I've coded a small raytracer that renders a scene (based on Peter Shirley's tutorial, I just coded it in Swift). The raytracer itself works fine, outputs a PPM file which is correct. However, I was hoping to enclose this in a UI that will update the picture as each pixel value gets updated during the render. So to that end I made a MacOS app, with a basic model-view architecture. Here is my model: // // RGBViewModel.swift // rtweekend_gui // // import SwiftUI // RGB structure to hold color values struct RGB { var r: UInt8 var g: UInt8 var b: UInt8 } // ViewModel to handle the RGB array and updates class RGBViewModel: ObservableObject { // Define the dimensions of your 2D array let width = 1200 let height = 675 // Published property to trigger UI updates @Published var rgbArray: [[RGB]] init() { // Initialize with black pixels rgbArray = Array(repeating: Array(repeating: RGB(r: 0, g: 0, b: 0), count: width), count: height) } func render_scene() { for j in 0..<height { for i in 0..<width { // Generate a random color let r = UInt8.random(in: 0...255) let g = UInt8.random(in: 0...255) let b = UInt8.random(in: 0...255) // Update on the main thread since this affects the UI DispatchQueue.main.async { // Update the array self.rgbArray[j][i] = RGB(r: r, g: g, b: b) } } } } and here is my view: // // RGBArrayView.swift // rtweekend_gui // // import SwiftUI struct RGBArrayView: View { // The 2D array of RGB values @StateObject private var viewModel = RGBViewModel() // Control the size of each pixel private let pixelSize: CGFloat = 1 var body: some View { VStack { // Display the RGB array Canvas { context, size in for y in 0..<viewModel.rgbArray.count { for x in 0..<viewModel.rgbArray[y].count { let rgb = viewModel.rgbArray[y][x] let rect = CGRect( x: CGFloat(x) * pixelSize, y: CGFloat(y) * pixelSize, width: pixelSize, height: pixelSize ) context.fill( Path(rect), with: .color(Color( red: Double(rgb.r) / 255.0, green: Double(rgb.g) / 255.0, blue: Double(rgb.b) / 255.0 )) ) } } } .border(Color.gray) // Button to start filling the array Button("Render") { viewModel.render_scene() } .padding() } .padding() .frame(width: CGFloat(viewModel.width) * pixelSize + 40, height: CGFloat(viewModel.height) * pixelSize + 80) } } // Preview for SwiftUI struct RGBArrayView_Previews: PreviewProvider { static var previews: some View { RGBArrayView() } } The render does work and the image displays, however, I thought I set it up to show the image updating pixel by pixel and that doesn't happen, the image shows up all at once. What am I doing wrong?

I'm writing a simple app for iOS and I'd like to be able to do some text to speech in it. I have a basic audio manager class with a "speak" function: import Foundation import AVFoundation class AudioManager { static let shared = AudioManager() var audioPlayer: AVAudioPlayer? var isPlaying: Bool { return audioPlayer?.isPlaying ?? false } var playbackPosition: TimeInterval = 0 func playSound(named name: String) { guard let url = Bundle.main.url(forResource: name, withExtension: "mp3") else { print("Sound file not found") return } do { if audioPlayer == nil || !isPlaying { audioPlayer = try AVAudioPlayer(contentsOf: url) audioPlayer?.currentTime = playbackPosition audioPlayer?.prepareToPlay() audioPlayer?.play() } else { print("Sound is already playing") } } catch { print("Error playing sound: \(error.localizedDescription)") } } func stopSound() { if let player = audioPlayer { playbackPosition = player.currentTime player.stop() } } func speak(text: String) { let synthesizer = AVSpeechSynthesizer() let utterance = AVSpeechUtterance(string: text) utterance.voice = AVSpeechSynthesisVoice(language: "en-GB") synthesizer.speak(utterance) } } And my app shows text in a ScrollView: ScrollView { Text(self.description) .padding() .foregroundColor(.black) .font(.headline) .background(Color.gray.opacity(0)) }.onAppear { AudioManager.shared.speak(text: self.description) } However, the text doesn't get read out (in the simulator). I see some output in the console: Error fetching voices: Swift.DecodingError.dataCorrupted(Swift.DecodingError.Context(codingPath: [], debugDescription: "Invalid container metadata for _UnkeyedDecodingContainer, found keyedGraphEncodingNodeID", underlyingError: nil)). Using fallback voices. I'm probably doing something wrong here, but not sure what.