Add hit-detection image to atlas (RegularShape)

src/ol/style/regularshapestyle.js

@@ -56,6 +56,12 @@ ol.style.RegularShape = function(opt_options) {
    */
   this.origin_ = [0, 0];
 
+  /**
+   * @private
+   * @type {Array.<number>}
+   */
+  this.hitDetectionOrigin_ = [0, 0];
+
   /**
    * @private
    * @type {number}
@@ -105,6 +111,12 @@ ol.style.RegularShape = function(opt_options) {
    */
   this.imageSize_ = null;
 
+  /**
+   * @private
+   * @type {ol.Size}
+   */
+  this.hitDetectionImageSize_ = null;
+
   this.render_(options.atlasManager);
 
   /**
@@ -168,6 +180,14 @@ ol.style.RegularShape.prototype.getImageSize = function() {
 };
 
 
+/**
+ * @inheritDoc
+ */
+ol.style.RegularShape.prototype.getHitDetectionImageSize = function() {
+  return this.hitDetectionImageSize_;
+};
+
+
 /**
  * @inheritDoc
  */
@@ -185,6 +205,14 @@ ol.style.RegularShape.prototype.getOrigin = function() {
 };
 
 
+/**
+ * @inheritDoc
+ */
+ol.style.RegularShape.prototype.getHitDetectionOrigin = function() {
+  return this.hitDetectionOrigin_;
+};
+
+
 /**
  * @return {number} Radius.
  * @api
@@ -276,30 +304,45 @@ ol.style.RegularShape.prototype.render_ = function(atlasManager) {
     var context = /** @type {CanvasRenderingContext2D} */
         (this.canvas_.getContext('2d'));
     this.draw_(renderOptions, context, 0, 0);
+
+    this.createHitDetectionCanvas_(renderOptions);
   } else {
     // an atlas manager is used, add the symbol to an atlas
     size = Math.round(size);
 
+    var hasCustomHitDetectionImage = goog.isNull(this.fill_);
+    var renderHitDetectionCallback;
+    if (hasCustomHitDetectionImage) {
+      // render the hit-detection image into a separate atlas image
+      renderHitDetectionCallback =
+          goog.bind(this.drawHitDetectionCanvas_, this, renderOptions);
+    }
+
     var id = this.getChecksum();
     var info = atlasManager.add(
-        id, size, size, goog.bind(this.draw_, this, renderOptions));
+        id, size, size, goog.bind(this.draw_, this, renderOptions),
+        renderHitDetectionCallback);
     goog.asserts.assert(info !== null, 'shape size is too large');
 
     this.canvas_ = info.image;
     this.origin_ = [info.offsetX, info.offsetY];
     imageSize = info.image.width;
+
+    if (hasCustomHitDetectionImage) {
+      this.hitDetectionCanvas_ = info.hitImage;
+      this.hitDetectionOrigin_ = [info.hitOffsetX, info.hitOffsetY];
+      this.hitDetectionImageSize_ =
+          [info.hitImage.width, info.hitImage.height];
+    } else {
+      this.hitDetectionCanvas_ = this.canvas_;
+      this.hitDetectionOrigin_ = this.origin_;
+      this.hitDetectionImageSize_ = [imageSize, imageSize];
+    }
   }
 
   this.anchor_ = [size / 2, size / 2];
   this.size_ = [size, size];
   this.imageSize_ = [imageSize, imageSize];
-
-  // deal with the hit detection canvas
-  if (!goog.isNull(this.fill_)) {
-    this.hitDetectionCanvas_ = this.canvas_;
-  } else {
-    this.createHitDetectionCanvas_(renderOptions);
-  }
 };
 
 
@@ -348,6 +391,14 @@ ol.style.RegularShape.prototype.draw_ = function(renderOptions, context, x, y) {
  */
 ol.style.RegularShape.prototype.createHitDetectionCanvas_ =
     function(renderOptions) {
+  this.hitDetectionImageSize_ = [renderOptions.size, renderOptions.size];
+  if (!goog.isNull(this.fill_)) {
+    this.hitDetectionCanvas_ = this.canvas_;
+    return;
+  }
+
+  // if no fill style is set, create an extra hit-detection image with a
+  // default fill style
   this.hitDetectionCanvas_ = /** @type {HTMLCanvasElement} */
       (goog.dom.createElement(goog.dom.TagName.CANVAS));
   var canvas = this.hitDetectionCanvas_;
@@ -357,6 +408,25 @@ ol.style.RegularShape.prototype.createHitDetectionCanvas_ =
 
