Annotate intersecting roads and maneuver points along the current route

Example/ViewController.swift

@@ -573,6 +573,7 @@ class ViewController: UIViewController {
                                            completion: CompletionHandler? = nil) {
         navigationViewController.modalPresentationStyle = .fullScreen
         activeNavigationViewController = navigationViewController
+        activeNavigationViewController?.showIntersectionAnnotations = true
 
         present(navigationViewController, animated: true) {
             completion?()
@@ -591,6 +592,7 @@ class ViewController: UIViewController {
 
     func dismissActiveNavigationViewController() {
         activeNavigationViewController?.dismiss(animated: true) {
+            self.activeNavigationViewController?.showIntersectionAnnotations = false
             self.activeNavigationViewController = nil
         }
     }

MapboxNavigation.xcodeproj/project.pbxproj

@@ -485,6 +485,10 @@
 		E2DAFABA27BCF3C200BA12BD /* RoutesCoordinator.swift in Sources */ = {isa = PBXBuildFile; fileRef = E2DAFAB927BCF3C200BA12BD /* RoutesCoordinator.swift */; };
 		E2F08C70269DB17C002EFDC5 /* AccessToken.swift in Sources */ = {isa = PBXBuildFile; fileRef = E2F08C6F269DB17C002EFDC5 /* AccessToken.swift */; };
 		F46FF187260277F7007CC0E0 /* DateComponentsFormatter+NavigationAdditions.swift in Sources */ = {isa = PBXBuildFile; fileRef = F46FF186260277F7007CC0E0 /* DateComponentsFormatter+NavigationAdditions.swift */; };
+		F43EE329261F98DC0039D56F /* NavigationMapView+RoadAnnotations.swift in Sources */ = {isa = PBXBuildFile; fileRef = F43EE328261F98DC0039D56F /* NavigationMapView+RoadAnnotations.swift */; };
+		F43EE32A261F98DC0039D56F /* NavigationMapView+RoadAnnotations.swift in Sources */ = {isa = PBXBuildFile; fileRef = F43EE328261F98DC0039D56F /* NavigationMapView+RoadAnnotations.swift */; };
+		F488A0BE26261C4600A4CC8C /* NavigationMapView+IntersectionAnnotations.swift in Sources */ = {isa = PBXBuildFile; fileRef = F488A0BD26261C4600A4CC8C /* NavigationMapView+IntersectionAnnotations.swift */; };
+		F488A0C826261D8100A4CC8C /* ElectronicHorizon.swift in Sources */ = {isa = PBXBuildFile; fileRef = F488A0C726261D8100A4CC8C /* ElectronicHorizon.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -1139,6 +1143,9 @@
 		E2DAFAB927BCF3C200BA12BD /* RoutesCoordinator.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = RoutesCoordinator.swift; sourceTree = "<group>"; };
 		E2F08C6F269DB17C002EFDC5 /* AccessToken.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = AccessToken.swift; sourceTree = "<group>"; };
 		F46FF186260277F7007CC0E0 /* DateComponentsFormatter+NavigationAdditions.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "DateComponentsFormatter+NavigationAdditions.swift"; sourceTree = "<group>"; };
+		F43EE328261F98DC0039D56F /* NavigationMapView+RoadAnnotations.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "NavigationMapView+RoadAnnotations.swift"; sourceTree = "<group>"; };
+		F488A0BD26261C4600A4CC8C /* NavigationMapView+IntersectionAnnotations.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "NavigationMapView+IntersectionAnnotations.swift"; sourceTree = "<group>"; };
+		F488A0C726261D8100A4CC8C /* ElectronicHorizon.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ElectronicHorizon.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -1868,6 +1875,8 @@
 				8A11FEEF27A3514C00285B6F /* CPRouteChoice.swift */,
 				8AD220AA27C091EE000734A5 /* Solar.swift */,
 				8AD220AE27C09544000734A5 /* Date.swift */,
+				F488A0BD26261C4600A4CC8C /* NavigationMapView+IntersectionAnnotations.swift */,
+				F488A0C726261D8100A4CC8C /* ElectronicHorizon.swift */,
 			);
 			name = Extensions;
 			sourceTree = "<group>";
@@ -2712,6 +2721,7 @@
 				8AD2210F27C434CD000734A5 /* TitleLabel.swift in Sources */,
 				8A50A3CB26EC09FB00894A8E /* FeedbackSubtypeCollectionViewCell.swift in Sources */,
 				8A50A3D326EC0AE100894A8E /* IdleTimerManager.swift in Sources */,
+				F488A0C826261D8100A4CC8C /* ElectronicHorizon.swift in Sources */,
 				8D5DFFF1207C04840093765A /* NSAttributedString.swift in Sources */,
 				8AD2211F27C43D11000734A5 /* FloatingButton.swift in Sources */,
 				8A2081CB25E07CED00F9B8A6 /* NavigationMapViewIdentifiers.swift in Sources */,
@@ -2745,6 +2755,7 @@
 				2EBF20AE25D6F89000DB7BF2 /* Utils.swift in Sources */,
 				160D8279205996DA00D278D6 /* DataCache.swift in Sources */,
 				351BEBF21E5BCC63006FE110 /* Style.swift in Sources */,
+				F488A0BE26261C4600A4CC8C /* NavigationMapView+IntersectionAnnotations.swift in Sources */,
 				43FB386923A202420064481E /* Route.swift in Sources */,
 				3EA937B1F4DF73EB004BA6BE /* InstructionPresenter.swift in Sources */,
 				5A1C075824BDEB44000A6330 /* PassiveLocationProvider.swift in Sources */,

