trips-layer.md

TripsLayer

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

The TripsLayer renders animated paths that represent vehicle trips.

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

import {Deck} from '@deck.gl/core';
import {TripsLayer} from '@deck.gl/geo-layers';

const layer = new TripsLayer({
  id: 'TripsLayer',
  data: 'https://raw.githubusercontent.com/visgl/deck.gl-data/master/website/sf.trips.json',
  
  getPath: d => d.waypoints.map(p => p.coordinates),
  // Timestamp is stored as float32, do not return a long int as it will cause precision loss
  getTimestamps: d => d.waypoints.map(p => p.timestamp - 1554772579000),
  getColor: [253, 128, 93],
  currentTime: 500,
  trailLength: 600,
  capRounded: true,
  jointRounded: true,
  widthMinPixels: 8
});

new Deck({
  initialViewState: {
    longitude: -122.4,
    latitude: 37.74,
    zoom: 11
  },
  controller: true,
  layers: [layer]
});

import {Deck} from '@deck.gl/core';
import {TripsLayer} from '@deck.gl/geo-layers';

type DataType = {
  waypoints: {
    coordinates: [longitude: number, latitude: number];
    timestamp: number;
  }[]
};

const layer = new TripsLayer<DataType>({
  id: 'TripsLayer',
  data: 'https://raw.githubusercontent.com/visgl/deck.gl-data/master/website/sf.trips.json',
  
  getPath: (d: DataType) => d.waypoints.map(p => p.coordinates),
  // Timestamp is stored as float32, do not return a long int as it will cause precision loss
  getTimestamps: (d: DataType) => d.waypoints.map(p => p.timestamp - 1554772579000),
  getColor: [253, 128, 93],
  currentTime: 500,
  trailLength: 600,
  capRounded: true,
  jointRounded: true,
  widthMinPixels: 8
});

new Deck({
  initialViewState: {
    longitude: -122.4,
    latitude: 37.74,
    zoom: 11
  },
  controller: true,
  layers: [layer]
});

import React from 'react';
import DeckGL from '@deck.gl/react';
import {TripsLayer} from '@deck.gl/geo-layers';

type DataType = {
  waypoints: {
    coordinates: [longitude: number, latitude: number];
    timestamp: number;
  }[]
};

function App() {
  const layer = new TripsLayer<DataType>({
    id: 'TripsLayer',
    data: 'https://raw.githubusercontent.com/visgl/deck.gl-data/master/website/sf.trips.json',
    
    getPath: (d: DataType) => d.waypoints.map(p => p.coordinates),
    // Timestamp is stored as float32, do not return a long int as it will cause precision loss
    getTimestamps: (d: DataType) => d.waypoints.map(p => p.timestamp - 1554772579000),
    getColor: [253, 128, 93],
    currentTime: 500,
    trailLength: 600,
    capRounded: true,
    jointRounded: true,
    widthMinPixels: 8
  });

  return <DeckGL
    initialViewState={{
      longitude: -122.4,
      latitude: 37.74,
      zoom: 11
    }}
    controller
    layers={[layer]}
  />;
}

Installation

To install the dependencies from NPM:

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

import {TripsLayer} from '@deck.gl/geo-layers';
import type {TripsLayerProps} from '@deck.gl/geo-layers';

new TripsLayer<DataT>(...props: TripsLayerProps<DataT>[]);

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/geo-layers@^9.0.0/dist.min.js"></script>

new deck.TripsLayer({});

Properties

Inherits from all Base Layer and PathLayer properties, plus the following:

Render Options

currentTime (number, optional) {#currenttime}

• Default: 0

The current time of the frame, i.e. the playhead of the animation.

This value should be in the same units as the timestamps from getPath.

fadeTrail (boolean, optional) {#fadetrail}

• Default: true

Whether or not the path fades out.

If false, trailLength has no effect.

trailLength (number, optional) {#traillength}

• Default: 120

How long it takes for a path to completely fade out.

This value should be in the same units as the timestamps from getPath.

Data Accessors

getPath (Accessor<PathGeometry>, optional) {#getpath}

• Default: d => d.path

Called for each data object to retrieve paths. Returns an array of navigation points on a single path.

See PathLayer documentation for supported path formats.

getTimestamps (Accessor<number[]>, optional) {#gettimestamps}

• Default: d => d.timestamps

Returns an array of timestamps, one for each navigation point in the geometry returned by getPath, representing the time that the point is visited.

Because timestamps are stored as 32-bit floating numbers, raw unix epoch time can not be used. You may test the validity of a timestamp by calling Math.fround(t) to check if there would be any loss of precision.

Source

modules/geo-layers/src/trips-layer