Adding tiled WMS source

As shown in the example, this adds support for tiled WMS layers.
2012-10-26 21:36:30 +02:00
parent d0e532eadf
commit 084506cdb5
6 changed files with 246 additions and 0 deletions
--- a/src/ol/source/tiledwms.exports
+++ b/src/ol/source/tiledwms.exports
@@ -0,0 +1 @@
+@exportSymbol ol.source.TiledWMS
--- a/src/ol/source/tiledwmssource.js
+++ b/src/ol/source/tiledwmssource.js
@@ -0,0 +1,131 @@
+// FIXME add minZoom support
+
+goog.provide('ol.source.TiledWMS');
+goog.provide('ol.source.TiledWMSOptions');
+
+goog.require('goog.asserts');
+goog.require('goog.object');
+goog.require('ol.Attribution');
+goog.require('ol.Projection');
+goog.require('ol.TileCoord');
+goog.require('ol.TileUrlFunction');
+goog.require('ol.source.TileSource');
+goog.require('ol.tilegrid.TileGrid');
+
+
+/**
+ * @typedef {{attributions: (Array.<ol.Attribution>|undefined),
+ *            params: Object,
+ *            version: (string|undefined),
+ *            crossOrigin: (string|undefined),
+ *            extent: (ol.Extent|undefined),
+ *            tileGrid: (ol.tilegrid.TileGrid|undefined),
+ *            maxZoom: (number|undefined),
+ *            projection: (ol.Projection|undefined),
+ *            url: (string|undefined),
+ *            urls: (Array.<string>|undefined)}}
+ */
+ol.source.TiledWMSOptions;
+
+
+
+/**
+ * @constructor
+ * @extends {ol.source.TileSource}
+ * @param {ol.source.TiledWMSOptions} tiledWMSOptions options.
+ */
+ol.source.TiledWMS = function(tiledWMSOptions) {
+  goog.asserts.assert(tiledWMSOptions.params);
+
+  var projection = goog.isDef(tiledWMSOptions.projection) ?
+      tiledWMSOptions.projection : ol.Projection.getFromCode('EPSG:3857');
+
+  var extent = goog.isDef(tiledWMSOptions.extent) ?
+      tiledWMSOptions.extent : projection.getExtent();
+
+  var version = goog.isDef(tiledWMSOptions.version) ?
+      tiledWMSOptions.version : '1.3';
+
+  var tileGrid = tiledWMSOptions.tileGrid;
+  if (!goog.isDef(tileGrid)) {
+    // FIXME Factor this out to a more central/generic place.
+    var size = Math.max(extent.maxX - extent.minX, extent.maxY - extent.minY);
+    var maxZoom = goog.isDef(tiledWMSOptions.maxZoom) ?
+        tiledWMSOptions.maxZoom : 18;
+    var resolutions = new Array(maxZoom + 1);
+    for (var z = 0, zz = resolutions.length; z < zz; ++z) {
+      resolutions[z] = size / (256 << z);
+    }
+    tileGrid = new ol.tilegrid.TileGrid({
+      origin: extent.getTopLeft(),
+      resolutions: resolutions
+    });
+  }
+
+  function tileUrlFunction(tileCoord) {
+    if (goog.isNull(tileCoord)) {
+      return undefined;
+    }
+    var tileSize = tileGrid.getTileSize();
+    var tileExtent = tileGrid.getTileCoordExtent(tileCoord);
+    var params = {
+      'SERVICE': 'WMS',
+      'VERSION': version,
+      'REQUEST': 'GetMap',
+      'WIDTH': tileSize.width,
+      'HEIGHT': tileSize.height,
+      'STYLES': '',
+      'FORMAT': 'image/png',
+      'TRANSPARENT': true,
+      // FIXME Projection dependant axis order.
+      'BBOX': [
+        tileExtent.minX, tileExtent.minY, tileExtent.maxX, tileExtent.maxY
+      ].join(',')
+    };
+    params[version >= '1.3' ? 'CRS' : 'SRS'] = projection.getCode();
+    goog.object.extend(params, tiledWMSOptions.params);
+    var url = tiledWMSOptions.urls ?
+        tiledWMSOptions.urls[goog.math.modulo(
+            tileCoord.hash(), tiledWMSOptions.urls.length)] :
+        tiledWMSOptions.url;
+    for (var param in params) {
+      url += (~url.indexOf('?') ? '&' : '?') +
+          param + '=' + encodeURIComponent(params[param]);
+    }
+    return url;
+  }
+
+  function tileCoordTransform(tileCoord) {
+    if (tileGrid.getResolutions().length <= tileCoord.z) {
+      return null;
+    }
+    var x = tileCoord.x;
+    var projectionExtent = projection.getExtent();
+    // FIXME do we want a wrapDateLine param? The code below will break maps
+    // with projections that do not span the whole world width.
+    if (extent.minX === projectionExtent.minX &&
+        extent.maxX === projectionExtent.maxX) {
+      var n = 1 << tileCoord.z;
+      x = goog.math.modulo(x, n);
+    }
+    var tileExtent = tileGrid.getTileCoordExtent(
+        new ol.TileCoord(tileCoord.z, x, tileCoord.y));
+    // FIXME We shouldn't need a typecast here.
+    if (!tileExtent.intersects(/** @type {ol.Extent} */ (extent))) {
+      return null;
+    }
+    return new ol.TileCoord(tileCoord.z, x, tileCoord.y);
+  }
+
+  goog.base(this, {
+    attributions: tiledWMSOptions.attributions,
+    crossOrigin: tiledWMSOptions.crossOrigin,
+    extent: extent,
+    tileGrid: tileGrid,
+    projection: projection,
+    tileUrlFunction: ol.TileUrlFunction.withTileCoordTransform(
+        tileCoordTransform, tileUrlFunction)
+  });
+
+};
+goog.inherits(ol.source.TiledWMS, ol.source.TileSource);