BrushingExtension

The BrushingExtension adds GPU-based data brushing functionalities to layers. It allows the layer to show/hide objects based on the current pointer position.

import {ScatterplotLayer} from '@deck.gl/layers';
import {BrushingExtension} from '@deck.gl/extensions';

const layer = new ScatterplotLayer({
  id: 'points',
  data: POINTS,

  // props from ScatterplotLayer
  getPosition: d => d.position,
  getRadius: d => d.radius,

  // props added by BrushingExtension
  brushingEnabled: true,
  brushingRadius: 100000,

  // Define extensions
  extensions: [new BrushingExtension()]
});

Installation

To install the dependencies from NPM:

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

import {BrushingExtension} from '@deck.gl/extensions';
new BrushingExtension();

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>
<script src="https://unpkg.com/@deck.gl/extensions@^9.0.0/dist.min.js"></script>

new deck.BrushingExtension();

Constructor

new BrushingExtension();

Layer Properties

When added to a layer via the extensions prop, the BrushingExtension adds the following properties to the layer:

brushingRadius (number) {#brushingradius}

The brushing radius centered at the pointer, in meters. If a data object is within this circle, it is rendered; otherwise it is hidden.

brushingEnabled (boolean, optional) {#brushingenabled}

• Default: true

Enable/disable brushing. If brushing is disabled, all objects are rendered.

Brushing is always disabled when the pointer leaves the current viewport.

brushingTarget (string, optional) {#brushingtarget}

• Default: source

The position used to filter each object by. One of the following:

• 'source': Use the primary position for each object. This can mean different things depending on the layer. It usually refers to the coordinates returned by getPosition or getSourcePosition accessors.
• 'target': Use the secondary position for each object. This may not be available in some layers. It usually refers to the coordinates returned by getTargetPosition accessors.
• 'source_target': Use both the primary position and secondary position for each object. Show objet if either is in brushing range.
• 'custom': Some layers may not describe their data objects with one or two coordinates, for example PathLayer and PolygonLayer. Use this option with the getBrushingTarget prop to provide a custom position that each object should be filtered by.

getBrushingTarget (Accessor<Position>, optional) {#getbrushingtarget}

• Default: null

Called to retrieve an arbitrary position for each object that it will be filtered by. Returns an array [x, y]. Only effective if brushingTarget is set to custom.

Source

modules/extensions/src/brushing