 for xy and size=3 for xyz
polygonIndices: {value: Uint16Array([0, 100, ...]), size: 1}, // First polygon contains vertex 0-99
primitivePolygonIndices: {value: 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: Float32Array([value0, value1, ...], size: 1}
},
// properties
} as BinaryPointFeature
Both properties
and numericProps
are specified per-feature.
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:
Global feature ID | Feature ID | Feature type | Vertex count |
---|---|---|---|
0 | 0 | Point | 1 |
1 | 0 | LineString | 10 |
2 | 0 | Polygon | 5 |
3 | 1 | MultiPoint | 3 |
4 | 2 | Point | 1 |
5 | 1 | Polygon | 5 |
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: Float32Array([1,23, 4.56]), size: 2},
properties: [{name: 'London'}],
numericProps: {
population: {value: Float32Array([10000000], size: 1}
},
featureIds: {value: Uint16Array([0]), size: 1},
globalFeatureIds: {value: 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.