Order callback calls by distance to click position

All callback calls for hits with a tolerance > 0 are queued and
called ordered by distance after all hits are detected.

src/ol/render/canvas/Executor.js

@@ -55,7 +55,7 @@ import {transform2D} from '../../geom/flat/transform.js';
 
 /**
  * @template T
- * @typedef {function(import("../../Feature.js").FeatureLike, import("../../geom/SimpleGeometry.js").default): T=} FeatureCallback
+ * @typedef {function(import("../../Feature.js").FeatureLike, import("../../geom/SimpleGeometry.js").default): T} FeatureCallback
  */
 
 /**
@@ -602,9 +602,9 @@ class Executor {
    * @param {import("../../transform.js").Transform} transform Transform.
    * @param {Array<*>} instructions Instructions array.
    * @param {boolean} snapToPixel Snap point symbols and text to integer pixels.
-   * @param {FeatureCallback<T>|undefined} featureCallback Feature callback.
+   * @param {FeatureCallback<T>=} opt_featureCallback Feature callback.
-   * @param {import("../../extent.js").Extent=} opt_hitExtent Only check features that intersect this
+   * @param {import("../../extent.js").Extent=} opt_hitExtent Only check
-   *     extent.
+   *     features that intersect this extent.
    * @param {import("rbush").default=} opt_declutterTree Declutter tree.
    * @return {T|undefined} Callback result.
    * @template T
@@ -615,7 +615,7 @@ class Executor {
     transform,
     instructions,
     snapToPixel,
-    featureCallback,
+    opt_featureCallback,
     opt_hitExtent,
     opt_declutterTree
   ) {
@@ -1052,9 +1052,9 @@ class Executor {
           ++i;
           break;
         case CanvasInstruction.END_GEOMETRY:
-          if (featureCallback !== undefined) {
+          if (opt_featureCallback !== undefined) {
             feature = /** @type {import("../../Feature.js").FeatureLike} */ (instruction[1]);
-            const result = featureCallback(feature, currentGeometry);
+            const result = opt_featureCallback(feature, currentGeometry);
             if (result) {
               return result;
             }
@@ -1174,10 +1174,9 @@ class Executor {
    * @param {CanvasRenderingContext2D} context Context.
    * @param {import("../../transform.js").Transform} transform Transform.
    * @param {number} viewRotation View rotation.
-   * @param {FeatureCallback<T>} opt_featureCallback
+   * @param {FeatureCallback<T>=} opt_featureCallback Feature callback.
-   *     Feature callback.
+   * @param {import("../../extent.js").Extent=} opt_hitExtent Only check
-   * @param {import("../../extent.js").Extent=} opt_hitExtent Only check features that intersect this
+   *     features that intersect this extent.
-   *     extent.
    * @return {T|undefined} Callback result.
    * @template T
    */

src/ol/render/canvas/ExecutorGroup.js

@@ -161,7 +161,7 @@ class ExecutorGroup {
    * @param {number} resolution Resolution.
    * @param {number} rotation Rotation.
    * @param {number} hitTolerance Hit tolerance in pixels.
-   * @param {import("./Executor.js").FeatureCallback<T>} callback Feature callback.
+   * @param {function(import("../../Feature.js").FeatureLike, import("../../geom/SimpleGeometry.js").default, number): T} callback Feature callback.
    * @param {Array<import("../../Feature.js").FeatureLike>} declutteredFeatures Decluttered features.
    * @return {T|undefined} Callback result.
    * @template T
@@ -187,7 +187,8 @@ class ExecutorGroup {
       -coordinate[1]
     );
 
-    if (!this.hitDetectionContext_) {
+    const newContext = !this.hitDetectionContext_;
+    if (newContext) {
       this.hitDetectionContext_ = createCanvasContext2D(
         contextSize,
         contextSize
@@ -201,7 +202,7 @@ class ExecutorGroup {
     ) {
       context.canvas.width = contextSize;
       context.canvas.height = contextSize;
-    } else {
+    } else if (!newContext) {
       context.clearRect(0, 0, contextSize, contextSize);
     }
 
