Canvas Tiles Tms

<!--
  说明：TMS 瓦片编号的中文示例，数据在页面内生成，可独立运行。
  核心逻辑：TileGrid origin 取左上或左下 + y 编号翻转
  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>TMS 瓦片编号</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:10px;align-items:center;flex-wrap:wrap;font-size:12px;color:#58606e}
  .bar label{display:flex;gap:5px;align-items:center;cursor:pointer}
  .bar button{font:inherit;padding:3px 9px;border:1px solid #c9ced6;background:#fff;
       border-radius:5px;cursor:pointer;color:#333}
  .bar button:hover{background:#eef2f8}
  .bar input[type=range]{width:110px;vertical-align:middle}
  .bar input[type=text]{font:inherit;padding:2px 6px;border:1px solid #c9ced6;border-radius:4px}
  #map{flex:1 1 auto;min-height:0;background:#eef0f3;position:relative}
  .panel{flex:0 0 auto;max-height:34%;overflow:auto;padding:8px 12px;font-size:12px;
       background:#fff;border-top:1px solid #e3e6ea;color:#3d4451}
  .panel pre{margin:0;font-family:Consolas,"Courier New",monospace;font-size:11px;
       white-space:pre-wrap;word-break:break-all;line-height:1.5}
  .ol-attribution{font-size:11px}

</style>
</head>
<body>
<div class="bar">
<label><input type="checkbox" id="tms"> 使用 TMS 编号（左下原点）</label>
<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') {
    var errBox = document.getElementById('map');
    if (errBox) {
      errBox.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 resolutions = [];
  (function () {
    var res = 156543.03392804097;
    for (var z = 0; z <= 6; z++) { resolutions.push(res); res = res / 2; }
  })();

  var world = ol.proj.get('EPSG:3857').getExtent();

  function makeGrid(tms) {
    return new ol.tilegrid.TileGrid({
      origin: tms ? ol.extent.getBottomLeft(world) : ol.extent.getTopLeft(world),
      resolutions: resolutions,
      tileSize: 256
    });
  }

  function makeSource(tms) {
    var grid = makeGrid(tms);
    return new ol.source.TileImage({
      projection: 'EPSG:3857',
      tileGrid: grid,
      tileUrlFunction: function (tileCoord) {
        if (!tileCoord) { return ''; }
        var z = tileCoord[0];
        var x = tileCoord[1];
        var y = tileCoord[2];
        var flipped = Math.pow(2, z) - 1 - y;

        var c = document.createElement('canvas');
        c.width = c.height = 256;
        var ctx = c.getContext('2d');
        var hue = Math.abs(z * 29 + x * 11 + y * 23) % 360;
        ctx.fillStyle = 'hsl(' + hue + ',38%,93%)';
        ctx.fillRect(0, 0, 256, 256);
        ctx.strokeStyle = 'hsl(' + hue + ',50%,58%)';
        ctx.lineWidth = 2;
        ctx.strokeRect(1, 1, 254, 254);

        ctx.fillStyle = '#2b3444';
        ctx.font = 'bold 24px monospace';
        ctx.fillText('z ' + z, 14, 46);
        ctx.fillText('x ' + x, 14, 82);
        ctx.fillText('y ' + y, 14, 118);
        ctx.font = '13px monospace';
        ctx.fillStyle = '#5a6473';
        ctx.fillText(tms ? 'TMS 行号 ' + flipped : 'XYZ 行号 ' + y, 14, 150);
        return c.toDataURL('image/png');
      }
    });
  }

  var tileLayer = new ol.layer.Tile({source: makeSource(false), opacity: 0.9});
  var info = document.getElementById('info');

  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'})}), tileLayer],
    view: new ol.View({center: fromLonLat([104, 35]), zoom: 3}),
    controls: ol.control.defaults.defaults({attribution: false, zoom: true, rotate: false})
  });

  function rebuild(tms) {
    tileLayer.setSource(makeSource(tms));
    info.textContent = tms
      ? 'TMS：origin 取世界范围左下角，y 自下向上递增'
      : 'XYZ：origin 取世界范围左上角，y 自上向下递增';
  }

  document.getElementById('tms').addEventListener('change', function () {
    rebuild(this.checked);
  });

  rebuild(false);
})();
</script>
</body>
</html>