nicklockwood

//
//  ARC Helper
//
//  Version 2.2
//
//  Created by Nick Lockwood on 05/01/2012.
//  Copyright 2012 Charcoal Design
//
//  Distributed under the permissive zlib license
//  Get the latest version from here:

andrewgleave

MKMapRect zoomRect = MKMapRectNull;
for (id <MKAnnotation> annotation in mapView.annotations) {
    MKMapPoint annotationPoint = MKMapPointForCoordinate(annotation.coordinate);
    MKMapRect pointRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0, 0);
    if (MKMapRectIsNull(zoomRect)) {
        zoomRect = pointRect;
    } else {
        zoomRect = MKMapRectUnion(zoomRect, pointRect);
    }
}