Czml Billboard Label

<!--
  示例：用 CZML 描述广告牌与标签
  说明：billboard 与 label 挂在同一个 position 上，图标由 canvas 生成 dataURL 写进 CZML
  核心逻辑：CzmlDataSource.load → dataSources.add → 相机飞到城市上方
  依赖：CesiumJS 1.121 · jsDelivr CDN，图像在页面内生成
-->
<!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>CZML 广告牌与标签</title>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/cesium@1.121.0/Build/Cesium/Widgets/widgets.css">
<style>
  html,body{height:100%;margin:0}
  body{background:#0e1116;color:#e6e8ec;overflow:hidden;
       font:13px/1.6 -apple-system,"Segoe UI","PingFang SC",sans-serif}
  #c{height:100%}
  .cesium-viewer-bottom .cesium-widget-credits,.cesium-viewer-animationContainer,
  .cesium-viewer-timelineContainer{display:none!important}
</style>
</head>
<body>
<div id="c"></div>
<script src="https://cdn.jsdelivr.net/npm/cesium@1.121.0/Build/Cesium/Cesium.js"></script>
<script>
(function () {
  'use strict';

  var viewer = new Cesium.Viewer('c', {
    baseLayer: false,
    baseLayerPicker: false, geocoder: false, homeButton: false,
    sceneModePicker: false, navigationHelpButton: false,
    animation: false, timeline: false, fullscreenButton: false,
    infoBox: false, selectionIndicator: false
  });

  var scene = viewer.scene;
  scene.globe.baseColor = Cesium.Color.fromCssColorString('#1c2733');
  scene.backgroundColor = Cesium.Color.fromCssColorString('#0e1116');
  scene.skyBox.show = false;
  scene.sun.show = false;
  scene.moon.show = false;
  if (scene.skyAtmosphere) scene.skyAtmosphere.show = false;

  /* ---------- 图标：圆形标记 ---------- */
  function makeIcon(fill) {
    var canvas = document.createElement('canvas');
    canvas.width = 64;
    canvas.height = 64;
    var g = canvas.getContext('2d');
    g.beginPath();
    g.arc(32, 32, 26, 0, Math.PI * 2);
    g.fillStyle = fill;
    g.fill();
    g.lineWidth = 5;
    g.strokeStyle = '#ffffff';
    g.stroke();
    g.beginPath();
    g.arc(32, 32, 9, 0, Math.PI * 2);
    g.fillStyle = 'rgba(255,255,255,.9)';
    g.fill();
    return canvas.toDataURL('image/png');
  }

  var data = [
    { id: 'document', name: '广告牌与标签', version: '1.0' },
    {
      id: 'beijing',
      position: { cartographicDegrees: [116.391263, 39.907359, 300] },
      billboard: {
        image: makeIcon('#4d9bff'),
        scale: 1.6,
        verticalOrigin: 'BOTTOM',
        disableDepthTestDistance: Number.POSITIVE_INFINITY
      },
      label: {
        text: '北京 · 主标记',
        font: '500 14px "Microsoft YaHei", sans-serif',
        fillColor: { rgba: [255, 255, 255, 255] },
        outlineColor: { rgba: [14, 17, 22, 255] },
        outlineWidth: 4,
        style: 'FILL_AND_OUTLINE',
        verticalOrigin: 'TOP',
        pixelOffset: { cartesian2: [0, 6] },
        disableDepthTestDistance: Number.POSITIVE_INFINITY
      }
    },
    {
      id: 'tianjin',
      position: { cartographicDegrees: [117.201, 39.084, 300] },
      billboard: {
        image: makeIcon('#39c0a0'),
        scale: 0.9,
        verticalOrigin: 'BOTTOM',
        disableDepthTestDistance: Number.POSITIVE_INFINITY
      },
      label: {
        text: '天津 · 小图标',
        font: '500 12px "Microsoft YaHei", sans-serif',
        fillColor: { rgba: [214, 226, 240, 255] },
        outlineColor: { rgba: [14, 17, 22, 255] },
        outlineWidth: 3,
        style: 'FILL_AND_OUTLINE',
        verticalOrigin: 'TOP',
        pixelOffset: { cartesian2: [0, 6] },
        disableDepthTestDistance: Number.POSITIVE_INFINITY
      }
    }
  ];

  Cesium.CzmlDataSource.load(data).then(function (ds) {
    viewer.dataSources.add(ds);
  });

  viewer.camera.flyTo({
    destination: Cesium.Cartesian3.fromDegrees(116.80, 39.40, 120000),
    orientation: {
      heading: 0,
      pitch: Cesium.Math.toRadians(-58),
      roll: 0
    },
    duration: 0
  });
})();
</script>
</body>
</html>