Get tilePixelRatio from MVT tiles

examples/mapbox-vector-tiles-advanced.js

@@ -44,7 +44,6 @@ var map = new ol.Map({
           resolutions: resolutions,
           tileSize: 512
         }),
-        tilePixelRatio: 8,
         tileUrlFunction: tileUrlFunction
       }),
       style: createMapboxStreetsV6Style()

examples/mapbox-vector-tiles.js

@@ -24,7 +24,6 @@ var map = new ol.Map({
           'OpenStreetMap contributors</a>',
         format: new ol.format.MVT(),
         tileGrid: ol.tilegrid.createXYZ({tileSize: 512, maxZoom: 22}),
-        tilePixelRatio: 8,
         url: 'https://{a-d}.tiles.mapbox.com/v4/mapbox.mapbox-streets-v6/' +
             '{z}/{x}/{y}.vector.pbf?access_token=' + key
       }),

externs/olx.js

@@ -4994,6 +4994,8 @@ olx.source.VectorTileOptions.prototype.tileGrid;
  *     var format = tile.getFormat();
  *     tile.setFeatures(format.readFeatures(data));
  *     tile.setProjection(format.readProjection(data));
+ *     // uncomment the line below for ol.format.MVT only
+ *     //tile.setExtent(format.getLastExtent());
  *   };
  * });
  * ```
@@ -5004,10 +5006,12 @@ olx.source.VectorTileOptions.prototype.tileLoadFunction;
 
 
 /**
- * The pixel ratio used by the tile service. For example, if the tile
- * service advertizes 256px by 256px tiles but actually sends 512px
- * by 512px tiles (for retina/hidpi devices) then `tilePixelRatio`
- * should be set to `2`. Default is `1`.
+ * The pixel ratio used by the tile service. For example, if the tile service
+ * advertizes 512px by 512px tiles but actually sends tiles with coordinates in
+ * the range of 0..4096 pixels, then `tilePixelRatio` should be set to `8`.
+ * When {@link ol.format.MVT} is used to parse the features, this setting will
+ * be overridden by the coordinate range advertized in the tile.
+ * Default is `1`.
  * @type {number|undefined}
  * @api
  */

src/ol/featureloader.js

@@ -8,7 +8,7 @@ goog.require('ol.xml');
 /**
  * @param {string|ol.FeatureUrlFunction} url Feature URL service.
  * @param {ol.format.Feature} format Feature format.
- * @param {function(this:ol.VectorTile, Array.<ol.Feature>, ol.proj.Projection)|function(this:ol.source.Vector, Array.<ol.Feature>)} success
+ * @param {function(this:ol.VectorTile, Array.<ol.Feature>, ol.proj.Projection, ol.Extent)|function(this:ol.source.Vector, Array.<ol.Feature>)} success
  *     Function called with the loaded features and optionally with the data
  *     projection. Called with the vector tile or source as `this`.
  * @param {function(this:ol.VectorTile)|function(this:ol.source.Vector)} failure
@@ -56,7 +56,7 @@ ol.featureloader.loadFeaturesXhr = function(url, format, success, failure) {
           if (source) {
             success.call(this, format.readFeatures(source,
                 {featureProjection: projection}),
-            format.readProjection(source));
+            format.readProjection(source), format.getLastExtent());
           } else {
             failure.call(this);
           }

src/ol/format/feature.js

@@ -72,6 +72,15 @@ ol.format.Feature.prototype.adaptOptions = function(options) {
 };
 
 
+/**
+ * Get the extent from the source of the last {@link readFeatures} call.
+ * @return {ol.Extent} Tile extent.
+ */
+ol.format.Feature.prototype.getLastExtent = function() {
+  return null;
+};
+
+
 /**
  * @abstract
  * @return {ol.format.FormatType} Format.