@@ -226,7 +227,7 @@ class ExecutorGroup {
     /**
      * @param {import("../../Feature.js").FeatureLike} feature Feature.
      * @param {import("../../geom/SimpleGeometry.js").default} geometry Geometry.
-     * @return {?} Callback result.
+     * @return {T|undefined} Callback result.
      */
     function featureCallback(feature, geometry) {
       const imageData = context.getImageData(0, 0, contextSize, contextSize)
@@ -239,7 +240,10 @@ class ExecutorGroup {
               builderType !== BuilderType.TEXT) ||
             declutteredFeatures.indexOf(feature) !== -1
           ) {
-            const result = callback(feature, geometry);
+            const idx = (indexes[i] - 3) / 4;
+            const x = hitTolerance - (idx % contextSize);
+            const y = hitTolerance - ((idx / contextSize) | 0);
+            const result = callback(feature, geometry, x * x + y * y);
             if (result) {
               return result;
             }

src/ol/renderer/Layer.js

@@ -106,10 +106,19 @@ class LayerRenderer extends Observable {
    * @param {import("../PluggableMap.js").FrameState} frameState Frame state.
    * @param {number} hitTolerance Hit tolerance in pixels.
    * @param {import("./vector.js").FeatureCallback<T>} callback Feature callback.
-   * @return {T|void} Callback result.
+   * @param {Array<import("./Map.js").HitMatch<T>>} matches The hit detected matches with tolerance.
+   * @return {T|undefined} Callback result.
    * @template T
    */
-  forEachFeatureAtCoordinate(coordinate, frameState, hitTolerance, callback) {}
+  forEachFeatureAtCoordinate(
+    coordinate,
+    frameState,
+    hitTolerance,
+    callback,
+    matches
+  ) {
+    return undefined;
+  }
 
   /**
    * @abstract

src/ol/renderer/Map.js

@@ -10,6 +10,16 @@ import {shared as iconImageCache} from '../style/IconImageCache.js';
 import {inView} from '../layer/Layer.js';
 import {wrapX} from '../coordinate.js';
 
+/**
+ * @typedef HitMatch
+ * @property {import("../Feature.js").FeatureLike} feature
+ * @property {import("../layer/Layer.js").default} layer
+ * @property {import("../geom/SimpleGeometry.js").default} geometry
+ * @property {number} distanceSq
+ * @property {import("./vector.js").FeatureCallback<T>} callback
+ * @template T
+ */
+
 /**
  * @abstract
  */
@@ -92,7 +102,7 @@ class MapRenderer extends Disposable {
      * @param {import("../Feature.js").FeatureLike} feature Feature.
      * @param {import("../layer/Layer.js").default} layer Layer.
      * @param {import("../geom/Geometry.js").default} geometry Geometry.
-     * @return {?} Callback result.
+     * @return {T|undefined} Callback result.
      */
     function forEachFeatureAtCoordinate(managed, feature, layer, geometry) {
       return callback.call(thisArg, feature, managed ? layer : null, geometry);
@@ -111,11 +121,12 @@ class MapRenderer extends Disposable {
     const layerStates = frameState.layerStatesArray;
     const numLayers = layerStates.length;
 
+    const matches = /** @type {Array<HitMatch<T>>} */ ([]);
     const tmpCoord = [];
     for (let i = 0; i < offsets.length; i++) {
       for (let j = numLayers - 1; j >= 0; --j) {
         const layerState = layerStates[j];
-        const layer = /** @type {import("../layer/Layer.js").default} */ (layerState.layer);
+        const layer = layerState.layer;
         if (
           layer.hasRenderer() &&
           inView(layerState, viewState) &&
@@ -137,7 +148,8 @@ class MapRenderer extends Disposable {
               tmpCoord,
               frameState,
               hitTolerance,
-              callback
+              callback,
+              matches
             );
           }
           if (result) {
@@ -146,7 +158,16 @@ class MapRenderer extends Disposable {
         }
       }
     }
-    return undefined;
+    if (matches.length === 0) {
+      return undefined;
+    }
+    const order = 1 / matches.length;
+    matches.forEach((m, i) => (m.distanceSq += i * order));
+    matches.sort((a, b) => a.distanceSq - b.distanceSq);
+    matches.some((m) => {
+      return (result = m.callback(m.feature, m.layer, m.geometry));
+    });
+    return result;
   }
 
