Added BoundingBox.position(of:) - position of a coordinate in relation to a bounding box

Author: trasch

Sources/GISTools/Algorithms/BoundingBoxPosition.swift

@@ -0,0 +1,83 @@
+#if !os(Linux)
+import CoreLocation
+#endif
+import Foundation
+
+extension BoundingBox {
+
+    /// Position of a coordinate in relation to a bounding box.
+    public struct CoordinatePosition: OptionSet, Sendable {
+        public let rawValue: Int
+
+        public init(rawValue: Int) {
+            self.rawValue = rawValue
+        }
+
+        public static let center = CoordinatePosition(rawValue: 1 << 0)
+        public static let top = CoordinatePosition(rawValue: 1 << 1)
+        public static let right = CoordinatePosition(rawValue: 1 << 2)
+        public static let bottom = CoordinatePosition(rawValue: 1 << 3)
+        public static let left = CoordinatePosition(rawValue: 1 << 4)
+        public static let outside = CoordinatePosition(rawValue: 1 << 5)
+    }
+
+    /// Returns the relative position of a coordinate with regards to the bounding box.
+    public func position(of coordinate: Coordinate3D) -> CoordinatePosition {
+        var position: CoordinatePosition = []
+
+        if !contains(coordinate) {
+            position.insert(.outside)
+        }
+
+        let latitudeSpan = northEast.latitude - southWest.latitude
+        let longitudeSpan = northEast.longitude - southWest.longitude
+
+        let topCutoff = southWest.latitude + (latitudeSpan * 0.65)
+        if coordinate.latitude > topCutoff {
+            position.insert(.top)
+        }
+
+        let rightCutoff = southWest.longitude + (longitudeSpan * 0.65)
+        if coordinate.longitude > rightCutoff {
+            position.insert(.right)
+        }
+
+        let bottomCutoff = southWest.latitude + (latitudeSpan * 0.35)
+        if coordinate.latitude < bottomCutoff {
+            position.insert(.bottom)
+        }
+
+        let leftCutoff = southWest.longitude + (longitudeSpan * 0.35)
+        if coordinate.longitude < leftCutoff {
+            position.insert(.left)
+        }
+
+        if position.isEmpty {
+            position.insert(.center)
+        }
+
+        return position
+    }
+
+    /// Returns the relative position of a point with regards to the bounding box.
+    public func postion(of point: Point) -> CoordinatePosition {
+        position(of: point.coordinate)
+    }
+
+    // MARK: - CoreLocation compatibility
+
+#if !os(Linux)
+
+    /// Returns the relative position of a coordinate with regards to the bounding box.
+    public func postion(of coordinate: CLLocationCoordinate2D) -> CoordinatePosition {
+        position(of: Coordinate3D(coordinate))
+    }
+
+    /// Returns the relative position of a location with regards to the bounding box.
+    public func postion(of coordinate: CLLocation) -> CoordinatePosition {
+        position(of: Coordinate3D(coordinate))
+    }
+
+#endif
+
+}