Sources/MapboxCoreNavigation/CoreConstants.swift

@@ -483,6 +483,8 @@ extension RoadGraph {
         /**
          A key in the user info dictionary of a `Notification.Name.electronicHorizonDidEnterRoadObject` or `Notification.Name.electronicHorizonDidExitRoadObject` notification. The corresponding value is a `RoadObject.Identifier` identifying the road object that the user entered or exited. */
         public static let roadObjectIdentifierKey: NotificationUserInfoKey = .init(rawValue: "roadObjectIdentifier")
+
+        public static let roadGraphIdentifierKey: NotificationUserInfoKey = .init(rawValue: "roadGraph")
 
         /**
          A key in the user info dictionary of a `Notification.Name.electronicHorizonDidEnterRoadObject` or `Notification.Name.electronicHorizonDidExitRoadObject` notification. The corresponding value is an `NSNumber` containing a Boolean value set to `true` if the user entered at the beginning or exited at the end of the road object, or `false` if they entered or exited somewhere along the road object. */

Sources/MapboxCoreNavigation/CoreNavigationNavigator.swift

@@ -313,6 +313,7 @@ class NavigatorElectronicHorizonObserver: ElectronicHorizonObserver {
             .treeKey: RoadGraph.Edge(position.tree().start),
             .updatesMostProbablePathKey: position.type() == .update,
             .distancesByRoadObjectKey: distances.map(DistancedRoadObject.init),
+            .roadGraphIdentifierKey: Navigator.shared.roadGraph,
         ]
         NotificationCenter.default.post(name: .electronicHorizonDidUpdatePosition, object: nil, userInfo: userInfo)
     }

Sources/MapboxNavigation/DayStyle.swift

@@ -172,6 +172,7 @@ open class DayStyle: Style {
         NavigationMapView.appearance().routeDurationAnnotationFontNames = UIFont.defaultNavigationSymbolLayerFontNames
         NavigationMapView.appearance().routeDurationAnnotationTextColor = #colorLiteral(red: 0.09803921569, green: 0.09803921569, blue: 0.09803921569, alpha: 1)
         NavigationMapView.appearance().routeDurationAnnotationSelectedTextColor = #colorLiteral(red: 1, green: 1, blue: 1, alpha: 1)
+        NavigationMapView.appearance().intersectionAnnotationFontNames = ["DIN Pro Medium", "Noto Sans CJK JP Medium", "Arial Unicode MS Regular"]
         NavigationView.appearance().backgroundColor = #colorLiteral(red: 0.764706, green: 0.752941, blue: 0.733333, alpha: 1)
         NextBannerView.appearance().backgroundColor = #colorLiteral(red: 0.9675388083, green: 0.9675388083, blue: 0.9675388083, alpha: 1)
         NextBannerView.appearance(whenContainedInInstancesOf:[InstructionsCardContainerView.self]).backgroundColor = #colorLiteral(red: 0.9675388083, green: 0.9675388083, blue: 0.9675388083, alpha: 1)

Sources/MapboxNavigation/ElectronicHorizon.swift

@@ -0,0 +1,38 @@
+import MapboxCoreNavigation
+
+extension RoadGraph.Edge {
+    var mpp: [RoadGraph.Edge]? {
+
+        guard level == 0 else { return nil }
+
+        var mostProbablePath = [self]
+
+        for child in outletEdges {
+            if let childMPP = child.mpp {
+                mostProbablePath.append(contentsOf: childMPP)
+            }
+        }
+
+        return mostProbablePath
+    }
+
+    func edgeNames(roadGraph: RoadGraph) -> [String] {
+        guard let metadata = roadGraph.edgeMetadata(edgeIdentifier: identifier) else {
+            return []
+        }
+        let names = metadata.names.map { name -> String in
+            switch name {
+            case .name(let name):
+                return name
+            case .code(let code):
+                return "(\(code))"
+            }
+        }
+
+        // If the road is unnamed, fall back to the road class.
+        if names.isEmpty {
+            return ["\(metadata.mapboxStreetsRoadClass.rawValue)"]
+        }
+        return names
+    }
+}

