Custom Virtual Earth Clustering

Question

I want to implement my own clustering algorithm using this Virtual Earth javascript API: http://msdn.microsoft.com/en-us/library/cc966716.aspx However, the VE engine calls my cluster function once for every shape in the layer. This makes it very slow! It seems to me that VE should put all the shapes into a layer, then ask my function to cluster them. Not repeatedly call cluster!

Why does the VE engine do this? Is there another way to do client side clustering with this API?

More Information: I am loading the shapes from a GeoRSS feed.

Answer 1

It should only be calling your code once per VEShapeLayer - otherwise, clustering is pointless since you can't cluster a single shape. Are you using VEMap.AddShape instead of adding VEShape objects to a VEShapeLayer? If so, try creating a single VEShapeLayer, add it to the VEMap, and then add all VEShape objects to the shape layer instead of the map.

Answer 2

The custom clustering algorithm method will only get called once for that VEShapeLayer.

Adam Byram, There's not much difference in between using the VEMap.AddShape method and adding a VEShapeLayer to the map with all the Shapes inside. The AddShape method adds the Shape to the "default" ShapeLayer, which is the ShapeLayer with 0 (zero) index, and adding a VEShapeLayer adds a new layer in addition the the existing "default" layer.

It is probable that if you are using VEMap.AddShape to add the VEShape object to the map, that it is calling your clusting algorithm method everytime a VEShape is added to the Map. This would be correct behavior since it will need to re-calculate the clustering each time a shape is added.

To improve overall performance when adding all the shapes to the map, and to get VE to call your custom algorithm method only once when adding all the shapes; you can create a VEShapeLayer, add all the Shapes to it, then add that shape layer to the map. This will cause VE to only do the rendering of all the Shapes once (at time of loading them all) instead of each and every time you add a single VEShape.