Problem Description We are developing a app for iOS and iPadOS that involves extensive custom drawing of paths, shapes, texts, etc. To improve drawing and rendering speed, we use CARenderer to generate cached images (CGImage) on a background thread. We adopted this approach based on this StackOverflow post: https://stackoverflow.com/a/75497329/9202699. However, we are experiencing frequent crashes in our production environment that we can hardly reproduce in our development environment. Despite months of debugging and seeking support from DTS and the Apple Feedback platform, we have not been able to fully resolve this issue. Our recent crash reports indicate that the crashes occur when calling CATransaction.commit(). We suspect that CATransaction may not be functioning properly outside the main thread. However, based on feedback from the Apple Feedback platform, we were advised to use CATransaction.begin() and CATransaction.commit() on a background thread. If anyone has any insights, we would greatly appreciate it. Code Sample The line CATransaction.commit() is causing the crash: [EXC_BREAKPOINT: com.apple.root.****-qos.cooperative] private let transactionLock = NSLock() // to ensure one transaction at a time private let device = MTLCreateSystemDefaultDevice()! @inline(never) static func drawOnCGImageWithCARenderer( layerRect: CGRect, itemsToDraw: [ItemsToDraw] ) -> CGImage? { // We have encapsulated everything related to CALayer and its // associated creations and manipulations within CATransaction // as suggested by engineers from Apple Feedback Portal. transactionLock.lock() CATransaction.begin() // Create the root layer. let layer = CALayer() layer.bounds = layerRect layer.masksToBounds = true // Add one sublayer for each item to draw itemsToDraw.forEach { item in // We have thousands or hundred thousands of drawing items to add. // Each drawing item may produce a CALayer, CAShapeLayer or CATextLayer. // This is also why we want to utilise CARenderer to leverage GPU rendering. layer.addSublayer( item.createCALayerOrCATextLayerOrCAShapeLayer() ) } // Create MTLTexture and CARenderer. let textureDescriptor = MTLTextureDescriptor.texture2DDescriptor( pixelFormat: .rgba8Unorm, width: Int(layer.frame.size.width), height: Int(layer.frame.size.height), mipmapped: false ) textureDescriptor.usage = [MTLTextureUsage.shaderRead, .shaderWrite, .renderTarget] let texture = device.makeTexture(descriptor: textureDescriptor)! let renderer = CARenderer(mtlTexture: texture) renderer.bounds = layer.frame renderer.layer = layer.self /* ********************************************************* */ // From our crash report, this is where the crash happens. CATransaction.commit() /* ********************************************************* */ transactionLock.unlock() // Rendering layers onto MTLTexture using CARenderer. renderer.beginFrame(atTime: 0, timeStamp: nil) renderer.render() renderer.endFrame() // Draw MTLTexture onto image. guard let colorSpace = CGColorSpace(name: CGColorSpace.sRGB), let ciImage = CIImage(mtlTexture: texture, options: [.colorSpace: colorSpace]) else { return nil } // Convert CIImage to CGImage. let context = CIContext() return context.createCGImage(ciImage, from: ciImage.extent) }