src/ol/format/mvt.js

@@ -69,10 +69,25 @@ ol.format.MVT = function(opt_options) {
    */
   this.layers_ = options.layers ? options.layers : null;
 
+  /**
+   * @private
+   * @type {ol.Extent}
+   */
+  this.extent_ = null;
+
 };
 ol.inherits(ol.format.MVT, ol.format.Feature);
 
 
+/**
+ * @inheritDoc
+ * @api
+ */
+ol.format.MVT.prototype.getLastExtent = function() {
+  return this.extent_;
+};
+
+
 /**
  * @inheritDoc
  */
@@ -161,14 +176,17 @@ ol.format.MVT.prototype.readFeatures = function(source, opt_options) {
     }
     layer = tile.layers[name];
 
+    var rawFeature;
     for (var i = 0, ii = layer.length; i < ii; ++i) {
+      rawFeature = layer.feature(i);
       if (featureClass === ol.render.Feature) {
-        feature = this.readRenderFeature_(layer.feature(i), name);
+        feature = this.readRenderFeature_(rawFeature, name);
       } else {
-        feature = this.readFeature_(layer.feature(i), name, opt_options);
+        feature = this.readFeature_(rawFeature, name, opt_options);
       }
       features.push(feature);
     }
+    this.extent_ = layer ? [0, 0, layer.extent, layer.extent] : null;
   }
 
   return features;

src/ol/renderer/canvas/vectortilelayer.js

@@ -13,6 +13,7 @@ goog.require('ol.render.canvas.ReplayGroup');
 goog.require('ol.render.replay');
 goog.require('ol.renderer.canvas.TileLayer');
 goog.require('ol.renderer.vector');
+goog.require('ol.size');
 goog.require('ol.transform');
 
 
@@ -119,23 +120,24 @@ ol.renderer.canvas.VectorTileLayer.prototype.createReplayGroup_ = function(
     return;
   }
 
+  var source = /** @type {ol.source.VectorTile} */ (layer.getSource());
+  var sourceTileGrid = source.getTileGrid();
+  var tileGrid = source.getTileGridForProjection(projection);
+  var resolution = tileGrid.getResolution(tile.tileCoord[0]);
+  var tileExtent = tileGrid.getTileCoordExtent(tile.wrappedTileCoord);
+
   for (var t = 0, tt = tile.tileKeys.length; t < tt; ++t) {
     var sourceTile = tile.getTile(tile.tileKeys[t]);
     replayState.dirty = false;
 
-    var source = /** @type {ol.source.VectorTile} */ (layer.getSource());
-    var sourceTileGrid = source.getTileGrid();
     var sourceTileCoord = sourceTile.tileCoord;
     var tileProjection = sourceTile.getProjection();
-    var tileGrid = source.getTileGridForProjection(projection);
-    var resolution = tileGrid.getResolution(tile.tileCoord[0]);
     var sourceTileResolution = sourceTileGrid.getResolution(sourceTile.tileCoord[0]);
-    var tileExtent = tileGrid.getTileCoordExtent(tile.wrappedTileCoord);
     var sourceTileExtent = sourceTileGrid.getTileCoordExtent(sourceTileCoord);
     var sharedExtent = ol.extent.getIntersection(tileExtent, sourceTileExtent);
     var extent, reproject, tileResolution;
     if (tileProjection.getUnits() == ol.proj.Units.TILE_PIXELS) {
-      var tilePixelRatio = tileResolution = source.getTilePixelRatio();
+      var tilePixelRatio = tileResolution = this.getTilePixelRatio_(source, sourceTile);
       var transform = ol.transform.compose(this.tmpTransform_,
           0, 0,
           1 / sourceTileResolution * tilePixelRatio, -1 / sourceTileResolution * tilePixelRatio,
@@ -251,7 +253,7 @@ ol.renderer.canvas.VectorTileLayer.prototype.forEachFeatureAtCoordinate = functi
         var sourceTileCoord = sourceTile.tileCoord;
         var sourceTileExtent = sourceTileGrid.getTileCoordExtent(sourceTileCoord, this.tmpExtent);
         origin = ol.extent.getTopLeft(sourceTileExtent);
-        tilePixelRatio = source.getTilePixelRatio();
+        tilePixelRatio = this.getTilePixelRatio_(source, sourceTile);
         tileResolution = sourceTileGrid.getResolution(sourceTileCoord[0]) / tilePixelRatio;
         tileSpaceCoordinate = [
           (coordinate[0] - origin[0]) / tileResolution,
@@ -294,7 +296,7 @@ ol.renderer.canvas.VectorTileLayer.prototype.getReplayTransform_ = function(tile
     var tileGrid = source.getTileGrid();
     var tileCoord = tile.tileCoord;
     var tileResolution =
-        tileGrid.getResolution(tileCoord[0]) / source.getTilePixelRatio();
+        tileGrid.getResolution(tileCoord[0]) / this.getTilePixelRatio_(source, tile);
     var viewState = frameState.viewState;
     var pixelRatio = frameState.pixelRatio;
     var renderResolution = viewState.resolution / pixelRatio;
@@ -316,6 +318,21 @@ ol.renderer.canvas.VectorTileLayer.prototype.getReplayTransform_ = function(tile
 };
 
 
+/**
+ * @private
+ * @param {ol.source.VectorTile} source Source.