   /**

src/ol/renderer/canvas/VectorImageLayer.js

@@ -195,23 +195,32 @@ class CanvasVectorImageLayerRenderer extends CanvasImageLayerRenderer {
    * @param {import("../../PluggableMap.js").FrameState} frameState Frame state.
    * @param {number} hitTolerance Hit tolerance in pixels.
    * @param {import("../vector.js").FeatureCallback<T>} callback Feature callback.
-   * @return {T|void} Callback result.
+   * @param {Array<import("../Map.js").HitMatch<T>>} matches The hit detected matches with tolerance.
+   * @return {T|undefined} Callback result.
    * @template T
    */
-  forEachFeatureAtCoordinate(coordinate, frameState, hitTolerance, callback) {
+  forEachFeatureAtCoordinate(
+    coordinate,
+    frameState,
+    hitTolerance,
+    callback,
+    matches
+  ) {
     if (this.vectorRenderer_) {
       return this.vectorRenderer_.forEachFeatureAtCoordinate(
         coordinate,
         frameState,
         hitTolerance,
-        callback
+        callback,
+        matches
       );
     } else {
       return super.forEachFeatureAtCoordinate(
         coordinate,
         frameState,
         hitTolerance,
-        callback
+        callback,
+        matches
       );
     }
   }

src/ol/renderer/canvas/VectorLayer.js

@@ -407,55 +407,81 @@ class CanvasVectorLayerRenderer extends CanvasLayerRenderer {
    * @param {import("../../PluggableMap.js").FrameState} frameState Frame state.
    * @param {number} hitTolerance Hit tolerance in pixels.
    * @param {import("../vector.js").FeatureCallback<T>} callback Feature callback.
-   * @return {T|void} Callback result.
+   * @param {Array<import("../Map.js").HitMatch<T>>} matches The hit detected matches with tolerance.
+   * @return {T|undefined} Callback result.
    * @template T
    */
-  forEachFeatureAtCoordinate(coordinate, frameState, hitTolerance, callback) {
+  forEachFeatureAtCoordinate(
+    coordinate,
+    frameState,
+    hitTolerance,
+    callback,
+    matches
+  ) {
     if (!this.replayGroup_) {
       return undefined;
-    } else {
+    }
-      const resolution = frameState.viewState.resolution;
+    const resolution = frameState.viewState.resolution;
-      const rotation = frameState.viewState.rotation;
+    const rotation = frameState.viewState.rotation;
-      const layer = this.getLayer();
+    const layer = this.getLayer();
 
-      /** @type {!Object<string, boolean>} */
+    /** @type {!Object<string, import("../Map.js").HitMatch<T>|true>} */
-      const features = {};
+    const features = {};
 
-      /**
+    /**
-       * @param {import("../../Feature.js").FeatureLike} feature Feature.
+     * @param {import("../../Feature.js").FeatureLike} feature Feature.
-       * @param {import("../../geom/SimpleGeometry.js").default} geometry Geometry.
+     * @param {import("../../geom/SimpleGeometry.js").default} geometry Geometry.
-       * @return {?} Callback result.
+     * @param {number} distanceSq The squared distance to the click position
-       */
+     * @return {T|undefined} Callback result.
-      const featureCallback = function (feature, geometry) {
+     */
-        const key = getUid(feature);
+    const featureCallback = function (feature, geometry, distanceSq) {
-        if (!(key in features)) {
+      const key = getUid(feature);
+      const match = features[key];
+      if (!match) {
+        if (distanceSq === 0) {
           features[key] = true;
           return callback(feature, layer, geometry);
         }
-      };
+        matches.push(
-
+          (features[key] = {
-      let result;
+            feature: feature,
-      const executorGroups = [this.replayGroup_];
+            layer: layer,
-      if (this.declutterExecutorGroup) {
+            geometry: geometry,
-        executorGroups.push(this.declutterExecutorGroup);
+            distanceSq: distanceSq,
+            callback: callback,
+          })
+        );
+      } else if (match !== true && distanceSq < match.distanceSq) {
+        if (distanceSq === 0) {
+          features[key] = true;
+          matches.splice(matches.lastIndexOf(match), 1);
+          return callback(feature, layer, geometry);
+        }
+        match.geometry = geometry;
+        match.distanceSq = distanceSq;
       }
-      executorGroups.forEach((executorGroup) => {
+      return undefined;
-        result =
+    };
-          result ||
-          executorGroup.forEachFeatureAtCoordinate(
-            coordinate,
-            resolution,
-            rotation,
-            hitTolerance,
-            featureCallback,
-            executorGroup === this.declutterExecutorGroup
-              ? frameState.declutterTree.all().map((item) => item.value)
-              : null
-          );
-      });
 