Description We are developing a app for iOS and iPadOS that involves extensive custom drawing of paths, shapes, texts, etc. To improve drawing and rendering speed, we use CARenderer to generate cached images (CGImage) on a background thread. We adopted this approach based on this StackOverflow post: https://stackoverflow.com/a/75497329/9202699. However, we are experiencing frequent crashes in our production environment that we cannot reproduce in our development environment. Despite months of debugging and seeking support from DTS and the Apple Feedback platform, we have not been able to fully resolve this issue. Our recent crash reports indicate that the crashes occur when calling CATransaction.commit(). Crash traceback The method names in this traceback are mapped to those in the code sample below. The app name has been masked. Crashed: com.apple.root.user-initiated-qos.cooperative 0 MyApp 0x887408 specialized static CAUtils.commitCATransaction() + 4340151304 (<compiler-generated>:4340151304) 1 MyApp 0x887408 specialized static CAUtils.commitCATransaction() + 4340151304 (<compiler-generated>:4340151304) 2 MyApp 0x8874a4 specialized static CAUtils.addDrawingItemsToRenderer(***) + 250 (CAUtils.swift:250) 3 MyApp 0x887710 specialized static CAUtils.drawOnCGImageWithCARenderer(***) + 267 (CAUtils.swift:267) 4 MyApp 0x8878c0 specialized static CAUtils.drawOnCGImageWithCARendererWithRetry(***) + 315 (CAUtils.swift:315) 5 MyApp 0x736294 XXXManager.generateCGImages(***) + 570 (XXXManager.swift:570) 6 MyApp 0x73404c closure #1 in XXXManager.updateCachedCGImages(***) + 427 (XXXManager.swift:427) 7 libswift_Concurrency.dylib 0x61104 swift::runJobInEstablishedExecutorContext(swift::Job*) + 252 8 libswift_Concurrency.dylib 0x62514 swift_job_runImpl(swift::Job*, swift::SerialExecutorRef) + 144 9 libdispatch.dylib 0x15d8c _dispatch_root_queue_drain + 392 10 libdispatch.dylib 0x16590 _dispatch_worker_thread2 + 156 11 libsystem_pthread.dylib 0x4c40 _pthread_wqthread + 228 12 libsystem_pthread.dylib 0x1488 start_wqthread + 8 Code Sample Below is a sample of our code. While the complete snippet is too long, the issue occurs in addDrawingItemsToRenderer. Please refer to the other methods for completeness and reference purposes. private let transactionLock = NSLock() private let deviceLock = NSLock() private let device = MTLCreateSystemDefaultDevice()! /// This is the method we call from outside. @inline(never) static func drawOnCGImageWithCARenderer( layerRect: CGRect, drawingItems: [DrawingItem] ) -> CGImage? { guard let (texture, renderer) = addDrawingItemsToRenderer( layerRect: layerRect, drawingItems: drawingItems ) else { return nil } renderer.beginFrame(atTime: 0, timeStamp: nil) renderer.render() renderer.endFrame() guard let colorSpace = CGColorSpace(name: CGColorSpace.sRGB), let ciImage = CIImage(mtlTexture: texture, options: [.colorSpace: colorSpace]) else { return nil } let context = CIContext() return context.createCGImage(ciImage, from: ciImage.extent) } /// This is the method will the crash happens @inline(never) fileprivate static func addDrawingItemsToRenderer( layerRect: CGRect, drawingItems: [DrawingItem] ) -> (MTLTexture, CARenderer)? { // We have encapsulated everything related to CALayer and its // associated creations and manipulations within CATransaction // as suggested by engineers from Apple Feedback Portal. beginCATransaction() defer { commitCATransaction() // The crash happens here } let (layer, imageWidth, imageHeight) = addDrawingItemsToLayer(layerRect: layerRect, drawingItems: drawingItems) return createTextureAndRenderer( layer: layer, imageWidth: imageWidth, imageHeight: imageHeight ) } // Below are all internal methods. We have split the method into very // granular parts and marked them as @inline(never) to prevent the // compiler from inlining our code, which may otherwise obscure usage // trackback information in our crash reports. @inline(never) fileprivate static func beginCATransaction() { transactionLock.lock() CATransaction.begin() } @inline(never) fileprivate static func commitCATransaction() { // From our crash report, we believe the crash happens on this line. CATransaction.commit() // It is unlikely that the lock cause the crash as we added it only recently // to ensure that there is only one transaction on our background thread, // and after we added this lock, the crash rate indeed lowered, but still // not fully disappear transactionLock.unlock() } -------------------------------- // The methods below are provided for reference and completeness. While // they may have issues, they do not frequently appear in our crash // reports as the one caused by `CATransaction.commit()` @inline(never) fileprivate static func addDrawingItemsToLayer( layerRect: CGRect, drawingItems: [DrawingItem] ) -> (layer: CALayer, imageWidth: CGFloat, imageHeight: CGFloat) { let layer = CALayer() layer.isGeometryFlipped = SharedAppUtils.isIOS layer.anchorPoint = CGPoint.zero layer.bounds = layerRect layer.masksToBounds = true for drawingItem in drawingItems { // We have thousands or hundred thousands of drawing items to add. // Each drawing item may produce a CALayer, CAShapeLayer or CATextLayer. // This is also why we want to utilise CARenderer to leverage GPU rendering. let sublayerForDrawingItem = drawingItem.createCALayerOrCATextLayerOrCAShapeLayer() layer.addSublayer(sublayerForDrawingItem) } let imageWidth = max(1, layer.frame.size.width * UIScreen.main.scale) let imageHeight = max(1, layer.frame.size.height * UIScreen.main.scale) layer.transform = CATransform3DMakeScale(UIScreen.main.scale, UIScreen.main.scale, 1) layer.frame = .init(origin: .zero, size: .init(width: imageWidth, height: imageHeight)) return (layer, imageWidth, imageHeight) } @inline(never) fileprivate static func createTextureAndRenderer( layer: CALayer, imageWidth: CGFloat, imageHeight: CGFloat ) -> (MTLTexture, CARenderer)? { deviceLock.lock() defer { deviceLock.unlock() } let textureDescriptor = MTLTextureDescriptor.texture2DDescriptor( pixelFormat: .rgba8Unorm, width: Int(imageWidth), height: Int(imageHeight), mipmapped: false ) textureDescriptor.usage = [MTLTextureUsage.shaderRead, .shaderWrite, .renderTarget] guard let texture = device.makeTexture(descriptor: textureDescriptor) else { return nil } let renderer = CARenderer(mtlTexture: texture) renderer.bounds = layer.frame renderer.layer = layer.self return (texture, renderer) }

