6.0.0-beta.15

Only check extent when a url tile coordinate is available

config/jsdoc/api/plugins/api.js

@@ -31,6 +31,24 @@ function hasApiMembers(doclet) {
 }
 
 function includeAugments(doclet) {
+  // Make sure that `observables` and `fires` are taken from an already processed `class` doclet.
+  // This is necessary because JSDoc generates multiple doclets with the same longname.
+  const cls = classes[doclet.longname];
+  if (cls.observables && !doclet.observables) {
+    doclet.observables = cls.observables;
+  }
+  if (doclet.fires && cls.fires) {
+    for (let i = 0, ii = cls.fires.length; i < ii; ++i) {
+      const fires = cls.fires[i];
+      if (doclet.fires.indexOf(fires) == -1) {
+        doclet.fires.push(fires);
+      }
+    }
+  }
+  if (cls.fires && !doclet.fires) {
+    doclet.fires = cls.fires;
+  }
+
   const augments = doclet.augments;
   if (augments) {
     let cls;
@@ -148,7 +166,7 @@ exports.handlers = {
         // constructor from the docs.
         doclet._hideConstructor = true;
         includeAugments(doclet);
-      } else if (doclet.undocumented !== false && !doclet._hideConstructor && !(doclet.kind == 'typedef' && doclet.longname in types)) {
+      } else if (!doclet._hideConstructor && !(doclet.kind == 'typedef' && doclet.longname in types)) {
         // Remove all other undocumented symbols
         doclet.undocumented = true;
       }

doc/errors/index.md

@@ -236,3 +236,7 @@ A `WebGLArrayBuffer` must either be of type `ELEMENT_ARRAY_BUFFER` or `ARRAY_BUF
 ### 63
 
 Support for the `OES_element_index_uint` WebGL extension is mandatory for WebGL layers.
+
+### 64
+
+Layer opacity must be a number.

doc/tutorials/concepts.hbs

@@ -75,7 +75,7 @@ The above snippets can be combined into a single script that renders a map with
 import Map from 'ol/Map';
 import View from 'ol/View';
 import OSM from 'ol/source/OSM';
-import TileLayer from 'ol/source/Tile';
+import TileLayer from 'ol/layer/Tile';
 
 new Map({
   layers: [

examples/export-pdf.js

@@ -65,18 +65,18 @@ exportButton.addEventListener('click', function() {
   const width = Math.round(dim[0] * resolution / 25.4);
   const height = Math.round(dim[1] * resolution / 25.4);
   const size = map.getSize();
-  const extent = map.getView().calculateExtent(size);
+  const viewResolution = map.getView().getResolution();
 
   map.once('rendercomplete', function() {
-    toJpeg(map.getTargetElement(), exportOptions).then(function(dataUrl) {
+    exportOptions.width = width;
+    exportOptions.height = height;
+    toJpeg(map.getViewport(), exportOptions).then(function(dataUrl) {
       const pdf = new jsPDF('landscape', undefined, format);
       pdf.addImage(dataUrl, 'JPEG', 0, 0, dim[0], dim[1]);
       pdf.save('map.pdf');
       // Reset original map size
       map.setSize(size);
-      map.getView().fit(extent, {
-        size: size
-      });
+      map.getView().setResolution(viewResolution);
       exportButton.disabled = false;
       document.body.style.cursor = 'auto';
     });
@@ -85,6 +85,7 @@ exportButton.addEventListener('click', function() {
   // Set print size
   const printSize = [width, height];
   map.setSize(printSize);
-  map.getView().fit(extent, {size: printSize});
+  const scaling = Math.min(width / size[0], height / size[1]);
+  map.getView().setResolution(viewResolution / scaling);
 
 }, false);

examples/feature-animation.js

@@ -21,7 +21,8 @@ const map = new Map({
   target: 'map',
   view: new View({
     center: [0, 0],
-    zoom: 1
+    zoom: 1,
+    multiWorld: true
   })
 });
 

examples/icon-sprite-webgl.html

@@ -18,3 +18,4 @@ cloak:
     value: Your Mapbox access token from https://mapbox.com/ here
 ---
 <div id="map" class="map"></div>
+<div>Current sighting: <span id="info"></span></div>

examples/icon-sprite-webgl.js

@@ -103,7 +103,7 @@ function loadData() {
 
 loadData();
 
-new Map({
+const map = new Map({
   layers: [
     new TileLayer({
       source: new TileJSON({
@@ -121,3 +121,18 @@ new Map({
     zoom: 2
   })
 });
+
+const info = document.getElementById('info');
+map.on('pointermove', function(evt) {
+  if (map.getView().getInteracting()) {
+    return;
+  }
+  const pixel = evt.pixel;
+  info.innerText = '';
+  map.forEachFeatureAtPixel(pixel, function(feature) {
+    const datetime = feature.get('datetime');
+    const duration = feature.get('duration');
+    const shape = feature.get('shape');
+    info.innerText = 'On ' + datetime + ', lasted ' + duration + ' seconds and had a "' + shape + '" shape.';
+  });
+});

examples/layer-zoom-limits.html

@@ -0,0 +1,13 @@
+---
+layout: example.html
+title: Layer Zoom Limits
+shortdesc: Using minZoom and maxZoom to control layer visibility.
+docs: >
+  Layers support `minZoom` and `maxZoom` options for controlling visibility based on the view's zoom level.
+  If min or max zoom are set, the layer will only be visible at zoom levels greater than the `minZoom` and
+  less than or equal to the `maxZoom`.  After construction, the layer's `setMinZoom` and `setMaxZoom` can
+  be used to set limits.  This example shows an OSM layer at zoom levels 14 and lower and a USGS layer at
+  zoom levels higher than 14.
+tags: "minZoom, maxZoom, layer"
+---
+<div id="map" class="map"></div>

examples/layer-zoom-limits.js

@@ -0,0 +1,33 @@
+import Map from '../src/ol/Map.js';
+import View from '../src/ol/View.js';
+import TileLayer from '../src/ol/layer/Tile.js';
+import OSM from '../src/ol/source/OSM.js';
+import XYZ from '../src/ol/source/XYZ.js';
+import {transformExtent, fromLonLat} from '../src/ol/proj.js';
+
+const mapExtent = [-112.261791, 35.983744, -112.113981, 36.132062];
+
+const map = new Map({
+  target: 'map',
+  layers: [
+    new TileLayer({
+      maxZoom: 14, // visible at zoom levels 14 and below
+      source: new OSM()
+    }),
+    new TileLayer({
+      minZoom: 14, // visible at zoom levels above 14
+      source: new XYZ({
+        attributions: 'Tiles © USGS, rendered with ' +
+        '<a href="http://www.maptiler.com/">MapTiler</a>',
+        url: 'https://tileserver.maptiler.com/grandcanyon/{z}/{x}/{y}.png'
+      })
+    })
+  ],
+  view: new View({
+    center: fromLonLat([-112.18688965, 36.057944835]),
+    zoom: 15,
+    maxZoom: 18,
+    extent: transformExtent(mapExtent, 'EPSG:4326', 'EPSG:3857'),
+    constrainOnlyCenter: true
+  })
+});

examples/mapbox-layer.html

@@ -9,7 +9,7 @@ resources:
   - https://unpkg.com/mapbox-gl@0.54.0/dist/mapbox-gl.js
   - https://unpkg.com/mapbox-gl@0.54.0/dist/mapbox-gl.css
 cloak:
-  - key: ER67WIiPdCQvhgsUjoWK
+  - key: get_your_own_D6rA4zTHduk6KOKTXzGB
     value: Get your own API key at https://www.maptiler.com/cloud/
 ---
 <div id="map" class="map"></div>

examples/mapbox-layer.js

@@ -8,7 +8,7 @@ import VectorSource from '../src/ol/source/Vector.js';
 import GeoJSON from '../src/ol/format/GeoJSON.js';
 
 const center = [-98.8, 37.9];
-const key = 'ER67WIiPdCQvhgsUjoWK';
+const key = 'get_your_own_D6rA4zTHduk6KOKTXzGB';
 
 const mbMap = new mapboxgl.Map({
   style: 'https://api.maptiler.com/maps/bright/style.json?key=' + key,

examples/mapbox-style.html

@@ -4,7 +4,7 @@ title: Vector tiles created from a Mapbox Style object
 shortdesc: Example of using ol-mapbox-style with tiles from tilehosting.com.
 tags: "vector tiles, mapbox style, ol-mapbox-style, maptiler"
 cloak:
-  - key: ER67WIiPdCQvhgsUjoWK
+  - key: get_your_own_D6rA4zTHduk6KOKTXzGB
     value: Get your own API key at https://www.maptiler.com/cloud/
 ---
 <!doctype html>

examples/mapbox-style.js

@@ -1,3 +1,3 @@
 import apply from 'ol-mapbox-style';
 
-apply('map', 'https://api.maptiler.com/maps/topo/style.json?key=ER67WIiPdCQvhgsUjoWK');
+apply('map', 'https://api.maptiler.com/maps/topo/style.json?key=get_your_own_D6rA4zTHduk6KOKTXzGB');

examples/osm-vector-tiles.html

@@ -6,7 +6,7 @@ docs: >
   A simple vector tiles map with Mapzen vector tiles. This example uses the TopoJSON format's `layerName` option to determine the layer ("water", "roads", "buildings") for styling. **Note**: [`ol/format/MVT`] is an even more efficient format for vector tiles.
 tags: "vector, tiles, osm, mapzen"
 cloak:
-  - key: vector-tiles-5eJz6JX
-    value: Your Mapzen API key from https://mapzen.com/developers
+  - key: uZNs91nMR-muUTP99MyBSg
+    value: Your Nextzen API key from https://developers.nextzen.org/
 ---
 <div id="map" class="map"></div>

examples/osm-vector-tiles.js

@@ -6,7 +6,7 @@ import {fromLonLat} from '../src/ol/proj.js';
 import VectorTileSource from '../src/ol/source/VectorTile.js';
 import {Fill, Stroke, Style} from '../src/ol/style.js';
 
-const key = 'vector-tiles-5eJz6JX';
+const key = 'uZNs91nMR-muUTP99MyBSg';
 
 const roadStyleCache = {};
 const roadColor = {
@@ -67,7 +67,7 @@ const map = new Map({
           layers: ['water', 'roads', 'buildings']
         }),
         maxZoom: 19,
-        url: 'https://tile.mapzen.com/mapzen/vector/v1/all/{z}/{x}/{y}.topojson?api_key=' + key
+        url: 'https://tile.nextzen.org/tilezen/vector/v1/all/{z}/{x}/{y}.topojson?api_key=' + key
       }),
       style: function(feature, resolution) {
         switch (feature.get('layer')) {

examples/side-by-side.css

@@ -0,0 +1,10 @@
+@media (min-width: 800px) {
+  .wrapper {
+    display: flex;
+  }
+  .half {
+    padding: 0 10px;
+    width: 50%;
+    float: left;
+  }
+}

examples/side-by-side.html

@@ -0,0 +1,21 @@
+---
+layout: example.html
+title: Shared Views
+shortdesc: Two maps share view properties
+docs: >
+  Two maps (one Road, one Aerial) share the same center, resolution and rotation.
+tags: "side-by-side, bing, bing-maps"
+cloak:
+  - key: As1HiMj1PvLPlqc_gtM7AqZfBL8ZL3VrjaS3zIb22Uvb9WKhuJObROC-qUpa81U5
+    value: Your Bing Maps Key from http://www.bingmapsportal.com/ here
+---
+<div class="wrapper">
+  <div class="half">
+    <h4>Road</h4>
+    <div id="roadMap" class="map"></div>
+  </div>
+  <div class="half">
+    <h4>Aerial</h4>
+    <div id="aerialMap" class="map"></div>
+  </div>
+</div>

examples/side-by-side.js

@@ -0,0 +1,37 @@
+import Map from '../src/ol/Map.js';
+import View from '../src/ol/View.js';
+import TileLayer from '../src/ol/layer/Tile.js';
+import BingMaps from '../src/ol/source/BingMaps.js';
+
+const roadLayer = new TileLayer({
+  source: new BingMaps({
+    key: 'As1HiMj1PvLPlqc_gtM7AqZfBL8ZL3VrjaS3zIb22Uvb9WKhuJObROC-qUpa81U5',
+    imagerySet: 'RoadOnDemand',
+    maxZoom: 19
+  })
+});
+
+const aerialLayer = new TileLayer({
+  source: new BingMaps({
+    key: 'As1HiMj1PvLPlqc_gtM7AqZfBL8ZL3VrjaS3zIb22Uvb9WKhuJObROC-qUpa81U5',
+    imagerySet: 'Aerial',
+    maxZoom: 19
+  })
+});
+
+const view = new View({
+  center: [-6655.5402445057125, 6709968.258934638],
+  zoom: 13
+});
+
+const map1 = new Map({
+  target: 'roadMap',
+  layers: [roadLayer],
+  view: view
+});
+
+const map2 = new Map({
+  target: 'aerialMap',
+  layers: [aerialLayer],
+  view: view
+});

examples/vector-label-decluttering.html

@@ -5,7 +5,7 @@ shortdesc: Label decluttering with a custom renderer.
 resources:
   - https://cdn.polyfill.io/v2/polyfill.min.js?features=Set"
 docs: >
-  Decluttering is used to avoid overlapping labels with `overflow: true` set on the text style. For MultiPolygon geometries, only the widest polygon is selected in a custom `geometry` function.
+  Decluttering is used to avoid overlapping labels. The `overflow: true` setting on the text style makes it so labels that do not fit within the bounds of a polygon are also included.
 tags: "vector, decluttering, labels"
 ---
 <div id="map" class="map"></div>

examples/vector-label-decluttering.js

@@ -1,6 +1,5 @@
 import Map from '../src/ol/Map.js';
 import View from '../src/ol/View.js';
-import {getWidth} from '../src/ol/extent.js';
 import GeoJSON from '../src/ol/format/GeoJSON.js';
 import VectorLayer from '../src/ol/layer/Vector.js';
 import VectorSource from '../src/ol/source/Vector.js';
@@ -15,23 +14,6 @@ const map = new Map({
 });
 
 const labelStyle = new Style({
-  geometry: function(feature) {
-    let geometry = feature.getGeometry();
-    if (geometry.getType() == 'MultiPolygon') {
-      // Only render label for the widest polygon of a multipolygon
-      const polygons = geometry.getPolygons();
-      let widest = 0;
-      for (let i = 0, ii = polygons.length; i < ii; ++i) {
-        const polygon = polygons[i];
-        const width = getWidth(polygon.getExtent());
-        if (width > widest) {
-          widest = width;
-          geometry = polygon;
-        }
-      }
-    }
-    return geometry;
-  },
   text: new Text({
     font: '12px Calibri,sans-serif',
     overflow: true,

examples/wms-getlegendgraphic.html

@@ -0,0 +1,15 @@
+---
+layout: example.html
+title: WMS GetLegendGraphic
+shortdesc: Example of a WMS GetLegendGraphic.
+docs: >
+  WMS supports the [getLegendGraphic request](https://docs.geoserver.org/latest/en/user/services/wms/get_legend_graphic/index.html).
+  This example demonstrates the use of the `getGetLegendGraphicUrl` method.
+
+
+  As a legend can be responsive to the scale it is updated on every change of the resolution.
+tags: "GetLegendGraphic, getGetLegendGraphicURL, WMS"
+---
+<div id="map" class="map"></div>
+Legend:
+<div><img id="legend" src=""/></div>

examples/wms-getlegendgraphic.js

@@ -0,0 +1,47 @@
+import Map from '../src/ol/Map.js';
+import View from '../src/ol/View.js';
+import {Image as ImageLayer, Tile as TileLayer} from '../src/ol/layer.js';
+import ImageWMS from '../src/ol/source/ImageWMS.js';
+import OSM from '../src/ol/source/OSM.js';
+
+const wmsSource = new ImageWMS({
+  url: 'https://ahocevar.com/geoserver/wms',
+  params: {'LAYERS': 'topp:states'},
+  ratio: 1,
+  serverType: 'geoserver'
+});
+
+const updateLegend = function(resolution) {
+  const graphicUrl = wmsSource.getGetLegendGraphicUrl(resolution);
+  const img = document.getElementById('legend');
+  img.src = graphicUrl;
+};
+
+const layers = [
+  new TileLayer({
+    source: new OSM()
+  }),
+  new ImageLayer({
+    extent: [-13884991, 2870341, -7455066, 6338219],
+    source: wmsSource
+  })
+];
+
+const map = new Map({
+  layers: layers,
+  target: 'map',
+  view: new View({
+    center: [-10997148, 4569099],
+    zoom: 4
+  })
+});
+
+// Initial legend
+const resolution = map.getView().getResolution();
+updateLegend(resolution);
+
+// Update the legend when the resolution changes
+map.getView().on('change:resolution', function(event) {
+  const resolution = event.target.getResolution();
+  updateLegend(resolution);
+});