-      return result;
+    let result;
+    const executorGroups = [this.replayGroup_];
+    if (this.declutterExecutorGroup) {
+      executorGroups.push(this.declutterExecutorGroup);
     }
+    executorGroups.some((executorGroup) => {
+      return (result = executorGroup.forEachFeatureAtCoordinate(
+        coordinate,
+        resolution,
+        rotation,
+        hitTolerance,
+        featureCallback,
+        executorGroup === this.declutterExecutorGroup
+          ? frameState.declutterTree.all().map((item) => item.value)
+          : null
+      ));
+    });
+
+    return result;
   }
 
   /**

src/ol/renderer/canvas/VectorTileLayer.js

@@ -381,10 +381,17 @@ class CanvasVectorTileLayerRenderer extends CanvasTileLayerRenderer {
    * @param {import("../../PluggableMap.js").FrameState} frameState Frame state.
    * @param {number} hitTolerance Hit tolerance in pixels.
    * @param {import("../vector.js").FeatureCallback<T>} callback Feature callback.
-   * @return {T|void} Callback result.
+   * @param {Array<import("../Map.js").HitMatch<T>>} matches The hit detected matches with tolerance.
+   * @return {T|undefined} Callback result.
    * @template T
    */
-  forEachFeatureAtCoordinate(coordinate, frameState, hitTolerance, callback) {
+  forEachFeatureAtCoordinate(
+    coordinate,
+    frameState,
+    hitTolerance,
+    callback,
+    matches
+  ) {
     const resolution = frameState.viewState.resolution;
     const rotation = frameState.viewState.rotation;
     hitTolerance = hitTolerance == undefined ? 0 : hitTolerance;
@@ -397,55 +404,82 @@ class CanvasVectorTileLayerRenderer extends CanvasTileLayerRenderer {
     const hitExtent = boundingExtent([coordinate]);
     buffer(hitExtent, resolution * hitTolerance, hitExtent);
 
-    /** @type {!Object<string, boolean>} */
+    /** @type {!Object<string, import("../Map.js").HitMatch<T>|true>} */
     const features = {};
 
+    /**
+     * @param {import("../../Feature.js").FeatureLike} feature Feature.
+     * @param {import("../../geom/SimpleGeometry.js").default} geometry Geometry.
+     * @param {number} distanceSq The squared distance to the click position.
+     * @return {T|undefined} Callback result.
+     */
+    const featureCallback = function (feature, geometry, distanceSq) {
+      let key = feature.getId();
+      if (key === undefined) {
+        key = getUid(feature);
+      }
+      const match = features[key];
+      if (!match) {
+        if (distanceSq === 0) {
+          features[key] = true;
+          return callback(feature, layer, geometry);
+        }
+        matches.push(
+          (features[key] = {
+            feature: feature,
+            layer: layer,
+            geometry: geometry,
+            distanceSq: distanceSq,
+            callback: callback,
+          })
+        );
+      } else if (match !== true && distanceSq < match.distanceSq) {
+        if (distanceSq === 0) {
+          features[key] = true;
+          matches.splice(matches.lastIndexOf(match), 1);
+          return callback(feature, layer, geometry);
+        }
+        match.geometry = geometry;
+        match.distanceSq = distanceSq;
+      }
+      return undefined;
+    };
+
     const renderedTiles = /** @type {Array<import("../../VectorRenderTile.js").default>} */ (this
       .renderedTiles);
 
