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GameKit Turn Based Matches Push Notifications
I'm developing a game that supports GameKit turn based matches. What I don't understand is this: Is tapping on the Game Center notification push messages the only way for the GKTurnBasedEventListener to trigger? What if someone misses the push message (swiping it away by accident or something like that) but still wants to join? Is there some inbox somewhere where the pending messages can be seen or fetched? Also it was mentioned in a very old WWDC video (from 2013, I think that's the latest with information about turn based matches) that the notification also includes a badge for the icon. However, I do not understand how to implement that. Is there any documentation for that?
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881
Jan ’26
Unable to find intelgpu_kbl_gt2r0 slice or a compatible one in binary archive
Unable to find intelgpu_kbl_gt2r0 slice or a compatible one in binary archive 'file:///System/Library/PrivateFrameworks/IconRendering.framework/Resources/binary.metallib' available slices: applegpu_g13g, applegpu_g13s, applegpu_g13d, applegpu_g14g, applegpu_g14s, applegpu_g14d, applegpu_g15g, applegpu_g15s, applegpu_g15d, applegpu_g16g, applegpu_g16s, applegpu_g17g, applegpu_g15g, applegpu_g15s, applegpu_g15d, applegpu_g16s Is it related to performance of applications in macOS 26.2 on Intel Macs?
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294
Feb ’26
Memory leak when no draw calls issued to encoder
I noticed that when the render command encoder adds no draw calls an apps memory usage seems to grow unboundedly. Using a super simple MTKView-based drawing with the following delegate (code at end). If I add the simplest of draw calls, e.g., a single vertex, the app's memory usage is normal, around 100-ish MBs. I am attaching a couple screenshot, one from Xcode and one from Instruments. What's going on here? Is this an illegal program? If yes, why does it not crash, such as if the encode or command buffer weren't ended. Or is there some race condition at play here due to the lack of draws? class Renderer: NSObject, MTKViewDelegate { var device: MTLDevice var commandQueue: MTL4CommandQueue var commandBuffer: MTL4CommandBuffer var allocator: MTL4CommandAllocator override init() { guard let d = MTLCreateSystemDefaultDevice(), let queue = d.makeMTL4CommandQueue(), let cmdBuffer = d.makeCommandBuffer(), let alloc = d.makeCommandAllocator() else { fatalError("unable to create metal 4 objects") } self.device = d self.commandQueue = queue self.commandBuffer = cmdBuffer self.allocator = alloc super.init() } func mtkView(_ view: MTKView, drawableSizeWillChange size: CGSize) {} func draw(in view: MTKView) { guard let drawable = view.currentDrawable else { return } commandBuffer.beginCommandBuffer(allocator: allocator) guard let descriptor = view.currentMTL4RenderPassDescriptor, let encoder = commandBuffer.makeRenderCommandEncoder( descriptor: descriptor ) else { fatalError("unable to create encoder") } encoder.endEncoding() commandBuffer.endCommandBuffer() commandQueue.waitForDrawable(drawable) commandQueue.commit([commandBuffer]) commandQueue.signalDrawable(drawable) drawable.present() } }
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Jan ’26
What good is NSBitmapFormatAlphaNonpremultiplied?
