> For the complete documentation index, see [llms.txt](https://docs.mapbox.com/mapbox-gl-js/ja/llms.txt)
# Animate a point along a route
Use [Turf](http://turfjs.org/) to smoothly animate a point along the distance of a line.
> Example code:
**JavaScript**
```html
Animate a point along a route
Replay
```
**React**
```jsx
import React, { useEffect, useRef, useState } from 'react';
import * as mapboxgl from 'mapbox-gl/esm';
import 'mapbox-gl/dist/mapbox-gl.css';
import * as turf from '@turf/turf';
const MapboxExample = () => {
const mapContainerRef = useRef();
const mapRef = useRef();
const pointRef = useRef(null);
const originRef = useRef(null);
const routeRef = useRef(null);
const [disabled, setDisabled] = useState(true);
const steps = 500;
let counter = 0;
function handleClick() {
pointRef.current.features[0].geometry.coordinates = originRef.current;
mapRef.current.getSource('point').setData(pointRef.current);
animate(0);
setDisabled(true);
}
function animate() {
const start =
routeRef.current.features[0].geometry.coordinates[
counter >= steps ? counter - 1 : counter
];
const end =
routeRef.current.features[0].geometry.coordinates[
counter >= steps ? counter : counter + 1
];
if (!start || !end) {
setDisabled(false);
return;
}
pointRef.current.features[0].geometry.coordinates =
routeRef.current.features[0].geometry.coordinates[counter];
pointRef.current.features[0].properties.bearing = turf.bearing(
turf.point(start),
turf.point(end)
);
mapRef.current.getSource('point').setData(pointRef.current);
if (counter < steps) {
requestAnimationFrame(animate);
}
counter = counter + 1;
}
useEffect(() => {
mapRef.current = new mapboxgl.Map({
// TO MAKE THE MAP APPEAR YOU MUST
// ADD YOUR ACCESS TOKEN FROM
// https://account.mapbox.com
accessToken: 'YOUR_MAPBOX_ACCESS_TOKEN',
container: mapContainerRef.current,
style: 'mapbox://styles/mapbox/standard',
config: {
basemap: {
theme: 'monochrome',
lightPreset: 'night'
}
},
center: [-96, 37.8],
zoom: 3,
pitch: 40
});
const origin = [-122.414, 37.776];
originRef.current = origin;
const destination = [-77.032, 38.913];
const route = {
type: 'FeatureCollection',
features: [
{
type: 'Feature',
geometry: {
type: 'LineString',
coordinates: [origin, destination]
}
}
]
};
routeRef.current = route;
const point = {
type: 'FeatureCollection',
features: [
{
type: 'Feature',
properties: {},
geometry: {
type: 'Point',
coordinates: origin
}
}
]
};
pointRef.current = point;
const lineDistance = turf.length(route.features[0]);
const arc = [];
for (let i = 0; i < lineDistance; i += lineDistance / steps) {
const segment = turf.along(route.features[0], i);
arc.push(segment.geometry.coordinates);
}
route.features[0].geometry.coordinates = arc;
mapRef.current.on('load', () => {
mapRef.current.addSource('route', {
type: 'geojson',
data: route
});
mapRef.current.addSource('point', {
type: 'geojson',
data: point
});
mapRef.current.addLayer({
id: 'route',
source: 'route',
type: 'line',
paint: {
'line-width': 2,
'line-color': '#007cbf',
'line-emissive-strength': 1
}
});
mapRef.current.addLayer({
id: 'point',
source: 'point',
type: 'circle',
paint: {
'circle-radius': 6,
'circle-color': '#007cbf',
'circle-emissive-strength': 1,
'circle-stroke-width': 2,
'circle-stroke-color': '#ffffff'
}
});
animate(counter);
});
// Cleanup function
return () => mapRef.current.remove();
}, []);
return (
);
};
export default MapboxExample;
```