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ol",
-  "version": "6.0.0-beta.10",
+  "version": "6.0.0-beta.15",
   "description": "OpenLayers mapping library",
   "keywords": [
     "map",
@@ -54,23 +54,23 @@
     "chaikin-smooth": "^1.0.4",
     "clean-css-cli": "4.3.0",
     "copy-webpack-plugin": "^5.0.3",
-    "coveralls": "3.0.4",
+    "coveralls": "3.0.6",
     "eslint": "^6.0.0",
     "eslint-config-openlayers": "^12.0.0",
     "expect.js": "0.3.1",
     "front-matter": "^3.0.2",
     "fs-extra": "^8.0.0",
     "glob": "^7.1.4",
-    "globby": "^9.2.0",
+    "globby": "^10.0.0",
     "handlebars": "4.1.2",
     "html-to-image": "^0.1.0",
     "istanbul": "0.4.5",
     "istanbul-instrumenter-loader": "^3.0.1",
     "jquery": "3.4.1",
-    "jsdoc": "3.6.2",
+    "jsdoc": "3.6.3",
     "jsdoc-plugin-typescript": "^2.0.1",
     "karma": "^4.1.0",
-    "karma-chrome-launcher": "2.2.0",
+    "karma-chrome-launcher": "3.1.0",
     "karma-coverage": "^1.1.2",
     "karma-coverage-istanbul-reporter": "^2.0.5",
     "karma-firefox-launcher": "^1.1.0",
@@ -78,13 +78,13 @@
     "karma-sourcemap-loader": "^0.3.7",
     "karma-webpack": "^4.0.0-rc.2",
     "loglevelnext": "^3.0.1",
-    "marked": "0.6.2",
-    "mocha": "6.1.4",
-    "ol-mapbox-style": "^5.0.0-beta.2",
+    "marked": "0.7.0",
+    "mocha": "6.2.0",
+    "ol-mapbox-style": "^5.0.0-beta.3",
     "pixelmatch": "^5.0.0",
     "pngjs": "^3.4.0",
     "proj4": "2.5.0",
-    "puppeteer": "~1.18.0",
+    "puppeteer": "~1.19.0",
     "rollup": "^1.12.0",
     "rollup-plugin-babel": "^4.3.2",
     "rollup-plugin-commonjs": "^10.0.0",
@@ -97,11 +97,11 @@
     "typescript": "^3.4.5",
     "url-polyfill": "^1.1.5",
     "walk": "^2.3.9",
-    "webpack": "4.35.0",
+    "webpack": "4.39.2",
     "webpack-cli": "^3.3.2",
     "webpack-dev-middleware": "^3.6.2",
     "webpack-dev-server": "^3.3.1",
-    "yargs": "^13.2.2"
+    "yargs": "^14.0.0"
   },
   "eslintConfig": {
     "extends": "openlayers",

rendering/cases/circle-style/main.js

@@ -0,0 +1,57 @@
+import Map from '../../../src/ol/Map.js';
+import View from '../../../src/ol/View.js';
+import Feature from '../../../src/ol/Feature.js';
+import Point from '../../../src/ol/geom/Point.js';
+import VectorLayer from '../../../src/ol/layer/Vector.js';
+import VectorSource from '../../../src/ol/source/Vector.js';
+import Circle from '../../../src/ol/style/Circle.js';
+import Style from '../../../src/ol/style/Style.js';
+import Stroke from '../../../src/ol/style/Stroke.js';
+
+
+const vectorSource = new VectorSource();
+
+vectorSource.addFeatures([
+  new Feature({
+    geometry: new Point([-50, 50]),
+    radius: 10
+  }),
+  new Feature({
+    geometry: new Point([50, -50]),
+    radius: 20
+  }),
+  new Feature({
+    geometry: new Point([50, 50]),
+    radius: 30
+  })
+]);
+
+const style = new Style({
+  image: new Circle({
+    radius: 1,
+    stroke: new Stroke({
+      color: '#00f',
+      width: 3
+    })
+  })
+});
+
+new Map({
+  pixelRatio: 1,
+  layers: [
+    new VectorLayer({
+      source: vectorSource,
+      style: function(feature) {
+        style.getImage().setRadius(feature.get('radius'));
+        return style;
+      }
+    })
+  ],
+  target: 'map',
+  view: new View({
+    center: [0, 0],
+    resolution: 1
+  })
+});
+
+render();

rendering/cases/layer-tile-render-listener/main.js

@@ -0,0 +1,46 @@
+import Map from '../../../src/ol/Map.js';
+import View from '../../../src/ol/View.js';
+import TileLayer from '../../../src/ol/layer/Tile.js';
+import {transform, fromLonLat} from '../../../src/ol/proj.js';
+import XYZ from '../../../src/ol/source/XYZ.js';
+import CircleStyle from '../../../src/ol/style/Circle.js';
+import Fill from '../../../src/ol/style/Fill.js';
+import Stroke from '../../../src/ol/style/Stroke.js';
+import Point from '../../../src/ol/geom/Point.js';
+import {getVectorContext} from '../../../src/ol/render.js';
+
+const center = fromLonLat([8.6, 50.1]);
+
+const layer = new TileLayer({
+  source: new XYZ({
+    url: '/data/tiles/satellite/{z}/{x}/{y}.jpg',
+    transition: 0
+  })
+});
+
+const onRender = function(event) {
+  const context = event.context;
+  context.restore();
+  const vectorContext = getVectorContext(event);
+  vectorContext.setImageStyle(new CircleStyle({
+    radius: 12,
+    fill: new Fill({color: 'yellow'}),
+    stroke: new Stroke({color: 'red', width: 1})
+  }));
+  vectorContext.drawPoint(new Point(
+    transform([13, 37], 'EPSG:4326', 'EPSG:3857')));
+};
+layer.on('postrender', onRender);
+
+const map = new Map({
+  layers: [
+  ],
+  target: 'map',
+  view: new View({
+    center: center,
+    zoom: 3
+  })
+});
+map.addLayer(layer);
+
+render();

rendering/cases/layer-vector-multigeometry-decluttering/main.js

@@ -0,0 +1,55 @@
+import Map from '../../../src/ol/Map.js';
+import View from '../../../src/ol/View.js';
+import GeoJSON from '../../../src/ol/format/GeoJSON.js';
+import VectorLayer from '../../../src/ol/layer/Vector.js';
+import VectorSource from '../../../src/ol/source/Vector.js';
+import {Fill, Stroke, Style, Text} from '../../../src/ol/style.js';
+
+const map = new Map({
+  target: 'map',
+  view: new View({
+    center: [-17465028, 2331736],
+    zoom: 5
+  })
+});
+
+const labelStyle = new Style({
+  text: new Text({
+    font: '16px Ubuntu',
+    overflow: true,
+    fill: new Fill({
+      color: '#000'
+    }),
+    stroke: new Stroke({
+      color: '#fff',
+      width: 3
+    })
+  })
+});
+const countryStyle = new Style({
+  fill: new Fill({
+    color: 'rgba(255, 255, 255, 0.6)'
+  }),
+  stroke: new Stroke({
+    color: '#319FD3',
+    width: 1
+  })
+});
+const style = [countryStyle, labelStyle];
+
+const vectorLayer = new VectorLayer({
+  source: new VectorSource({
+    url: '/data/countries.json',
+    format: new GeoJSON()
+  }),
+  style: function(feature) {
+    labelStyle.getText().setText(feature.get('name'));
+    return style;
+  },
+  declutter: true
+});
+
+map.addLayer(vectorLayer);
+
+
+render({tolerance: 0.007});

rendering/cases/reproj-image/main.js

@@ -0,0 +1,31 @@
+import Map from '../../../src/ol/Map.js';
+import View from '../../../src/ol/View.js';
+import Static from '../../../src/ol/source/ImageStatic.js';
+import {
+  get as getProjection,
+  transformExtent
+} from '../../../src/ol/proj.js';
+import ImageLayer from '../../../src/ol/layer/Image.js';
+
+const source = new Static({
+  url: '/data/tiles/osm/5/5/12.png',
+  imageExtent: transformExtent([-123, 37, -122, 38], 'EPSG:4326', 'EPSG:3857'),
+  projection: getProjection('EPSG:3857')
+});
+
+new Map({
+  pixelRatio: 1,
+  target: 'map',
+  layers: [new ImageLayer({
+    source: source
+  })],
+  view: new View({
+    center: [-122.416667, 37.783333],
+    zoom: 8,
+    projection: 'EPSG:4326'
+  })
+});
+
+render({
+  tolerance: 0.001
+});

rendering/cases/reproj-tile-4326/main.js

@@ -0,0 +1,36 @@
+import Map from '../../../src/ol/Map.js';
+import View from '../../../src/ol/View.js';
+import XYZ from '../../../src/ol/source/XYZ.js';
+import TileLayer from '../../../src/ol/layer/Tile.js';
+import {toLonLat, get} from '../../../src/ol/proj.js';
+import {createXYZ, createForProjection} from '../../../src/ol/tilegrid.js';
+
+const tileGrid = createXYZ();
+const extent = tileGrid.getTileCoordExtent([5, 5, 12]);
+const center = [(extent[0] + extent[2]) / 2, extent[1]];
+
+const source = new XYZ({
+  transition: 0,
+  minZoom: 5,
+  maxZoom: 5,
+  url: '/data/tiles/osm/{z}/{x}/{y}.png'
+});
+
+source.setTileGridForProjection(get('EPSG:4326'), createForProjection(get('EPSG:4326'), 7, [64, 64]));
+
+new Map({
+  pixelRatio: 1,
+  target: 'map',
+  layers: [
+    new TileLayer({
+      source: source
+    })
+  ],
+  view: new View({
+    projection: 'EPSG:4326',
+    center: toLonLat(center),
+    zoom: 5
+  })
+});
+
+render();

rendering/cases/reproj-tile-5070/main.js

@@ -0,0 +1,41 @@
+import Map from '../../../src/ol/Map.js';
+import View from '../../../src/ol/View.js';
+import XYZ from '../../../src/ol/source/XYZ.js';
+import TileLayer from '../../../src/ol/layer/Tile.js';
+import {get, transform} from '../../../src/ol/proj.js';
+import {register} from '../../../src/ol/proj/proj4.js';
+import proj4 from 'proj4';
+
+proj4.defs('EPSG:5070',
+  '+proj=aea +lat_1=29.5 +lat_2=45.5 +lat_0=23 +lon_0=-96 +x_0=0 ' +
+          '+y_0=0 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs');
+register(proj4);
+const proj5070 = get('EPSG:5070');
+proj5070.setExtent([-6e6, 0, 4e6, 6e6]);
+
+const center4326 = [-118.125, 31.95];
+const center = transform(center4326, 'EPSG:4326', 'EPSG:5070');
+
+const source = new XYZ({
+  transition: 0,
+  minZoom: 5,
+  maxZoom: 5,
+  url: '/data/tiles/osm/{z}/{x}/{y}.png'
+});
+
+new Map({
+  pixelRatio: 1,
+  target: 'map',
+  layers: [
+    new TileLayer({
+      source: source
+    })
+  ],
+  view: new View({
+    projection: 'EPSG:5070',
+    center: center,
+    zoom: 4
+  })
+});
+
+render();

rendering/cases/reproj-tile-54009/main.js

@@ -0,0 +1,40 @@
+import Map from '../../../src/ol/Map.js';
+import View from '../../../src/ol/View.js';
+import XYZ from '../../../src/ol/source/XYZ.js';
+import TileLayer from '../../../src/ol/layer/Tile.js';
+import {get, transform} from '../../../src/ol/proj.js';
+import {register} from '../../../src/ol/proj/proj4.js';
+import proj4 from 'proj4';
+
+proj4.defs('ESRI:54009', '+proj=moll +lon_0=0 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs');
+
+register(proj4);
+const proj54009 = get('ESRI:54009');
+proj54009.setExtent([-18e6, -9e6, 18e6, 9e6]);
+
+const center4326 = [-118.125, 31.95];
+const center = transform(center4326, 'EPSG:4326', 'ESRI:54009');
+
+const source = new XYZ({
+  transition: 0,
+  minZoom: 5,
+  maxZoom: 5,
+  url: '/data/tiles/osm/{z}/{x}/{y}.png'
+});
+
+new Map({
+  pixelRatio: 1,
+  target: 'map',
+  layers: [
+    new TileLayer({
+      source: source
+    })
+  ],
+  view: new View({
+    projection: 'ESRI:54009',
+    center: center,
+    zoom: 6
+  })
+});
+
+render();

rendering/cases/reproj-tile-dateline-merc/main.js

@@ -0,0 +1,40 @@
+import Map from '../../../src/ol/Map.js';
+import View from '../../../src/ol/View.js';
+import XYZ from '../../../src/ol/source/XYZ.js';
+import TileLayer from '../../../src/ol/layer/Tile.js';
+import {get, transform} from '../../../src/ol/proj.js';
+import {register} from '../../../src/ol/proj/proj4.js';
+import proj4 from 'proj4';
+
+proj4.defs('merc_180', '+proj=merc +lon_0=180 +units=m +no_defs');
+
+register(proj4);
+const merc = get('merc_180');
+merc.setExtent([-20026376.39, -20048966.10, 20026376.39, 20048966.10]);
+
+const center4326 = [180, 0];
+const center = transform(center4326, 'EPSG:4326', 'merc_180');
+
+const source = new XYZ({
+  projection: 'EPSG:4326',
+  minZoom: 0,
+  maxZoom: 0,
+  url: '/data/tiles/4326/{z}/{x}/{y}.png'
+});
+
+new Map({
+  pixelRatio: 1,
+  target: 'map',
+  layers: [
+    new TileLayer({
+      source: source
+    })
+  ],
+  view: new View({
+    projection: 'merc_180',
+    center: center,
+    zoom: 0
+  })
+});
+
+render();

rendering/cases/reproj-tile-none-square/main.js

@@ -0,0 +1,38 @@
+import Map from '../../../src/ol/Map.js';
+import View from '../../../src/ol/View.js';
+import XYZ from '../../../src/ol/source/XYZ.js';
+import TileLayer from '../../../src/ol/layer/Tile.js';
+import {toLonLat} from '../../../src/ol/proj.js';
+import {createXYZ} from '../../../src/ol/tilegrid.js';
+
+const tileGrid = createXYZ({tileSize: [512, 256]});
+const extent = tileGrid.getTileCoordExtent([5, 3, 12]);
+const center = [
+  (extent[0] + extent[2]) / 2,
+  (extent[1] + extent[3]) / 2
+];
+
+const source = new XYZ({
+  projection: 'EPSG:3857',
+  minZoom: 5,
+  maxZoom: 5,
+  url: '/data/tiles/512x256/{z}/{x}/{y}.png',
+  tileSize: [512, 256]
+});
+
+new Map({
+  pixelRatio: 1,
+  target: 'map',
+  layers: [
+    new TileLayer({
+      source: source
+    })
+  ],
+  view: new View({
+    projection: 'EPSG:4326',
+    center: toLonLat(center),
+    zoom: 5
+  })
+});
+
+render();

rendering/cases/reproj-tile-northpole/main.js

@@ -0,0 +1,40 @@
+import Map from '../../../src/ol/Map.js';
+import View from '../../../src/ol/View.js';
+import XYZ from '../../../src/ol/source/XYZ.js';
+import TileLayer from '../../../src/ol/layer/Tile.js';
+import {get, transform} from '../../../src/ol/proj.js';
+import {register} from '../../../src/ol/proj/proj4.js';
+import proj4 from 'proj4';
+
+proj4.defs('EPSG:3413', '+proj=stere +lat_0=90 +lat_ts=70 +lon_0=-45 ' +
+          '+k=1 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs');
+
+register(proj4);
+const proj3413 = get('EPSG:3413');
+proj3413.setExtent([-4194304, -4194304, 4194304, 4194304]);
+
+const center4326 = [0, 90];
+const center = transform(center4326, 'EPSG:4326', 'EPSG:3413');
+
+const source = new XYZ({
+  maxZoom: 0,
+  projection: 'EPSG:4326',
+  url: '/data/tiles/4326/{z}/{x}/{y}.png'
+});
+
+new Map({
+  pixelRatio: 1,
+  target: 'map',
+  layers: [
+    new TileLayer({
+      source: source
+    })
+  ],
+  view: new View({
+    projection: 'EPSG:3413',
+    center: center,
+    zoom: 0
+  })
+});
+
+render();

rendering/test.js

@@ -357,7 +357,7 @@ if (require.main === module) {
     option('puppeteer-args', {
       describe: 'Additional args for Puppeteer',
       type: 'array',
-      default: process.env.CI ? ['--no-sandbox', '--disable-setuid-sandbox'] : []
+      default: process.env.CI ? ['--no-sandbox', '--disable-setuid-sandbox', '--disable-dev-shm-usage'] : []
     }).
     parse();
 

src/ol/Image.js

@@ -159,7 +159,7 @@ class ImageWrapper extends ImageBase {
 export function listenImage(image, loadHandler, errorHandler) {
   const img = /** @type {HTMLImageElement} */ (image);
 
-  if (IMAGE_DECODE) {
+  if (img.src && IMAGE_DECODE) {
     const promise = img.decode();
     let listening = true;
     const unlisten = function() {

src/ol/ImageState.js

@@ -9,5 +9,6 @@ export default {
   IDLE: 0,
   LOADING: 1,
   LOADED: 2,
-  ERROR: 3
+  ERROR: 3,
+  EMPTY: 4
 };

src/ol/PluggableMap.js

@@ -1224,7 +1224,7 @@ class PluggableMap extends BaseObject {
     let frameState = null;
     if (size !== undefined && hasArea(size) && view && view.isDef()) {
       const viewHints = view.getHints(this.frameState_ ? this.frameState_.viewHints : undefined);
-      viewState = view.getState(this.pixelRatio_);
+      viewState = view.getState();
       frameState = {
         animate: false,
         coordinateToPixelTransform: this.coordinateToPixelTransform_,

src/ol/View.js

@@ -927,10 +927,9 @@ class View extends BaseObject {
   }
 
   /**
-   * @param {number} pixelRatio Pixel ratio for center rounding.
    * @return {State} View state.
    */
-  getState(pixelRatio) {
+  getState() {
     const center = /** @type {import("./coordinate.js").Coordinate} */ (this.getCenter());
     const projection = this.getProjection();
     const resolution = /** @type {number} */ (this.getResolution());
@@ -1148,7 +1147,6 @@ class View extends BaseObject {
    * constraint will apply.
    * @param {number} ratio The ratio to apply on the view resolution.
    * @param {import("./coordinate.js").Coordinate=} opt_anchor The origin of the transformation.
-   * @observable
    * @api
    */
   adjustResolution(ratio, opt_anchor) {
@@ -1180,7 +1178,6 @@ class View extends BaseObject {
    * constraint will apply.
    * @param {number} delta Relative value to add to the zoom rotation, in radians.
    * @param {import("./coordinate.js").Coordinate=} opt_anchor The rotation center.
-   * @observable
    * @api
    */
   adjustRotation(delta, opt_anchor) {

src/ol/control/Attribution.js

@@ -7,7 +7,7 @@ import {CLASS_CONTROL, CLASS_UNSELECTABLE, CLASS_COLLAPSED} from '../css.js';
 import {removeChildren, replaceNode} from '../dom.js';
 import {listen} from '../events.js';
 import EventType from '../events/EventType.js';
-import {visibleAtResolution} from '../layer/Layer.js';
+import {inView} from '../layer/Layer.js';
 
 
 /**
@@ -170,10 +170,9 @@ class Attribution extends Control {
     const visibleAttributions = [];
 
     const layerStatesArray = frameState.layerStatesArray;
-    const resolution = frameState.viewState.resolution;
     for (let i = 0, ii = layerStatesArray.length; i < ii; ++i) {
       const layerState = layerStatesArray[i];
-      if (!visibleAtResolution(layerState, resolution)) {
+      if (!inView(layerState, frameState.viewState)) {
         continue;
       }
 

src/ol/control/MousePosition.js

@@ -108,12 +108,6 @@ class MousePosition extends Control {
      */
     this.transform_ = null;
 
-    /**
-     * @private
-     * @type {import("../pixel.js").Pixel}
-     */
-    this.lastMouseMovePixel_ = null;
-
   }
 