+ * @param {ol.VectorTile} tile Tile.
+ * @return {number} The tile's pixel ratio.
+ */
+ol.renderer.canvas.VectorTileLayer.prototype.getTilePixelRatio_ = function(source, tile) {
+  var extent = tile.getExtent();
+  return extent ?
+    ol.extent.getWidth(extent) /
+        ol.size.toSize(source.getTileGrid().getTileSize(tile.tileCoord[0]))[0] :
+    source.getTilePixelRatio();
+};
+
+
 /**
  * Handle changes in image style state.
  * @param {ol.events.Event} event Image style change event.
@@ -331,7 +348,7 @@ ol.renderer.canvas.VectorTileLayer.prototype.handleStyleImageChange_ = function(
  */
 ol.renderer.canvas.VectorTileLayer.prototype.postCompose = function(context, frameState, layerState) {
   var layer = this.getLayer();
-  var source = layer.getSource();
+  var source = /** @type {ol.source.VectorTile} */ (layer.getSource());
   var renderMode = layer.getRenderMode();
   var replays = ol.renderer.canvas.VectorTileLayer.VECTOR_REPLAYS[renderMode];
   var pixelRatio = frameState.pixelRatio;
@@ -340,7 +357,6 @@ ol.renderer.canvas.VectorTileLayer.prototype.postCompose = function(context, fra
   var offsetX = Math.round(pixelRatio * size[0] / 2);
   var offsetY = Math.round(pixelRatio * size[1] / 2);
   var tiles = this.renderedTiles;
-  var tilePixelRatio = layer.getSource().getTilePixelRatio();
   var sourceTileGrid = source.getTileGrid();
   var tileGrid = source.getTileGridForProjection(frameState.viewState.projection);
   var clips = [];
@@ -355,6 +371,7 @@ ol.renderer.canvas.VectorTileLayer.prototype.postCompose = function(context, fra
         tileGrid.getTileCoordExtent(tile.wrappedTileCoord)[0];
     for (var t = 0, tt = tile.tileKeys.length; t < tt; ++t) {
       var sourceTile = tile.getTile(tile.tileKeys[t]);
+      var tilePixelRatio = this.getTilePixelRatio_(source, sourceTile);
       var replayGroup = sourceTile.getReplayGroup(layer, tileCoord.toString());
       if (renderMode != ol.layer.VectorTileRenderType.VECTOR && !replayGroup.hasReplays(replays)) {
         continue;
@@ -441,11 +458,10 @@ ol.renderer.canvas.VectorTileLayer.prototype.renderTileImage_ = function(
     var tileCoord = tile.wrappedTileCoord;
     var z = tileCoord[0];
     var pixelRatio = frameState.pixelRatio;
-    var source = layer.getSource();
+    var source = /** @type {ol.source.VectorTile} */ (layer.getSource());
     var sourceTileGrid = source.getTileGrid();
     var tileGrid = source.getTileGridForProjection(frameState.viewState.projection);
     var resolution = tileGrid.getResolution(z);
-    var tilePixelRatio = source.getTilePixelRatio();
     var context = tile.getContext(layer);
     var size = source.getTilePixelSize(z, pixelRatio, frameState.viewState.projection);
     context.canvas.width = size[0];
@@ -453,6 +469,7 @@ ol.renderer.canvas.VectorTileLayer.prototype.renderTileImage_ = function(
     var tileExtent = tileGrid.getTileCoordExtent(tileCoord);
     for (var i = 0, ii = tile.tileKeys.length; i < ii; ++i) {
       var sourceTile = tile.getTile(tile.tileKeys[i]);
+      var tilePixelRatio = this.getTilePixelRatio_(source, sourceTile);
       var sourceTileCoord = sourceTile.tileCoord;
