VNContoursObservation is taking 715 times as long as OpenCV’s findContours() when creating directly comparable results. VNContoursObservation creates comparable results when I have set the maximumImageDimension property to 1024. If I set it lower, it runs a bit faster, but creates lower quality contours and still takes over 100 times as long. I have a hard time believing Apple doesn’t know what they are doing, so does anyone have an idea what is going on and how to get it to run much faster? There doesn’t seem to be many options, but nothing I’ve tried closes the gap. Setting the detectsDarkOnLight property to true makes it run even slower. OpenCV findContours runs with a binary image, but I am passing a RGB image to Vision assuming it would convert it to an appropriate format. OpenCV: double taskStart = CFAbsoluteTimeGetCurrent(); int contoursApproximation = CV_CHAIN_APPROX_NONE; int contourRetrievalMode = CV_RETR_LIST; findContours(input, contours, hierarchy, contourRetrievalMode, contoursApproximation, cv::Point(0,0)); NSLog(@"###### opencv findContours: %f", CFAbsoluteTimeGetCurrent() - taskStart); ###### opencv findContours: 0.017616 seconds Vision: let taskStart = CFAbsoluteTimeGetCurrent() let contourRequest = VNDetectContoursRequest.init() contourRequest.revision = VNDetectContourRequestRevision1 contourRequest.contrastAdjustment = 1.0 contourRequest.detectsDarkOnLight = false contourRequest.maximumImageDimension = 1024 let requestHandler = VNImageRequestHandler.init(cgImage: sourceImage.cgImage!, options: [:]) try! requestHandler.perform([contourRequest]) let contoursObservation = contourRequest.results?.first as! VNContoursObservation print(" ###### contoursObservation: \(CFAbsoluteTimeGetCurrent() - taskStart)") ###### contoursObservation: 12.605962038040161 The image I am providing OpenCV is 2048 pixels and the image I am providing Vision is 1024.

I'm experiencing 100% reproducible bug with Xcode. It took me days to figure it out. After many tears shed. Xcode is producing a corrupt binary. It seems like my metal buffers are being mis-aligned or something. The problem showed up after changing the Deployment to iOS 15. It had been at iOS 13 and built and ran without any related issues - for years that I've been developing this app. So at some point after changing the target to iOS 15, compiling the shaders went from about 0.001 seconds to 30 seconds. When that happens, the GPU will also hang with the messages: GPUDebug] Invalid device load executing kernel function "computeArtPointsToRender" encoder: "0", dispatch: 0, at offset 22080048 Shaders.metal:1290:41 - computeArtPointsToRender() To fix the issue, I have to change the build target to iOS 13, clean, build, change to iOS 15, clean, build and then works again as expected (until it doesn't at some random point or until I have restarted the machine). This is 100% reproducible: Restart mac Build project Issue occurs Change build target to iOS 13 Clean build folder Build Change build target to iOS 15 Delete derived files Build Works as expected Xcode: Version 13.1 (13A1030d) macOS: 11.5.2 (20G95) Mac mini (M1, 2020) In my 11+ years as a full time iOS developer, I've never encountered such a serious issue with Xcode. If I don't have stable tools, it is impossible for me to develop.

Ever since switching to an M1 Mac for my development, Xcode no longer shows any image previews at break points. Quick Look is not functioning with any images: CGImages, UIIMages, CIImages, MTLTextures, etc. I am working on an image-based app, so this is extremely frustrating. I am running in debug mode. I tried linking to images to show some screenshots but apparently they are not allowed on this forum. Xcode 12.5 macOS 11.3

When using an exclusion path with an UITextView, the text view is not properly wrapping the words for the first and last line in the example shown (lower text). It does render properly using word-wrap with Core Text (top example).(Hmm - the image link I provided in the HTML here works with the preview, but not the post. The example image is at: http i.stack.imgur.com/Z91ge.pngHere is the code for the UITextView (both this and the Core Text example use the same size bezier path, and both use the appropriate corresponding font and paragraph settings; wrap by word and centered):NSString *testText = @"Text Kit exclusion paths ..."; / UIBezierPath *viewPath = [UIBezierPath bezierPathWithRect:CGRectMake(0, 0, 280, 280)]; UIBezierPath *shapePath = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(10, 10, 265, 265)]; viewPath.usesEvenOddFillRule = true; shapePath.usesEvenOddFillRule = true; [shapePath appendPath:viewPath]; NSMutableAttributedString *title = [[NSMutableAttributedString alloc]initWithString:testText]; UIFont *font = [UIFont fontWithName:@"BradleyHandITCTT-Bold" size:14]; [title addAttribute:NSFontAttributeName value:font range:NSMakeRange(0, title.length)]; [title addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(0, title.length)]; NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init]; [paragraphStyle setAlignment:NSTextAlignmentCenter]; [paragraphStyle setLineBreakMode:NSLineBreakByWordWrapping]; [title addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, title.length)]; UITextView *textView = [[UITextView alloc] initWithFrame:CGRectMake(0.0, 370.0, 280, 280)]; textView.textContainerInset = UIEdgeInsetsMake(0,0,0,0); textView.textContainer.exclusionPaths = @[shapePath]; [textView.textContainer setLineBreakMode:NSLineBreakByWordWrapping]; textView.contentInset = UIEdgeInsetsMake(0,0,0,0); textView.attributedText = title; textView.backgroundColor = [UIColor clearColor];It is worth noting that the Text Kit is respecting the word wrapping rules except for the first and (possibly last) line where the text does not actually fit. I need this to work with a UITextView because text entry is required, or I would be done with my Core Text example.I have tried everything I can think of to reliably work-around the issue. I don't fully understand how UITextView is working with Core Text (or I would expect to get the same results which I don’t), so any suggestions would be greatly appreciated.