   /**
@@ -156,8 +150,7 @@ class MousePosition extends Control {
    */
   handleMouseMove(event) {
     const map = this.getMap();
-    this.lastMouseMovePixel_ = map.getEventPixel(event);
-    this.updateHTML_(this.lastMouseMovePixel_);
+    this.updateHTML_(map.getEventPixel(event));
   }
 
   /**
@@ -166,7 +159,6 @@ class MousePosition extends Control {
    */
   handleMouseOut(event) {
     this.updateHTML_(null);
-    this.lastMouseMovePixel_ = null;
   }
 
   /**

src/ol/css.js

@@ -2,6 +2,13 @@
  * @module ol/css
  */
 
+/**
+ * @typedef {Object} FontParameters
+ * @property {Array<string>} families
+ * @property {string} style
+ * @property {string} weight
+ */
+
 
 /**
  * The CSS class for hidden feature.
@@ -62,10 +69,13 @@ export const CLASS_COLLAPSED = 'ol-collapsed';
  * Get the list of font families from a font spec.  Note that this doesn't work
  * for font families that have commas in them.
  * @param {string} The CSS font property.
- * @return {Object<string>} The font families (or null if the input spec is invalid).
+ * @return {FontParameters} The font families (or null if the input spec is invalid).
  */
-export const getFontFamilies = (function() {
+export const getFontParameters = (function() {
   let style;
+  /**
+   * @type {Object<string, FontParameters>}
+   */
   const cache = {};
   return function(font) {
     if (!style) {
@@ -74,11 +84,18 @@ export const getFontFamilies = (function() {
     if (!(font in cache)) {
       style.font = font;
       const family = style.fontFamily;
+      const fontWeight = style.fontWeight;
+      const fontStyle = style.fontStyle;
       style.font = '';
       if (!family) {
         return null;
       }
-      cache[font] = family.split(/,\s?/);
+      const families = family.split(/,\s?/);
+      cache[font] = {
+        families: families,
+        weight: fontWeight,
+        style: fontStyle
+      };
     }
     return cache[font];
   };

src/ol/format/EsriJSON.js

@@ -256,10 +256,10 @@ function readGeometry(object, opt_options) {
     const rings = convertRings(esriJSONPolygon.rings, layout);
     if (rings.length === 1) {
       type = GeometryType.POLYGON;
-      object['rings'] = rings[0];
+      object = Object.assign({}, object, {['rings']: rings[0]});
     } else {
       type = GeometryType.MULTI_POLYGON;
-      object['rings'] = rings;
+      object = Object.assign({}, object, {['rings']: rings});
     }
   }
   const geometryReader = GEOMETRY_READERS[type];

src/ol/format/Feature.js

@@ -4,6 +4,7 @@
 import {assign} from '../obj.js';
 import {abstract} from '../util.js';
 import {get as getProjection, equivalent as equivalentProjection, transformExtent} from '../proj.js';
+import Units from '../proj/Units.js';
 
 
 /**
@@ -89,8 +90,9 @@ class FeatureFormat {
     let options;
     if (opt_options) {
       let dataProjection = opt_options.dataProjection ?
-        opt_options.dataProjection : this.readProjection(source);
-      if (opt_options.extent) {
+        getProjection(opt_options.dataProjection) : this.readProjection(source);
+      if (opt_options.extent &&
+          dataProjection && dataProjection.getUnits() === Units.TILE_PIXELS) {
         dataProjection = getProjection(dataProjection);
         dataProjection.setWorldExtent(opt_options.extent);
       }

src/ol/format/IIIFInfo.js

@@ -94,6 +94,8 @@ import {assert} from '../asserts.js';
  * image service additional to the ones indicated by the compliance level.
  * @property {Array<string>} [extraFeatures] Additional supported features whose support
  * is not indicated by the compliance level.
+ * @property {Array<string>} [preferredFormats] Image formats that should preferrably
+ * be used.
  */
 
 /**
@@ -156,15 +158,15 @@ IIIF_PROFILE_VALUES[Versions.VERSION3] = {
     qualities: ['default']
   },
   'level1': {
-    supports: ['regionByPx', 'regionSquare', 'sizeByW', 'sizeByH'],
+    supports: ['regionByPx', 'regionSquare', 'sizeByW', 'sizeByH', 'sizeByWh'],
     formats: ['jpg'],
     qualities: ['default']
   },
   'level2': {
     supports: ['regionByPx', 'regionSquare', 'regionByPct',
       'sizeByW', 'sizeByH', 'sizeByPct', 'sizeByConfinedWh', 'sizeByWh'],
-    formats: ['jpg'],
-    qualities: ['default', 'bitonal']
+    formats: ['jpg', 'png'],
+    qualities: ['default']
   }
 };
 IIIF_PROFILE_VALUES['none'] = {
@@ -231,7 +233,16 @@ function generateVersion2Options(iiifInfo) {
 }
 
 function generateVersion3Options(iiifInfo) {
-  const levelProfile = iiifInfo.getComplianceLevelSupportedFeatures();
+  const levelProfile = iiifInfo.getComplianceLevelSupportedFeatures(),
+      formats = iiifInfo.imageInfo.extraFormats === undefined ? levelProfile.formats :
+        [...levelProfile.formats, ...iiifInfo.imageInfo.extraFormats],
+      preferredFormat = iiifInfo.imageInfo.preferredFormats !== undefined && Array.isArray(iiifInfo.imageInfo.preferredFormats) &&
+        iiifInfo.imageInfo.preferredFormats.length > 0 ?
+        iiifInfo.imageInfo.preferredFormats.filter(function(format) {
+          return ['jpg', 'png', 'gif'].includes(format);
+        }).reduce(function(acc, format) {
+          return acc === undefined && formats.includes(format) ? format : acc;
+        }, undefined) : undefined;
   return {
     url: iiifInfo.imageInfo['id'],
     sizes: iiifInfo.imageInfo.sizes === undefined ? undefined : iiifInfo.imageInfo.sizes.map(function(size) {
@@ -251,13 +262,10 @@ function generateVersion3Options(iiifInfo) {
       })[0],
     supports: iiifInfo.imageInfo.extraFeatures === undefined ? levelProfile.supports :
       [...levelProfile.supports, ...iiifInfo.imageInfo.extraFeatures],
-    formats: iiifInfo.imageInfo.extraFormats === undefined ? levelProfile.formats :
-      [...levelProfile.formats, ...iiifInfo.imageInfo.extraFormats],
+    formats: formats,
     qualities: iiifInfo.imageInfo.extraQualities === undefined ? levelProfile.qualities :
-      [...levelProfile.supports, ...iiifInfo.imageInfo.extraQualities],
-    maxWidth: undefined,
-    maxHeight: undefined,
-    maxArea: undefined
+      [...levelProfile.qualities, ...iiifInfo.imageInfo.extraQualities],
+    preferredFormat: preferredFormat
   };
 }
 
@@ -414,7 +422,8 @@ class IIIFInfo {
       version: version,
       size: [this.imageInfo.width, this.imageInfo.height],
       sizes: imageOptions.sizes,
-      format: imageOptions.formats.includes(options.format) ? options.format : 'jpg',
+      format: options.format !== undefined && imageOptions.formats.includes(options.format) ? options.format :
+        imageOptions.preferredFormat !== undefined ? imageOptions.preferredFormat : 'jpg',
       supports: imageOptions.supports,
       quality: options.quality && imageOptions.qualities.includes(options.quality) ?
         options.quality : imageOptions.qualities.includes('native') ? 'native' : 'default',

src/ol/format/MVT.js

@@ -31,6 +31,7 @@ import {get} from '../proj.js';
  * @property {string} [geometryName='geometry'] Geometry name to use when creating features.
  * @property {string} [layerName='layer'] Name of the feature attribute that holds the layer name.
  * @property {Array<string>} [layers] Layers to read features from. If not provided, features will be read from all
+ * @property {string} [idProperty] Optional property that will be assigned as the feature id and removed from the properties.
  * layers.
  */
 
@@ -84,6 +85,12 @@ class MVT extends FeatureFormat {
      */
     this.layers_ = options.layers ? options.layers : null;
 
+    /**
+     * @private
+     * @type {string}
+     */
+    this.idProperty_ = options.idProperty;
+
   }
 
   /**
@@ -164,8 +171,16 @@ class MVT extends FeatureFormat {
     }
 
     let feature;
-    const id = rawFeature.id;
     const values = rawFeature.properties;
+
+    let id;
+    if (!this.idProperty_) {
+      id = rawFeature.id;
+    } else {
+      id = values[this.idProperty_];
+      delete values[this.idProperty_];
+    }
+
     values[this.layerName_] = rawFeature.layer.name;
 
     const flatCoordinates = [];

src/ol/format/WFS.js

@@ -408,7 +408,7 @@ class WFS extends XMLFeature {
         node.setAttribute('count', String(options.count));
       }
       if (options.viewParams !== undefined) {
-        node.setAttribute('viewParams ', options.viewParams);
+        node.setAttribute('viewParams', options.viewParams);
       }
       filter = options.filter;
       if (options.bbox) {

src/ol/interaction/DragZoom.js

@@ -17,6 +17,8 @@ import DragBox from './DragBox.js';
  * Default is {@link module:ol/events/condition~shiftKeyOnly}.
  * @property {number} [duration=200] Animation duration in milliseconds.
  * @property {boolean} [out=false] Use interaction for zooming out.
+ * @property {number} [minArea=64] The minimum area of the box in pixel, this value is used by the parent default
+ * `boxEndCondition` function.
  */
 
 
@@ -42,6 +44,7 @@ class DragZoom extends DragBox {
     super({
       condition: condition,
       className: options.className || 'ol-dragzoom',
+      minArea: options.minArea,
       onBoxEnd: onBoxEnd
     });
 

src/ol/layer/Base.js

@@ -6,6 +6,7 @@ import BaseObject from '../Object.js';
 import LayerProperty from './Property.js';
 import {clamp} from '../math.js';
 import {assign} from '../obj.js';
+import {assert} from '../asserts.js';
 
 
 /**
@@ -23,6 +24,10 @@ import {assign} from '../obj.js';
  * visible.
  * @property {number} [maxResolution] The maximum resolution (exclusive) below which this layer will
  * be visible.
+ * @property {number} [minZoom] The minimum view zoom level (exclusive) above which this layer will be
+ * visible.
+ * @property {number} [maxZoom] The maximum view zoom level (inclusive) at which this layer will
+ * be visible.
  */
 
 
@@ -48,8 +53,11 @@ class BaseLayer extends BaseObject {
      * @type {Object<string, *>}
      */
     const properties = assign({}, options);
+
     properties[LayerProperty.OPACITY] =
-       options.opacity !== undefined ? options.opacity : 1;
+        options.opacity !== undefined ? options.opacity : 1;
+    assert(typeof properties[LayerProperty.OPACITY] === 'number', 64); // Layer opacity must be a number
+
     properties[LayerProperty.VISIBLE] =
        options.visible !== undefined ? options.visible : true;
     properties[LayerProperty.Z_INDEX] = options.zIndex;
@@ -57,6 +65,10 @@ class BaseLayer extends BaseObject {
        options.maxResolution !== undefined ? options.maxResolution : Infinity;
     properties[LayerProperty.MIN_RESOLUTION] =
        options.minResolution !== undefined ? options.minResolution : 0;
+    properties[LayerProperty.MIN_ZOOM] =
+       options.minZoom !== undefined ? options.minZoom : -Infinity;
+    properties[LayerProperty.MAX_ZOOM] =
+       options.maxZoom !== undefined ? options.maxZoom : Infinity;
 
     /**
      * @type {string}
@@ -103,6 +115,8 @@ class BaseLayer extends BaseObject {
     state.zIndex = this.getZIndex() || (state.managed === false ? Infinity : 0);
     state.maxResolution = this.getMaxResolution();
     state.minResolution = Math.max(this.getMinResolution(), 0);
+    state.minZoom = this.getMinZoom();
+    state.maxZoom = this.getMaxZoom();
     this.state_ = state;
 
     return state;
@@ -161,6 +175,26 @@ class BaseLayer extends BaseObject {
     return /** @type {number} */ (this.get(LayerProperty.MIN_RESOLUTION));
   }
 
+  /**
+   * Return the minimum zoom level of the layer.
+   * @return {number} The minimum zoom level of the layer.
+   * @observable
+   * @api
+   */
+  getMinZoom() {
+    return /** @type {number} */ (this.get(LayerProperty.MIN_ZOOM));
+  }
+
+  /**
+   * Return the maximum zoom level of the layer.
+   * @return {number} The maximum zoom level of the layer.
+   * @observable
+   * @api
+   */
+  getMaxZoom() {
+    return /** @type {number} */ (this.get(LayerProperty.MAX_ZOOM));
+  }
+
   /**
    * Return the opacity of the layer (between 0 and 1).
    * @return {number} The opacity of the layer.
@@ -231,6 +265,30 @@ class BaseLayer extends BaseObject {
     this.set(LayerProperty.MIN_RESOLUTION, minResolution);
   }
 
+  /**
+   * Set the maximum zoom (exclusive) at which the layer is visible.
+   * Note that the zoom levels for layer visibility are based on the
+   * view zoom level, which may be different from a tile source zoom level.
+   * @param {number} maxZoom The maximum zoom of the layer.
+   * @observable
+   * @api
+   */
+  setMaxZoom(maxZoom) {
+    this.set(LayerProperty.MAX_ZOOM, maxZoom);
+  }
+
+  /**
+   * Set the minimum zoom (inclusive) at which the layer is visible.
+   * Note that the zoom levels for layer visibility are based on the
+   * view zoom level, which may be different from a tile source zoom level.
+   * @param {number} minZoom The minimum zoom of the layer.
+   * @observable
+   * @api
+   */
+  setMinZoom(minZoom) {
+    this.set(LayerProperty.MIN_ZOOM, minZoom);
+  }
+
   /**
    * Set the opacity of the layer, allowed values range from 0 to 1.
    * @param {number} opacity The opacity of the layer.
@@ -238,6 +296,7 @@ class BaseLayer extends BaseObject {
    * @api
    */
   setOpacity(opacity) {
+    assert(typeof opacity === 'number', 64); // Layer opacity must be a number
     this.set(LayerProperty.OPACITY, opacity);
   }
 

src/ol/layer/Group.js

@@ -29,6 +29,10 @@ import SourceState from '../source/State.js';
  * visible.
  * @property {number} [maxResolution] The maximum resolution (exclusive) below which this layer will
  * be visible.
+ * @property {number} [minZoom] The minimum view zoom level (exclusive) above which this layer will be
+ * visible.
+ * @property {number} [maxZoom] The maximum view zoom level (inclusive) at which this layer will
+ * be visible.
  * @property {Array<import("./Base.js").default>|import("../Collection.js").default<import("./Base.js").default>} [layers] Child layers.
  */
 
@@ -215,6 +219,10 @@ class LayerGroup extends BaseLayer {
         layerState.maxResolution, ownLayerState.maxResolution);
       layerState.minResolution = Math.max(
         layerState.minResolution, ownLayerState.minResolution);
+      layerState.minZoom = Math.max(
+        layerState.minZoom, ownLayerState.minZoom);
+      layerState.maxZoom = Math.min(
+        layerState.maxZoom, ownLayerState.maxZoom);
       if (ownLayerState.extent !== undefined) {
         if (layerState.extent !== undefined) {
           layerState.extent = getIntersection(layerState.extent, ownLayerState.extent);

src/ol/layer/Heatmap.js

@@ -183,31 +183,24 @@ class Heatmap extends VectorLayer {
         precision mediump float;
         attribute vec2 a_position;
         attribute vec2 a_texCoord;
-        attribute float a_rotateWithView;
         attribute vec2 a_offsets;
         attribute float a_opacity;
 
         uniform mat4 u_projectionMatrix;
         uniform mat4 u_offsetScaleMatrix;
-        uniform mat4 u_offsetRotateMatrix;
         uniform float u_size;
 
         varying vec2 v_texCoord;
         varying float v_opacity;
 
         void main(void) {
-          mat4 offsetMatrix = u_offsetScaleMatrix;
-          if (a_rotateWithView == 1.0) {
-            offsetMatrix = u_offsetScaleMatrix * u_offsetRotateMatrix;
-          }
-          vec4 offsets = offsetMatrix * vec4(a_offsets, 0.0, 0.0);
+          vec4 offsets = u_offsetScaleMatrix * vec4(a_offsets, 0.0, 0.0);
           gl_Position = u_projectionMatrix * vec4(a_position, 0.0, 1.0) + offsets * u_size;
           v_texCoord = a_texCoord;
           v_opacity = a_opacity;
         }`,
       fragmentShader: `
         precision mediump float;
-        uniform float u_resolution;
         uniform float u_blurSlope;
 
         varying vec2 v_texCoord;
@@ -226,10 +219,7 @@ class Heatmap extends VectorLayer {
         }.bind(this),
         u_blurSlope: function() {
           return this.get(Property.RADIUS) / Math.max(1, this.get(Property.BLUR));
-        }.bind(this),
-        u_resolution: function(frameState) {
-          return frameState.viewState.resolution;
-        }
+        }.bind(this)
       },
       postProcesses: [
         {
@@ -240,7 +230,6 @@ class Heatmap extends VectorLayer {
             uniform sampler2D u_gradientTexture;
 
             varying vec2 v_texCoord;
-            varying vec2 v_screenCoord;
 
             void main() {
               vec4 color = texture2D(u_image, v_texCoord);

src/ol/layer/Layer.js

@@ -50,6 +50,8 @@ import SourceState from '../source/State.js';
  * @property {number} zIndex
  * @property {number} maxResolution
  * @property {number} minResolution
+ * @property {number} minZoom
+ * @property {number} maxZoom
  */
 
 /**
@@ -277,17 +279,22 @@ class Layer extends BaseLayer {
 
 
 /**
- * Return `true` if the layer is visible, and if the passed resolution is
- * between the layer's minResolution and maxResolution. The comparison is
- * inclusive for `minResolution` and exclusive for `maxResolution`.
+ * Return `true` if the layer is visible and if the provided view state
+ * has resolution and zoom levels that are in range of the layer's min/max.
  * @param {State} layerState Layer state.
- * @param {number} resolution Resolution.
- * @return {boolean} The layer is visible at the given resolution.
+ * @param {import("../View.js").State} viewState View state.
+ * @return {boolean} The layer is visible at the given view state.
  */
-export function visibleAtResolution(layerState, resolution) {
-  return layerState.visible && resolution >= layerState.minResolution &&
-      resolution < layerState.maxResolution;
+export function inView(layerState, viewState) {
+  if (!layerState.visible) {
+    return false;
+  }
+  const resolution = viewState.resolution;
+  if (resolution < layerState.minResolution || resolution >= layerState.maxResolution) {
+    return false;
+  }
+  const zoom = viewState.zoom;
+  return zoom > layerState.minZoom && zoom <= layerState.maxZoom;
 }
 
