Map View

<!--
  示例：地图视图
  要点：显式 MapView 配合 viewState 插值，按钮触发全国到城市的视角飞行
  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>地图视图</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"><button id="fly">飞到城市</button><span>视角由 viewState 插值，手工控制</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 pts = [];
  for (var i = 0; i < 4000; i++) {
    pts.push({
      lng: 116.24 + Math.random() * 0.32,
      lat: 39.80 + Math.random() * 0.18
    });
  }

  var from = { longitude: 108, latitude: 34, zoom: 3.4, pitch: 0, bearing: 0 };
  var to = { longitude: 116.40, latitude: 39.89, zoom: 10.8, pitch: 35, bearing: -15 };
  var state = { longitude: from.longitude, latitude: from.latitude, zoom: from.zoom, pitch: 0, bearing: 0 };

  var layer = new deck.ScatterplotLayer({
    id: 'pts',
    data: pts,
    getPosition: function (d) { return [d.lng, d.lat]; },
    getRadius: 2.4,
    radiusUnits: 'pixels',
    radiusMinPixels: 1,
    getFillColor: [96, 186, 255, 195]
  });

  var deckgl = new deck.Deck({
    canvas: 'cv',
    width: '100%',
    height: '100%',
    views: new deck.MapView({ id: 'main', controller: true }),
    viewState: state,
    onViewStateChange: function (e) {
      state = e.viewState;
      deckgl.setProps({ viewState: state });
    },
    layers: [layer]
  });

  var flying = false;

  function ease(t) { return t < 0.5 ? 2 * t * t : -1 + (4 - 2 * t) * t; }

  function fly() {
    if (flying) return;
    flying = true;
    var start = performance.now();
    var duration = 1400;
    function step(now) {
      var t = Math.min(1, (now - start) / duration);
      var k = ease(t);
      state = {
        longitude: from.longitude + (to.longitude - from.longitude) * k,
        latitude: from.latitude + (to.latitude - from.latitude) * k,
        zoom: from.zoom + (to.zoom - from.zoom) * k,
        pitch: to.pitch * k,
        bearing: to.bearing * k
      };
      deckgl.setProps({ viewState: state });
      if (t < 1) {
        requestAnimationFrame(step);
      } else {
        flying = false;
      }
    }
    requestAnimationFrame(step);
  }

  document.getElementById('fly').addEventListener('click', fly);
  window.__deck = deckgl;
})();
</script>
</body>
</html>