   var context = /** @type {CanvasRenderingContext2D} */
       (canvas.getContext('2d'));
+  this.drawHitDetectionCanvas_(renderOptions, context, 0, 0);
+};
+
+
+/**
+ * @private
+ * @param {ol.style.RegularShape.RenderOptions} renderOptions
+ * @param {CanvasRenderingContext2D} context
+ * @param {number} x The origin for the symbol (x).
+ * @param {number} y The origin for the symbol (y).
+ */
+ol.style.RegularShape.prototype.drawHitDetectionCanvas_ =
+    function(renderOptions, context, x, y) {
+  // reset transform
+  context.setTransform(1, 0, 0, 1, 0, 0);
+
+  // then move to (x, y)
+  context.translate(x, y);
+
   context.beginPath();
   if (this.radius2_ !== this.radius_) {
     this.points_ = 2 * this.points_;
@@ -376,6 +446,7 @@ ol.style.RegularShape.prototype.createHitDetectionCanvas_ =
     context.lineWidth = renderOptions.strokeWidth;
     context.stroke();
   }
+  context.closePath();
 };
 
 

test/spec/ol/style/regularshapestyle.test.js

@@ -5,18 +5,40 @@ describe('ol.style.RegularShape', function() {
 
   describe('#constructor', function() {
 
-    it('creates a canvas if no atlas is used', function() {
+    it('creates a canvas if no atlas is used (no fill-style)', function() {
       var style = new ol.style.RegularShape({radius: 10});
       expect(style.getImage()).to.be.an(HTMLCanvasElement);
       expect(style.getSize()).to.eql([21, 21]);
       expect(style.getImageSize()).to.eql([21, 21]);
       expect(style.getOrigin()).to.eql([0, 0]);
       expect(style.getAnchor()).to.eql([10.5, 10.5]);
+      // hit-detection image is created, because no fill style is set
       expect(style.getImage()).to.not.be(style.getHitDetectionImage());
       expect(style.getHitDetectionImage()).to.be.an(HTMLCanvasElement);
+      expect(style.getHitDetectionImageSize()).to.eql([21, 21]);
+      expect(style.getHitDetectionOrigin()).to.eql([0, 0]);
     });
 
-    it('adds itself to an atlas manager', function() {
+    it('creates a canvas if no atlas is used (fill-style)', function() {
+      var style = new ol.style.RegularShape({
+        radius: 10,
+        fill: new ol.style.Fill({
+          color: '#FFFF00'
+        })
+      });
+      expect(style.getImage()).to.be.an(HTMLCanvasElement);
+      expect(style.getSize()).to.eql([21, 21]);
+      expect(style.getImageSize()).to.eql([21, 21]);
+      expect(style.getOrigin()).to.eql([0, 0]);
+      expect(style.getAnchor()).to.eql([10.5, 10.5]);
+      // no hit-detection image is created, because fill style is set
+      expect(style.getImage()).to.be(style.getHitDetectionImage());
+      expect(style.getHitDetectionImage()).to.be.an(HTMLCanvasElement);
+      expect(style.getHitDetectionImageSize()).to.eql([21, 21]);
+      expect(style.getHitDetectionOrigin()).to.eql([0, 0]);
+    });
+
+    it('adds itself to an atlas manager (no fill-style)', function() {
       var atlasManager = new ol.style.AtlasManager({size: 512});
       var style = new ol.style.RegularShape(
           {radius: 10, atlasManager: atlasManager});
@@ -25,8 +47,32 @@ describe('ol.style.RegularShape', function() {
       expect(style.getImageSize()).to.eql([512, 512]);
       expect(style.getOrigin()).to.eql([1, 1]);
       expect(style.getAnchor()).to.eql([10.5, 10.5]);
+      // hit-detection image is created, because no fill style is set
       expect(style.getImage()).to.not.be(style.getHitDetectionImage());
       expect(style.getHitDetectionImage()).to.be.an(HTMLCanvasElement);
+      expect(style.getHitDetectionImageSize()).to.eql([512, 512]);
+      expect(style.getHitDetectionOrigin()).to.eql([1, 1]);
+    });
+
+    it('adds itself to an atlas manager (fill-style)', function() {
+      var atlasManager = new ol.style.AtlasManager({size: 512});
+      var style = new ol.style.RegularShape({
+        radius: 10,
+        atlasManager: atlasManager,
+        fill: new ol.style.Fill({
+          color: '#FFFF00'
+        })
+      });
+      expect(style.getImage()).to.be.an(HTMLCanvasElement);
+      expect(style.getSize()).to.eql([21, 21]);
+      expect(style.getImageSize()).to.eql([512, 512]);
+      expect(style.getOrigin()).to.eql([1, 1]);
+      expect(style.getAnchor()).to.eql([10.5, 10.5]);
+      // no hit-detection image is created, because fill style is set
+      expect(style.getImage()).to.be(style.getHitDetectionImage());
+      expect(style.getHitDetectionImage()).to.be.an(HTMLCanvasElement);
+      expect(style.getHitDetectionImageSize()).to.eql([512, 512]);
+      expect(style.getHitDetectionOrigin()).to.eql([1, 1]);
     });
   });