-
 export default Layer;

src/ol/layer/Property.js

@@ -12,5 +12,7 @@ export default {
   Z_INDEX: 'zIndex',
   MAX_RESOLUTION: 'maxResolution',
   MIN_RESOLUTION: 'minResolution',
+  MAX_ZOOM: 'maxZoom',
+  MIN_ZOOM: 'minZoom',
   SOURCE: 'source'
 };

src/ol/render/VectorContext.js

@@ -106,9 +106,9 @@ class VectorContext {
 
   /**
    * @param {import("../style/Text.js").default} textStyle Text style.
-   * @param {import("./canvas.js").DeclutterGroup=} opt_declutterGroup Declutter.
+   * @param {import("./canvas.js").DeclutterGroups=} opt_declutterGroups Declutter.
    */
-  setTextStyle(textStyle, opt_declutterGroup) {}
+  setTextStyle(textStyle, opt_declutterGroups) {}
 }
 
 export default VectorContext;

src/ol/render/canvas.js

@@ -1,7 +1,7 @@
 /**
  * @module ol/render/canvas
  */
-import {getFontFamilies} from '../css.js';
+import {getFontParameters} from '../css.js';
 import {createCanvasContext2D} from '../dom.js';
 import {clear} from '../obj.js';
 import {create as createTransform} from '../transform.js';
@@ -18,19 +18,19 @@ import LabelCache from './canvas/LabelCache.js';
  * @typedef {Object} FillStrokeState
  * @property {import("../colorlike.js").ColorLike} [currentFillStyle]
  * @property {import("../colorlike.js").ColorLike} [currentStrokeStyle]
- * @property {string} [currentLineCap]
+ * @property {CanvasLineCap} [currentLineCap]
  * @property {Array<number>} currentLineDash
  * @property {number} [currentLineDashOffset]
- * @property {string} [currentLineJoin]
+ * @property {CanvasLineJoin} [currentLineJoin]
  * @property {number} [currentLineWidth]
  * @property {number} [currentMiterLimit]
  * @property {number} [lastStroke]
  * @property {import("../colorlike.js").ColorLike} [fillStyle]
  * @property {import("../colorlike.js").ColorLike} [strokeStyle]
- * @property {string} [lineCap]
+ * @property {CanvasLineCap} [lineCap]
  * @property {Array<number>} lineDash
  * @property {number} [lineDashOffset]
- * @property {string} [lineJoin]
+ * @property {CanvasLineJoin} [lineJoin]
  * @property {number} [lineWidth]
  * @property {number} [miterLimit]
  */
@@ -38,10 +38,10 @@ import LabelCache from './canvas/LabelCache.js';
 
 /**
  * @typedef {Object} StrokeState
- * @property {string} lineCap
+ * @property {CanvasLineCap} lineCap
  * @property {Array<number>} lineDash
  * @property {number} lineDashOffset
- * @property {string} lineJoin
+ * @property {CanvasLineJoin} lineJoin
  * @property {number} lineWidth
  * @property {number} miterLimit
  * @property {import("../colorlike.js").ColorLike} strokeStyle
@@ -62,7 +62,6 @@ import LabelCache from './canvas/LabelCache.js';
  * @property {Array<number>} [padding]
  */
 
-
 /**
  * Container for decluttered replay instructions that need to be rendered or
  * omitted together, i.e. when styles render both an image and text, or for the
@@ -76,6 +75,12 @@ import LabelCache from './canvas/LabelCache.js';
  */
 
 
+/**
+ * Declutter groups for support of multi geometries.
+ * @typedef {Array<DeclutterGroup>} DeclutterGroups
+ */
+
+
 /**
  * @const
  * @type {string}
@@ -92,7 +97,7 @@ export const defaultFillStyle = '#000';
 
 /**
  * @const
- * @type {string}
+ * @type {CanvasLineCap}
  */
 export const defaultLineCap = 'round';
 
@@ -113,7 +118,7 @@ export const defaultLineDashOffset = 0;
 
 /**
  * @const
- * @type {string}
+ * @type {CanvasLineJoin}
  */
 export const defaultLineJoin = 'round';
 
@@ -180,6 +185,10 @@ export const checkedFonts = {};
  */
 let measureContext = null;
 
+/**
+ * @type {string}
+ */
+let measureFont;
 
 /**
  * @type {!Object<string, number>}
@@ -192,7 +201,7 @@ export const textHeights = {};
  * @param {string} fontSpec CSS font spec.
  */
 export const checkFont = (function() {
-  const retries = 60;
+  const retries = 100;
   const checked = checkedFonts;
   const size = '32px ';
   const referenceFonts = ['monospace', 'serif'];
@@ -200,32 +209,30 @@ export const checkFont = (function() {
   const text = 'wmytzilWMYTZIL@#/&?$%10\uF013';
   let interval, referenceWidth;
 
-  function isAvailable(font) {
+  /**
+   * @param {string} fontStyle Css font-style
+   * @param {string} fontWeight Css font-weight
+   * @param {*} fontFamily Css font-family
+   * @return {boolean} Font with style and weight is available
+   */
+  function isAvailable(fontStyle, fontWeight, fontFamily) {
     const context = getMeasureContext();
-    // Check weight ranges according to
-    // https://developer.mozilla.org/en-US/docs/Web/CSS/font-weight#Fallback_weights
-    for (let weight = 100; weight <= 700; weight += 300) {
-      const fontWeight = weight + ' ';
-      let available = true;
-      for (let i = 0; i < len; ++i) {
-        const referenceFont = referenceFonts[i];
-        context.font = fontWeight + size + referenceFont;
-        referenceWidth = context.measureText(text).width;
-        if (font != referenceFont) {
-          context.font = fontWeight + size + font + ',' + referenceFont;
-          const width = context.measureText(text).width;
-          // If width and referenceWidth are the same, then the fallback was used
-          // instead of the font we wanted, so the font is not available.
-          available = available && width != referenceWidth;
-        }
-      }
-      if (available) {
-        // Consider font available when it is available in one weight range.
-        //FIXME With this we miss rare corner cases, so we should consider
-        //FIXME checking availability for each requested weight range.
-        return true;
+    let available = true;
+    for (let i = 0; i < len; ++i) {
+      const referenceFont = referenceFonts[i];
+      context.font = fontStyle + ' ' + fontWeight + ' ' + size + referenceFont;
+      referenceWidth = context.measureText(text).width;
+      if (fontFamily != referenceFont) {
+        context.font = fontStyle + ' ' + fontWeight + ' ' + size + fontFamily + ',' + referenceFont;
+        const width = context.measureText(text).width;
+        // If width and referenceWidth are the same, then the fallback was used
+        // instead of the font we wanted, so the font is not available.
+        available = available && width != referenceWidth;
       }
     }
+    if (available) {
+      return true;
+    }
     return false;
   }
 
@@ -233,12 +240,15 @@ export const checkFont = (function() {
     let done = true;
     for (const font in checked) {
       if (checked[font] < retries) {
-        if (isAvailable(font)) {
+        if (isAvailable.apply(this, font.split('\n'))) {
           checked[font] = retries;
           clear(textHeights);
           // Make sure that loaded fonts are picked up by Safari
           measureContext = null;
-          labelCache.clear();
+          measureFont = undefined;
+          if (labelCache.getCount()) {
+            labelCache.clear();
+          }
         } else {
           ++checked[font];
           done = false;
@@ -252,16 +262,18 @@ export const checkFont = (function() {
   }
 
   return function(fontSpec) {
-    const fontFamilies = getFontFamilies(fontSpec);
-    if (!fontFamilies) {
+    const font = getFontParameters(fontSpec);
+    if (!font) {
       return;
     }
-    for (let i = 0, ii = fontFamilies.length; i < ii; ++i) {
-      const fontFamily = fontFamilies[i];
-      if (!(fontFamily in checked)) {
-        checked[fontFamily] = retries;
-        if (!isAvailable(fontFamily)) {
-          checked[fontFamily] = 0;
+    const families = font.families;
+    for (let i = 0, ii = families.length; i < ii; ++i) {
+      const family = families[i];
+      const key = font.style + '\n' + font.weight + '\n' + family;
+      if (!(key in checked)) {
+        checked[key] = retries;
+        if (!isAvailable(font.style, font.weight, family)) {
+          checked[key] = 0;
           if (interval === undefined) {
             interval = setInterval(check, 32);
           }
@@ -317,8 +329,8 @@ export const measureTextHeight = (function() {
  */
 export function measureTextWidth(font, text) {
   const measureContext = getMeasureContext();
-  if (font != measureContext.font) {
-    measureContext.font = font;
+  if (font != measureFont) {
+    measureContext.font = measureFont = font;
   }
   return measureContext.measureText(text).width;
 }

src/ol/render/canvas/BuilderGroup.js

@@ -40,10 +40,10 @@ class BuilderGroup {
     this.declutter_ = declutter;
 
     /**
-     * @type {import("../canvas.js").DeclutterGroup}
+     * @type {import("../canvas.js").DeclutterGroups}
      * @private
      */
-    this.declutterGroup_ = null;
+    this.declutterGroups_ = null;
 
     /**
      * @private
@@ -78,17 +78,17 @@ class BuilderGroup {
 
   /**
    * @param {boolean} group Group with previous builder.
-   * @return {Array<*>} The resulting instruction group.
+   * @return {import("../canvas").DeclutterGroups} The resulting instruction groups.
    */
   addDeclutter(group) {
     let declutter = null;
     if (this.declutter_) {
       if (group) {
-        declutter = this.declutterGroup_;
-        /** @type {number} */ (declutter[4])++;
+        declutter = this.declutterGroups_;
+        /** @type {number} */ (declutter[0][4])++;
       } else {
-        declutter = this.declutterGroup_ = createEmpty();
-        declutter.push(1);
+        declutter = this.declutterGroups_ = [createEmpty()];
+        declutter[0].push(1);
       }
     }
     return declutter;

src/ol/render/canvas/Executor.js

@@ -207,8 +207,8 @@ class Executor extends Disposable {
       if (strokeKey) {
         context.strokeStyle = strokeState.strokeStyle;
         context.lineWidth = strokeWidth;
-        context.lineCap = /** @type {CanvasLineCap} */ (strokeState.lineCap);
-        context.lineJoin = /** @type {CanvasLineJoin} */ (strokeState.lineJoin);
+        context.lineCap = strokeState.lineCap;
+        context.lineJoin = strokeState.lineJoin;
         context.miterLimit = strokeState.miterLimit;
         if (context.setLineDash && strokeState.lineDash.length) {
           context.setLineDash(strokeState.lineDash);
@@ -535,7 +535,7 @@ class Executor extends Disposable {
     const ii = instructions.length; // end of instructions
     let d = 0; // data index
     let dd; // end of per-instruction data
-    let anchorX, anchorY, prevX, prevY, roundX, roundY, declutterGroup, image, text, textKey;
+    let anchorX, anchorY, prevX, prevY, roundX, roundY, declutterGroup, declutterGroups, image, text, textKey;
     let strokeKey, fillKey;
     let pendingFill = 0;
     let pendingStroke = 0;
@@ -633,7 +633,7 @@ class Executor extends Disposable {
           // Remaining arguments in DRAW_IMAGE are in alphabetical order
           anchorX = /** @type {number} */ (instruction[4]);
           anchorY = /** @type {number} */ (instruction[5]);
-          declutterGroup = featureCallback ? null : /** @type {import("../canvas.js").DeclutterGroup} */ (instruction[6]);
+          declutterGroups = featureCallback ? null : instruction[6];
           let height = /** @type {number} */ (instruction[7]);
           const opacity = /** @type {number} */ (instruction[8]);
           const originX = /** @type {number} */ (instruction[9]);
@@ -643,7 +643,6 @@ class Executor extends Disposable {
           const scale = /** @type {number} */ (instruction[13]);
           let width = /** @type {number} */ (instruction[14]);
 
-
           if (!image && instruction.length >= 19) {
             // create label images
             text = /** @type {string} */ (instruction[18]);
@@ -679,25 +678,41 @@ class Executor extends Disposable {
             rotation += viewRotation;
           }
           let widthIndex = 0;
+          let declutterGroupIndex = 0;
           for (; d < dd; d += 2) {
             if (geometryWidths && geometryWidths[widthIndex++] < width / this.pixelRatio) {
               continue;
             }
+            if (declutterGroups) {
+              const index = Math.floor(declutterGroupIndex);
+              if (declutterGroups.length < index + 1) {
+                declutterGroup = createEmpty();
+                declutterGroup.push(declutterGroups[0][4]);
+                declutterGroups.push(declutterGroup);
+              }
+              declutterGroup = declutterGroups[index];
+            }
             this.replayImage_(context,
               pixelCoordinates[d], pixelCoordinates[d + 1], image, anchorX, anchorY,
               declutterGroup, height, opacity, originX, originY, rotation, scale,
               snapToPixel, width, padding,
               backgroundFill ? /** @type {Array<*>} */ (lastFillInstruction) : null,
               backgroundStroke ? /** @type {Array<*>} */ (lastStrokeInstruction) : null);
+            if (declutterGroup) {
+              if (declutterGroupIndex === Math.floor(declutterGroupIndex)) {
+                this.declutterItems.push(this, declutterGroup, feature);
+              }
+              declutterGroupIndex += 1 / declutterGroup[4];
+
+            }
           }
-          this.declutterItems.push(this, declutterGroup, feature);
           ++i;
           break;
         case CanvasInstruction.DRAW_CHARS:
           const begin = /** @type {number} */ (instruction[1]);
           const end = /** @type {number} */ (instruction[2]);
           const baseline = /** @type {number} */ (instruction[3]);
-          declutterGroup = featureCallback ? null : /** @type {import("../canvas.js").DeclutterGroup} */ (instruction[4]);
+          declutterGroup = featureCallback ? null : instruction[4];
           const overflow = /** @type {number} */ (instruction[5]);
           fillKey = /** @type {string} */ (instruction[6]);
           const maxAngle = /** @type {number} */ (instruction[7]);

src/ol/render/canvas/ImageBuilder.js

@@ -16,9 +16,9 @@ class CanvasImageBuilder extends CanvasBuilder {
 
     /**
      * @private
-     * @type {import("../canvas.js").DeclutterGroup}
+     * @type {import("../canvas.js").DeclutterGroups}
      */
-    this.declutterGroup_ = null;
+    this.declutterGroups_ = null;
 
     /**
      * @private
@@ -121,14 +121,14 @@ class CanvasImageBuilder extends CanvasBuilder {
     this.instructions.push([
       CanvasInstruction.DRAW_IMAGE, myBegin, myEnd, this.image_,
       // Remaining arguments to DRAW_IMAGE are in alphabetical order
-      this.anchorX_, this.anchorY_, this.declutterGroup_, this.height_, this.opacity_,
+      this.anchorX_, this.anchorY_, this.declutterGroups_, this.height_, this.opacity_,
       this.originX_, this.originY_, this.rotateWithView_, this.rotation_,
       this.scale_ * this.pixelRatio, this.width_
     ]);
     this.hitDetectionInstructions.push([
       CanvasInstruction.DRAW_IMAGE, myBegin, myEnd, this.hitDetectionImage_,
       // Remaining arguments to DRAW_IMAGE are in alphabetical order
-      this.anchorX_, this.anchorY_, this.declutterGroup_, this.height_, this.opacity_,
+      this.anchorX_, this.anchorY_, this.declutterGroups_, this.height_, this.opacity_,
       this.originX_, this.originY_, this.rotateWithView_, this.rotation_,
       this.scale_, this.width_
     ]);
@@ -151,14 +151,14 @@ class CanvasImageBuilder extends CanvasBuilder {
     this.instructions.push([
       CanvasInstruction.DRAW_IMAGE, myBegin, myEnd, this.image_,
       // Remaining arguments to DRAW_IMAGE are in alphabetical order
-      this.anchorX_, this.anchorY_, this.declutterGroup_, this.height_, this.opacity_,
+      this.anchorX_, this.anchorY_, this.declutterGroups_, this.height_, this.opacity_,
       this.originX_, this.originY_, this.rotateWithView_, this.rotation_,
       this.scale_ * this.pixelRatio, this.width_
     ]);
     this.hitDetectionInstructions.push([
       CanvasInstruction.DRAW_IMAGE, myBegin, myEnd, this.hitDetectionImage_,
       // Remaining arguments to DRAW_IMAGE are in alphabetical order
-      this.anchorX_, this.anchorY_, this.declutterGroup_, this.height_, this.opacity_,
+      this.anchorX_, this.anchorY_, this.declutterGroups_, this.height_, this.opacity_,
       this.originX_, this.originY_, this.rotateWithView_, this.rotation_,
       this.scale_, this.width_
     ]);
@@ -189,7 +189,7 @@ class CanvasImageBuilder extends CanvasBuilder {
   /**
    * @inheritDoc
    */
-  setImageStyle(imageStyle, declutterGroup) {
+  setImageStyle(imageStyle, declutterGroups) {
     const anchor = imageStyle.getAnchor();
     const size = imageStyle.getSize();
     const hitDetectionImage = imageStyle.getHitDetectionImage(1);
@@ -197,7 +197,7 @@ class CanvasImageBuilder extends CanvasBuilder {
     const origin = imageStyle.getOrigin();
     this.anchorX_ = anchor[0];
     this.anchorY_ = anchor[1];
-    this.declutterGroup_ = /** @type {import("../canvas.js").DeclutterGroup} */ (declutterGroup);
+    this.declutterGroups_ = /** @type {import("../canvas.js").DeclutterGroups} */ (declutterGroups);
     this.hitDetectionImage_ = hitDetectionImage;
     this.image_ = image;
     this.height_ = size[1];

src/ol/render/canvas/Immediate.js

@@ -692,12 +692,12 @@ class CanvasImmediateRenderer extends VectorContext {
     const context = this.context_;
     const contextStrokeState = this.contextStrokeState_;
     if (!contextStrokeState) {
-      context.lineCap = /** @type {CanvasLineCap} */ (strokeState.lineCap);
+      context.lineCap = strokeState.lineCap;
       if (context.setLineDash) {
         context.setLineDash(strokeState.lineDash);
         context.lineDashOffset = strokeState.lineDashOffset;
       }
-      context.lineJoin = /** @type {CanvasLineJoin} */ (strokeState.lineJoin);
+      context.lineJoin = strokeState.lineJoin;
       context.lineWidth = strokeState.lineWidth;
       context.miterLimit = strokeState.miterLimit;
       context.strokeStyle = strokeState.strokeStyle;
@@ -712,7 +712,7 @@ class CanvasImmediateRenderer extends VectorContext {
       };
     } else {
       if (contextStrokeState.lineCap != strokeState.lineCap) {
-        contextStrokeState.lineCap = context.lineCap = /** @type {CanvasLineCap} */ (strokeState.lineCap);
+        contextStrokeState.lineCap = context.lineCap = strokeState.lineCap;
       }
       if (context.setLineDash) {
         if (!equals(contextStrokeState.lineDash, strokeState.lineDash)) {
@@ -724,7 +724,7 @@ class CanvasImmediateRenderer extends VectorContext {
         }
       }
       if (contextStrokeState.lineJoin != strokeState.lineJoin) {
-        contextStrokeState.lineJoin = context.lineJoin = /** @type {CanvasLineJoin} */ (strokeState.lineJoin);
+        contextStrokeState.lineJoin = context.lineJoin = strokeState.lineJoin;
       }
       if (contextStrokeState.lineWidth != strokeState.lineWidth) {
         contextStrokeState.lineWidth = context.lineWidth = strokeState.lineWidth;

src/ol/render/canvas/LabelCache.js

@@ -21,8 +21,8 @@ class LabelCache extends LRUCache {
   }
 
   clear() {
-    super.clear();
     this.consumers = {};
+    super.clear();
   }
 
   /**

src/ol/render/canvas/TextBuilder.js

@@ -40,9 +40,9 @@ class CanvasTextBuilder extends CanvasBuilder {
 
     /**
      * @private
-     * @type {import("../canvas.js").DeclutterGroup}
+     * @type {import("../canvas.js").DeclutterGroups}
      */
-    this.declutterGroup_;
+    this.declutterGroups_;
 
