Merge pull request #7774 from fredj/memory

Pass destination extent to avoid garbage generation

src/ol/VectorImageTile.js

@@ -97,7 +97,7 @@ const VectorImageTile = function(tileCoord, state, sourceRevision, format,
         sourceTileGrid.getTileCoordExtent(sourceTileCoord));
       const sourceExtent = sourceTileGrid.getExtent();
       if (sourceExtent) {
-        sharedExtent = getIntersection(sharedExtent, sourceExtent);
+        sharedExtent = getIntersection(sharedExtent, sourceExtent, sharedExtent);
       }
       if (getWidth(sharedExtent) / resolution >= 0.5 &&
           getHeight(sharedExtent) / resolution >= 0.5) {

src/ol/extent.js

@@ -593,6 +593,8 @@ export function getIntersection(extent1, extent2, opt_extent) {
     } else {
       intersection[3] = extent2[3];
     }
+  } else {
+    createOrUpdateEmpty(intersection);
   }
   return intersection;
 }

test/spec/ol/extent.test.js

@@ -291,6 +291,20 @@ describe('ol.extent', function() {
       expect(_ol_extent_.getIntersection(north, west)).to.eql([-180, 0, 0, 90]);
       expect(_ol_extent_.getIntersection(east, south)).to.eql([0, -90, 180, 0]);
     });
+
+
+    it('can take an destination extent', function() {
+      const world = [-180, -90, 180, 90];
+      const north = [-180, 0, 180, 90];
+      const none = _ol_extent_.createEmpty();
+      let tmpExtent = [-180, 45, 180, 90];
+      expect(_ol_extent_.getIntersection(world, north, tmpExtent)).to.eql(north);
+      expect(_ol_extent_.getIntersection(world, none, tmpExtent)).to.eql(none);
+
+      tmpExtent = [-180, -90, 180, 90];
+      expect(_ol_extent_.getIntersection(tmpExtent, north, tmpExtent)).to.eql(north);
+    });
+
   });
 
   describe('containsCoordinate', function() {