Animate a point

Animate the position of a point by updating a GeoJSON source on each frame.

Animate a point

<!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://cdn.jsdelivr.net/npm/@goongmaps/goong-js@1.0.9/dist/goong-js.js"></script>
<link href="https://cdn.jsdelivr.net/npm/@goongmaps/goong-js@1.0.9/dist/goong-js.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>
    goongjs.accessToken = 'wnicbAmnNkoMHNYUKWnlFHezV189FjmMwkNJ7hKW';
    var map = new goongjs.Map({
        container: 'map',
        style: 'https://tiles.goong.io/assets/goong_map_web.json',
        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>