0

I'm trying to clip a layer by vector in OpenLayers 5. I've found this answer that kind of works, but it does not solve my specific problem, namely bandwidth.

I'm combining WMTS services from two different countries, and would like to block one service from serving tiles over the other country's area, since that just wastes bandwidth. The countries are Norway and Sweden, so simple bounds won't help me (the border goes on the diagonal of any bounding box).

1

You could customise the tileUrlFunction to only return a url if the tile extent intersects the country's geometry

var defaultUrlFunction = source.getTileUrlFunction();
source.setTileUrlFunction( function(tileCoord, pixelRatio, projection) {
    if (countryGeometry.intersectsExtent(this.getTileGrid().getTileCoordExtent(tileCoord))) {
        return defaultUrlFunction(tileCoord, pixelRatio, projection);
    }
});
| improve this answer | |
  • This worked beautifully. I had to make some changes as my vector was a vectorLayer: var seUrlFunction = seXYZ.getSource().getTileUrlFunction(); seXYZ.getSource().setTileUrlFunction(function(tileCoord, pixelRatio, projection) { for (var feature of seBounds.getSource().getFeatures()) { var featureIntersects = feature.getGeometry() .intersectsExtent(this.getTileGrid() .getTileCoordExtent(tileCoord)); if (featureIntersects) { return seUrlFunction(tileCoord, pixelRatio, projection); } }; }); – Aron Widforss Dec 9 '18 at 23:56
  • I've just had a custom url function stop working after moving to the latest version of OL. I fixed it by changing to var defaultUrlFunction = source.getTileUrlFunction().bind(source); It was a TileWMS source but be aware it might affect other sources in the future. – Mike Dec 18 '18 at 11:53

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.