Add scale to/from resolution calculations

examples/data/countries.sld

@@ -25,6 +25,7 @@
           </sld:PolygonSymbolizer>
         </sld:Rule>
         <sld:Rule>  
+          <sld:MaxScaleDenominator>20000000</sld:MaxScaleDenominator>
           <sld:TextSymbolizer>
             <sld:Label>
               <ogc:PropertyName>name</ogc:PropertyName>

examples/vector-layer-sld.html

@@ -44,12 +44,7 @@
           </div>
           <div id="tags">vector, geojson, style, SLD, Styled Layer Descriptor</div>
         </div>
-        <div class="span4 offset4">
-          <div id="info" class="alert alert-success">
-            &nbsp;
-          </div>
-        </div>
-
+        
       </div>
 
     </div>

examples/vector-layer-sld.js

@@ -1,6 +1,8 @@
 goog.require('ol.Map');
 goog.require('ol.RendererHint');
 goog.require('ol.View2D');
+goog.require('ol.control');
+goog.require('ol.control.ScaleLine');
 goog.require('ol.layer.Tile');
 goog.require('ol.layer.Vector');
 goog.require('ol.parser.GeoJSON');
@@ -22,7 +24,20 @@ xhr.open('GET', 'data/countries.sld', true);
  */
 xhr.onload = function() {
   if (xhr.status == 200) {
-    var sld = new ol.parser.ogc.SLD().read(xhr.responseText);
+    var map = new ol.Map({
+      controls: ol.control.defaults().extend([
+        new ol.control.ScaleLine()
+      ]),
+      layers: [raster],
+      renderer: ol.RendererHint.CANVAS,
+      target: 'map',
+      view: new ol.View2D({
+        center: [0, 0],
+        zoom: 1
+      })
+    });
+    var units = map.getView().getProjection().getUnits();
+    var sld = new ol.parser.ogc.SLD().read(xhr.responseText, units);
     var style = sld.namedLayers['countries'].userStyles[0];
     var vector = new ol.layer.Vector({
       source: new ol.source.Vector({
@@ -31,15 +46,7 @@ xhr.onload = function() {
       }),
       style: style
     });
-    new ol.Map({
-      layers: [raster, vector],
-      renderer: ol.RendererHint.CANVAS,
-      target: 'map',
-      view: new ol.View2D({
-        center: [0, 0],
-        zoom: 1
-      })
-    });
+    map.getLayers().push(vector);
   }
 };
 xhr.send();

src/objectliterals.jsdoc

@@ -567,6 +567,12 @@
  * @todo stability experimental
  */
 
+ /**
+ * @typedef {Object} ol.parser.SLDReadOptions
+ * @property {ol.proj.Units} units The units to use in scale to resolution
+ *     calculations.
+ */
+
 /**
  * @typedef {Object} ol.source.BingMapsOptions
  * @property {string|undefined} culture Culture.

src/ol/parser/ogc/sldparser_v1.js

@@ -76,10 +76,12 @@ ol.parser.ogc.SLD_v1 = function() {
         rule.elseFilter = true;
       },
       'MinScaleDenominator': function(node, rule) {
-        rule.minScaleDenominator = parseFloat(this.getChildValue(node));
+        rule.minResolution = this.getResolutionFromScale_(
+            parseFloat(this.getChildValue(node)));
       },
       'MaxScaleDenominator': function(node, rule) {
-        rule.maxScaleDenominator = parseFloat(this.getChildValue(node));
+        rule.maxResolution = this.getResolutionFromScale_(
+            parseFloat(this.getChildValue(node)));
       },
       'TextSymbolizer': function(node, rule) {
         var config = {};
@@ -188,6 +190,7 @@ ol.parser.ogc.SLD_v1 = function() {
         var ogcreaders = this.readers['http://www.opengis.net/ogc'];
         var radius = ogcreaders._expression.call(this, node);
         if (goog.isDef(radius)) {
+          symbolizer.haloRadius = radius;
         }
       },
       'RasterSymbolizer': function(node, rule) {
@@ -412,11 +415,31 @@ ol.parser.ogc.SLD_v1.cssMap_ = {
 };
 
 
+/**
+ * @private
+ * @param {number} scaleDenominator The scale denominator to convert to
+ * resolution.
+ * @return {number} resolution.
+ */
+ol.parser.ogc.SLD_v1.prototype.getResolutionFromScale_ =
+    function(scaleDenominator) {
+  var dpi = 25.4 / 0.28;
+  var mpu = ol.METERS_PER_UNIT[this.units];
+  return 1 / ((1 / scaleDenominator) * (mpu * 39.37) * dpi);
+};
+
+
 /**
  * @param {string|Document|Element} data Data to read.
+ * @param {ol.parser.SLDReadOptions=} opt_options Read options.
  * @return {Object} An object representing the document.
  */
-ol.parser.ogc.SLD_v1.prototype.read = function(data) {
+ol.parser.ogc.SLD_v1.prototype.read = function(data, opt_options) {
+  var units = 'm';
+  if (goog.isDef(opt_options) && goog.isDef(opt_options.units)) {
+    units = opt_options.units;
+  }
+  this.units = units;
   if (goog.isString(data)) {
     data = goog.dom.xml.loadXml(data);
   }
@@ -425,5 +448,6 @@ ol.parser.ogc.SLD_v1.prototype.read = function(data) {
   }
   var obj = {namedLayers: {}};
   this.readNode(data, obj);
+  delete this.units;
   return obj;
 };