A bounding box implementation that can be initialized either with NE/SE or with an array of coordinates.

BoundingBox.swift

import CoreLocation

/**
A bounding box implementation that can be initialized either with NE/SE or with an array of coordinates.
*/
struct BoundingBox {
    let ne: CLLocationCoordinate2D
    let sw: CLLocationCoordinate2D
    let center: CLLocationCoordinate2D
    let latitudeSpread: CLLocationDegrees
    let longitudeSpread: CLLocationDegrees
    
    init(ne: CLLocationCoordinate2D, sw: CLLocationCoordinate2D) {
        self.ne = ne
        self.sw = sw
        
        latitudeSpread = ne.latitude - sw.latitude
        longitudeSpread = ne.longitude - sw.longitude
        
        center = CLLocationCoordinate2D(latitude: sw.latitude + latitudeSpread / 2,
                                        longitude: sw.longitude + longitudeSpread / 2)
    }
    
    init(coordinates: [CLLocationCoordinate2D]) {
        if coordinates.count == 0 {
            self.init(ne: CLLocationCoordinate2D(latitude: 0.0, longitude: 0.0),
                      sw: CLLocationCoordinate2D(latitude: 0.0, longitude: 0.0))
            return
        }
        
        if coordinates.count == 1 {
            self.init(ne: coordinates[0], sw: coordinates[0])
            return
        }
        
        var ne = CLLocationCoordinate2D(latitude: -.infinity, longitude: -.infinity)
        var sw = CLLocationCoordinate2D(latitude: .infinity, longitude: .infinity)
        
        for coordinate in coordinates {
            ne.latitude = max(ne.latitude, coordinate.latitude)
            ne.longitude = max(ne.longitude, coordinate.longitude)
            
            sw.latitude = min(sw.latitude, coordinate.latitude)
            sw.longitude = min(sw.longitude, coordinate.longitude)
        }
        
        self.init(ne: ne, sw: sw)
    }
}