replace annotations with visible rect

Author: Achyut Kumar M

GoInfoGame/GoInfoGame/UI/Map/CustomMap.swift

@@ -37,6 +37,8 @@ struct CustomMap: UIViewRepresentable {
     @Binding var useBingMaps: Bool 
 
     @Binding var tappedCoordinate: CLLocationCoordinate2D?
+    
+    var shadowOverlay: ShadowOverlay
 
     // Creates and configures the UIView
     func makeUIView(context: Context) -> MKMapView {
@@ -84,13 +86,9 @@ struct CustomMap: UIViewRepresentable {
 
         // Remove existing overlays
         mapView.overlays.forEach { mapView.removeOverlay($0) }
-                
-        // Add shadow overlay with rectangular cutouts
-        if mapView.overlays.first(where: { $0 is ShadowOverlay }) == nil {
-               let overlay = ShadowOverlay(annotations: mapView.annotations)
-               mapView.addOverlay(overlay)
-           }
-                
+        
+        mapView.addOverlay(shadowOverlay)
+
 
            // Re-add overlays based on selection
            if useBingMaps {
@@ -126,7 +124,7 @@ struct CustomMap: UIViewRepresentable {
 
     // Creates the coordinator
     func makeCoordinator() -> Coordinator {
-        Coordinator(self)
+        Coordinator(self, shadowOverlay: shadowOverlay)
     }
 
     // Coordinator class for managing delegate methods
@@ -139,12 +137,15 @@ struct CustomMap: UIViewRepresentable {
         var currentAnnotation: DisplayUnitAnnotation?
         var mapView: MKMapView?
 
+        let shadowOverlay: ShadowOverlay
+        
         private let maxZoomAltitude: CLLocationDistance = 100
         private var zoomReachedLimit: Bool = false
 
-        init(_ parent: CustomMap) {
+        init(_ parent: CustomMap, shadowOverlay: ShadowOverlay) {
             self.parent = parent
             self.contextualInfo = parent.contextualInfo
+            self.shadowOverlay = shadowOverlay
         }
 
         @objc func handleMapTap(_ gestureRecognizer: UITapGestureRecognizer) {
@@ -181,6 +182,16 @@ struct CustomMap: UIViewRepresentable {
                   mapView.setRegion(newRegion, animated: true)
               }
 
+        func mapViewDidFinishRenderingMap(_ mapView: MKMapView, fullyRendered: Bool) {
+            guard fullyRendered else { return }
+            
+            if shadowOverlay.visibleRects.isEmpty {
+                shadowOverlay.addVisibleRect(mapView.visibleMapRect)
+                mapView.removeOverlay(shadowOverlay)
+                mapView.addOverlay(shadowOverlay)
+            }
+        }
+        
         //renders polyline
         func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
             if let routePolyline = overlay as? MKPolyline {

GoInfoGame/GoInfoGame/UI/Map/MapView.swift

@@ -51,6 +51,8 @@ struct MapView: View {
     @State private var showManageQuestSheet = false
 
     @State private var showZoomInAlert = false
+    
+    @State private var shadowOverlay = ShadowOverlay()
 
     var body: some View {
         NavigationStack {
@@ -79,7 +81,7 @@ struct MapView: View {
                 print(contextualInfo)
                 selectedDetent = .fraction(0.8)
                 self.setContextualInfo(contextualinfo: contextualInfo)
-            }, useBingMaps: $useBingMaps, tappedCoordinate: $tappedCoordinate)
+                }, useBingMaps: $useBingMaps, tappedCoordinate: $tappedCoordinate, shadowOverlay: shadowOverlay)
             .onChange(of: tappedCoordinate) { _ in
                 showMapLongPressedSheet = tappedCoordinate != nil
             }
@@ -237,6 +239,9 @@ struct MapView: View {
                                    return
                                }
                             viewModel.fetchOSMDataFor(from: .visibleRect(mapView: mapView))
+                            let rect = mapView.visibleMapRect
+                            let extendedVisibleRect = rect.insetBy(dx: -rect.size.width * 0.25, dy: -rect.size.height * 0.25)
+                            shadowOverlay.addVisibleRect(extendedVisibleRect)
 
                         }
                     }

GoInfoGame/GoInfoGame/UI/Map/ShadowOverlayRenderer.swift

@@ -20,47 +20,29 @@ class ShadowOverlayRenderer: MKOverlayRenderer {
         context.setBlendMode(.clear)
         context.setAllowsAntialiasing(false)
         context.setShouldAntialias(false)
-
-        for mapRect in shadowOverlay.annotationRects {
-            let cutout = self.rect(for: mapRect).integral
+        
+        for rect in shadowOverlay.visibleRects {
+            let cutout = self.rect(for: rect).integral
             context.fill(cutout)
         }
-
+        
         context.setBlendMode(.normal)
     }
+    
+    func addVisibleRect(_ rect: MKMapRect) {
+           guard let shadowOverlay = overlay as? ShadowOverlay else { return }
+           shadowOverlay.addVisibleRect(rect)
+           setNeedsDisplay()
+       }
 }
 
 class ShadowOverlay: NSObject, MKOverlay {
     let coordinate: CLLocationCoordinate2D = CLLocationCoordinate2D(latitude: 0, longitude: 0)
     let boundingMapRect: MKMapRect = MKMapRect.world
-    let annotationRects: [MKMapRect]
-
-    init(annotations: [MKAnnotation]) {
-        self.annotationRects = annotations.map { annotation in
-            let center = MKMapPoint(annotation.coordinate)
-            let width = MKMapPointsPerMeterAtLatitude(annotation.coordinate.latitude) * 500 // 500m box
-            return MKMapRect(
-                origin: MKMapPoint(x: center.x - width / 2, y: center.y - width / 2),
-                size: MKMapSize(width: width, height: width)
-            )
-        }
-    }
-}
-
-
+    private(set) var visibleRects: [MKMapRect] = []
 
-extension MKCoordinateRegion {
-    func corners() -> [CLLocationCoordinate2D] {
-        let latMin = center.latitude - span.latitudeDelta / 2
-        let latMax = center.latitude + span.latitudeDelta / 2
-        let lonMin = center.longitude - span.longitudeDelta / 2
-        let lonMax = center.longitude + span.longitudeDelta / 2
-        return [
-            CLLocationCoordinate2D(latitude: latMin, longitude: lonMin),
-            CLLocationCoordinate2D(latitude: latMin, longitude: lonMax),
-            CLLocationCoordinate2D(latitude: latMax, longitude: lonMax),
-            CLLocationCoordinate2D(latitude: latMax, longitude: lonMin)
-        ]
+    func addVisibleRect(_ rect: MKMapRect) {
+        visibleRects.append(rect)
     }
 }