Safari throw a ViewTransition error, called ' Unhandled Promise Rejection: AbortError: Old view transition aborted by new view transition.' however, i don't find how to catch it. i used 'try..catch' or Promise.catch, or catch it in finished/ready/updateCallbackDone Promise. These all don't work.

Hi everyone, im in the process of delving more into coregraphics with swiftui, but I am at a roadblock. First I would like to ask, what are some good resources to learn coregraphics? Secondly: I currently have a circle view made and what I want to do is to make my circle view modular so that it can be directly connected to another given circle by a line. How can I do this? For example, I want my circles to represent nodes and be able to connect by lines to other nodes that are related. Thanks in advanced. Here is my code for the circle view: @State private var circleProgress: CGFloat = 0 let timer = Timer.publish(every: 0.016, on: .main, in: .common).autoconnect() private let animationDuration: TimeInterval = 1.5 @Binding var startPoint: CGPoint @Binding var endPoint: CGPoint var body: some View { GeometryReader { geometry in Canvas { context, size in // Circle parameters let circleSize: CGFloat = 50 let circleOrigin = CGPoint( x: size.width / 4, y: size.height / 2 - circleSize / 2 ) let circleRect = CGRect( origin: circleOrigin, size: CGSize(width: circleSize, height: circleSize) ) let circleCenter = CGPoint( x: circleOrigin.x + circleSize / 2, y: circleOrigin.y + circleSize / 2 ) // Animate circle creation var circlePath = Path() circlePath.addArc( center: circleCenter, radius: circleSize / 2, startAngle: .degrees(0), endAngle: .degrees(360 * circleProgress), clockwise: false ) context.addFilter(.shadow(color: .white.opacity(0.6), radius: 5, x: 1, y: 1)) // Add white shadow context.stroke( circlePath, with: .linearGradient( Gradient(colors: [.purple, .white]), startPoint: circleRect.origin, endPoint: CGPoint(x: circleRect.maxX, y: circleRect.maxY) ), lineWidth: 5 ) } .frame(width: 300, height: 150) .onReceive(timer) { _ in // Update circle progress let progressChange = 0.02 / animationDuration if circleProgress < 1.0 { circleProgress = min(circleProgress + progressChange, 1.0) } else { circleProgress = 0.0 // Reset the circle to repeat the animation } // Get the starting and ending points of the Canvas view startPoint = CGPoint(x: geometry.frame(in: .global).minX, y: geometry.frame(in: .global).minY) endPoint = CGPoint(x: geometry.frame(in: .global).maxX, y: geometry.frame(in: .global).maxY) // Print the points for debugging print("Start Point: \(startPoint.x), \(startPoint.y)") print("End Point: \(endPoint.x), \(endPoint.y)") } } .frame(width: 300, height: 150) } }

I plan to create a simple motion graphics software for macOS that animates text, basic shapes, and handles audio. I'll use SwiftUI for the UI. What are the commonly used technologies for rendering animated graphics? Core Animation is suitable for UI animations but not for exporting and controlling UI animations. Basic requirements: Timeline user interface Animation of text and basic shapes Viewer in SwiftUI GUI with transport control (play, pause, scrub, …) Export to video file Is Metal or Core Graphics typically used directly? I want to keep it as simple as possible.