     let found;
-    let i, ii;
+    for (let i = 0, ii = renderedTiles.length; !found && i < ii; ++i) {
-    for (i = 0, ii = renderedTiles.length; i < ii; ++i) {
       const tile = renderedTiles[i];
       const tileExtent = tileGrid.getTileCoordExtent(tile.wrappedTileCoord);
       if (!intersects(tileExtent, hitExtent)) {
         continue;
       }
+
       const layerUid = getUid(layer);
       const executorGroups = [tile.executorGroups[layerUid]];
       const declutterExecutorGroups = tile.declutterExecutorGroups[layerUid];
       if (declutterExecutorGroups) {
         executorGroups.push(declutterExecutorGroups);
       }
-      executorGroups.forEach((executorGroups) => {
+      executorGroups.some((executorGroups) => {
+        const declutteredFeatures =
+          executorGroups === declutterExecutorGroups
+            ? frameState.declutterTree.all().map((item) => item.value)
+            : null;
         for (let t = 0, tt = executorGroups.length; t < tt; ++t) {
           const executorGroup = executorGroups[t];
-          found =
+          found = executorGroup.forEachFeatureAtCoordinate(
-            found ||
+            coordinate,
-            executorGroup.forEachFeatureAtCoordinate(
+            resolution,
-              coordinate,
+            rotation,
-              resolution,
+            hitTolerance,
-              rotation,
+            featureCallback,
-              hitTolerance,
+            declutteredFeatures
-              /**
+          );
-               * @param {import("../../Feature.js").FeatureLike} feature Feature.
+          if (found) {
-               * @param {import("../../geom/SimpleGeometry.js").default} geometry Geometry.
+            return true;
-               * @return {?} Callback result.
+          }
-               */
-              function (feature, geometry) {
-                let key = feature.getId();
-                if (key === undefined) {
-                  key = getUid(feature);
-                }
-                if (!(key in features)) {
-                  features[key] = true;
-                  return callback(feature, layer, geometry);
-                }
-              },
-              executorGroups === declutterExecutorGroups
-                ? frameState.declutterTree.all().map((item) => item.value)
-                : null
-            );
         }
       });
     }

src/ol/renderer/webgl/PointsLayer.js

@@ -598,13 +598,20 @@ class WebGLPointsLayerRenderer extends WebGLLayerRenderer {
    * @param {import("../../PluggableMap.js").FrameState} frameState Frame state.
    * @param {number} hitTolerance Hit tolerance in pixels.
    * @param {import("../vector.js").FeatureCallback<T>} callback Feature callback.
-   * @return {T|void} Callback result.
+   * @param {Array<import("../Map.js").HitMatch<T>>} matches The hit detected matches with tolerance.
+   * @return {T|undefined} Callback result.
    * @template T
    */
-  forEachFeatureAtCoordinate(coordinate, frameState, hitTolerance, callback) {
+  forEachFeatureAtCoordinate(
+    coordinate,
+    frameState,
+    hitTolerance,
+    callback,
+    matches
+  ) {
     assert(this.hitDetectionEnabled_, 66);
     if (!this.hitRenderInstructions_) {
-      return;
+      return undefined;
     }
 
     const pixel = applyTransform(
@@ -623,6 +630,7 @@ class WebGLPointsLayerRenderer extends WebGLLayerRenderer {
     if (feature) {
       return callback(feature, this.getLayer(), null);
     }
+    return undefined;
   }
 
