ORMapView - MKMapView with clustering

ORMapView is a drop-in subclass of MKMapView that displays clusters of annotations. This is very useful in cases where you have to display many annotations on the map.

ORMapView is actually a fork of ADClusterMapView

I liked their cluster implementation, but didn't need the complex animation code. I also wanted ORMapView to be a true drop-in replacement for MKMapView that does not wrap annotations in it's own MKAnnotation implementation, forcing you to modify your existing MKMapViewDelegate code.

The cluster algorithm and code itself (the hard part) is a plain copy from ADClusterMapView. The algorithm concept is described on Applidium's website.

Differences to ADClusterMapView are:

1. Does not warp your annotations in a custom MKAnnotation implementation which would force you to rewrite your MKMapViewDelegate delegate methods which have an MKAnnotation as a parameter.
2. Allows you to enable and disable clustering anytime by just setting the clusteringEnabled property.
3. Does not support animations.
4. Provides a default cluster annotation view.
5. ADClusterMapView classes convert to ARC.

Quick start

1. Add the content of the ORMapView folder to your iOS project.
2. Link against the MapKit and CoreLocation frameworks if you don't already.
3. Turn your MKMapView instance into an ORMapView instance.
4. Look at the example project on how to use a custom MKAnnotationView subclass for displaying a ORClusterAnnotation on the map.