I have a CALayer and I'd like to animate a property on it. But, the property that triggers the animation change is different to the one that is being changed. A basic example of what I'm trying to do is below. I'm trying to create an animation on count by changing triggerProperty. This example is simplified (in my project, the triggerProperty is not an Int, but a more complex non-animatable type. So, I'm trying to animate it by creating animations for some of it's properties that can be matched to CABasicAnimation - and rendering a version of that class based on the interpolated values). @objc class AnimatableLayer: CALayer { @NSManaged var triggerProperty: Int @NSManaged var count: Int override init() { super.init() triggerProperty = 1 setNeedsDisplay() } override init(layer: Any) { super.init(layer: layer) } required init?(coder: NSCoder) { fatalError("init(coder:) has not been implemented") } override class func needsDisplay(forKey key: String) -> Bool { return key == String(keypath: \AnimatableLayer.triggerProperty) || super.needsDisplay(forKey: key) } override func action(forKey event: String) -> (any CAAction)? { if event == String(keypath: \AnimatableLayer.triggerProperty) { if let presentation = self.presentation() { let keyPath = String(keypath: \AnimatableLayer.count) let animation = CABasicAnimation(keyPath: keyPath) animation.duration = 2.0 animation.timingFunction = CAMediaTimingFunction(name: CAMediaTimingFunctionName.linear) animation.fromValue = presentation.count animation.toValue = 10 return animation } } return super.action(forKey: event) } override func draw(in ctx: CGContext) { print("draw") NSGraphicsContext.saveGraphicsState() let nsctx = NSGraphicsContext(cgContext: ctx, flipped: true) // create NSGraphicsContext NSGraphicsContext.current = nsctx // set current context let renderText = NSAttributedString(string: "\(self.presentation()?.count ?? self.count)", attributes: [.font: NSFont.systemFont(ofSize: 30)]) renderText.draw(in: bounds) NSGraphicsContext.restoreGraphicsState() } func animate() { print("animate") self.triggerProperty = 10 } } With this code, the animation isn't triggered. It seems to get triggered only if the animation's keypath matches the one on the event (in the action func). Is it possible to do something like this?

I am working on a SceneKit project where I use a CAShapeLayer as the content for SCNMaterial's diffuse.contents to display a progress bar. Here's my initial code: func setupProgressWithCAShapeLayer() { let progressLayer = createProgressLayer() progressBarPlane?.firstMaterial?.diffuse.contents = progressLayer DispatchQueue.main.async { var progress: CGFloat = 0.0 Timer.scheduledTimer(withTimeInterval: 0.1, repeats: true) { timer in progress += 0.01 if progress > 1.0 { progress = 0.0 } progressLayer.strokeEnd = progress // Update progress } } } // MARK: - ARSCNViewDelegate func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) { progressBarPlane = SCNPlane(width: 0.2, height: 0.2) setupProgressWithCAShapeLayer() let planeNode = SCNNode(geometry: progressBarPlane) planeNode.position = SCNVector3(x: 0, y: 0.2, z: 0) node.addChildNode(planeNode) } This works fine, and the progress bar updates smoothly. However, when I change the code to use a class property (self.progressLayer) instead of a local variable, the rendering starts flickering on the screen: func setupProgressWithCAShapeLayer() { self.progressLayer = createProgressLayer() progressBarPlane?.firstMaterial?.diffuse.contents = progressLayer DispatchQueue.main.async { [weak self] in var progress: CGFloat = 0.0 Timer.scheduledTimer(withTimeInterval: 0.1, repeats: true) { [weak self] timer in progress += 0.01 if progress > 1.0 { progress = 0.0 } self?.progressLayer?.strokeEnd = progress // Update progress } } } After this change, the progressBarPlane in SceneKit starts flickering while being rendered on the screen. My Question: Why does switching from a local variable (progressLayer) to a class property (self.progressLayer) cause the flickering issue in SceneKit rendering?