   /**

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

@@ -189,7 +189,8 @@ describe('ol.renderer.canvas.VectorLayer', function () {
   });
 
   describe('#forEachFeatureAtCoordinate', function () {
-    let layer, renderer;
+    /** @type {VectorLayer} */ let layer;
+    /** @type {CanvasVectorLayerRenderer} */ let renderer;
 
     beforeEach(function () {
       layer = new VectorLayer({
@@ -205,15 +206,17 @@ describe('ol.renderer.canvas.VectorLayer', function () {
         hitTolerance,
         callback
       ) {
-        const feature = new Feature();
+        const feature = new Feature(new Point([0, 0]));
-        callback(feature);
+        const distanceSq = 0;
-        callback(feature);
+        callback(feature, feature.getGeometry(), distanceSq);
+        callback(feature, feature.getGeometry(), distanceSq);
       };
     });
 
     it('calls callback once per feature with a layer as 2nd arg', function () {
       const spy = sinon.spy();
       const coordinate = [0, 0];
+      const matches = [];
       const frameState = {
         layerStatesArray: [{}],
         viewState: {
@@ -227,10 +230,11 @@ describe('ol.renderer.canvas.VectorLayer', function () {
         frameState,
         0,
         spy,
-        undefined
+        matches
       );
       expect(spy.callCount).to.be(1);
-      expect(spy.getCall(0).args[1]).to.equal(layer);
+      expect(spy.getCall(0).args[1]).to.be(layer);
+      expect(matches).to.be.empty();
     });
   });
 

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

@@ -114,7 +114,7 @@ describe('ol.renderer.canvas.VectorTileLayer', function () {
     it('creates a new instance', function () {
       const renderer = new CanvasVectorTileLayerRenderer(layer);
       expect(renderer).to.be.a(CanvasVectorTileLayerRenderer);
-      expect(renderer.getLayer()).to.equal(layer);
+      expect(renderer.getLayer()).to.be(layer);
     });
 
     it('does not render replays for pure image rendering', function () {
@@ -321,7 +321,10 @@ describe('ol.renderer.canvas.VectorTileLayer', function () {
   });
 
   describe('#forEachFeatureAtCoordinate', function () {
-    let layer, renderer, executorGroup, source;
+    /** @type {VectorTileLayer] */ let layer;
+    /** @type {CanvasVectorTileLayerRenderer} */ let renderer;
+    /** @type {VectorTileSource} */ let source;
+    let executorGroup;
     class TileClass extends VectorRenderTile {
       constructor() {
         super(...arguments);
@@ -339,6 +342,18 @@ describe('ol.renderer.canvas.VectorTileLayer', function () {
       });
       source.sourceTileCache.set('0/0/0.mvt', sourceTile);
       executorGroup = {};
+      executorGroup.forEachFeatureAtCoordinate = function (
+        coordinate,
+        resolution,
+        rotation,
+        hitTolerance,
+        callback
+      ) {
+        const feature = new Feature(new Point([0, 0]));
+        const distanceSq = 0;
+        callback(feature, feature.getGeometry(), distanceSq);
+        callback(feature, feature.getGeometry(), distanceSq);
+      };
       source.getTile = function () {
         const tile = VectorTileSource.prototype.getTile.apply(
           source,
@@ -352,22 +367,12 @@ describe('ol.renderer.canvas.VectorTileLayer', function () {
         source: source,
       });
       renderer = new CanvasVectorTileLayerRenderer(layer);
-      executorGroup.forEachFeatureAtCoordinate = function (
-        coordinate,
-        resolution,
-        rotation,
-        hitTolerance,
-        callback
-      ) {
-        const feature = new Feature();
-        callback(feature);
-        callback(feature);
-      };
     });
 
     it('calls callback once per feature with a layer as 2nd arg', function () {
       const spy = sinon.spy();
       const coordinate = [0, 0];
+      const matches = [];
       const frameState = {
         layerStatesArray: [{}],
         viewState: {
@@ -384,10 +389,11 @@ describe('ol.renderer.canvas.VectorTileLayer', function () {
         frameState,
         0,
         spy,
-        undefined
+        matches
       );
       expect(spy.callCount).to.be(1);
-      expect(spy.getCall(0).args[1]).to.equal(layer);
+      expect(spy.getCall(0).args[1]).to.be(layer);
+      expect(matches).to.be.empty();
     });
 
     it('does not give false positives when overzoomed', function (done) {