line-layer.md

LineLayer

The Line Layer renders flat lines joining pairs of source and target points, specified as latitude/longitude coordinates.

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

const App = ({data, viewport}) => {

  /**
   * 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 LineLayer({
    id: 'line-layer',
    data,
    pickable: true,
    getWidth: 50,
    getSourcePosition: d => d.from.coordinates,
    getTargetPosition: d => d.to.coordinates,
    getColor: d => [Math.sqrt(d.inbound + d.outbound), 140, 0],
    onHover: ({object, x, y}) => {
      const tooltip = `${object.from.name} to ${object.to.name}`;
      /* Update tooltip
         http://deck.gl/#/documentation/developer-guide/adding-interactivity?section=example-display-a-tooltip-for-hovered-object
      */
    }
  });

  return (<DeckGL {...viewport} layers={[layer]} />);
};

Installation

To install the dependencies from NPM:

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

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

To use pre-bundled scripts:

<script src="https://unpkg.com/deck.gl@~7.0.0/dist.min.js"></script>
<!-- or -->
<script src="https://unpkg.com/@deck.gl/core@~7.0.0/dist.min.js"></script>
<script src="https://unpkg.com/@deck.gl/layers@~7.0.0/dist.min.js"></script>

new deck.LineLayer({});

Properties

Inherits from all Base Layer properties.

Render Options

The width used to draw each line. Unit is pixels.

widthUnits (String, optional)

• Default: 'pixels'

The units of the line width, one of 'meters', 'pixels'. When zooming in and out, meter sizes scale with the base map, and pixel sizes remain the same on screen.

widthScale (Number, optional)

• 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)

• Default: 0

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

widthMaxPixels (Number, optional)

• Default: Number.MAX_SAFE_INTEGER

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

Data Accessors

getSourcePosition (Function, optional)

• Default: object => object.sourcePosition

Method called to retrieve the source position of each object.

getTargetPosition (Function, optional)

• Default: object => object.targetPosition

Method called to retrieve the target position of each object.

getColor (Function|Array, optional)

• Default: [0, 0, 0, 255]

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

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

getWidth (Function|Number, optional)

• 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.

Source

modules/layers/src/line-layer