I'm new to developing with SwiftUI and I created a Pomodoro app for macOS that runs in the menu bar. I added 4 animations and when the user selects the snow animation, it starts snowing on the screen. But the app uses 20%-30% of the CPU and has high energy consumption. I can't reduce it and I couldn't find a solution. // snow animation import SwiftUI struct SnowflakeView: View { @State private var flakeYPosition: CGFloat = -100 @State private var isAnimating = false private let flakeSize: CGFloat = CGFloat.random(in: 10...30) private let flakeColor: Color = Color( red: Double.random(in: 0.8...1), green: Double.random(in: 0.9...1), blue: Double.random(in: 1...1), opacity: Double.random(in: 0.6...0.8) ) private let animationDuration: Double = Double.random(in: 1...3) private let flakeXPosition: CGFloat = CGFloat.random(in: 0...310) var body: some View { Text("❄️") .font(.system(size: flakeSize)) .foregroundColor(flakeColor) .position(x: flakeXPosition, y: flakeYPosition) .onAppear { if !isAnimating { withAnimation(Animation.linear(duration: animationDuration).repeatForever(autoreverses: false)) { flakeYPosition = 280 + 50 } isAnimating = true } } } } I also have how I run the animation below. ZStack { ForEach(0..<10, id: \.self) { index in if selectedAnimal == "Snow" { SnowflakeView() } else if selectedAnimal == "Rain" { RainDropAnimation() }else if selectedAnimal == "Leaf"{ LeafFallAnimation() }else if selectedAnimal == "Confetti"{ ConfettiAnimation() } } }

I have facing an above crash for many users device running on iOS 17.6.1 mostly on iPad devices. I'm not sure why this happening only in 17.X. In Xcode Organizer unable to see this crash in any devices running on OS 18.x. Our app crashes got spiked due to this. I am unable to fix or reproduce the same. The crash log is not pointing to our app code to find the root cause and fix this issue. Have attached the crash log in this post also the crash log roles have mixed values Background &amp;amp; Foreground. But most of the crash is in background. Is this any crash related to system and that only solved by OS update? I have updated the app using Xcode 16 and 16.1 still facing this crash unable to symbolicate the crash report as well. Any ideas/solution how to solve this or how to proceed further. Have attached the entire crash log below. RoleBackgroundCrash.crash RoleForeGroundCrash.crash

I created a simple animation of a circle that changes sizes. The circle pulses like a heartbeat in the center of the screen. My expectation was for the CPU use to be very low, but that is not the case. In addition, even if the CPU use isn't as low as I would expect, I did not expect the CPU use to increase over time because nothing else is happening in the app. Here is the code: import SwiftUI @main struct TestApp: App { var body: some Scene { WindowGroup { SplashScreenView() } } } import SwiftUI struct SplashScreenView: View { var body: some View { ZStack { SplashNucleusView(minSize: 50, maxSize: 100) } } } import SwiftUI struct SplashNucleusView: View { let minSize: Double let maxSize: Double @State private var nucleusColor: Color = .primary @State private var nucleusRadius: Double = 10 @State private var nucleusOpacity: Double = 1.0 private var nucleusAnimation: Animation { .easeInOut(duration: 0.25) .repeatForever(autoreverses: true) } let timer = Timer.publish(every: 0.5, on: .main, in: .common).autoconnect() var body: some View { Circle() .fill(nucleusColor) .frame(width: nucleusRadius) .opacity(nucleusOpacity) .onReceive(timer) { _ in withAnimation(nucleusAnimation) { nucleusRadius = Double.random(in: minSize...maxSize) } } } } This is how the animation looks: The animation is snappy until the CPU use reaches 95%, at which point there is visible stuttering. Here is how the CPU looks when the animation duration value is 0.5 seconds and the timer publishing interval is 3 seconds: Changing the animation duration value to 0.25 seconds and the timer publishing interval to 0.5 seconds changes the CPU use as follows: The complete view has many other moving parts, which make the issue much worse. The issue is evident with only the circle view. I spent hours working with the debugger, reading about animations, and testing new approaches, but the result is always the same. Why is this happening?

I am looking to implement CAMetalDisplayLink on a separate thread on a macOS application. I am basing my implementation on the following example project: Achieving Smooth Frame Rates with Metal Display Link This project allows you to configure whether a separate thread is used for rendering by setting RENDER_ON_MAIN_THREAD in GameConfig to 0. However, when I set it to use a separate thread nothing is rendered. Stepping through the code shows that a separate thread is created, but a CAMetalDisplayLinkUpdate is never received. Does anyone know why this does not work?

I found that there is such a click-to-expand horizontally and smoothly effect in the system application called "message", which is good. I wonder if I can add a similar effect to my own app. If possible, are there any implementation ideas or examples that I can refer to? Thanks!