     /**
      * @private
@@ -201,7 +201,10 @@ class CanvasTextBuilder extends CanvasBuilder {
         }
         end = this.coordinates.length;
         flatOffset = ends[o];
-        this.drawChars_(begin, end, this.declutterGroup_);
+        const declutterGroup = this.declutterGroups_ ?
+          (o === 0 ? this.declutterGroups_[0] : [].concat(this.declutterGroups_[0])) :
+          null;
+        this.drawChars_(begin, end, declutterGroup);
         begin = end;
       }
       this.endGeometry(feature);
@@ -274,7 +277,7 @@ class CanvasTextBuilder extends CanvasBuilder {
       // render time.
       const pixelRatio = this.pixelRatio;
       this.instructions.push([CanvasInstruction.DRAW_IMAGE, begin, end,
-        null, NaN, NaN, this.declutterGroup_, NaN, 1, 0, 0,
+        null, NaN, NaN, this.declutterGroups_, NaN, 1, 0, 0,
         this.textRotateWithView_, this.textRotation_, 1, NaN,
         textState.padding == defaultPadding ?
           defaultPadding : textState.padding.map(function(p) {
@@ -285,7 +288,7 @@ class CanvasTextBuilder extends CanvasBuilder {
         this.textOffsetX_, this.textOffsetY_, geometryWidths
       ]);
       this.hitDetectionInstructions.push([CanvasInstruction.DRAW_IMAGE, begin, end,
-        null, NaN, NaN, this.declutterGroup_, NaN, 1, 0, 0,
+        null, NaN, NaN, this.declutterGroups_, NaN, 1, 0, 0,
         this.textRotateWithView_, this.textRotation_, 1 / this.pixelRatio, NaN,
         textState.padding,
         !!textState.backgroundFill, !!textState.backgroundStroke,
@@ -379,12 +382,12 @@ class CanvasTextBuilder extends CanvasBuilder {
   /**
    * @inheritDoc
    */
-  setTextStyle(textStyle, declutterGroup) {
+  setTextStyle(textStyle, declutterGroups) {
     let textState, fillState, strokeState;
     if (!textStyle) {
       this.text_ = '';
     } else {
-      this.declutterGroup_ = /** @type {import("../canvas.js").DeclutterGroup} */ (declutterGroup);
+      this.declutterGroups_ = /** @type {import("../canvas.js").DeclutterGroups} */ (declutterGroups);
 
       const textFillStyle = textStyle.getFill();
       if (!textFillStyle) {

src/ol/renderer/Composite.js

@@ -2,7 +2,7 @@
  * @module ol/renderer/Composite
  */
 import {CLASS_UNSELECTABLE} from '../css.js';
-import {visibleAtResolution} from '../layer/Layer.js';
+import {inView} from '../layer/Layer.js';
 import RenderEvent from '../render/Event.js';
 import RenderEventType from '../render/EventType.js';
 import MapRenderer from './Map.js';
@@ -95,7 +95,7 @@ class CompositeMapRenderer extends MapRenderer {
     const layerStatesArray = frameState.layerStatesArray.sort(function(a, b) {
       return a.zIndex - b.zIndex;
     });
-    const viewResolution = frameState.viewState.resolution;
+    const viewState = frameState.viewState;
 
     this.children_.length = 0;
     let hasOverlay = false;
@@ -104,7 +104,7 @@ class CompositeMapRenderer extends MapRenderer {
       const layerState = layerStatesArray[i];
       hasOverlay = hasOverlay || layerState.hasOverlay;
       frameState.layerIndex = i;
-      if (!visibleAtResolution(layerState, viewResolution) ||
+      if (!inView(layerState, viewState) ||
         (layerState.sourceState != SourceState.READY && layerState.sourceState != SourceState.UNDEFINED)) {
         continue;
       }
@@ -142,7 +142,6 @@ class CompositeMapRenderer extends MapRenderer {
    */
   forEachLayerAtPixel(pixel, frameState, hitTolerance, callback, layerFilter) {
     const viewState = frameState.viewState;
-    const viewResolution = viewState.resolution;
 
     const layerStates = frameState.layerStatesArray;
     const numLayers = layerStates.length;
@@ -150,7 +149,7 @@ class CompositeMapRenderer extends MapRenderer {
     for (let i = numLayers - 1; i >= 0; --i) {
       const layerState = layerStates[i];
       const layer = layerState.layer;
-      if (layer.hasRenderer() && visibleAtResolution(layerState, viewResolution) && layerFilter(layer)) {
+      if (layer.hasRenderer() && inView(layerState, viewState) && layerFilter(layer)) {
         const layerRenderer = layer.getRenderer();
         const data = layerRenderer.getDataAtPixel(pixel, frameState, hitTolerance);
         if (data) {

src/ol/renderer/Layer.js

@@ -132,15 +132,6 @@ class LayerRenderer extends Observable {
     }
   }
 
-  /**
-   * @param {import("../coordinate.js").Coordinate} coordinate Coordinate.
-   * @param {import("../PluggableMap.js").FrameState} frameState Frame state.
-   * @return {boolean} Is there a feature at the given coordinate?
-   */
-  hasFeatureAtCoordinate(coordinate, frameState) {
-    return false;
-  }
-
   /**
    * Load the image if not already loaded, and register the image change
    * listener if needed.

src/ol/renderer/Map.js

@@ -5,7 +5,7 @@ import {abstract, getUid} from '../util.js';
 import Disposable from '../Disposable.js';
 import {getWidth} from '../extent.js';
 import {TRUE} from '../functions.js';
-import {visibleAtResolution} from '../layer/Layer.js';
+import {inView} from '../layer/Layer.js';
 import {shared as iconImageCache} from '../style/IconImageCache.js';
 import {compose as composeTransform, makeInverse} from '../transform.js';
 import {renderDeclutterItems} from '../render.js';
@@ -87,7 +87,6 @@ class MapRenderer extends Disposable {
   ) {
     let result;
     const viewState = frameState.viewState;
-    const viewResolution = viewState.resolution;
 
     /**
      * @param {boolean} managed Managed layer.
@@ -126,7 +125,7 @@ class MapRenderer extends Disposable {
     for (i = numLayers - 1; i >= 0; --i) {
       const layerState = layerStates[i];
       const layer = /** @type {import("../layer/Layer.js").default} */ (layerState.layer);
-      if (layer.hasRenderer() && visibleAtResolution(layerState, viewResolution) && layerFilter.call(thisArg2, layer)) {
+      if (layer.hasRenderer() && inView(layerState, viewState) && layerFilter.call(thisArg2, layer)) {
         const layerRenderer = layer.getRenderer();
         const source = layer.getSource();
         if (layerRenderer && source) {

src/ol/renderer/canvas/TileLayer.js

@@ -63,12 +63,6 @@ class CanvasTileLayerRenderer extends CanvasLayerRenderer {
      * @type {import("../../TileRange.js").default}
      */
     this.tmpTileRange_ = new TileRange(0, 0, 0, 0);
-
-    /**
-     * @protected
-     * @type {number}
-     */
-    this.zDirection = 0;
   }
 
   /**
@@ -151,8 +145,7 @@ class CanvasTileLayerRenderer extends CanvasLayerRenderer {
     const tileSource = tileLayer.getSource();
     const sourceRevision = tileSource.getRevision();
     const tileGrid = tileSource.getTileGridForProjection(projection);
-    const zDirection = tileSource.zDirection === undefined ? this.zDirection : tileSource.zDirection;
-    const z = tileGrid.getZForResolution(viewResolution, zDirection);
+    const z = tileGrid.getZForResolution(viewResolution, tileSource.zDirection);
     const tileResolution = tileGrid.getResolution(z);
     let extent = frameState.extent;
 
@@ -384,7 +377,8 @@ class CanvasTileLayerRenderer extends CanvasLayerRenderer {
       return;
     }
     const uid = getUid(this);
-    const alpha = opacity * (transition ? tile.getAlpha(uid, frameState.time) : 1);
+    const tileAlpha = transition ? tile.getAlpha(uid, frameState.time) : 1;
+    const alpha = opacity * tileAlpha;
     const alphaChanged = alpha !== this.context.globalAlpha;
     if (alphaChanged) {
       this.context.save();
@@ -396,7 +390,7 @@ class CanvasTileLayerRenderer extends CanvasLayerRenderer {
     if (alphaChanged) {
       this.context.restore();
     }
-    if (alpha !== 1) {
+    if (tileAlpha !== 1) {
       frameState.animate = true;
     } else if (transition) {
       tile.endTransition(uid);

src/ol/renderer/canvas/VectorLayer.js

@@ -299,6 +299,8 @@ class CanvasVectorLayerRenderer extends CanvasLayerRenderer {
 
     vectorSource.loadFeatures(extent, resolution, projection);
 
+    const squaredTolerance = getSquaredRenderTolerance(resolution, pixelRatio);
+
     /**
      * @param {import("../../Feature.js").default} feature Feature.
      * @this {CanvasVectorLayerRenderer}
@@ -310,11 +312,11 @@ class CanvasVectorLayerRenderer extends CanvasLayerRenderer {
         styles = styleFunction(feature, resolution);
       }
       if (styles) {
-        const dirty = this.renderFeature(
-          feature, resolution, pixelRatio, styles, replayGroup);
+        const dirty = this.renderFeature(feature, squaredTolerance, styles, replayGroup);
         this.dirty_ = this.dirty_ || dirty;
       }
     }.bind(this);
+
     if (vectorLayerRenderOrder) {
       /** @type {Array<import("../../Feature.js").default>} */
       const features = [];
@@ -350,13 +352,12 @@ class CanvasVectorLayerRenderer extends CanvasLayerRenderer {
 
   /**
    * @param {import("../../Feature.js").default} feature Feature.
-   * @param {number} resolution Resolution.
-   * @param {number} pixelRatio Pixel ratio.
+   * @param {number} squaredTolerance Squared render tolerance.
    * @param {import("../../style/Style.js").default|Array<import("../../style/Style.js").default>} styles The style or array of styles.
    * @param {import("../../render/canvas/BuilderGroup.js").default} builderGroup Builder group.
    * @return {boolean} `true` if an image is loading.
    */
-  renderFeature(feature, resolution, pixelRatio, styles, builderGroup) {
+  renderFeature(feature, squaredTolerance, styles, builderGroup) {
     if (!styles) {
       return false;
     }
@@ -364,14 +365,12 @@ class CanvasVectorLayerRenderer extends CanvasLayerRenderer {
     if (Array.isArray(styles)) {
       for (let i = 0, ii = styles.length; i < ii; ++i) {
         loading = renderFeature(
-          builderGroup, feature, styles[i],
-          getSquaredRenderTolerance(resolution, pixelRatio),
+          builderGroup, feature, styles[i], squaredTolerance,
           this.handleStyleImageChange_, this) || loading;
       }
     } else {
       loading = renderFeature(
-        builderGroup, feature, styles,
-        getSquaredRenderTolerance(resolution, pixelRatio),
+        builderGroup, feature, styles, squaredTolerance,
         this.handleStyleImageChange_, this);
     }
     return loading;

src/ol/renderer/canvas/VectorTileLayer.js

@@ -24,6 +24,7 @@ import {
   makeInverse
 } from '../../transform.js';
 import CanvasExecutorGroup, {replayDeclutter} from '../../render/canvas/ExecutorGroup.js';
+import {clear} from '../../obj.js';
 
 
 /**
@@ -112,8 +113,6 @@ class CanvasVectorTileLayerRenderer extends CanvasTileLayerRenderer {
      */
     this.tmpTransform_ = createTransform();
 
-    // Use nearest lower resolution.
-    this.zDirection = 1;
   }
 
   /**
@@ -343,11 +342,13 @@ class CanvasVectorTileLayerRenderer extends CanvasTileLayerRenderer {
     let i, ii;
     for (i = 0, ii = renderedTiles.length; i < ii; ++i) {
       const tile = renderedTiles[i];
+      const tileExtent = tileGrid.getTileCoordExtent(tile.wrappedTileCoord);
+      const tileContainsCoordinate = containsCoordinate(tileExtent, coordinate);
+
       if (!declutter) {
         // When not decluttering, we only need to consider the tile that contains the given
         // coordinate, because each feature will be rendered for each tile that contains it.
-        const tileExtent = tileGrid.getTileCoordExtent(tile.wrappedTileCoord);
-        if (!containsCoordinate(tileExtent, coordinate)) {
+        if (!tileContainsCoordinate) {
           continue;
         }
       }
@@ -360,13 +361,15 @@ class CanvasVectorTileLayerRenderer extends CanvasTileLayerRenderer {
            * @return {?} Callback result.
            */
           function(feature) {
-            let key = feature.getId();
-            if (key === undefined) {
-              key = getUid(feature);
-            }
-            if (!(key in features)) {
-              features[key] = true;
-              return callback(feature, layer);
+            if (tileContainsCoordinate || (declutteredFeatures && declutteredFeatures.indexOf(feature) !== -1)) {
+              let key = feature.getId();
+              if (key === undefined) {
+                key = getUid(feature);
+              }
+              if (!(key in features)) {
+                features[key] = true;
+                return callback(feature, layer);
+              }
             }
           }, layer.getDeclutter() ? declutteredFeatures : null);
       }
@@ -378,6 +381,7 @@ class CanvasVectorTileLayerRenderer extends CanvasTileLayerRenderer {
    * @inheritDoc
    */
   handleFontsChanged() {
+    clear(this.renderTileImageQueue_);
     const layer = this.getLayer();
     if (layer.getVisible() && this.renderedLayerRevision_ !== undefined) {
       layer.changed();

src/ol/renderer/webgl/Layer.js

@@ -81,6 +81,7 @@ class WebGLLayerRenderer extends LayerRenderer {
   getShaderCompileErrors() {
     return this.helper.getShaderCompileErrors();
   }
+
 }
 
 
@@ -231,11 +232,47 @@ export function writePointFeatureToBuffers(instructions, elementIndex, vertexBuf
  * @private
  * @return {ImageData} Image data.
  */
-export function getBlankTexture() {
+export function getBlankImageData() {
   const canvas = document.createElement('canvas');
   const image = canvas.getContext('2d').createImageData(1, 1);
   image.data[0] = image.data[1] = image.data[2] = image.data[3] = 255;
   return image;
 }
 
+/**
+ * Generates a color array based on a numerical id
+ * Note: the range for each component is 0 to 1 with 256 steps
+ * @param {number} id Id
+ * @param {Array<number>} [opt_array] Reusable array
+ * @return {Array<number>} Color array containing the encoded id
+ */
+export function colorEncodeId(id, opt_array) {
+  const array = opt_array || [];
+  const radix = 256;
+  const divide = radix - 1;
+  array[0] = Math.floor(id / radix / radix / radix) / divide;
+  array[1] = (Math.floor(id / radix / radix) % radix) / divide;
+  array[2] = (Math.floor(id / radix) % radix) / divide;
+  array[3] = (id % radix) / divide;
+  return array;
+}
+
+
+/**
+ * Reads an id from a color-encoded array
+ * Note: the expected range for each component is 0 to 1 with 256 steps.
+ * @param {Array<number>} color Color array containing the encoded id
+ * @return {number} Decoded id
+ */
+export function colorDecodeId(color) {
+  let id = 0;
+  const radix = 256;
+  const mult = radix - 1;
+  id += Math.round(color[0] * radix * radix * radix * mult);
+  id += Math.round(color[1] * radix * radix * mult);
+  id += Math.round(color[2] * radix * mult);
+  id += Math.round(color[3] * mult);
+  return id;
+}
+
 export default WebGLLayerRenderer;

src/ol/renderer/webgl/PointsLayer.js

@@ -6,7 +6,9 @@ import {DYNAMIC_DRAW, ARRAY_BUFFER, ELEMENT_ARRAY_BUFFER, FLOAT} from '../../web
 import {DefaultAttrib, DefaultUniform} from '../../webgl/Helper.js';
 import GeometryType from '../../geom/GeometryType.js';
 import WebGLLayerRenderer, {
-  getBlankTexture,
+  colorDecodeId,
+  colorEncodeId,
+  getBlankImageData,
   POINT_INSTRUCTIONS_COUNT, POINT_VERTEX_STRIDE, WebGLWorkerMessageType,
   writePointFeatureInstructions
 } from './Layer.js';
@@ -19,6 +21,8 @@ import {
   apply as applyTransform
 } from '../../transform.js';
 import {create as createWebGLWorker} from '../../worker/webgl.js';
+import {getUid} from '../../util.js';
+import WebGLRenderTarget from '../../webgl/RenderTarget.js';
 
 const VERTEX_SHADER = `
   precision mediump float;
@@ -68,6 +72,26 @@ const FRAGMENT_SHADER = `
     gl_FragColor.rgb *= gl_FragColor.a;
   }`;
 
