Animate a point | TrackAsia GL JS Docs

Animate the position of a point by updating a GeoJSON source on each frame.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Animate a point</title>
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
<script src="https://unpkg.com/trackasia-gl@1.0.5/dist/trackasia-gl.js"></script>
<link href="https://unpkg.com/trackasia-gl@1.0.5/dist/trackasia-gl.css" rel="stylesheet" />
<style>
	body { margin: 0; padding: 0; }
	#map { position: absolute; top: 0; bottom: 0; width: 100%; }
</style>
</head>
<body>
<div id="map"></div>
<script>
var map = new trackasiagl.Map({
container: 'map',
style: 'https://maps.track-asia.com/styles/v1/streets.json?key=public_key',
center: [0, 0],
zoom: 2
});
 
var radius = 20;
 
function pointOnCircle(angle) {
return {
'type': 'Point',
'coordinates': [Math.cos(angle) * radius, Math.sin(angle) * radius]
};
}
 
map.on('load', function () {
// Add a source and layer displaying a point which will be animated in a circle.
map.addSource('point', {
'type': 'geojson',
'data': pointOnCircle(0)
});
 
map.addLayer({
'id': 'point',
'source': 'point',
'type': 'circle',
'paint': {
'circle-radius': 10,
'circle-color': '#007cbf'
}
});
 
function animateMarker(timestamp) {
// Update the data to a new position based on the animation timestamp. The
// divisor in the expression `timestamp / 1000` controls the animation speed.
map.getSource('point').setData(pointOnCircle(timestamp / 1000));
 
// Request the next frame of the animation.
requestAnimationFrame(animateMarker);
}
 
// Start the animation.
animateMarker(0);
});
</script>
 
</body>
</html>