Initial commit for first version of project

GasTankAR/Views/TankAR/PhotoEncoder.swift

@@ -0,0 +1,107 @@
+//
+//  PhotoEncoder.swift
+//  GasTankAR
+//
+//  Created by Dennis Nemec on 28.08.26.
+//
+
+import ImageIO
+import UniformTypeIdentifiers
+import CoreLocation
+import UIKit
+
+/// Kodiert einen Snapshot als JPEG und bettet dabei EXIF-Aufnahmezeit sowie – falls vorhanden –
+/// GPS-Metadaten direkt in die Bilddatei ein (ImageIO). So tragen auch exportierte Bilder ihren
+/// Aufnahmeort mit sich.
+enum PhotoEncoder {
+    /// Erzeugt JPEG-Daten mit eingebetteten Metadaten. Fällt bei Fehlern auf `UIImage.jpegData` zurück.
+    static func jpegData(
+        from image: UIImage,
+        coordinate: CLLocationCoordinate2D?,
+        date: Date,
+        compressionQuality: CGFloat = 0.9
+    ) -> Data? {
+        guard let cgImage = image.cgImage else {
+            return image.jpegData(compressionQuality: compressionQuality)
+        }
+
+        let output = NSMutableData()
+        guard let destination = CGImageDestinationCreateWithData(
+            output, UTType.jpeg.identifier as CFString, 1, nil
+        ) else {
+            return image.jpegData(compressionQuality: compressionQuality)
+        }
+
+        var properties: [CFString: Any] = [
+            kCGImageDestinationLossyCompressionQuality: compressionQuality,
+            kCGImagePropertyOrientation: CGImagePropertyOrientation(image.imageOrientation).rawValue,
+            kCGImagePropertyExifDictionary: [
+                kCGImagePropertyExifDateTimeOriginal: Self.exifDateFormatter.string(from: date),
+                kCGImagePropertyExifDateTimeDigitized: Self.exifDateFormatter.string(from: date),
+            ],
+        ]
+
+        if let coordinate {
+            properties[kCGImagePropertyGPSDictionary] = gpsProperties(for: coordinate, date: date)
+        }
+
+        CGImageDestinationAddImage(destination, cgImage, properties as CFDictionary)
+        guard CGImageDestinationFinalize(destination) else {
+            return image.jpegData(compressionQuality: compressionQuality)
+        }
+        return output as Data
+    }
+
+    private static func gpsProperties(for coordinate: CLLocationCoordinate2D, date: Date) -> [CFString: Any] {
+        [
+            kCGImagePropertyGPSLatitude: abs(coordinate.latitude),
+            kCGImagePropertyGPSLatitudeRef: coordinate.latitude >= 0 ? "N" : "S",
+            kCGImagePropertyGPSLongitude: abs(coordinate.longitude),
+            kCGImagePropertyGPSLongitudeRef: coordinate.longitude >= 0 ? "E" : "W",
+            kCGImagePropertyGPSDateStamp: Self.gpsDateFormatter.string(from: date),
+            kCGImagePropertyGPSTimeStamp: Self.gpsTimeFormatter.string(from: date),
+        ]
+    }
+
+    /// EXIF-Zeitstempel in lokaler Zeit („yyyy:MM:dd HH:mm:ss").
+    private static let exifDateFormatter: DateFormatter = {
+        let formatter = DateFormatter()
+        formatter.locale = Locale(identifier: "en_US_POSIX")
+        formatter.dateFormat = "yyyy:MM:dd HH:mm:ss"
+        return formatter
+    }()
+
+    /// GPS-Datum in UTC („yyyy:MM:dd").
+    private static let gpsDateFormatter: DateFormatter = {
+        let formatter = DateFormatter()
+        formatter.locale = Locale(identifier: "en_US_POSIX")
+        formatter.timeZone = TimeZone(identifier: "UTC")
+        formatter.dateFormat = "yyyy:MM:dd"
+        return formatter
+    }()
+
+    /// GPS-Uhrzeit in UTC („HH:mm:ss").
+    private static let gpsTimeFormatter: DateFormatter = {
+        let formatter = DateFormatter()
+        formatter.locale = Locale(identifier: "en_US_POSIX")
+        formatter.timeZone = TimeZone(identifier: "UTC")
+        formatter.dateFormat = "HH:mm:ss"
+        return formatter
+    }()
+}
+
+private extension CGImagePropertyOrientation {
+    init(_ orientation: UIImage.Orientation) {
+        switch orientation {
+        case .up: self = .up
+        case .down: self = .down
+        case .left: self = .left
+        case .right: self = .right
+        case .upMirrored: self = .upMirrored
+        case .downMirrored: self = .downMirrored
+        case .leftMirrored: self = .leftMirrored
+        case .rightMirrored: self = .rightMirrored
+        @unknown default: self = .up
+        }
+    }
+}