Hi. Since Xcode 16 and/or iOS 18.0 (I upgraded at the same time), I have an strange effect in the lower (let's say) 20% section of the Navigation Bar when changing to another tab, and this independently if large titles are used or not. Mentioned section is brighter or darker than the rest of the Navigation Bar background, depending on which background tint is used. This effect lasts about 0.3 seconds, but is clearly visible, quite disturbing and new as of Xcode 16 and/or iOS 18.0. I use the code below in AppDelegate to get a gradient coloured Navigation Bar background. let appearance = UINavigationBarAppearance() UINavigationBar.appearance().standardAppearance = appearance UINavigationBar.appearance().compactAppearance = appearance UINavigationBar.appearance().scrollEdgeAppearance = appearance UINavigationBar.appearance().compactScrollEdgeAppearance = appearance If I don't use above code., the background color is filled and without gradient. Subject effect doesn't show in this case. The effect basically looks like when changing tab, the new Navigation Bar background doesn't clear right away, and keeps the background from the previous Navigation Bar for 0.3 seconds before new one Navigation Bar background is rendered. I spent quite some time on changing every possible setting, in code as well as storyboard ... no success so far. Any ideas how to disable this undesired animation?

Hi Friends! I’m facing an issue with SceneKit. I’m developing a 3D mobile game. I have a character 3D model and several skeletal animations CAAnimation. I import both the model and the animations from Maya in *.dae format. The character’s animations play continuously one after the other, with each new animation being triggered randomly. The transition between animations makes smoothly by setting the fadeInDuration and fadeOutDuration properties. Here’s an example of the code: import UIKit import QuartzCore import SceneKit class TestAnimationController: UIViewController { var bodyNode: SCNNode? override func viewDidLoad() { super.viewDidLoad() let scnView = SCNView(frame: self.view.bounds) scnView.backgroundColor = .black // Set your desired background color scnView.autoresizingMask = [.flexibleWidth, .flexibleHeight] let scene = SCNScene(named: "art.scnassets/scene/Base_room/ROOM5.scn")! bodyNode = collada2SCNNode(filepath: "art.scnassets/female/girl_body_races.dae")! bodyNode?.renderingOrder = 10 scene.rootNode.addChildNode(bodyNode!) playIdleAnimation() scnView.scene = scene // Assign the scene to the SCNView self.view.addSubview(scnView) // Add the SCNView to your main view) } func collada2SCNNode(filepath:String) -> SCNNode? { if let scene = SCNScene(named: filepath) { let node = scene.rootNode.childNodes[0] return node } else { return nil } } func playIdleAnimation() { let array = [ "art.scnassets/female/animations/idle/girl_idle_4.dae", "art.scnassets/female/animations/idle/girl_idle1.dae", "art.scnassets/female/animations/idle/girl_idle2.dae", "art.scnassets/female/animations/idle/Girl_idle3.dae", ] let animation = CAAnimation.animationWithSceneNamed(array.randomElement() ?? "")! self.setAnimationAdd( fadeInDuration: 1.0, fadeOutDuration: 1.0, keyTime: 0.99, animation, isLooped: false ) { [weak self] in guard let self = self else { return } try? self.playBoringAnimations() } } func playBoringAnimations() { let array = [ "art.scnassets/female/animations/boring/girl_boring1.dae", "art.scnassets/female/animations/boring/girl_boring2.dae", "art.scnassets/female/animations/boring/girl_boring3.dae", "art.scnassets/female/animations/boring/girl_boring4.dae", "art.scnassets/female/animations/boring/girl_boring5.dae", "art.scnassets/female/animations/boring/girl_boring6.dae", "art.scnassets/female/animations/boring/girl_boring8.dae" ] let animation = CAAnimation.animationWithSceneNamed(array.randomElement() ?? "")! self.setAnimationAdd( fadeInDuration: 1.0, fadeOutDuration: 1.0, keyTime: 0.99, animation, isLooped: false ) { [weak self] in guard let self = self else { return } try? self.playIdleAnimation() } } func setAnimationAdd(fadeInDuration : CGFloat, fadeOutDuration : CGFloat, keyTime : CGFloat, _ animation: CAAnimation, isLooped: Bool, completion: (() -> Void)?) { animation.fadeInDuration = fadeInDuration animation.fadeOutDuration = fadeOutDuration if !isLooped { animation.repeatCount = 1 } else { animation.repeatCount = Float.greatestFiniteMagnitude } animation.animationEvents = [ SCNAnimationEvent(keyTime: keyTime, block: { _, _, _ in completion?() }) ] bodyNode?.addAnimation(animation, forKey: "avatarAnimation") } } Everything worked perfectly until I updated to iOS 18. On a physical device, the animations now transition abruptly without the smooth blending that was present in earlier iOS versions. The switch between them is very noticeable, as if the fadeInDuration and fadeOutDuration parameters are being ignored. However, in the iOS 18 simulator, the animations still transition smoothly as before. Here two example videos - IOS 17.5 and IOS 18 https://youtube.com/shorts/jzoMRF4skAQ - IOS 17,5 smooth https://youtube.com/shorts/VJXrZzO9wl0 - IOS 18 not smooth I try this code in IOS 17.5, everything works fine Does anyone have any ideas on how to fix this issue?

