I use xcode16 and swiftUI for programming on a macos15 system. There is a problem. When I render a picture through mtkview, it is normal when displayed on a regular view. However, when the view is displayed through the .sheet method, the image cannot be displayed. There is no error message from xcode.
import Foundation
import MetalKit
import SwiftUI
struct CIImageDisplayView: NSViewRepresentable {
typealias NSViewType = MTKView
var ciImage: CIImage
init(ciImage: CIImage) {
self.ciImage = ciImage
}
func makeNSView(context: Context) -> MTKView {
let view = MTKView()
view.delegate = context.coordinator
view.preferredFramesPerSecond = 60
view.enableSetNeedsDisplay = true
view.isPaused = true
view.framebufferOnly = false
if let defaultDevice = MTLCreateSystemDefaultDevice() {
view.device = defaultDevice
}
view.delegate = context.coordinator
return view
}
func updateNSView(_ nsView: MTKView, context: Context) {
}
func makeCoordinator() -> RawDisplayRender {
RawDisplayRender(ciImage: self.ciImage)
}
class RawDisplayRender: NSObject, MTKViewDelegate {
// MARK: Metal resources
var device: MTLDevice!
var commandQueue: MTLCommandQueue!
// MARK: Core Image resources
var context: CIContext!
var ciImage: CIImage
init(ciImage: CIImage) {
self.ciImage = ciImage
self.device = MTLCreateSystemDefaultDevice()
self.commandQueue = self.device.makeCommandQueue()
self.context = CIContext(mtlDevice: self.device)
}
func mtkView(_ view: MTKView, drawableSizeWillChange size: CGSize) {}
func draw(in view: MTKView) {
guard let currentDrawable = view.currentDrawable,
let commandBuffer = commandQueue.makeCommandBuffer()
else {
return
}
let dSize = view.drawableSize
let drawImage = self.ciImage
let destination = CIRenderDestination(width: Int(dSize.width),
height: Int(dSize.height),
pixelFormat: view.colorPixelFormat,
commandBuffer: commandBuffer,
mtlTextureProvider: { () -> MTLTexture in
return currentDrawable.texture
})
_ = try? self.context.startTask(toClear: destination)
_ = try? self.context.startTask(toRender: drawImage, from: drawImage.extent,
to: destination, at: CGPoint(x: (dSize.width - drawImage.extent.width) / 2, y: 0))
commandBuffer.present(currentDrawable)
commandBuffer.commit()
}
}
}
struct ShowCIImageView: View {
let cii = CIImage.init(contentsOf: Bundle.main.url(forResource: "9-10", withExtension: "jpg")!)!
var body: some View {
CIImageDisplayView.init(ciImage: cii).frame(width: 500, height: 500).background(.red)
}
}
struct ContentView: View {
@State var showImage = false
var body: some View {
VStack {
Image(systemName: "globe")
.imageScale(.large)
.foregroundStyle(.tint)
Text("Hello, world!")
ShowCIImageView()
Button {
showImage = true
} label: {
Text("showImage")
}
}
.frame(width: 800, height: 800)
.padding()
.sheet(isPresented: $showImage) {
ShowCIImageView()
}
}
}
As mentioned elsewhere, this appears to be a constraint on the .sheet View modifier.
In particular, .sheet is expected to work with an NSViewControllerRepresentable i.e. a wrapped NSViewController, instead of an NSViewRepresentable (wrapped NSView). See https://developer.apple.com/documentation/swiftui/nsviewcontrollerrepresentable. See https://developer.apple.com/documentation/swiftui/nsviewrepresentable.
The .sheet presents whatever content the NSViewControllerRepresentable renders.
That said, to present your image in a .sheet you will need to create an NSViewControllerRepresentable with an MTKView that renders the image.