Clusters Dynamic

<!--
  说明：动态聚合
  核心逻辑：Cluster 源按像素距离聚合，setDistance 调半径，点击聚合点 fit 到其范围
  依赖：OpenLayers 10.3.1 · jsDelivr CDN
-->
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta name="robots" content="noindex,follow">
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>动态聚合</title>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/ol@10.3.1/ol.css">
<style>
  html,body{height:100%;margin:0}
  body{display:flex;flex-direction:column;overflow:hidden;
       font:13px/1.6 -apple-system,"Segoe UI","PingFang SC",sans-serif}
  .bar{flex:0 0 auto;padding:8px 12px;background:#f6f7f9;border-bottom:1px solid #e3e6ea;
       display:flex;gap:12px;align-items:center;font-size:12px;color:#58606e;flex-wrap:wrap}
  .bar button{font:inherit;padding:4px 10px;border:1px solid #c9d0da;border-radius:5px;
              background:#fff;color:#1f2a37;cursor:pointer}
  .bar input[type=range]{width:140px}
  #info{margin-left:auto}
  #map{flex:1 1 auto;min-height:0;background:#eef0f3}
</style>
</head>
<body>
<div class="bar">
  <label>聚合距离 <input type="range" id="dist" min="10" max="90" step="5" value="40"></label>
  <span id="dv">40 px</span>
  <button id="regen">重新生成</button>
  <span id="info">—</span>
</div>
<div id="map"></div>
<script src="https://cdn.jsdelivr.net/npm/ol@10.3.1/dist/ol.js"></script>
<script>
(function () {
  'use strict';

  if (typeof ol === 'undefined') {
    document.getElementById('map').innerHTML =
      '<div style="padding:20px;color:#b42318">OpenLayers 加载失败，请检查能否访问 cdn.jsdelivr.net</div>';
    return;
  }

  var fromLonLat = ol.proj.fromLonLat;

  var rawSource = new ol.source.Vector();

  function regenerate() {
    rawSource.clear();
    var feats = [];
    for (var i = 0; i < 600; i++) {
      var lon = 116.10 + Math.random() * 0.70;
      var lat = 39.65 + Math.random() * 0.55;
      feats.push(new ol.Feature({
        geometry: new ol.geom.Point(fromLonLat([lon, lat])),
        id: i
      }));
    }
    rawSource.addFeatures(feats);
  }

  regenerate();

  var clusterSource = new ol.source.Cluster({
    distance: 40,
    minDistance: 12,
    source: rawSource
  });

  var info = document.getElementById('info');

  function clusterStyle(feature) {
    var members = feature.get('features');
    var size = members.length;
    var radius = Math.min(9 + Math.log2(size + 1) * 4, 28);
    return new ol.style.Style({
      image: new ol.style.Circle({
        radius: radius,
        fill: new ol.style.Fill({
          color: size > 30 ? 'rgba(226,72,60,0.85)'
            : size > 10 ? 'rgba(224,140,40,0.85)' : 'rgba(31,95,208,0.85)'
        }),
        stroke: new ol.style.Stroke({ color: '#ffffff', width: 2 })
      }),
      text: new ol.style.Text({
        text: size > 1 ? String(size) : '',
        font: '600 12px sans-serif',
        fill: new ol.style.Fill({ color: '#ffffff' })
      })
    });
  }

  var layer = new ol.layer.Vector({ source: clusterSource, style: clusterStyle });

  var map = new ol.Map({
    target: 'map',
    layers: [new ol.layer.Tile({ source: new ol.source.XYZ({url: 'https://server.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer/tile/{z}/{y}/{x}', attributions: 'Tiles © Esri'}) }), layer],
    view: new ol.View({ center: fromLonLat([116.45, 39.92]), zoom: 10, minZoom: 2, maxZoom: 19 }),
    controls: ol.control.defaults.defaults({ attribution: false, rotate: false })
  });

  map.on('click', function (evt) {
    var hit = map.forEachFeatureAtPixel(evt.pixel, function (f) { return f; }, {
      hitTolerance: 4
    });
    if (!hit) return;
    var members = hit.get('features');
    if (members && members.length > 1) {
      var extent = ol.extent.createEmpty();
      members.forEach(function (f) {
        ol.extent.extend(extent, f.getGeometry().getExtent());
      });
      map.getView().fit(extent, { padding: [70, 70, 70, 70], duration: 500, maxZoom: 16 });
      info.textContent = '展开聚合点：' + members.length + ' 个';
    }
  });

  document.getElementById('dist').addEventListener('input', function () {
    var d = Number(this.value);
    clusterSource.setDistance(d);
    document.getElementById('dv').textContent = d + ' px';
    info.textContent = '聚合距离 ' + d + ' px · 聚合要素 ' + clusterSource.getFeatures().length + ' 个';
  });

  document.getElementById('regen').addEventListener('click', function () {
    regenerate();
    info.textContent = '已重新生成 600 个点';
  });

  info.textContent = '聚合距离 40 px';
})();
</script>
</body>
</html>