arc-layer.md

ArcLayer

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

The ArcLayer renders raised arcs joining pairs of source and target coordinates.

import DeckGL from '@deck.gl/react';
import {ArcLayer} from '@deck.gl/layers';

function App({data, viewState}) {
  /**
   * Data format:
   * [
   *   {
   *     inbound: 72633,
   *     outbound: 74735,
   *     from: {
   *       name: '19th St. Oakland (19TH)',
   *       coordinates: [-122.269029, 37.80787]
   *     },
   *     to: {
   *       name: '12th St. Oakland City Center (12TH)',
   *       coordinates: [-122.271604, 37.803664]
   *   },
   *   ...
   * ]
   */
  const layer = new ArcLayer({
    id: 'arc-layer',
    data,
    pickable: true,
    getWidth: 12,
    getSourcePosition: d => d.from.coordinates,
    getTargetPosition: d => d.to.coordinates,
    getSourceColor: d => [Math.sqrt(d.inbound), 140, 0],
    getTargetColor: d => [Math.sqrt(d.outbound), 140, 0],
  });

  return <DeckGL viewState={viewState}
    layers={[layer]}
    getTooltip={({object}) => object && `${object.from.name} to ${object.to.name}`} />;
}

Installation

To install the dependencies from NPM:

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

import {ArcLayer} from '@deck.gl/layers';
new ArcLayer({});

To use pre-bundled scripts:

<script src="https://unpkg.com/deck.gl@^8.0.0/dist.min.js"></script>
<!-- or -->
<script src="https://unpkg.com/@deck.gl/core@^8.0.0/dist.min.js"></script>
<script src="https://unpkg.com/@deck.gl/layers@^8.0.0/dist.min.js"></script>

new deck.ArcLayer({});

Properties

Inherits from all Base Layer properties.

Render Options

greatCircle (Boolean, optional) {#greatcircle}

• Default: false

If true, create the arc along the shortest path on the earth surface. This option is only effective with data in the LNGLAT coordinate system.

numSegments (Number, optional) {#numsegments}

• Default: 50

The number of segments used to draw each arc. This prop can be used to make arcs smooth when using greatCircle with long paths.

widthUnits (String, optional) {#widthunits}

• Default: 'pixels'

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

widthScale (Number, optional) {#widthscale}

• Default: 1

The scaling multiplier for the width of each line. This prop is a very efficient way to change the width of all objects, comparing to recalculating the width for each object with getWidth.

widthMinPixels (Number, optional) {#widthminpixels}

• Default: 0

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

widthMaxPixels (Number, optional) {#widthmaxpixels}

• 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.

Data Accessors

getSourcePosition (Function, optional) {#getsourceposition}

• Default: object => object.sourcePosition

Method called to retrieve the source position of each object.

getTargetPosition (Function, optional) {#gettargetposition}

• Default: object => object.targetPosition

Method called to retrieve the target position of each object.

getSourceColor (Function|Array, optional) {#getsourcecolor}

• Default: [0, 0, 0, 255]

The rgba color 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 source color for all objects.
• If a function is provided, it is called on each object to retrieve its source color.

getTargetColor (Function|Array, optional) {#gettargetcolor}

• Default [0, 0, 0, 255]

The rgba color at the target, in r, g, b, [a]. Each component is in the 0-255 range.

• If an array is provided, it is used as the target color for all objects.
• If a function is provided, it is called on each object to retrieve its target color.

getWidth (Function|Number, optional) {#getwidth}

• Default: 1

The line width of each object, in units specified by widthUnits (default pixels).

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

getHeight (Function|Number, optional) {#getheight}

• Default: 1

Multiplier of layer height. 0 will make the layer flat.

getTilt (Function|Number, optional) {#gettilt}

• Default: 0

Use to tilt the arc to the side if you have multiple arcs with the same source and target positions. In degrees, can be positive or negative (-90 to +90).

Source

modules/layers/src/arc-layer