Sources/MapboxNavigation/NavigationMapView+IntersectionAnnotations.swift

@@ -0,0 +1,133 @@
+import CoreLocation
+import UIKit
+import MapboxDirections
+import MapboxCoreNavigation
+import Turf
+import MapboxMaps
+
+extension NavigationMapView {
+
+    struct EdgeIntersection {
+        var root: RoadGraph.Edge
+        var branch: RoadGraph.Edge
+        var rootMetadata: RoadGraph.Edge.Metadata
+        var rootShape: LineString
+        var branchMetadata: RoadGraph.Edge.Metadata
+        var branchShape: LineString
+
+        var coordinate: CLLocationCoordinate2D? {
+            rootShape.coordinates.first
+        }
+
+        var annotationPoint: CLLocationCoordinate2D? {
+            guard let length = branchShape.distance() else { return nil }
+            let targetDistance = min(length / 2, Double.random(in: 15...30))
+            guard let annotationPoint = branchShape.coordinateFromStart(distance: targetDistance) else { return nil }
+            return annotationPoint
+        }
+
+        var wayName: String? {
+            guard let roadName = rootMetadata.names.first else { return nil }
+
+            switch roadName {
+            case .name(let name):
+                return name
+            case .code(let code):
+                return "(\(code))"
+            }
+        }
+        var intersectingWayName: String? {
+            guard let roadName = branchMetadata.names.first else { return nil }
+
+            switch roadName {
+            case .name(let name):
+                return name
+            case .code(let code):
+                return "(\(code))"
+            }
+        }
+
+        var incidentAngle: CLLocationDegrees {
+            return (branchMetadata.heading - rootMetadata.heading).wrap(min: 0, max: 360)
+        }
+
+        var description: String {
+            return "EdgeIntersection: root: \(wayName ?? "") intersection: \(intersectingWayName ?? "") coordinate: \(String(describing: coordinate))"
+        }
+    }
+
+    enum AnnotationTailPosition: Int {
+        case left
+        case right
+        case center
+    }
+
+    class AnnotationCacheEntry: Equatable, Hashable {
+        var wayname: String
+        var coordinate: CLLocationCoordinate2D
+        var intersection: EdgeIntersection?
+        var feature: Feature
+        var lastAccessTime: Date
+
+        init(coordinate: CLLocationCoordinate2D, wayname: String, intersection: EdgeIntersection? = nil, feature: Feature) {
+            self.wayname = wayname
+            self.coordinate = coordinate
+            self.intersection = intersection
+            self.feature = feature
+            self.lastAccessTime = Date()
+        }
+
+        static func == (lhs: AnnotationCacheEntry, rhs: AnnotationCacheEntry) -> Bool {
+            return lhs.wayname == rhs.wayname
+        }
+
+        func hash(into hasher: inout Hasher) {
+            hasher.combine(wayname.hashValue)
+        }
+    }
+
+    class AnnotationCache {
+        private let maxEntryAge = TimeInterval(30)
+        var entries = Set<AnnotationCacheEntry>()
+        var cachePruningTimer: Timer?
+
+        init() {
+            // periodically prune the cache to remove entries that have been passed already
+            cachePruningTimer = Timer.scheduledTimer(withTimeInterval: 15, repeats: true, block: { [weak self] _ in
+                self?.prune()
+            })
+        }
+
+        deinit {
+            cachePruningTimer?.invalidate()
+            cachePruningTimer = nil
+        }
+
+        func setValue(feature: Feature, coordinate: CLLocationCoordinate2D, intersection: EdgeIntersection?, for wayname: String) {
+            entries.insert(AnnotationCacheEntry(coordinate: coordinate, wayname: wayname, intersection: intersection, feature: feature))
+        }
+
+        func value(for wayname: String) -> AnnotationCacheEntry? {
+            let matchingEntry = entries.first { entry -> Bool in
+                entry.wayname == wayname
+            }
+
+            if let matchingEntry = matchingEntry {
+                // update the timestamp used for pruning the cache
+                matchingEntry.lastAccessTime = Date()
+            }
+
+            return matchingEntry
+        }
+
+        private func prune() {
+            let now = Date()
+
+            entries.filter { now.timeIntervalSince($0.lastAccessTime) > maxEntryAge }.forEach { remove($0) }
+        }
+
+        public func remove(_ entry: AnnotationCacheEntry) {
+            entries.remove(entry)
+        }
+    }
+}