Thank you for the sample project and the video — both were very helpful. We were able to reproduce the flickering on iPad with Apple Pencil using your sample project. We tested several potential app-level workarounds (deferring contentInset updates, guarding against layout recalculation during active drawing, consolidating CATransaction blocks) but none of them resolved the issue. Based on our investigation, the flicker appears to be occurring within PKCanvasView's internal tile rendering when drawing at non-1x zoom scales, rather than being caused by anything in your app code. Our engineering teams need to investigate this issue, as resolution may involve changes to Apple's software. Please file a bug report, include a small Xcode project and some directions that can be used to reproduce the problem, and post the Feedback number here once you do. I'll check the status next time I do a sweep of forums posts where I've suggested bug reports and post any information about changes I am able to share to
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Developer Tools & Services
SubTopic:
Xcode
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