If I create a bitmap image and then try to get ready to draw into it, like so: NSBitmapImageRep* newRep = [[NSBitmapImageRep alloc] initWithBitmapDataPlanes: nullptr pixelsWide: 128 pixelsHigh: 128 bitsPerSample: 8 samplesPerPixel: 4 hasAlpha: YES isPlanar: NO colorSpaceName: NSDeviceRGBColorSpace bitmapFormat: NSBitmapFormatAlphaNonpremultiplied | NSBitmapFormatThirtyTwoBitBigEndian bytesPerRow: 4 * 128 bitsPerPixel: 32]; [NSGraphicsContext setCurrentContext: [NSGraphicsContext graphicsContextWithBitmapImageRep: newRep]]; then the log shows this error: CGBitmapContextCreate: unsupported parameter combination: RGB 8 bits/component, integer 512 bytes/row kCGImageAlphaLast kCGImageByteOrderDefault kCGImagePixelFormatPacked Valid parameters for RGB color space model are: 16 bits per pixel, 5 bits per component, kCGImageAlphaNoneSkipFirst 32 bits per pixel, 8 bits per component, kCGImageAlphaNoneSkipFirst 32 bits per pixel, 8 bits per component, kCGImageAlphaNoneSkipLast 32 bits per pixel, 8 bits per component, kCGImageAlphaPremultipliedFirst 32 bits per pixel, 8 bits per component, kCGImageAlphaPremultipliedLast 32 bits per pixel, 10 bits per component, kCGImageAlphaNone|kCGImagePixelFormatRGBCIF10|kCGImageByteOrder16Little 64 bits per pixel, 16 bits per component, kCGImageAlphaPremultipliedLast 64 bits per pixel, 16 bits per component, kCGImageAlphaNoneSkipLast 64 bits per pixel, 16 bits per component, kCGImageAlphaPremultipliedLast|kCGBitmapFloatComponents|kCGImageByteOrder16Little 64 bits per pixel, 16 bits per component, kCGImageAlphaNoneSkipLast|kCGBitmapFloatComponents|kCGImageByteOrder16Little 128 bits per pixel, 32 bits per component, kCGImageAlphaPremultipliedLast|kCGBitmapFloatComponents 128 bits per pixel, 32 bits per component, kCGImageAlphaNoneSkipLast|kCGBitmapFloatComponents See Quartz 2D Programming Guide (available online) for more information. If I don't use NSBitmapFormatAlphaNonpremultiplied as part of the format, I don't get the error message. My question is, why does the constant NSBitmapFormatAlphaNonpremultiplied exist if you can't use it like this? If you're wondering why I wanted to do this: I want to extract the RGBA pixel data from an image, which might have non-premultiplied alpha. And elsewhere online, I saw advice that if you want to look at the pixels of an image, draw it into a bitmap whose format you know and look at those pixels. And I don't want the process of drawing to premultiply my alpha.
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175
Jun ’25
How does the automatch feature work in Game Kit?
I'm developing a turn based game. When I present the GKTurnBasedMatchmakerViewController players can opt in for automatch instead of selecting a specific friend as opponent. How exactly does the matching work if a player doesn't specify anything explicitly? Does Game Center send push notifications in a round robin fashion to all friends and the first one to accept is then matched as opponent? Is this documented somewhere?
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509
Jan ’26
PDFKit Page Rerender
I'm experiencing an issue with PDFKit where page.removeAnnotation(annotation) successfully removes the annotation from the page's data structure, but the PDFView no longer updates automatically to reflect the change visually. Issue Details: The annotation is removed (verified by checking page.annotations.count) The PDFView display doesn't refresh to show the removal This code was working correctly before and suddenly stopped working No code changes were made on my end
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885
Dec ’25
RealityView content scale factor
Hi, following the recent deprecation of SceneKit, I'm trying to move a couple of my SceneKit projects to RealityKit. One thing I can't seem to find is how to change the content scale factor when using a RealityView in SwiftUI. It was really easy to do in SceneKit with just a SCNView property, and it seems that it's also possible when using ARView, but I can't find a way to do it with a RealityView. Maybe it's a SwiftUI limitation?
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202
Jul ’25
SCNScene.write To USDZ, Node color fades
I use SCNScene.write To file ".usdz", then open the ".usdz" by SCNScene.url , all Nodes color fades. Export and load only once. The fading is not obvious. Return and repeat 4 or 5 times. It is obvious that the color is inconsistent with the original color and has become much lighter.