I have a game for iOS where I use CADisplayLink to animate a simulation, and for some reason the animation is not getting the full 120hz on capable devices (like iPhone 15 Pro). When I enable a 120hz refresh target, the animation is capped at only 90hz. This looks terrible because the animation works best when doubled (30, 60, 120, 240, etc). The really bizarre thing is that when I turn on Screen Recording, my frame rate instantly jumps to 120, and everything looks perfectly smooth. My game has never looked better on iPhone! When recording is stopped, the animation drops back down to 90 fps. What in the world is going on? [displayLink setPreferredFrameRateRange:CAFrameRateRangeMake(100,240,120)]; //Min. Max, Preferred [displayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; (Also, CADisableMinimumFrameDurationOnPhone is set to True in info.plist)

Hello, I want to create a painting app for iOS and I saw many examples use a CAShapeLayer to draw a UIBezierPath. As I understand CoreAnimation uses the GPU so I was wondering how is this implemented on the GPU? Or in other words, how would you do it with Metal or OpenGL? I can only think of continuously updating a texture in response to the user's drawing but that would be a very resource intensive operation... Thanks

I've got an iOS app that is using MetalKit to display raw video frames coming in from a network source. I read the pixel data in the packets into a single MTLTexture rows at a time, which is drawn into an MTKView each time a frame has been completely sent over the network. The app works, but only for several seconds (a seemingly random duration), before the MTKView seemingly freezes (while packets are still being received). Watching the debugger while my app was running revealed that the freezing of the display happened when there was a large spike in memory. Seeing the memory profile in Instruments revealed that the spike was related to a rapid creation of many IOSurfaces and IOAccelerators. Profiling CPU Usage shows that CAMetalLayerPrivateNextDrawableLocked is what happens during this rapid creation of surfaces. What does this function do? Being a complete newbie to iOS programming as a whole, I wonder if this issue comes from a misuse of the MetalKit library. Below is the code that I'm using to render the video frames themselves: class MTKViewController: UIViewController, MTKViewDelegate { /// Metal texture to be drawn whenever the view controller is asked to render its view. private var metalView: MTKView! private var device = MTLCreateSystemDefaultDevice() private var commandQueue: MTLCommandQueue? private var renderPipelineState: MTLRenderPipelineState? private var texture: MTLTexture? private var networkListener: NetworkListener! private var textureGenerator: TextureGenerator! override public func loadView() { super.loadView() assert(device != nil, "Failed creating a default system Metal device. Please, make sure Metal is available on your hardware.") initializeMetalView() initializeRenderPipelineState() networkListener = NetworkListener() textureGenerator = TextureGenerator(width: streamWidth, height: streamHeight, bytesPerPixel: 4, rowsPerPacket: 8, device: device!) networkListener.start(port: NWEndpoint.Port(8080)) networkListener.dataRecievedCallback = { data in self.textureGenerator.process(data: data) } textureGenerator.onTextureBuiltCallback = { texture in self.texture = texture self.draw(in: self.metalView) } commandQueue = device?.makeCommandQueue() } public func mtkView(_ view: MTKView, drawableSizeWillChange size: CGSize) { /// need implement? } public func draw(in view: MTKView) { guard let texture = texture, let _ = device else { return } let commandBuffer = commandQueue!.makeCommandBuffer()! guard let currentRenderPassDescriptor = metalView.currentRenderPassDescriptor, let currentDrawable = metalView.currentDrawable, let renderPipelineState = renderPipelineState else { return } currentRenderPassDescriptor.renderTargetWidth = streamWidth currentRenderPassDescriptor.renderTargetHeight = streamHeight let encoder = commandBuffer.makeRenderCommandEncoder(descriptor: currentRenderPassDescriptor)! encoder.pushDebugGroup("RenderFrame") encoder.setRenderPipelineState(renderPipelineState) encoder.setFragmentTexture(texture, index: 0) encoder.drawPrimitives(type: .triangleStrip, vertexStart: 0, vertexCount: 4, instanceCount: 1) encoder.popDebugGroup() encoder.endEncoding() commandBuffer.present(currentDrawable) commandBuffer.commit() } private func initializeMetalView() { metalView = MTKView(frame: CGRect(x: 0, y: 0, width: streamWidth, height: streamWidth), device: device) metalView.delegate = self metalView.framebufferOnly = true metalView.colorPixelFormat = .bgra8Unorm metalView.contentScaleFactor = UIScreen.main.scale metalView.autoresizingMask = [.flexibleWidth, .flexibleHeight] view.insertSubview(metalView, at: 0) } /// initializes render pipeline state with a default vertex function mapping texture to the view's frame and a simple fragment function returning texture pixel's value. private func initializeRenderPipelineState() { guard let device = device, let library = device.makeDefaultLibrary() else { return } let pipelineDescriptor = MTLRenderPipelineDescriptor() pipelineDescriptor.rasterSampleCount = 1 pipelineDescriptor.colorAttachments[0].pixelFormat = .bgra8Unorm pipelineDescriptor.depthAttachmentPixelFormat = .invalid /// Vertex function to map the texture to the view controller's view pipelineDescriptor.vertexFunction = library.makeFunction(name: "mapTexture") /// Fragment function to display texture's pixels in the area bounded by vertices of `mapTexture` shader pipelineDescriptor.fragmentFunction = library.makeFunction(name: "displayTexture") do { renderPipelineState = try device.makeRenderPipelineState(descriptor: pipelineDescriptor) } catch { assertionFailure("Failed creating a render state pipeline. Can't render the texture without one.") return } } } My question is simply: what gives?

