Path Width

<!--
  示例：路径分级
  要点：PathLayer 按道路等级映射宽度与颜色，宽度单位为像素
  依赖：deck.gl 9.0 · 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>路径分级</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:14px;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 input[type=range]{width:150px;accent-color:#4f9ef8}
  .bar button{font:inherit;font-size:12px;padding:3px 10px;border-radius:4px;cursor:pointer;
       border:1px solid #2f3947;background:#1d242e;color:#c9d3e0}
  .bar button:hover{background:#26303d}
  #cv{flex:1 1 auto;min-height:0;width:100%;display:block}

</style>
</head>
<body>
<div class="bar"><span>道路 <b id="n">—</b></span><span>快速路 7 px · 主干道 4 px · 支路 2 px</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 roads = [];
  for (var i = 0; i < 14; i++) {
    var path = [];
    var lng = 116.24 + Math.random() * 0.30;
    var lat = 39.80 + Math.random() * 0.16;
    var head = Math.random() * Math.PI * 2;
    for (var s = 0; s < 40; s++) {
      head += (Math.random() - 0.5) * 0.3;
      lng += Math.cos(head) * 0.0032;
      lat += Math.sin(head) * 0.0024;
      path.push([lng, lat]);
    }
    roads.push({ path: path, level: i < 3 ? 3 : (i < 8 ? 2 : 1) });
  }

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

  var deckgl = new deck.Deck({
    canvas: 'cv',
    width: '100%',
    height: '100%',
    initialViewState: { longitude: 116.39, latitude: 39.88, zoom: 10.8, pitch: 25, bearing: -12 },
    controller: true,
    layers: [
      new deck.PathLayer({
        id: 'roads',
        data: roads,
        getPath: function (d) { return d.path; },
        getWidth: function (d) { return d.level === 3 ? 7 : (d.level === 2 ? 4 : 2); },
        widthUnits: 'pixels',
        widthMinPixels: 1,
        getColor: function (d) {
          return d.level === 3 ? [255, 196, 96, 235] :
                 (d.level === 2 ? [110, 200, 255, 220] : [120, 145, 175, 190]);
        },
        jointRounded: true,
        capRounded: true,
        pickable: true
      })
    ],
    getTooltip: function (info) {
      if (!info.object) return null;
      var lv = info.object.level;
      return (lv === 3 ? '快速路' : (lv === 2 ? '主干道' : '支路'));
    }
  });
  window.__deck = deckgl;
})();
</script>
</body>
</html>