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304
May ’25
iOS Metal system delayed one Vsync period to really display the frame on the screen
View Layout Add the following views in a view controller: Label View A, with a subview of the same size: MTKView A View B, with a subview of the same size: MTKView B Refresh Rates of Each View The label view refreshes at 60fps (driven by CADisplayLink). MTKView A and B refresh at 15fps. MTKView Implementation Details The corresponding CAMetalLayer's maximumDrawableCount is set to 2, changed to double buffering. The scheduling mechanism is modified; drawing is not driven by the internal loop but is done manually. The draw call is triggered immediately upon receiving a frame. self.metalView.enableSetNeedsDisplay = NO; self.metalView.paused = YES; A new high-priority queue is created for drawing, instead of handling it on the main queue. MTKView Latency Tracking The GPU completion time T1 is observed through the addCompletedHandler callback of the CommandBuffer. The presentation time T2 of the frame is observed through the addPresentedHandler callback of the currentDrawable in MTKView. Testing shows that T2 - T1 > 16.6ms (the Vsync period at 60Hz). This means that after the GPU rendering in MTLView is finished, the frame is not actually displayed at the next Vsync instruction but only at the Vsync instruction after that. I believe there is an extra 16.6ms of latency here, which I want to eliminate by adjusting the rendering mechanism. Observation from Instruments From Instruments, the Surface presentation aligns with the above test results. After the Metal encoder finishes, the Surface in Display switches only after the next-next Vsync instruction. See the image in the link for details. Questions According to a beginner's understanding, after MTKView's GPU rendering is finished, the next Vsync instruction should officially display (make it visible). However, this is not what is observed. Does the subview MTKView need to wait for another Vsync cycle to be drawn to the actual display buffer? The label updates its text at 60fps, so the entire interface should be displayed at 60fps. Is the content of MTKView not synchronized when the display happens? Explanation of the Reasoning Behind Some MTKView Code Details Changing from the default triple buffering to double buffering helps reduce the latency introduced by rendering. Not using MTKView's own scheduling mechanism but using manual triggering of the draw method is because MTKView's own scheduling mechanism is driven by CADisplayLink. Therefore, if a frame falls within a Vsync window, it needs to wait for the next Vsync window to trigger the draw operation, which introduces waiting latency.
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595
Dec ’25
RealityKit captureHighResolutionFrame from session is broken on iOS26?
A bit of background on what our app is doing: We have a RealityKit ARView session running. During this period we place objects in RealityKit. At some point user can "take photo" and we use session.captureHighResolutionFrame to capture a frame. We then use captured frame and frame.camera.projectPoint to project my objects back to 2D Issue we found is that on devices that have iOS26, first photo user takes and the first frame received from session.captureHighResolutionFrame gives incorrect CGPoint for frame.camera.projectPoint. If user takes the second photo with the same camera phostion, second frame received from session.captureHighResolutionFrame gives correct CGPoint for frame.camera.projectPoint I notices some difference between first and subsequent frames that i believe is corresponding with the issue. Yaw value of camera (frame.camera.eulerAngles.y) on first frame is not correct ( inconsistent with any subsequent frame) I also created a small example app and i followed Building an Immersive Experience with RealityKit example to create it. The issue exists in this app for iOS26, while iOS18.