LineStringの境界に合わせる
最初の座標を LngLatBounds に引き継ぎ、最後の座標を含むようにチェーン拡張することで、LineString の境界を取得します。
<!DOCTYPE html><html><head><meta charset="utf-8"><title>LineStringの境界に合わせる</title><meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no"><link href="https://api.mapbox.com/mapbox-gl-js/v2.14.1/mapbox-gl.css" rel="stylesheet"><script src="https://api.mapbox.com/mapbox-gl-js/v2.14.1/mapbox-gl.js"></script><style>body { margin: 0; padding: 0; }#map { position: absolute; top: 0; bottom: 0; width: 100%; }</style></head><body><style>.btn-control {font: bold 12px/20px 'Helvetica Neue', Arial, Helvetica, sans-serif;background-color: #3386c0;color: #fff;position: absolute;top: 20px;left: 50%;z-index: 1;border: none;width: 200px;margin-left: -100px;display: block;cursor: pointer;padding: 10px 20px;border-radius: 3px;} .btn-control:hover {background-color: #4ea0da;}</style><div id="map"></div><button id="zoomto" class="btn-control">Zoom to bounds</button> <script> // TO MAKE THE MAP APPEAR YOU MUST // ADD YOUR ACCESS TOKEN FROM // https://account.mapbox.com mapboxgl.accessToken = 'YOUR_MAPBOX_ACCESS_TOKEN';// A GeoJSON object with a LineString route from the White House to Capitol Hillconst geojson = {'type': 'FeatureCollection','features': [{'type': 'Feature','geometry': {'type': 'LineString','properties': {},'coordinates': [[-77.0366048812866, 38.89873175227713],[-77.03364372253417, 38.89876515143842],[-77.03364372253417, 38.89549195896866],[-77.02982425689697, 38.89549195896866],[-77.02400922775269, 38.89387200688839],[-77.01519012451172, 38.891416957534204],[-77.01521158218382, 38.892068305429156],[-77.00813055038452, 38.892051604275686],[-77.00832366943358, 38.89143365883688],[-77.00818419456482, 38.89082405874451],[-77.00815200805664, 38.88989712255097]]}}]}; const map = new mapboxgl.Map({container: 'map',style: 'mapbox://styles/mapbox/light-v10',center: [-77.0214, 38.897],zoom: 12}); map.on('load', () => {map.addSource('LineString', {'type': 'geojson','data': geojson});map.addLayer({'id': 'LineString','type': 'line','source': 'LineString','layout': {'line-join': 'round','line-cap': 'round'},'paint': {'line-color': '#BF93E4','line-width': 5}}); document.getElementById('zoomto').addEventListener('click', () => {// Geographic coordinates of the LineStringconst coordinates = geojson.features[0].geometry.coordinates; // Create a 'LngLatBounds' with both corners at the first coordinate.const bounds = new mapboxgl.LngLatBounds(coordinates[0],coordinates[0]); // Extend the 'LngLatBounds' to include every coordinate in the bounds result.for (const coord of coordinates) {bounds.extend(coord);} map.fitBounds(bounds, {padding: 20});});});</script> </body></html>