DrawableQueue.swift

import SwiftUI
import RealityKit
import AVFoundation
import MetalKit

struct ImmersiveView: View {
    @State var textureResource: TextureResource?
    
    var body: some View {
        RealityView { content in
            // 🎬 Create video sphere ✅
            let player = AVPlayer(url: Bundle.main.url(forResource: "gorillaz-short", withExtension: "mov")!)
            player.isMuted = true
            player.play()
            
            let videoMaterial = VideoMaterial(avPlayer: player)
            let sphere1 = ModelEntity(mesh: .generateSphere(radius: 0.4), materials: [videoMaterial])
            sphere1.position = [0.5, 1.3, -1.5]
            content.add(sphere1)
            
            // 🔗 Create an image sphere based on DrawableQueue ❌
            var material = UnlitMaterial()
            let textureResource = try! TextureResource.generate(from: UIImage(named: "gorillaz.jpg")!.cgImage!, options: .init(semantic: .color))
            material.color = .init(texture: .init(textureResource))
            
            self.textureResource = textureResource
            
            let sphere2 = ModelEntity(mesh: .generateSphere(radius: 0.4), materials: [material])
            sphere2.position = [-0.5, 1.3, -1.5]
            content.add(sphere2)
        }
        .onAppear {
            DispatchQueue.main.asyncAfter(deadline: .now() + .seconds(2)) {
                let drawableQueue = try! TextureResource.DrawableQueue(.init(pixelFormat: .rgba8Unorm, width: 3840, height: 2048, usage: [.renderTarget, .shaderRead], mipmapsMode: .none))
                
                self.textureResource!.replace(withDrawables: drawableQueue)
                
                let device = MTLCreateSystemDefaultDevice()!
                let commandQueue = device.makeCommandQueue()!
                
                let textureLoader = MTKTextureLoader(device: device)
                let url = Bundle.main.url(forResource: "gorillaz", withExtension: "jpg")!
                let texture: MTLTexture = try! textureLoader.newTexture(URL: url, options: nil)
                
                let drawable = try! drawableQueue.nextDrawable()
                
                let commandBuffer = commandQueue.makeCommandBuffer()!
                let blitCommandEncoder = commandBuffer.makeBlitCommandEncoder()!
                
                blitCommandEncoder.copy(from: texture, to: drawable.texture)
                blitCommandEncoder.endEncoding()
                commandBuffer.commit()
                commandBuffer.waitUntilCompleted()
                
                drawable.present()
            }
        }
    }
}