* has consistent values between first and subsequent captured frames. Note: The yaw value seems to differ more if we start session in portrait but take photo in landscape. Example result for 3 captured frames: Frame captured with yaw: 1.4855177402496338 Frame captured with yaw: -0.08803760260343552 Frame captured with yaw: -0.08179682493209839 Example code: class CustomARView: ARView, ARSessionDelegate { required init(frame: CGRect) { super.init(frame: frame) } required init?(coder decoder: NSCoder) { fatalError("init(coder:) has not been implemented")} func setup() { let singleTap = UITapGestureRecognizer(target: self, action: #selector(handleTap)) addGestureRecognizer(singleTap) } @objc func handleTap(_ gestureRecognizer: UIGestureRecognizer) { Task { do { let frame = try await session.captureHighResolutionFrame() print("Frame captured with yaw: \(Double(frame.camera.eulerAngles.y))") } catch { } } } } struct CustomARViewUIViewRepresentable: UIViewRepresentable { func makeUIView(context: Context) -> some UIView { let arView = CustomARView(frame: .zero) arView.setup() return arView } func updateUIView(_ uiView: UIViewType, context: Context) { } } struct ContentView: View { var body: some View { CustomARViewUIViewRepresentable() .frame(maxWidth: .infinity, maxHeight: .infinity) .ignoresSafeArea() } }
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704
Sep ’25
App Freezes on iPadOS 26.x - GPU Metal Errors
I work on a Qt/QML app that uses Esri Maps SDK for Qt and that is deployed to both Windows and iPads. With a recent iPad OS upgrade to 26.1, many iPad users are reporting the application freezing after panning and/or identifying features in the map. It runs fine for our Windows users. I was able to reproduce this and grabbed the following error messages when the freeze happens: IOGPUMetalError: Caused GPU Address Fault Error (0000000b:kIOGPUCommandBufferCallbackErrorPageFault) IOGPUMetalError: Invalid Resource (00000009:kIOGPUCommandBufferCallbackErrorInvalidResource) Environment: Qt 6.5.4 (Qt for iOS) Esri Maps SDK for Qt 200.3 iPadOS 26.1 Because it appears to be a Metal error, I tried using OpenGL (Qt offers a way to easily set hte target graphics api): QQuickWindow::setGraphicsApi(QSGRendererInterface::GraphicsApi::OpenGL) Which worked! No more freezing. But I'm seeing many posts that OpenGL has been deprecated by Apple. I've seen posts that Apple deprecated OpenGL ES. But it seems to still be available with iPadOS 26.1. If so, will this fix (above) just cause problems with a future iPadOS update? Any other suggestions to address this issue? Upgrading our version of Qt + Esri SDK to the latest version is not an option for us. We are in the process to upgrade the full application, but it is a year or two out. So, we just need a fix to buy us some time for now. Appreciate any thoughts/insights....
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556
Dec ’25
Request: Allow Game Mode to be enabled locally for non-game App Store categories
Hi Apple team, Game Mode was introduced in iOS 18. To activate Game Mode, an app must include specific key-value pairs in its *.plist and be categorized as a "Game" on the App Store. My app (https://apps.apple.com/us/app/voidlink/id6747717070) works primarily as a self-hosted game streaming (PC->iPhone/iPad) client. Game Mode provides clear benefits in terms of latency and frame rate stability, but it can currently only be activated when running via Xcode or TestFlight. I am an individual iOS developer based in China, where an additional government license is required for apps to be listed under the "Game" category on the App Store. Obtaining such a license is very difficult for independent developers, so my app has been categorized under "Utilities" instead.(If move the app to game category, it will disappear from Chinese App Store immediately) Expectation / Suggestion: Please consider making Game Mode available as a local, user-controllable option on iOS18/26+, such as through a system “App Pool” where users can choose which apps to enable Game Mode for, regardless of App Store category. This would greatly benefit use cases like streaming clients, benchmarking tools, and remote play utilities, without requiring developers to reclassify their apps as “Games” on App Store.