+const HIT_FRAGMENT_SHADER = `
+  precision mediump float;
+
+  uniform sampler2D u_texture;
+
+  varying vec2 v_texCoord;
+  varying float v_opacity;
+  varying vec4 v_color;
+
+  void main(void) {
+    if (v_opacity == 0.0) {
+      discard;
+    }
+    vec4 textureColor = texture2D(u_texture, v_texCoord);
+    if (textureColor.a < 0.1) {
+      discard;
+    }
+    gl_FragColor = v_color;
+  }`;
+
 /**
  * @typedef {Object} Options
  * @property {function(import("../../Feature").default):number} [sizeCallback] Will be called on every feature in the
@@ -87,7 +111,7 @@ const FRAGMENT_SHADER = `
  * source to compute the opacity of the quad on screen (from 0 to 1). This is only done on source change.
  * Note: this is multiplied with the color of the point which can also have an alpha value < 1.
  * @property {function(import("../../Feature").default):boolean} [rotateWithViewCallback] Will be called on every feature in the
- * source to compute whether the quad on screen must stay upwards (`false`) or follow the view rotation (`true`).
+ * source to compute whether the quad on screen must stay upwards (`false`) or follow the view rotation (`true`). Default is `false`.
  * This is only done on source change.
  * @property {HTMLCanvasElement|HTMLImageElement|ImageData} [texture] Texture to use on points. `texCoordCallback` and `sizeCallback`
  * must be defined for this to have any effect.
@@ -200,7 +224,7 @@ class WebGLPointsLayerRenderer extends WebGLLayerRenderer {
     const options = opt_options || {};
 
     const uniforms = options.uniforms || {};
-    uniforms.u_texture = options.texture || getBlankTexture();
+    uniforms.u_texture = options.texture || getBlankImageData();
     const projectionMatrixTransform = createTransform();
     uniforms[DefaultUniform.PROJECTION_MATRIX] = projectionMatrixTransform;
 
@@ -212,14 +236,17 @@ class WebGLPointsLayerRenderer extends WebGLLayerRenderer {
     this.sourceRevision_ = -1;
 
     this.verticesBuffer_ = new WebGLArrayBuffer(ARRAY_BUFFER, DYNAMIC_DRAW);
+    this.hitVerticesBuffer_ = new WebGLArrayBuffer(ARRAY_BUFFER, DYNAMIC_DRAW);
     this.indicesBuffer_ = new WebGLArrayBuffer(ELEMENT_ARRAY_BUFFER, DYNAMIC_DRAW);
 
     this.program_ = this.helper.getProgram(
       options.fragmentShader || FRAGMENT_SHADER,
       options.vertexShader || VERTEX_SHADER
     );
-
-    this.helper.useProgram(this.program_);
+    this.hitProgram_ = this.helper.getProgram(
+      HIT_FRAGMENT_SHADER,
+      options.vertexShader || VERTEX_SHADER
+    );
 
     this.sizeCallback_ = options.sizeCallback || function() {
       return 1;
@@ -274,32 +301,45 @@ class WebGLPointsLayerRenderer extends WebGLLayerRenderer {
      */
     this.renderInstructions_ = new Float32Array(0);
 
+    /**
+     * These instructions are used for hit detection
+     * @type {Float32Array}
+     * @private
+     */
+    this.hitRenderInstructions_ = new Float32Array(0);
+
+    /**
+     * @type {WebGLRenderTarget}
+     * @private
+     */
+    this.hitRenderTarget_ = new WebGLRenderTarget(this.helper);
+
     this.worker_ = createWebGLWorker();
     this.worker_.addEventListener('message', function(event) {
       const received = event.data;
       if (received.type === WebGLWorkerMessageType.GENERATE_BUFFERS) {
         const projectionTransform = received.projectionTransform;
-        this.verticesBuffer_.fromArrayBuffer(received.vertexBuffer);
+        if (received.hitDetection) {
+          this.hitVerticesBuffer_.fromArrayBuffer(received.vertexBuffer);
+          this.helper.flushBufferData(this.hitVerticesBuffer_);
+        } else {
+          this.verticesBuffer_.fromArrayBuffer(received.vertexBuffer);
+          this.helper.flushBufferData(this.verticesBuffer_);
+        }
         this.indicesBuffer_.fromArrayBuffer(received.indexBuffer);
-        this.helper.flushBufferData(this.verticesBuffer_);
         this.helper.flushBufferData(this.indicesBuffer_);
 
-        // saves the projection transform for the current frame state
         this.renderTransform_ = projectionTransform;
         makeInverseTransform(this.invertRenderTransform_, this.renderTransform_);
-
-        this.renderInstructions_ = new Float32Array(event.data.renderInstructions);
+        if (received.hitDetection) {
+          this.hitRenderInstructions_ = new Float32Array(event.data.renderInstructions);
+        } else {
+          this.renderInstructions_ = new Float32Array(event.data.renderInstructions);
+        }
       }
     }.bind(this));
   }
 
-  /**
-   * @inheritDoc
-   */
-  disposeInternal() {
-    super.disposeInternal();
-  }
-
   /**
    * @inheritDoc
    */
@@ -315,6 +355,9 @@ class WebGLPointsLayerRenderer extends WebGLLayerRenderer {
       canvas.style.opacity = opacity;
     }
 
+    this.renderHitDetection(frameState);
+    this.hitRenderTarget_.clearCachedData();
+
     return canvas;
   }
 
@@ -332,7 +375,6 @@ class WebGLPointsLayerRenderer extends WebGLLayerRenderer {
     const sourceChanged = this.sourceRevision_ < vectorSource.getRevision();
     if (sourceChanged) {
       this.sourceRevision_ = vectorSource.getRevision();
-      this.geojsonFeatureCache_ = {};
 
       const projection = viewState.projection;
       const resolution = viewState.resolution;
@@ -350,6 +392,7 @@ class WebGLPointsLayerRenderer extends WebGLLayerRenderer {
     this.helper.makeProjectionTransform(frameState, this.currentTransform_);
     multiplyTransform(this.currentTransform_, this.invertRenderTransform_);
 
+    this.helper.useProgram(this.program_);
     this.helper.prepareDraw(frameState);
 
     // write new data
@@ -385,11 +428,16 @@ class WebGLPointsLayerRenderer extends WebGLLayerRenderer {
     if (!this.renderInstructions_ || this.renderInstructions_.length !== totalInstructionsCount) {
       this.renderInstructions_ = new Float32Array(totalInstructionsCount);
     }
+    if (!this.hitRenderInstructions_ || this.hitRenderInstructions_.length !== totalInstructionsCount) {
+      this.hitRenderInstructions_ = new Float32Array(totalInstructionsCount);
+    }
 
     // loop on features to fill the buffer
     let feature;
     const tmpCoords = [];
+    const tmpColor = [];
     let elementIndex = 0;
+    let u0, v0, u1, v1, size, opacity, rotateWithView, color;
     for (let i = 0; i < features.length; i++) {
       feature = features[i];
       if (!feature.getGeometry() || feature.getGeometry().getType() !== GeometryType.POINT) {
@@ -400,19 +448,45 @@ class WebGLPointsLayerRenderer extends WebGLLayerRenderer {
       tmpCoords[1] = this.coordCallback_(feature, 1);
       applyTransform(projectionTransform, tmpCoords);
 
-      elementIndex = writePointFeatureInstructions(
+      u0 = this.texCoordCallback_(feature, 0);
+      v0 = this.texCoordCallback_(feature, 1);
+      u1 = this.texCoordCallback_(feature, 2);
+      v1 = this.texCoordCallback_(feature, 3);
+      size = this.sizeCallback_(feature);
+      opacity = this.opacityCallback_(feature);
+      rotateWithView = this.rotateWithViewCallback_(feature);
+      color = this.colorCallback_(feature, this.colorArray_);
+
+      writePointFeatureInstructions(
         this.renderInstructions_,
         elementIndex,
         tmpCoords[0],
         tmpCoords[1],
-        this.texCoordCallback_(feature, 0),
-        this.texCoordCallback_(feature, 1),
-        this.texCoordCallback_(feature, 2),
-        this.texCoordCallback_(feature, 3),
-        this.sizeCallback_(feature),
-        this.opacityCallback_(feature),
-        this.rotateWithViewCallback_(feature),
-        this.colorCallback_(feature, this.colorArray_)
+        u0,
+        v0,
+        u1,
+        v1,
+        size,
+        opacity,
+        rotateWithView,
+        color
+      );
+
+      // for hit detection, the feature uid is saved in the opacity value
+      // and the index of the opacity value is encoded in the color values
+      elementIndex = writePointFeatureInstructions(
+        this.hitRenderInstructions_,
+        elementIndex,
+        tmpCoords[0],
+        tmpCoords[1],
+        u0,
+        v0,
+        u1,
+        v1,
+        size,
+        opacity > 0 ? Number(getUid(feature)) : 0,
+        rotateWithView,
+        colorEncodeId(elementIndex + 7, tmpColor)
       );
     }
 
@@ -423,12 +497,73 @@ class WebGLPointsLayerRenderer extends WebGLLayerRenderer {
     };
     // additional properties will be sent back as-is by the worker
     message['projectionTransform'] = projectionTransform;
-
     this.worker_.postMessage(message, [this.renderInstructions_.buffer]);
     this.renderInstructions_ = null;
+
+    /** @type import('./Layer').WebGLWorkerGenerateBuffersMessage */
+    const hitMessage = {
+      type: WebGLWorkerMessageType.GENERATE_BUFFERS,
+      renderInstructions: this.hitRenderInstructions_.buffer
+    };
+    hitMessage['projectionTransform'] = projectionTransform;
+    hitMessage['hitDetection'] = true;
+    this.worker_.postMessage(hitMessage, [this.hitRenderInstructions_.buffer]);
+    this.hitRenderInstructions_ = null;
   }
 
+  /**
+   * @inheritDoc
+   */
+  forEachFeatureAtCoordinate(coordinate, frameState, hitTolerance, callback, declutteredFeatures) {
+    if (!this.hitRenderInstructions_) {
+      return;
+    }
 
+    const pixel = applyTransform(frameState.coordinateToPixelTransform, coordinate.slice());
+
+    const data = this.hitRenderTarget_.readPixel(pixel[0], pixel[1]);
+    const color = [
+      data[0] / 255,
+      data[1] / 255,
+      data[2] / 255,
+      data[3] / 255
+    ];
+    const index = colorDecodeId(color);
+    const opacity = this.hitRenderInstructions_[index];
+    const uid = Math.floor(opacity).toString();
+
+    const source = this.getLayer().getSource();
+    const feature = source.getFeatureByUid(uid);
+    if (feature) {
+      return callback(feature, this.getLayer());
+    }
+  }
+
+  /**
+   * Render the hit detection data to the corresponding render target
+   * @param {import("../../PluggableMap.js").FrameState} frameState current frame state
+   */
+  renderHitDetection(frameState) {
+    this.hitRenderTarget_.setSize(frameState.size);
+
+    this.helper.useProgram(this.hitProgram_);
+    this.helper.prepareDrawToRenderTarget(frameState, this.hitRenderTarget_, true);
+
+    this.helper.bindBuffer(this.hitVerticesBuffer_);
+    this.helper.bindBuffer(this.indicesBuffer_);
+
+    const stride = POINT_VERTEX_STRIDE;
+    const bytesPerFloat = Float32Array.BYTES_PER_ELEMENT;
+    this.helper.enableAttributeArray(DefaultAttrib.POSITION, 2, FLOAT, bytesPerFloat * stride, 0);
+    this.helper.enableAttributeArray(DefaultAttrib.OFFSETS, 2, FLOAT, bytesPerFloat * stride, bytesPerFloat * 2);
+    this.helper.enableAttributeArray(DefaultAttrib.TEX_COORD, 2, FLOAT, bytesPerFloat * stride, bytesPerFloat * 4);
+    this.helper.enableAttributeArray(DefaultAttrib.OPACITY, 1, FLOAT, bytesPerFloat * stride, bytesPerFloat * 6);
+    this.helper.enableAttributeArray(DefaultAttrib.ROTATE_WITH_VIEW, 1, FLOAT, bytesPerFloat * stride, bytesPerFloat * 7);
+    this.helper.enableAttributeArray(DefaultAttrib.COLOR, 4, FLOAT, bytesPerFloat * stride, bytesPerFloat * 8);
+
+    const renderCount = this.indicesBuffer_.getArray() ? this.indicesBuffer_.getArray().length : 0;
+    this.helper.drawElements(0, renderCount);
+  }
 }
 
 export default WebGLPointsLayerRenderer;

src/ol/reproj/Image.js

@@ -51,10 +51,7 @@ class ReprojImage extends ImageBase {
 
     const sourceExtent = triangulation.calculateSourceExtent();
     const sourceImage = getImageFunction(sourceExtent, sourceResolution, pixelRatio);
-    let state = ImageState.LOADED;
-    if (sourceImage) {
-      state = ImageState.IDLE;
-    }
+    const state = sourceImage ? ImageState.IDLE : ImageState.EMPTY;
     const sourcePixelRatio = sourceImage ? sourceImage.getPixelRatio() : 1;
 
     super(targetExtent, targetResolution, sourcePixelRatio, state);

src/ol/source/BingMaps.js

@@ -269,7 +269,8 @@ class BingMaps extends TileImage {
         const attributions = [];
         const viewState = frameState.viewState;
         const tileGrid = this.getTileGrid();
-        const tileCoord = tileGrid.getTileCoordForCoordAndResolution(viewState.center, viewState.resolution);
+        const z = tileGrid.getZForResolution(viewState.resolution, this.zDirection);
+        const tileCoord = tileGrid.getTileCoordForCoordAndZ(viewState.center, z);
         const zoom = tileCoord[0];
         resource.imageryProviders.map(function(imageryProvider) {
           let intersecting = false;

src/ol/source/IIIF.js

@@ -40,8 +40,8 @@ import TileImage from './TileImage.js';
  * @property {string} [url] Base URL of the IIIF Image service.
  * This should be the same as the IIIF Image ID.
  * @property {Versions} [version=Versions.VERSION2] Service's IIIF Image API version.
- * @property {number} [zDirection] Indicate which resolution should be used
- * by a renderer if the views resolution does not match any resolution of the tile source.
+ * @property {number} [zDirection=0] Indicate which resolution should be used
+ * by a renderer if the view resolution does not match any resolution of the tile source.
  * If 0, the nearest resolution will be used. If 1, the nearest lower resolution
  * will be used. If -1, the nearest higher resolution will be used.
  */
@@ -65,7 +65,7 @@ class IIIF extends TileImage {
   constructor(opt_options) {
 
     /**
-     * @type {Partial<Options>} options
+     * @type {Partial<Options>}
      */
     const options = opt_options || {};
 

src/ol/source/ImageWMS.js

@@ -191,6 +191,45 @@ class ImageWMS extends ImageSource {
       1, sourceProjectionObj || projectionObj, baseParams);
   }
 
+  /**
+   * Return the GetLegendGraphic URL, optionally optimized for the passed
+   * resolution and possibly including any passed specific parameters. Returns
+   * `undefined` if the GetLegendGraphic URL cannot be constructed.
+   *
+   * @param {number} [resolution] Resolution. If set to undefined, `SCALE`
+   *     will not be calculated and included in URL.
+   * @param {Object} [params] GetLegendGraphic params. Default `FORMAT` is
+   *     `image/png`. `VERSION` should not be specified here.
+   * @return {string|undefined} GetLegendGraphic URL.
+   * @api
+   */
+  getGetLegendGraphicUrl(resolution, params) {
+    const layers = this.params_.LAYERS;
+    const isSingleLayer = !Array.isArray(layers) || this.params_['LAYERS'].length === 1;
+    if (this.url_ === undefined || !isSingleLayer) {
+      return undefined;
+    }
+
+    const baseParams = {
+      'SERVICE': 'WMS',
+      'VERSION': DEFAULT_WMS_VERSION,
+      'REQUEST': 'GetLegendGraphic',
+      'FORMAT': 'image/png',
+      'LAYER': layers
+    };
+
+    if (resolution !== undefined) {
+      const mpu = this.getProjection() ? this.getProjection().getMetersPerUnit() : 1;
+      const dpi = 25.4 / 0.28;
+      const inchesPerMeter = 39.37;
+      baseParams['SCALE'] = resolution * mpu * inchesPerMeter * dpi;
+    }
+
+    assign(baseParams, params);
+
+    return appendParams(/** @type {string} */ (this.url_), baseParams);
+  }
+
   /**
    * Get the user-provided params, i.e. those passed to the constructor through
    * the "params" option, and possibly updated using the updateParams method.

src/ol/source/Tile.js

@@ -24,6 +24,7 @@ import {wrapX, getForProjection as getTileGridForProjection} from '../tilegrid.j
  * @property {boolean} [wrapX=true]
  * @property {number} [transition]
  * @property {string} [key]
+ * @property {number} [zDirection=0]
  */
 
 
@@ -110,9 +111,9 @@ class TileSource extends Source {
      * by a renderer if the views resolution does not match any resolution of the tile source.
      * If 0, the nearest resolution will be used. If 1, the nearest lower resolution
      * will be used. If -1, the nearest higher resolution will be used.
-     * @type {number=}
+     * @type {number}
      */
-    this.zDirection;
+    this.zDirection = options.zDirection ? options.zDirection : 0;
   }
 
   /**

src/ol/source/TileDebug.js

@@ -80,6 +80,11 @@ class LabeledTile extends Tile {
  * @property {import("../proj.js").ProjectionLike} [projection='EPSG:3857'] Optional projection.
  * @property {import("../tilegrid/TileGrid.js").default} [tileGrid] Tile grid.
  * @property {boolean} [wrapX=true] Whether to wrap the world horizontally.
+ * @property {number} [zDirection=0] Set to `1` when debugging `VectorTile` sources with
+ * a default configuration. Indicates which resolution should be used by a renderer if
+ * the view resolution does not match any resolution of the tile source. If 0, the nearest
+ * resolution will be used. If 1, the nearest lower resolution will be used. If -1, the
+ * nearest higher resolution will be used.
  */
 
 
@@ -106,7 +111,8 @@ class TileDebug extends XYZ {
       opaque: false,
       projection: options.projection,
       tileGrid: options.tileGrid,
-      wrapX: options.wrapX !== undefined ? options.wrapX : true
+      wrapX: options.wrapX !== undefined ? options.wrapX : true,
+      zDirection: options.zDirection
     });
 
   }

src/ol/source/TileImage.js

@@ -52,6 +52,10 @@ import {getForProjection as getTileGridForProjection} from '../tilegrid.js';
  * @property {number} [transition] Duration of the opacity transition for rendering.
  * To disable the opacity transition, pass `transition: 0`.
  * @property {string} [key] Optional tile key for proper cache fetching
+ * @property {number} [zDirection=0] Indicate which resolution should be used
+ * by a renderer if the view resolution does not match any resolution of the tile source.
+ * If 0, the nearest resolution will be used. If 1, the nearest lower resolution
+ * will be used. If -1, the nearest higher resolution will be used.
  */
 
