Добавление пользовательского наложения в виде карты

Question

Я новичок в iOS, и моя цель - добавить пользовательский оверлей в виде карты с помощью Swift 3 и MapKit. Я следил за этим Add inverted circle overlay to map view. Вот код:

import UIKit 
import MapKit 

class MyMapOverlayRenderer: MKOverlayRenderer { 

let diameter: Double 
let fillColor: UIColor 

init(overlay: MKOverlay, diameter: Double, fillColor: UIColor) { 

    self.diameter = diameter 
    self.fillColor = fillColor 
    super.init(overlay: overlay) 

} 

override func draw(_ mapRect: MKMapRect, zoomScale: MKZoomScale, in context: CGContext) { 

    let path = UIBezierPath(rect: CGRect(x: mapRect.origin.x, y: mapRect.origin.y, width: mapRect.size.width, height: mapRect.size.height)) 
    path.usesEvenOddFillRule = true 
    let radiusInMapPoints = diameter * MKMapPointsPerMeterAtLatitude(self.overlay.coordinate.latitude) 
    let radiusSquared = MKMapSize(width: radiusInMapPoints, height: radiusInMapPoints) 
    let regionOrigin = MKMapPointForCoordinate(self.overlay.coordinate) 
    var regionRect = MKMapRect(origin: regionOrigin, size: radiusSquared) 
    regionRect = MKMapRectOffset(regionRect, -radiusInMapPoints/2, -radiusInMapPoints/2) 
    regionRect = MKMapRectIntersection(regionRect, MKMapRectWorld) 

    let cornerRadius = CGFloat(regionRect.size.width/Double(2)) 

    let excludePath = UIBezierPath(roundedRect: CGRect(x: regionRect.origin.x, y: regionRect.origin.y, width: regionRect.size.width, height: regionRect.size.height), cornerRadius: cornerRadius) 
    path.append(excludePath) 


    context.setFillColor(fillColor.cgColor) 
    context.addPath(path.cgPath) 
    context.fillPath() 

} 
} 

В конце концов, наложение показан без исключения пути (круг), любые предложения?

Answer 1

решаемая, просто добавил реверсирования():

path.append(excludePath.reversing()) 

Полный код функции:

override func draw(_ mapRect: MKMapRect, zoomScale: MKZoomScale, in context: CGContext) { 

    let path = UIBezierPath(rect: CGRect(x: mapRect.origin.x, y: mapRect.origin.y, width: mapRect.size.width, height: mapRect.size.height)) 
    path.usesEvenOddFillRule = true 
    let radiusInMapPoints = diameter * MKMapPointsPerMeterAtLatitude(MKMapPointsPerMeterAtLatitude(overlay.coordinate.latitude)) 

    let radiusSquared = MKMapSize(width: radiusInMapPoints, height: radiusInMapPoints) 

    let regionOrigin = MKMapPointForCoordinate(overlay.coordinate) 

    var regionRect = MKMapRect(origin: regionOrigin, size: radiusSquared) 

    regionRect = MKMapRectOffset(regionRect, -radiusInMapPoints/2, -radiusInMapPoints/2) 
    regionRect = MKMapRectIntersection(regionRect, MKMapRectWorld) 

    let midX = (regionOrigin.x + regionRect.origin.x)/2 
    let midY = (regionOrigin.y + regionRect.origin.y)/2 

    let cornerRadius = CGFloat(regionRect.size.width/Double(2)) 
    let excludePath = UIBezierPath(roundedRect: CGRect(x: midX, y: midY, width: regionRect.size.width/2, height: regionRect.size.height/2), cornerRadius: cornerRadius) 

    path.append(excludePath.reversing()) 

    context.setFillColor(fillColor.cgColor) 
    context.addPath(path.cgPath) 
    context.fillPath() 

}