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774
Nov ’25
Bug Report - Incorrect trackingAreaIdentifier in visionOS 26 Hover Effect Sample Code
Description: In the official visionOS 26 Hover Effect sample code project , I encountered an issue where the event.trackingAreaIdentifier returned by onSpatialEvent does not reset as expected. Steps to Reproduce: Select an object with trackingAreaID = 6 in the sample app. Look at a blank space (outside any tracking area) and perform a pinch gesture . Expected Behavior: The event.trackingAreaIdentifier should return 0 when interacting with a non-tracking area. Actual Behavior: The event.trackingAreaIdentifier still returns 6, even after restarting the app or killing the process. This persists regardless of where the pinch gesture is performed
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293
Jul ’25
CAMetalLayer nextDrawable crash
Hi , My application meet below crash backtrace at very low repro rate from the public users, i do not see it relate to a specific iOS version or iPhone model. The last code line from my application is calling CAMetalLayer nextDrawable API. I did some basic studying, suppose it may relate to the wrong CAMetaLayer configuration, like frame property w or h <= 0.0 bounds property w or h <= 0.0 drawableSize w or h <= 0.0 or w or h > max value (like 16384) Not sure my above thinking is right or not? Will the UIView which my CAMetaLayer attached will cause such nextDrawable crash or not ? Thanks a lot Main Thread - Crashed libsystem_kernel.dylib __pthread_kill libsystem_c.dylib abort libsystem_c.dylib __assert_rtn Metal MTLReportFailure.cold.1 Metal MTLReportFailure Metal _MTLMessageContextEnd Metal -[MTLTextureDescriptorInternal validateWithDevice:] AGXMetalA13 0x245b1a000 + 4522096 QuartzCore allocate_drawable_texture(id<MTLDevice>, __IOSurface*, unsigned int, unsigned int, MTLPixelFormat, unsigned long long, CAMetalLayerRotation, bool, NSString*, unsigned long) QuartzCore get_unused_drawable(_CAMetalLayerPrivate*, CAMetalLayerRotation, bool, bool) QuartzCore CAMetalLayerPrivateNextDrawableLocked(CAMetalLayer*, CAMetalDrawable**, unsigned long*) QuartzCore -[CAMetalLayer nextDrawable] SpaceApp -[MetalRender renderFrame:] MetalRenderer.mm:167 SpaceApp -[FrameBuffer acceptFrame:] VideoRender.mm:173 QuartzCore CA::Display::DisplayLinkItem::dispatch_(CA::SignPost::Interval<(CA::SignPost::CAEventCode)835322056>&) QuartzCore CA::Display::DisplayLink::dispatch_items(unsigned long long, unsigned long long, unsigned long long) QuartzCore CA::Display::DisplayLink::dispatch_deferred_display_links(unsigned int) UIKitCore _UIUpdateSequenceRun UIKitCore schedulerStepScheduledMainSection UIKitCore runloopSourceCallback CoreFoundation __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ CoreFoundation __CFRunLoopDoSource0 CoreFoundation __CFRunLoopDoSources0 CoreFoundation __CFRunLoopRun CoreFoundation CFRunLoopRunSpecific GraphicsServices GSEventRunModal UIKitCore -[UIApplication _run] UIKitCore UIApplicationMain
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373
Jul ’25
Moving from SceneKit - fog missing
I am rewriting an unfinished SceneKit project as RealityKit (NonAR). As far as I can see, RealityKit is missing basic fog functionality? Fog was simple & easy to implement in SCeneKit (fogStartDistance / fogEndDistance / fogDensityExponent / fogColor). Are there any plans to implement something like this in RealityKit? Are there any simple workarounds?
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610
Aug ’25
How do I test a new leaderboard added to a Published app with prior leaderboard?
Hi I have attempted to find a fix for my issue via documentation online and one phone support ( not code level support ) call to no end. I could continue to try various things but would like to see if someone else has encountered this issue and a fix for it. Background: My Game app is live on App Store and has 1 classic leaderboard . I am now getting ready to submit an update to the app and it also entails adding a new recurring leaderboard. I added the leaderboard in App Store. I however have NOT uploaded my new build yet. I have also not added my leaderboards ( currently live and not live ) to any set. When I try to submit scores using GKLeaderboard.submitScore(_:context:player:leaderboardIDs:completionHandler:) to the new non-live leaderboard it works ( gives me no error ) When I try to load the scores from the new non-live leaderboard GKLeaderboard.loadLeaderboards(IDs:completionHandler:) loadEntries(for:timeScope:range:completionHandler:) it fails. Error: "leaderboardID not found" I could try ( and will ) uploading the new build to AppStore connect and associating the new leaderboard to it before testing again. try associating each leaderboard to a set Is there anything else that I should be aware of ? Thanks in advance
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183
Jul ’25