Foveated Streaming for visionOS

import SwiftUI
import FoveatedStreaming

// MARK: - App Entry Point

@main
struct FoveatedStreamingApp: App {
    @State private var session = FoveatedStreamingSession()

    var body: some Scene {
        // Control window: pause / resume the session
        WindowGroup("Controls", id: "controls") {
            ContentView(session: session)
        }

        // Immersive space that renders the streamed content
        ImmersiveSpace(id: "stream") {
            StreamImmersiveView(session: session)
        }
        .immersionStyle(selection: .constant(.progressive), in: .progressive)
    }
}

// MARK: - Control Window

struct ContentView: View {
    let session: FoveatedStreamingSession
    @State private var isConnected = false
    @Environment(\.openImmersiveSpace) private var openImmersiveSpace
    @Environment(\.dismissImmersiveSpace) private var dismissImmersiveSpace

    var body: some View {
        VStack(spacing: 20) {
            Text(isConnected ? "Streaming" : "Not Connected")
                .font(.title)

            Button(isConnected ? "Disconnect" : "Connect to PC") {
                Task {
                    if isConnected {
                        session.disconnect()
                        await dismissImmersiveSpace()
                        isConnected = false
                    } else {
                        // connect() presents native endpoint picker and QR pairing UI
                        try await session.connect()
                        await openImmersiveSpace(id: "stream")
                        isConnected = true
                    }
                }
            }
            .buttonStyle(.borderedProminent)

            if isConnected {
                Button("Send Level Select") {
                    // Message channels: send opaque data to the PC host
                    let command = ["action": "loadLevel", "level": "canyon_01"]
                    if let data = try? JSONSerialization.data(withJSONObject: command) {
                        session.defaultMessageChannel.send(data)
                    }
                }
            }
        }
        .padding()
    }
}

// MARK: - Immersive Space

struct StreamImmersiveView: View {
    let session: FoveatedStreamingSession

    var body: some View {
        // Passing the session to ImmersiveSpace renders the streamed OpenXR content.
        // RealityView content composites on top with correct depth occlusion.
        RealityView { content in
            // Add native RealityKit entities alongside the stream if needed
            let anchor = AnchorEntity(.head)
            content.add(anchor)
        }
        .foveatedStreamingSession(session)
    }
}