 
@@ -84,7 +88,8 @@ class TileImage extends UrlTile {
       wrapX: options.wrapX,
       transition: options.transition,
       key: options.key,
-      attributionsCollapsible: options.attributionsCollapsible
+      attributionsCollapsible: options.attributionsCollapsible,
+      zDirection: options.zDirection
     });
 
     /**

src/ol/source/TileWMS.js

@@ -168,7 +168,8 @@ class TileWMS extends TileImage {
       tileGrid = this.getTileGridForProjection(projectionObj);
     }
 
-    const tileCoord = tileGrid.getTileCoordForCoordAndResolution(coordinate, resolution);
+    const z = tileGrid.getZForResolution(resolution, this.zDirection);
+    const tileCoord = tileGrid.getTileCoordForCoordAndZ(coordinate, z);
 
     if (tileGrid.getResolutions().length <= tileCoord[0]) {
       return undefined;
@@ -211,6 +212,45 @@ class TileWMS extends TileImage {
       1, sourceProjectionObj || projectionObj, baseParams);
   }
 
+  /**
+   * Return the GetLegendGraphic URL, optionally optimized for the passed
+   * resolution and possibly including any passed specific parameters. Returns
+   * `undefined` if the GetLegendGraphic URL cannot be constructed.
+   *
+   * @param {number} [resolution] Resolution. If set to undefined, `SCALE`
+   *     will not be calculated and included in URL.
+   * @param {Object} [params] GetLegendGraphic params. Default `FORMAT` is
+   *     `image/png`. `VERSION` should not be specified here.
+   * @return {string|undefined} GetLegendGraphic URL.
+   * @api
+   */
+  getGetLegendGraphicUrl(resolution, params) {
+    const layers = this.params_.LAYERS;
+    const isSingleLayer = !Array.isArray(layers) || this.params_['LAYERS'].length === 1;
+    if (this.urls[0] === undefined || !isSingleLayer) {
+      return undefined;
+    }
+
+    const baseParams = {
+      'SERVICE': 'WMS',
+      'VERSION': DEFAULT_WMS_VERSION,
+      'REQUEST': 'GetLegendGraphic',
+      'FORMAT': 'image/png',
+      'LAYER': layers
+    };
+
+    if (resolution !== undefined) {
+      const mpu = this.getProjection() ? this.getProjection().getMetersPerUnit() : 1;
+      const dpi = 25.4 / 0.28;
+      const inchesPerMeter = 39.37;
+      baseParams['SCALE'] = resolution * mpu * inchesPerMeter * dpi;
+    }
+
+    assign(baseParams, params);
+
+    return appendParams(/** @type {string} */ (this.urls[0]), baseParams);
+  }
+
   /**
    * @inheritDoc
    */

src/ol/source/UTFGrid.js

@@ -385,8 +385,8 @@ class UTFGrid extends TileSource {
   forDataAtCoordinateAndResolution(
     coordinate, resolution, callback, opt_request) {
     if (this.tileGrid) {
-      const tileCoord = this.tileGrid.getTileCoordForCoordAndResolution(
-        coordinate, resolution);
+      const z = this.tileGrid.getZForResolution(resolution, this.zDirection);
+      const tileCoord = this.tileGrid.getTileCoordForCoordAndZ(coordinate, z);
       const tile = /** @type {!CustomTile} */(this.getTile(
         tileCoord[0], tileCoord[1], tileCoord[2], 1, this.getProjection()));
       tile.forDataAtCoordinate(coordinate, callback, opt_request);

src/ol/source/UrlTile.js

@@ -25,6 +25,7 @@ import {getKeyZXY} from '../tilecoord.js';
  * @property {boolean} [wrapX=true]
  * @property {number} [transition]
  * @property {string} [key]
+ * @property {number} [zDirection=0]
  */
 
 
@@ -51,7 +52,8 @@ class UrlTile extends TileSource {
       wrapX: options.wrapX,
       transition: options.transition,
       key: options.key,
-      attributionsCollapsible: options.attributionsCollapsible
+      attributionsCollapsible: options.attributionsCollapsible,
+      zDirection: options.zDirection
     });
 
     /**

src/ol/source/Vector.js

@@ -155,7 +155,7 @@ export class VectorSourceEvent extends Event {
  * by this source are suitable for editing. See {@link module:ol/source/VectorTile~VectorTile} for
  * vector data that is optimized for rendering.
  *
- * @fires VectorSourceEvent<Geometry>
+ * @fires VectorSourceEvent
  * @api
  * @template {import("../geom/Geometry.js").default} Geometry
  */
@@ -241,11 +241,11 @@ class VectorSource extends Source {
     this.idIndex_ = {};
 
     /**
-     * A lookup of features without id (keyed by getUid(feature)).
+     * A lookup of features by uid (using getUid(feature)).
      * @private
      * @type {!Object<string, import("../Feature.js").default<Geometry>>}
      */
-    this.undefIdIndex_ = {};
+    this.uidIndex_ = {};
 
     /**
      * @private
@@ -359,10 +359,11 @@ class VectorSource extends Source {
       } else {
         valid = false;
       }
-    } else {
-      assert(!(featureKey in this.undefIdIndex_),
+    }
+    if (valid) {
+      assert(!(featureKey in this.uidIndex_),
         30); // The passed `feature` was already added to the source
-      this.undefIdIndex_[featureKey] = feature;
+      this.uidIndex_[featureKey] = feature;
     }
     return valid;
   }
@@ -489,7 +490,7 @@ class VectorSource extends Source {
       if (!this.featuresCollection_) {
         this.featureChangeKeys_ = {};
         this.idIndex_ = {};
-        this.undefIdIndex_ = {};
+        this.uidIndex_ = {};
       }
     } else {
       if (this.featuresRtree_) {
@@ -770,6 +771,18 @@ class VectorSource extends Source {
   }
 
 
+  /**
+   * Get a feature by its internal unique identifier (using `getUid`).
+   *
+   * @param {string} uid Feature identifier.
+   * @return {import("../Feature.js").default<Geometry>} The feature (or `null` if not found).
+   */
+  getFeatureByUid(uid) {
+    const feature = this.uidIndex_[uid];
+    return feature !== undefined ? feature : null;
+  }
+
+
   /**
    * Get the format associated with this source.
    *
@@ -831,20 +844,13 @@ class VectorSource extends Source {
     const id = feature.getId();
     if (id !== undefined) {
       const sid = id.toString();
-      if (featureKey in this.undefIdIndex_) {
-        delete this.undefIdIndex_[featureKey];
+      if (this.idIndex_[sid] !== feature) {
+        this.removeFromIdIndex_(feature);
         this.idIndex_[sid] = feature;
-      } else {
-        if (this.idIndex_[sid] !== feature) {
-          this.removeFromIdIndex_(feature);
-          this.idIndex_[sid] = feature;
-        }
       }
     } else {
-      if (!(featureKey in this.undefIdIndex_)) {
-        this.removeFromIdIndex_(feature);
-        this.undefIdIndex_[featureKey] = feature;
-      }
+      this.removeFromIdIndex_(feature);
+      this.uidIndex_[featureKey] = feature;
     }
     this.changed();
     this.dispatchEvent(new VectorSourceEvent(
@@ -862,7 +868,7 @@ class VectorSource extends Source {
     if (id !== undefined) {
       return id in this.idIndex_;
     } else {
-      return getUid(feature) in this.undefIdIndex_;
+      return getUid(feature) in this.uidIndex_;
     }
   }
 
@@ -964,9 +970,8 @@ class VectorSource extends Source {
     const id = feature.getId();
     if (id !== undefined) {
       delete this.idIndex_[id.toString()];
-    } else {
-      delete this.undefIdIndex_[featureKey];
     }
+    delete this.uidIndex_[featureKey];
     this.dispatchEvent(new VectorSourceEvent(
       VectorEventType.REMOVEFEATURE, feature));
   }

src/ol/source/VectorTile.js

@@ -9,7 +9,7 @@ import {toSize} from '../size.js';
 import UrlTile from './UrlTile.js';
 import {getKeyZXY, getKey} from '../tilecoord.js';
 import {createXYZ, extentFromProjection, createForProjection} from '../tilegrid.js';
-import {buffer as bufferExtent, getIntersection} from '../extent.js';
+import {buffer as bufferExtent, getIntersection, intersects} from '../extent.js';
 import {listen, unlistenByKey} from '../events.js';
 import EventType from '../events/EventType.js';
 import {loadFeaturesXhr} from '../featureloader.js';
@@ -64,6 +64,10 @@ import {equals} from '../array.js';
  * When set to `false`, only one world
  * will be rendered. When set to `true`, tiles will be wrapped horizontally to
  * render multiple worlds.
+ * @property {number} [zDirection=1] Indicate which resolution should be used
+ * by a renderer if the view resolution does not match any resolution of the tile source.
+ * If 0, the nearest resolution will be used. If 1, the nearest lower resolution
+ * will be used. If -1, the nearest higher resolution will be used.
  */
 
 
@@ -109,7 +113,8 @@ class VectorTile extends UrlTile {
       url: options.url,
       urls: options.urls,
       wrapX: options.wrapX === undefined ? true : options.wrapX,
-      transition: options.transition
+      transition: options.transition,
+      zDirection: options.zDirection === undefined ? 1 : options.zDirection
     });
 
     /**
@@ -127,7 +132,7 @@ class VectorTile extends UrlTile {
      * @private
      * @type {Object<string, import("../VectorTile.js").default>}
      */
-    this.sourceTiles_ = {};
+    this.sourceTileByCoordKey_ = {};
 
     /**
      * @private
@@ -168,7 +173,7 @@ class VectorTile extends UrlTile {
    */
   clear() {
     this.tileCache.clear();
-    this.sourceTiles_ = {};
+    this.sourceTileByCoordKey_ = {};
     this.sourceTilesByTileKey_ = {};
   }
 
@@ -179,34 +184,40 @@ class VectorTile extends UrlTile {
    * @return {Array<import("../VectorTile").default>} Tile keys.
    */
   getSourceTiles(pixelRatio, projection, tile) {
-    const sourceTiles = [];
     const urlTileCoord = tile.wrappedTileCoord;
-    if (urlTileCoord) {
-      const tileGrid = this.getTileGridForProjection(projection);
-      const extent = tileGrid.getTileCoordExtent(urlTileCoord);
-      const z = urlTileCoord[0];
-      const resolution = tileGrid.getResolution(z);
-      // make extent 1 pixel smaller so we don't load tiles for < 0.5 pixel render space
-      bufferExtent(extent, -1 / resolution, extent);
-      const sourceTileGrid = this.tileGrid;
-      const sourceExtent = sourceTileGrid.getExtent();
-      if (sourceExtent) {
-        getIntersection(extent, sourceExtent, extent);
-      }
-      const sourceZ = sourceTileGrid.getZForResolution(resolution, 1);
-      const minZoom = sourceTileGrid.getMinZoom();
+    const tileGrid = this.getTileGridForProjection(projection);
+    const extent = tileGrid.getTileCoordExtent(urlTileCoord);
+    const z = urlTileCoord[0];
+    const resolution = tileGrid.getResolution(z);
+    // make extent 1 pixel smaller so we don't load tiles for < 0.5 pixel render space
+    bufferExtent(extent, -1 / resolution, extent);
+    const sourceTileGrid = this.tileGrid;
+    const sourceExtent = sourceTileGrid.getExtent();
+    if (sourceExtent) {
+      getIntersection(extent, sourceExtent, extent);
+    }
+    const sourceZ = sourceTileGrid.getZForResolution(resolution, 1);
+    const minZoom = sourceTileGrid.getMinZoom();
 
-      let loadedZ = sourceZ + 1;
-      let covered, empty;
+    const previousSourceTiles = this.sourceTilesByTileKey_[tile.getKey()];
+    let sourceTiles, covered, empty, loadedZ;
+    if (previousSourceTiles && previousSourceTiles.length > 0 && previousSourceTiles[0].tileCoord[0] === sourceZ) {
+      sourceTiles = previousSourceTiles;
+      covered = true;
+      empty = false;
+      loadedZ = sourceZ;
+    } else {
+      sourceTiles = [];
+      loadedZ = sourceZ + 1;
       do {
         --loadedZ;
         covered = true;
         empty = true;
         sourceTileGrid.forEachTileCoord(extent, loadedZ, function(sourceTileCoord) {
-          const tileKey = getKey(sourceTileCoord);
+          const coordKey = getKey(sourceTileCoord);
           let sourceTile;
-          if (tileKey in this.sourceTiles_) {
-            sourceTile = this.sourceTiles_[tileKey];
+          if (coordKey in this.sourceTileByCoordKey_) {
+            sourceTile = this.sourceTileByCoordKey_[coordKey];
             const state = sourceTile.getState();
             if (state === TileState.LOADED || state === TileState.ERROR || state === TileState.EMPTY) {
               empty = empty && state === TileState.EMPTY;
@@ -215,17 +226,17 @@ class VectorTile extends UrlTile {
             }
           } else if (loadedZ === sourceZ) {
             const tileUrl = this.tileUrlFunction(sourceTileCoord, pixelRatio, projection);
-            sourceTile = new this.tileClass(sourceTileCoord,
-              tileUrl == undefined ? TileState.EMPTY : TileState.IDLE,
-              tileUrl == undefined ? '' : tileUrl,
-              this.format_, this.tileLoadFunction);
-            sourceTile.extent = sourceTileGrid.getTileCoordExtent(sourceTileCoord);
-            sourceTile.projection = projection;
-            sourceTile.resolution = sourceTileGrid.getResolution(sourceTileCoord[0]);
-            this.sourceTiles_[tileKey] = sourceTile;
-            empty = empty && sourceTile.getState() === TileState.EMPTY;
-            listen(sourceTile, EventType.CHANGE, this.handleTileChange, this);
-            sourceTile.load();
+            if (tileUrl !== undefined) {
+              sourceTile = new this.tileClass(sourceTileCoord, TileState.IDLE, tileUrl,
+                this.format_, this.tileLoadFunction);
+              sourceTile.extent = sourceTileGrid.getTileCoordExtent(sourceTileCoord);
+              sourceTile.projection = projection;
+              sourceTile.resolution = sourceTileGrid.getResolution(sourceTileCoord[0]);
+              this.sourceTileByCoordKey_[coordKey] = sourceTile;
+              empty = false;
+              listen(sourceTile, EventType.CHANGE, this.handleTileChange, this);
+              sourceTile.load();
+            }
           } else {
             empty = false;
           }
@@ -237,7 +248,7 @@ class VectorTile extends UrlTile {
             tile.loadingSourceTiles++;
             const key = listen(sourceTile, EventType.CHANGE, function() {
               const state = sourceTile.getState();
-              const sourceTileKey = getKey(sourceTile.tileCoord);
+              const sourceTileKey = sourceTile.getKey();
               if (state === TileState.LOADED || state === TileState.ERROR) {
                 if (state === TileState.LOADED) {
                   unlistenByKey(key);
@@ -259,19 +270,19 @@ class VectorTile extends UrlTile {
           sourceTiles.length = 0;
         }
       } while (!covered && loadedZ > minZoom);
-      if (!empty && tile.getState() === TileState.IDLE) {
-        tile.setState(TileState.LOADING);
-      }
-      if (covered || empty) {
-        tile.hifi = sourceZ === loadedZ;
-        tile.sourceZ = loadedZ;
-        const previousSourceTiles = this.sourceTilesByTileKey_[getKey(tile.tileCoord)];
-        if (tile.getState() < TileState.LOADED) {
-          tile.setState(empty ? TileState.EMPTY : TileState.LOADED);
-        } else if (!previousSourceTiles || !equals(sourceTiles, previousSourceTiles)) {
-          this.removeSourceTiles(tile);
-          this.addSourceTiles(tile, sourceTiles);
-        }
+    }
+
+    if (!empty && tile.getState() === TileState.IDLE) {
+      tile.setState(TileState.LOADING);
+    }
+    if (covered || empty) {
+      tile.hifi = sourceZ === loadedZ;
+      tile.sourceZ = loadedZ;
+      if (tile.getState() < TileState.LOADED) {
+        tile.setState(empty ? TileState.EMPTY : TileState.LOADED);
+      } else if (!previousSourceTiles || !equals(sourceTiles, previousSourceTiles)) {
+        this.removeSourceTiles(tile);
+        this.addSourceTiles(tile, sourceTiles);
       }
     }
     return sourceTiles;
@@ -282,7 +293,7 @@ class VectorTile extends UrlTile {
    * @param {Array<import("../VectorTile").default>} sourceTiles Source tiles.
    */
   addSourceTiles(tile, sourceTiles) {
-    this.sourceTilesByTileKey_[getKey(tile.tileCoord)] = sourceTiles;
+    this.sourceTilesByTileKey_[tile.getKey()] = sourceTiles;
     for (let i = 0, ii = sourceTiles.length; i < ii; ++i) {
       sourceTiles[i].consumers++;
     }
@@ -292,7 +303,7 @@ class VectorTile extends UrlTile {
    * @param {VectorRenderTile} tile Tile.
    */
   removeSourceTiles(tile) {
-    const tileKey = getKey(tile.tileCoord);
+    const tileKey = tile.getKey();
     if (tileKey in this.sourceTilesByTileKey_) {
       const sourceTiles = this.sourceTilesByTileKey_[tileKey];
       for (let i = 0, ii = sourceTiles.length; i < ii; ++i) {
@@ -300,7 +311,7 @@ class VectorTile extends UrlTile {
         sourceTile.consumers--;
         if (sourceTile.consumers === 0) {
           sourceTile.dispose();
-          delete this.sourceTiles_[getKey(sourceTile.tileCoord)];
+          delete this.sourceTileByCoordKey_[getKey(sourceTile.tileCoord)];
         }
       }
     }
@@ -311,27 +322,44 @@ class VectorTile extends UrlTile {
    * @inheritDoc
    */
   getTile(z, x, y, pixelRatio, projection) {
-    const tileCoordKey = getKeyZXY(z, x, y);
-    if (this.tileCache.containsKey(tileCoordKey)) {
-      return (
-        /** @type {!import("../Tile.js").default} */ (this.tileCache.get(tileCoordKey))
-      );
-    } else {
-      const tileCoord = [z, x, y];
-      const urlTileCoord = this.getTileCoordForTileUrlFunction(
-        tileCoord, projection);
-      const tile = new VectorRenderTile(
-        tileCoord,
-        urlTileCoord !== null ? TileState.IDLE : TileState.EMPTY,
-        urlTileCoord,
-        this.tileGrid,
-        this.getSourceTiles.bind(this, pixelRatio, projection),
-        this.removeSourceTiles.bind(this));
-
-      tile.key = this.getRevision().toString();
-      this.tileCache.set(tileCoordKey, tile);
-      return tile;
+    const coordKey = getKeyZXY(z, x, y);
+    const key = this.getKey();
+    let tile;
+    if (this.tileCache.containsKey(coordKey)) {
+      tile = /** @type {!import("../Tile.js").default} */ (this.tileCache.get(coordKey));
+      if (tile.key === key) {
+        return tile;
+      }
     }
+    const tileCoord = [z, x, y];
+    let urlTileCoord = this.getTileCoordForTileUrlFunction(tileCoord, projection);
+    const sourceExtent = this.getTileGrid().getExtent();
+    if (urlTileCoord && sourceExtent) {
+      const tileGrid = this.getTileGridForProjection(projection);
+      const tileExtent = tileGrid.getTileCoordExtent(urlTileCoord);
+      // make extent 1 pixel smaller so we don't load tiles for < 0.5 pixel render space
+      bufferExtent(tileExtent, -1 / tileGrid.getResolution(z), tileExtent);
+      if (!intersects(sourceExtent, tileExtent)) {
+        urlTileCoord = null;
+      }
+    }
+    const newTile = new VectorRenderTile(
+      tileCoord,
+      urlTileCoord !== null ? TileState.IDLE : TileState.EMPTY,
+      urlTileCoord,
+      this.tileGrid,
+      this.getSourceTiles.bind(this, pixelRatio, projection),
+      this.removeSourceTiles.bind(this));
+
+    newTile.key = key;
+    if (tile) {
+      newTile.interimTile = tile;
+      newTile.refreshInterimChain();
+      this.tileCache.replace(coordKey, newTile);
+    } else {
+      this.tileCache.set(coordKey, newTile);
+    }
+    return newTile;
   }
 
