Vector tiles with MVT

• Set layers on ol.format.MVT to the source layer name found inside the .pbf.
• Flip the internal y with -tileCoord[2] - 1 when building XYZ tile URLs.
• Use the resolution argument in the style function to keep stroke widths readable.

var parcels = new ol.layer.VectorTile({
  source: new ol.source.VectorTile({
    format: new ol.format.MVT({
      layers: ['parcels'],       // 只解析 parcels 这个源图层
      featureClass: ol.Feature
    }),
    url: 'https://tiles.example.com/parcels/{z}/{x}/{y}.pbf',
    maxZoom: 16,
    projection: 'EPSG:3857'
  }),
  declutter: false,
  style: function (feature, resolution) {
    var usage = feature.get('usage');
    var color = usage === 'residential' ? '#1f5fd0' : '#d0453a';

    return new ol.style.Style({
      stroke: new ol.style.Stroke({ color: color, width: resolution < 4 ? 1.5 : 1 }),
      fill: new ol.style.Fill({
        color: usage === 'residential' ? 'rgba(31, 95, 208, 0.18)' : 'rgba(208, 69, 58, 0.18)'
      })
    });
  }
});

map.addLayer(parcels);

function makeTileLayer(sourceLayer, styleFn, zIndex) {
  return new ol.layer.VectorTile({
    source: new ol.source.VectorTile({
      format: new ol.format.MVT({ layers: [sourceLayer] }),
      url: 'https://tiles.example.com/base/{z}/{x}/{y}.pbf',
      maxZoom: 16
    }),
    style: styleFn,
    zIndex: zIndex
  });
}

var roads = makeTileLayer('roads', function (feature) {
  return new ol.style.Style({
    stroke: new ol.style.Stroke({ color: '#f5f7fa', width: 3 })
  });
}, 10);

var labels = makeTileLayer('labels', function (feature) {
  return new ol.style.Style({
    text: new ol.style.Text({
      text: feature.get('name'),
      font: '500 12px sans-serif',
      fill: new ol.style.Fill({ color: '#16181d' }),
      stroke: new ol.style.Stroke({ color: '#fff', width: 3 })
    })
  });
}, 20);

map.addLayer(roads);
map.addLayer(labels);

• Features crossing tile boundaries are clipped, so area and adjacency stats are unreliable.
• An empty or misspelled layers name renders nothing and logs no error.