Shield size debug

by Tristen Brown

HTML

<script src="https://api.tiles.mapbox.com/mapbox-gl-js/v1.4.0/mapbox-gl.js"></script>
<link rel="stylesheet" href="https://api.tiles.mapbox.com/mapbox-gl-js/v1.4.0/mapbox-gl.css">
<div id="map"></div>
<div id="z">13</div>

CSS

body {
    margin: 0;
    padding: 0;
  }

  #map {
    position: absolute;
    top: 0;
    bottom: 0;
    width: 100%;
  }

  #z {
    background: black;
    font-family: 'Helvetica';
    color: white;
    position: absolute;
    top: 10px;
    left: 10px;
    padding: 5px;
    border-radius: 3px;
  }

JavaScript

mapboxgl.accessToken = 'pk.eyJ1IjoidHJpc3RlbiIsImEiOiJjajZoOXU4Z2kwNnppMnlxd2d6bTFvZ2xtIn0.PP7AoUakMfeqdXFHdsY0oA';

const style = {
  version: 8,
  name: 'shield-debug',
  center: [139.80666, 35.67313],
  zoom: 13,
  sources: {
    composite: {
      url: 'mapbox://mapbox.mapbox-streets-v8',
      type: 'vector'
    }
  },
  sprite: 'mapbox://sprites/mapbox/streets-v11',
  glyphs: 'mapbox://fonts/mapbox/{fontstack}/{range}.pbf',
  layers: [{
      id: 'land',
      type: 'background',
      paint: {
        'background-color': 'hsl(35, 12%, 89%)'
      }
    },
    {
      id: 'water',
      type: 'fill',
      source: 'composite',
      'source-layer': 'water',
      paint: {
        'fill-color': 'hsl(196, 80%, 70%)'
      }
    },
    {
      id: 'shield',
      type: 'symbol',
      source: 'composite',
      'source-layer': 'road',
      minzoom: 6,
      filter: [
        'all',
        ['has', 'reflen'],
        ['<=', ['get', 'reflen'], 6],
      ],
      layout: {
        'text-size': [

          'step',
          ['zoom'],
          8.5,
          14,
          10
        ],


        'icon-image': [
          'concat',
          ['get', 'shield'],
          '-',
          ['to-string', ['get', 'reflen']]
        ],
        'icon-size': [
          'interpolate',
          ['exponential', 1.5],
          ['zoom'],
          8,
          ['match', ['get', 'iso_3166_1'],
            ['JP'], 0.25, 1
          ],
          14,
          1
        ],
        'text-field': ['get', 'ref']
      },
      paint: {
        'text-color': 'black'
      }
    }
  ]
}

const map = new mapboxgl.Map({
  container: 'map',
  style
});

map.on('load', () => {
  const z = document.getElementById('z');
  map.on('move', () => {
    z.textContent = map.getZoom().toFixed(2);
  });
});