   /**

src/ol/source/WMSServerType.js

@@ -9,8 +9,24 @@
  * @enum {string}
  */
 export default {
+  /**
+   * HiDPI support for [Carmenta Server](https://www.carmenta.com/en/products/carmenta-server)
+   * @api
+   */
   CARMENTA_SERVER: 'carmentaserver',
+  /**
+   * HiDPI support for [GeoServer](https://geoserver.org/)
+   * @api
+   */
   GEOSERVER: 'geoserver',
+  /**
+   * HiDPI support for [MapServer](https://mapserver.org/)
+   * @api
+   */
   MAPSERVER: 'mapserver',
+  /**
+   * HiDPI support for [QGIS](https://qgis.org/)
+   * @api
+   */
   QGIS: 'qgis'
 };

src/ol/source/XYZ.js

@@ -41,6 +41,10 @@ import {createXYZ, extentFromProjection} from '../tilegrid.js';
  * @property {boolean} [wrapX=true] Whether to wrap the world horizontally.
  * @property {number} [transition] Duration of the opacity transition for rendering.
  * To disable the opacity transition, pass `transition: 0`.
+ * @property {number} [zDirection=0] Indicate which resolution should be used
+ * by a renderer if the view resolution does not match any resolution of the tile source.
+ * If 0, the nearest resolution will be used. If 1, the nearest lower resolution
+ * will be used. If -1, the nearest higher resolution will be used.
  */
 
 
@@ -94,7 +98,8 @@ class XYZ extends TileImage {
       urls: options.urls,
       wrapX: options.wrapX !== undefined ? options.wrapX : true,
       transition: options.transition,
-      attributionsCollapsible: options.attributionsCollapsible
+      attributionsCollapsible: options.attributionsCollapsible,
+      zDirection: options.zDirection
     });
 
   }

src/ol/source/Zoomify.js

@@ -114,8 +114,8 @@ export class CustomTile extends ImageTile {
  * @property {number} [transition] Duration of the opacity transition for rendering.
  * To disable the opacity transition, pass `transition: 0`.
  * @property {number} [tileSize=256] Tile size. Same tile size is used for all zoom levels.
- * @property {number} [zDirection] Indicate which resolution should be used
- * by a renderer if the views resolution does not match any resolution of the tile source.
+ * @property {number} [zDirection=0] Indicate which resolution should be used
+ * by a renderer if the view resolution does not match any resolution of the tile source.
  * If 0, the nearest resolution will be used. If 1, the nearest lower resolution
  * will be used. If -1, the nearest higher resolution will be used.
  */

src/ol/style/Circle.js

@@ -53,13 +53,14 @@ class CircleStyle extends RegularShape {
   }
 
   /**
-  * Set the circle radius.
-  *
-  * @param {number} radius Circle radius.
-  * @api
-  */
+   * Set the circle radius.
+   *
+   * @param {number} radius Circle radius.
+   * @api
+   */
   setRadius(radius) {
     this.radius_ = radius;
+    this.render();
   }
 }
 

src/ol/style/RegularShape.js

@@ -30,10 +30,10 @@ import ImageStyle from './Image.js';
  * @property {import("../colorlike.js").ColorLike} [strokeStyle]
  * @property {number} strokeWidth
  * @property {number} size
- * @property {string} lineCap
+ * @property {CanvasLineCap} lineCap
  * @property {Array<number>} lineDash
  * @property {number} lineDashOffset
- * @property {string} lineJoin
+ * @property {CanvasLineJoin} lineJoin
  * @property {number} miterLimit
  */
 
@@ -142,7 +142,7 @@ class RegularShape extends ImageStyle {
      */
     this.hitDetectionImageSize_ = null;
 
-    this.render_();
+    this.render();
 
   }
 
@@ -301,9 +301,9 @@ class RegularShape extends ImageStyle {
   /**
    * @protected
    */
-  render_() {
-    let lineCap = '';
-    let lineJoin = '';
+  render() {
+    let lineCap = defaultLineCap;
+    let lineJoin = defaultLineJoin;
     let miterLimit = 0;
     let lineDash = null;
     let lineDashOffset = 0;
@@ -338,7 +338,6 @@ class RegularShape extends ImageStyle {
 
     let size = 2 * (this.radius_ + strokeWidth) + 1;
 
-    /** @type {RenderOptions} */
     const renderOptions = {
       strokeStyle: strokeStyle,
       strokeWidth: strokeWidth,
@@ -418,8 +417,8 @@ class RegularShape extends ImageStyle {
         context.setLineDash(renderOptions.lineDash);
         context.lineDashOffset = renderOptions.lineDashOffset;
       }
-      context.lineCap = /** @type {CanvasLineCap} */ (renderOptions.lineCap);
-      context.lineJoin = /** @type {CanvasLineJoin} */ (renderOptions.lineJoin);
+      context.lineCap = renderOptions.lineCap;
+      context.lineJoin = renderOptions.lineJoin;
       context.miterLimit = renderOptions.miterLimit;
       context.stroke();
     }

src/ol/style/Stroke.js

@@ -8,8 +8,8 @@
  * @property {import("../color.js").Color|import("../colorlike.js").ColorLike} [color] A color, gradient or pattern.
  * See {@link module:ol/color~Color} and {@link module:ol/colorlike~ColorLike} for possible formats.
  * Default null; if null, the Canvas/renderer default black will be used.
- * @property {string} [lineCap='round'] Line cap style: `butt`, `round`, or `square`.
- * @property {string} [lineJoin='round'] Line join style: `bevel`, `round`, or `miter`.
+ * @property {CanvasLineCap} [lineCap='round'] Line cap style: `butt`, `round`, or `square`.
+ * @property {CanvasLineJoin} [lineJoin='round'] Line join style: `bevel`, `round`, or `miter`.
  * @property {Array<number>} [lineDash] Line dash pattern. Default is `undefined` (no dash).
  * Please note that Internet Explorer 10 and lower do not support the `setLineDash` method on
  * the `CanvasRenderingContext2D` and therefore this option will have no visual effect in these browsers.
@@ -43,7 +43,7 @@ class Stroke {
 
     /**
      * @private
-     * @type {string|undefined}
+     * @type {CanvasLineCap|undefined}
      */
     this.lineCap_ = options.lineCap;
 
@@ -61,7 +61,7 @@ class Stroke {
 
     /**
      * @private
-     * @type {string|undefined}
+     * @type {CanvasLineJoin|undefined}
      */
     this.lineJoin_ = options.lineJoin;
 
@@ -107,7 +107,7 @@ class Stroke {
 
   /**
    * Get the line cap type for the stroke.
-   * @return {string|undefined} Line cap.
+   * @return {CanvasLineCap|undefined} Line cap.
    * @api
    */
   getLineCap() {
@@ -134,7 +134,7 @@ class Stroke {
 
   /**
    * Get the line join type for the stroke.
-   * @return {string|undefined} Line join.
+   * @return {CanvasLineJoin|undefined} Line join.
    * @api
    */
   getLineJoin() {
@@ -172,7 +172,7 @@ class Stroke {
   /**
    * Set the line cap.
    *
-   * @param {string|undefined} lineCap Line cap.
+   * @param {CanvasLineCap|undefined} lineCap Line cap.
    * @api
    */
   setLineCap(lineCap) {
@@ -208,7 +208,7 @@ class Stroke {
   /**
    * Set the line join.
    *
-   * @param {string|undefined} lineJoin Line join.
+   * @param {CanvasLineJoin|undefined} lineJoin Line join.
    * @api
    */
   setLineJoin(lineJoin) {

src/ol/webgl/Helper.js

@@ -432,6 +432,31 @@ class WebGLHelper extends Disposable {
     gl.enable(gl.BLEND);
     gl.blendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA);
 
+    gl.useProgram(this.currentProgram_);
+    this.applyFrameState(frameState);
+    this.applyUniforms(frameState);
+  }
+
+  /**
+   * Clear the render target & bind it for future draw operations.
+   * This is similar to `prepareDraw`, only post processes will not be applied.
+   * Note: the whole viewport will be drawn to the render target, regardless of its size.
+   * @param {import("../PluggableMap.js").FrameState} frameState current frame state
+   * @param {import("./RenderTarget.js").default} renderTarget Render target to draw to
+   * @param {boolean} [opt_disableAlphaBlend] If true, no alpha blending will happen.
+   */
+  prepareDrawToRenderTarget(frameState, renderTarget, opt_disableAlphaBlend) {
+    const gl = this.getGL();
+
+    gl.bindFramebuffer(gl.FRAMEBUFFER, renderTarget.getFramebuffer());
+    gl.viewport(0, 0, frameState.size[0], frameState.size[1]);
+    gl.bindTexture(gl.TEXTURE_2D, renderTarget.getTexture());
+    gl.clearColor(0.0, 0.0, 0.0, 0.0);
+    gl.clear(gl.COLOR_BUFFER_BIT);
+    gl.enable(gl.BLEND);
+    gl.blendFunc(gl.ONE, opt_disableAlphaBlend ? gl.ZERO : gl.ONE_MINUS_SRC_ALPHA);
+
+    gl.useProgram(this.currentProgram_);
     this.applyFrameState(frameState);
     this.applyUniforms(frameState);
   }
@@ -742,57 +767,36 @@ class WebGLHelper extends Disposable {
   // TODO: shutdown program
 
   /**
-   * TODO: these are not used and should be reworked
-   * @param {number=} opt_wrapS wrapS.
-   * @param {number=} opt_wrapT wrapT.
-   * @return {WebGLTexture} The texture.
+   * Will create or reuse a given webgl texture and apply the given size. If no image data
+   * specified, the texture will be empty, otherwise image data will be used and the `size`
+   * parameter will be ignored.
+   * Note: wrap parameters are set to clamp to edge, min filter is set to linear.
+   * @param {Array<number>} size Expected size of the texture
+   * @param {ImageData|HTMLImageElement|HTMLCanvasElement} [opt_data] Image data/object to bind to the texture
+   * @param {WebGLTexture} [opt_texture] Existing texture to reuse
+   * @return {WebGLTexture} The generated texture
+   * @api
    */
-  createTextureInternal(opt_wrapS, opt_wrapT) {
+  createTexture(size, opt_data, opt_texture) {
     const gl = this.getGL();
-    const texture = gl.createTexture();
+    const texture = opt_texture || gl.createTexture();
+
+    // set params & size
+    const level = 0;
+    const internalFormat = gl.RGBA;
+    const border = 0;
+    const format = gl.RGBA;
+    const type = gl.UNSIGNED_BYTE;
     gl.bindTexture(gl.TEXTURE_2D, texture);
-    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
+    if (opt_data) {
+      gl.texImage2D(gl.TEXTURE_2D, level, internalFormat, format, type, opt_data);
+    } else {
+      gl.texImage2D(gl.TEXTURE_2D, level, internalFormat, size[0], size[1], border, format, type, null);
+    }
     gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
 
-    if (opt_wrapS !== undefined) {
-      gl.texParameteri(
-        gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, opt_wrapS);
-    }
-    if (opt_wrapT !== undefined) {
-      gl.texParameteri(
-        gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, opt_wrapT);
-    }
-
-    return texture;
-  }
-
-  /**
-   * TODO: these are not used and should be reworked
-   * @param {number} width Width.
-   * @param {number} height Height.
-   * @param {number=} opt_wrapS wrapS.
-   * @param {number=} opt_wrapT wrapT.
-   * @return {WebGLTexture} The texture.
-   */
-  createEmptyTexture(width, height, opt_wrapS, opt_wrapT) {
-    const gl = this.getGL();
-    const texture = this.createTextureInternal(opt_wrapS, opt_wrapT);
-    gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, width, height, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
-    return texture;
-  }
-
-
-  /**
-   * TODO: these are not used and should be reworked
-   * @param {HTMLCanvasElement|HTMLImageElement|HTMLVideoElement} image Image.
-   * @param {number=} opt_wrapS wrapS.
-   * @param {number=} opt_wrapT wrapT.
-   * @return {WebGLTexture} The texture.
-   */
-  createTexture(image, opt_wrapS, opt_wrapT) {
-    const gl = this.getGL();
-    const texture = this.createTextureInternal(opt_wrapS, opt_wrapT);
-    gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, image);
     return texture;
   }
 }

src/ol/webgl/RenderTarget.js

@@ -0,0 +1,164 @@
+/**
+ * A wrapper class to simplify rendering to a texture instead of the final canvas
+ * @module ol/webgl/RenderTarget
+ */
+import {equals} from '../array.js';
+
+// for pixel color reading
+const tmpArray4 = new Uint8Array(4);
+
+/**
+ * @classdesc
+ * This class is a wrapper around the association of both a `WebGLTexture` and a `WebGLFramebuffer` instances,
+ * simplifying initialization and binding for rendering.
+ * @api
+ */
+class WebGLRenderTarget {
+
+  /**
+   * @param {import("./Helper.js").default} helper WebGL helper; mandatory.
+   * @param {Array<number>} [opt_size] Expected size of the render target texture; note: this can be changed later on.
+   */
+  constructor(helper, opt_size) {
+    /**
+     * @private
+     * @type {import("./Helper.js").default}
+     */
+    this.helper_ = helper;
+    const gl = helper.getGL();
+
+    /**
+     * @private
+     * @type {WebGLTexture}
+     */
+    this.texture_ = gl.createTexture();
+
+    /**
+     * @private
+     * @type {WebGLFramebuffer}
+     */
+    this.framebuffer_ = gl.createFramebuffer();
+
+    /**
+     * @type {Array<number>}
+     * @private
+     */
+    this.size_ = opt_size || [1, 1];
+
+    /**
+     * @type {Uint8Array}
+     * @private
+     */
+    this.data_ = new Uint8Array(0);
+
+    /**
+     * @type {boolean}
+     * @private
+     */
+    this.dataCacheDirty_ = true;
+
+    this.updateSize_();
+  }
+
+  /**
+   * Changes the size of the render target texture. Note: will do nothing if the size
+   * is already the same.
+   * @param {Array<number>} size Expected size of the render target texture
+   * @api
+   */
+  setSize(size) {
+    if (equals(size, this.size_)) {
+      return;
+    }
+    this.size_[0] = size[0];
+    this.size_[1] = size[1];
+    this.updateSize_();
+  }
+
+  /**
+   * Returns the size of the render target texture
+   * @return {Array<number>} Size of the render target texture
+   * @api
+   */
+  getSize() {
+    return this.size_;
+  }
+
+  /**
+   * This will cause following calls to `#readAll` or `#readPixel` to download the content of the
+   * render target into memory, which is an expensive operation.
+   * This content will be kept in cache but should be cleared after each new render.
+   * @api
+   */
+  clearCachedData() {
+    this.dataCacheDirty_ = true;
+  }
+
+  /**
+   * Returns the full content of the frame buffer as a series of r, g, b, a components
+   * in the 0-255 range (unsigned byte).
+   * @return {Uint8Array} Integer array of color values
+   * @api
+   */
+  readAll() {
+    if (this.dataCacheDirty_) {
+      const size = this.size_;
+      const gl = this.helper_.getGL();
+
+      gl.bindFramebuffer(gl.FRAMEBUFFER, this.framebuffer_);
+      gl.readPixels(0, 0, size[0], size[1], gl.RGBA, gl.UNSIGNED_BYTE, this.data_);
+      this.dataCacheDirty_ = false;
+    }
+    return this.data_;
+  }
+
+  /**
+   * Reads one pixel of the frame buffer as an array of r, g, b, a components
+   * in the 0-255 range (unsigned byte).
+   * @param {number} x Pixel coordinate
+   * @param {number} y Pixel coordinate
+   * @returns {Uint8Array} Integer array with one color value (4 components)
+   * @api
+   */
+  readPixel(x, y) {
+    this.readAll();
+    const index = Math.floor(x) + (this.size_[1] - Math.floor(y) - 1) * this.size_[0];
+    tmpArray4[0] = this.data_[index * 4];
+    tmpArray4[1] = this.data_[index * 4 + 1];
+    tmpArray4[2] = this.data_[index * 4 + 2];
+    tmpArray4[3] = this.data_[index * 4 + 3];
+    return tmpArray4;
+  }
+
+  /**
+   * @return {WebGLTexture} Texture to render to
+   */
+  getTexture() {
+    return this.texture_;
+  }
+
+  /**
+   * @return {WebGLFramebuffer} Frame buffer of the render target
+   */
+  getFramebuffer() {
+    return this.framebuffer_;
+  }
+
+  /**
+   * @private
+   */
+  updateSize_() {
+    const size = this.size_;
+    const gl = this.helper_.getGL();
+
+    this.texture_ = this.helper_.createTexture(size, null, this.texture_);
+
+    gl.bindFramebuffer(gl.FRAMEBUFFER, this.framebuffer_);
+    gl.viewport(0, 0, size[0], size[1]);
+    gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, this.texture_, 0);
+
+    this.data_ = new Uint8Array(size[0] * size[1] * 4);
+  }
+}
+
+export default WebGLRenderTarget;