Overlay

<!--
  示例：deck.gl 地图与图层叠加
  要点：TileLayer 加载栅格瓦片作底图，ArcLayer 与 ScatterplotLayer 叠加其上
  依赖：deck.gl 9.0 · jsDelivr CDN · Esri 暗色底图
-->
<!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>地图与图层叠加</title>
<style>
  html,body{height:100%;margin:0;background:#0d1117}
  body{display:flex;flex-direction:column;overflow:hidden;
       font:13px/1.6 -apple-system,"Segoe UI","PingFang SC",sans-serif;color:#e6e8ec}
  .bar{position:relative;z-index:5;flex:0 0 auto;padding:8px 12px;background:#161b22;border-bottom:1px solid #252c36;
       display:flex;gap:16px;align-items:center;font-size:12px;color:#8b93a1;flex-wrap:wrap}
  .bar b{color:#58a6ff;font-weight:600}
  .bar label{display:flex;align-items:center;gap:5px;cursor:pointer}
  .bar input[type=checkbox]{accent-color:#4f9ef8}
  .bar .attr{margin-left:auto;font-size:11px;color:#6b7381}
  #cv{flex:1 1 auto;min-height:0;width:100%}
</style>
</head>
<body>
<div class="bar">
  <span>节点 <b id="n">—</b></span>
  <label><input type="checkbox" id="base" checked> 显示底图</label>
  <span>悬停查看线路流量</span>
  <span class="attr">Tiles © Esri · DeLorme, HERE</span>
</div>
<canvas id="cv"></canvas>
<script src="https://cdn.jsdelivr.net/npm/deck.gl@9.0.35/dist.min.js"></script>
<script>
(function () {
  'use strict';

  if (typeof deck === 'undefined') {
    document.body.innerHTML =
      '<div style="padding:24px;color:#ff8c74">deck.gl 加载失败，请检查能否访问 cdn.jsdelivr.net</div>';
    return;
  }

  var cities = {
    'BEIJING': [116.39, 39.90],
    'SHANGHAI': [121.47, 31.23],
    'GUANGZHOU': [113.26, 23.12],
    'CHENGDU': [104.06, 30.57],
    'XIAN': [108.94, 34.34],
    'WUHAN': [114.30, 30.59],
    'HARBIN': [126.64, 45.75],
    'URUMQI': [87.61, 43.82],
    'KUNMING': [102.71, 25.04],
    'LHASA': [91.11, 29.65]
  };

  var nodes = [];
  for (var name in cities) {
    if (!Object.prototype.hasOwnProperty.call(cities, name)) continue;
    nodes.push({
      name: name,
      lng: cities[name][0],
      lat: cities[name][1],
      load: 40 + Math.round(Math.random() * 60)
    });
  }

  var flows = [
    { from: 'BEIJING', to: 'SHANGHAI', v: 780 },
    { from: 'BEIJING', to: 'GUANGZHOU', v: 610 },
    { from: 'BEIJING', to: 'HARBIN', v: 320 },
    { from: 'BEIJING', to: 'URUMQI', v: 260 },
    { from: 'SHANGHAI', to: 'WUHAN', v: 370 },
    { from: 'SHANGHAI', to: 'CHENGDU', v: 300 },
    { from: 'GUANGZHOU', to: 'KUNMING', v: 220 },
    { from: 'CHENGDU', to: 'LHASA', v: 150 },
    { from: 'XIAN', to: 'BEIJING', v: 240 },
    { from: 'WUHAN', to: 'SHANGHAI', v: 280 }
  ];

  document.getElementById('n').textContent = nodes.length;

  function basemapLayer() {
    return new deck.TileLayer({
      id: 'basemap',
      data: 'https://services.arcgisonline.com/ArcGIS/rest/services/Canvas/World_Dark_Gray_Base/MapServer/tile/{z}/{y}/{x}',
      minZoom: 0,
      maxZoom: 16,
      tileSize: 256,
      renderSubLayers: function (props) {
        var bb = props.tile.boundingBox;
        return new deck.BitmapLayer(props, {
          data: null,
          image: props.data,
          bounds: [bb[0][0], bb[0][1], bb[1][0], bb[1][1]]
        });
      }
    });
  }

  var arcLayer = new deck.ArcLayer({
    id: 'flows',
    data: flows,
    getSourcePosition: function (d) { return cities[d.from]; },
    getTargetPosition: function (d) { return cities[d.to]; },
    getSourceColor: [96, 180, 255, 210],
    getTargetColor: [255, 176, 92, 210],
    getWidth: function (d) { return 1 + d.v / 240; },
    widthUnits: 'pixels',
    widthMinPixels: 1,
    getHeight: function (d) { return 0.3 + d.v / 3000; },
    greatCircle: true,
    pickable: true
  });

  var nodeLayer = new deck.ScatterplotLayer({
    id: 'nodes',
    data: nodes,
    getPosition: function (d) { return [d.lng, d.lat]; },
    getRadius: function (d) { return 3 + d.load / 28; },
    radiusUnits: 'pixels',
    radiusMinPixels: 3,
    radiusMaxPixels: 12,
    getFillColor: [255, 210, 120, 235],
    stroked: true,
    getLineColor: [20, 30, 46, 220],
    lineWidthUnits: 'pixels',
    getLineWidth: 1,
    pickable: true
  });

  var labelLayer = new deck.TextLayer({
    id: 'labels',
    data: nodes,
    getText: function (d) { return d.name; },
    getPosition: function (d) { return [d.lng, d.lat]; },
    getSize: 11,
    sizeUnits: 'pixels',
    getColor: [214, 228, 246, 255],
    getPixelOffset: [0, -15],
    getTextAnchor: 'middle',
    getAlignmentBaseline: 'center',
    characterSet: 'ABCDEFGHIJKLMNOPQRSTUVWXYZ ',
    outlineWidth: 0.1,
    outlineColor: [8, 14, 26, 210],
    billboard: true
  });

  var showBase = true;

  function layers() {
    var out = [];
    if (showBase && deck.TileLayer) out.push(basemapLayer());
    out.push(arcLayer, nodeLayer, labelLayer);
    return out;
  }

  var deckgl = new deck.Deck({
    canvas: 'cv',
    width: '100%',
    height: '100%',
    initialViewState: {
      longitude: 108.0,
      latitude: 34.0,
      zoom: 3.4,
      pitch: 22,
      bearing: 0,
      maxPitch: 60
    },
    controller: true,
    layers: layers(),
    getTooltip: function (info) {
      if (!info.object) return null;
      var o = info.object;
      if (o.from) return o.from + ' → ' + o.to + '：' + o.v;
      if (o.name) return o.name + ' · 负载 ' + o.load;
      return null;
    }
  });

  document.getElementById('base').addEventListener('change', function (e) {
    showBase = e.target.checked;
    deckgl.setProps({ layers: layers() });
  });

  window.__deck = deckgl;
})();
</script>
</body>
</html>