UI: Attachment(id: "tooptip") { if isRecording { TooltipView { HStack(spacing: 8) { Image(systemName: "waveform") .font(.title) .frame(minWidth: 100) } } .transition(.opacity.combined(with: .scale)) } } Trigger: Button("Toggle") { withAnimation{ isRecording.toggle() } } The above code did not show the animation effect when running. When I use isRecording to drive an element in a common SwiftUI view, there is an animation effect.

I want to achieve Fold animation when the user scrolls UICollectionView. I have UICollectionView with full-screen size cell and vertically scrolling with paging enabled. For that I've created sub-class of UICollectionViewFlowLayout which is as described below. class FoldingFlowLayout: UICollectionViewFlowLayout { private let logger = Logger(subsystem: bundleIdentifier, category: "FlowLayout") override func prepare() { super.prepare() scrollDirection = .vertical minimumLineSpacing = 0 minimumInteritemSpacing = 0 } override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? { let attributes = super.layoutAttributesForElements(in: rect) attributes?.forEach { attribute in transformLayoutAttributes(attribute) } return attributes } override func shouldInvalidateLayout(forBoundsChange newBounds: CGRect) -> Bool { return true } private func transformLayoutAttributes(_ attributes: UICollectionViewLayoutAttributes) { guard let collectionView = collectionView else { return } let contentOffsetY = collectionView.contentOffset.y let cellOffsetY = attributes.frame.origin.y - contentOffsetY let cellHeight = attributes.frame.height var transform = CATransform3DIdentity transform.m34 = -1.0 / 500.0 // Apply perspective if cellOffsetY < cellHeight && cellOffsetY > -cellHeight { let angle = (cellOffsetY / cellHeight) * .pi / 2 transform = CATransform3DRotate(transform, angle, -1, 0, 0) attributes.transform3D = transform attributes.alpha = 1.0 - (abs(cellOffsetY) / cellHeight) } else { attributes.transform3D = CATransform3DIdentity attributes.alpha = 1.0 } } } But this is not working as I expected. I want to create replica of this kind of animation. What am I missing here?

Hello, I noticed that the CADisplayLink seems to emit incorrect targetTimestamp and timestamp in the iOS 18 simulator. If you compute the actual duration of a frame, the duration is always a negative number. This only occurs in the iOS 18 simulator.