       var pixelScale = pixelRatio / resolution;
       var transform = ol.transform.reset(this.tmpTransform_);

src/ol/vectorimagetile.js

@@ -276,7 +276,7 @@ ol.VectorImageTile.prototype.finishLoading_ = function() {
  */
 ol.VectorImageTile.defaultLoadFunction = function(tile, url) {
   var loader = ol.featureloader.loadFeaturesXhr(
-      url, tile.getFormat(), tile.onLoad_.bind(tile), tile.onError_.bind(tile));
+      url, tile.getFormat(), tile.onLoad.bind(tile), tile.onError.bind(tile));
 
   tile.setLoader(loader);
 };

src/ol/vectortile.js

@@ -23,6 +23,12 @@ ol.VectorTile = function(tileCoord, state, src, format, tileLoadFunction) {
    */
   this.consumers = 0;
 
+  /**
+   * @private
+   * @type {ol.Extent}
+   */
+  this.extent_ = null;
+
   /**
    * @private
    * @type {ol.format.Feature}
@@ -82,6 +88,15 @@ ol.VectorTile.prototype.disposeInternal = function() {
 };
 
 
+/**
+ * Gets the extent of the vector tile.
+ * @return {ol.Extent} The extent.
+ */
+ol.VectorTile.prototype.getExtent = function() {
+  return this.extent_;
+};
+
+
 /**
  * Get the feature format assigned for reading this tile's features.
  * @return {ol.format.Feature} Feature format.
@@ -147,21 +162,33 @@ ol.VectorTile.prototype.load = function() {
  * Handler for successful tile load.
  * @param {Array.<ol.Feature>} features The loaded features.
  * @param {ol.proj.Projection} dataProjection Data projection.
+ * @param {ol.Extent} extent Extent.
  */
-ol.VectorTile.prototype.onLoad_ = function(features, dataProjection) {
+ol.VectorTile.prototype.onLoad = function(features, dataProjection, extent) {
   this.setProjection(dataProjection);
   this.setFeatures(features);
+  this.setExtent(extent);
 };
 
 
 /**
  * Handler for tile load errors.
  */
-ol.VectorTile.prototype.onError_ = function() {
+ol.VectorTile.prototype.onError = function() {
   this.setState(ol.TileState.ERROR);
 };
 
 
+/**
+ * Sets the extent of the vector tile.
+ * @param {ol.Extent} extent The extent.
+ * @api
+ */
+ol.VectorTile.prototype.setExtent = function(extent) {
+  this.extent_ = extent;
+};
+
+
 /**
  * @param {Array.<ol.Feature>} features Features.
  * @api

test/spec/ol/format/mvt.test.js

@@ -88,6 +88,13 @@ where('ArrayBuffer.isView').describe('ol.format.MVT', function() {
       expect(features[0].getId()).to.be(2);
     });
 
+    it('sets the extent of the last readFeatures call', function() {
+      var format = new ol.format.MVT();
+      format.readFeatures(data);
+      var extent = format.getLastExtent();
+      expect(extent.getWidth()).to.be(4096);
+    });
+
   });
 
 });

test/spec/ol/renderer/canvas/vectortilelayer.test.js

@@ -186,6 +186,14 @@ describe('ol.renderer.canvas.VectorTileLayer', function() {
       spy2.restore();
     });
 
+    it('uses the extent of the source tile', function() {
+      var renderer = map.getRenderer().getLayerRenderer(layer);
+      var tile = new ol.VectorTile([0, 0, 0], 2);
+      tile.setExtent([0, 0, 4096, 4096]);
+      var tilePixelRatio = renderer.getTilePixelRatio_(source, tile);
+      expect(tilePixelRatio).to.be(16);
+    });
+
   });
 
   describe('#prepareFrame', function() {