iOS 13 was presented by the Apple company in 2019 with many unexpected novelties, but also many functions that no one thought possible until now. One of them is related to iPadOS, the iOS 13 version for the iPad, the Apple company allowing developers to access information about the latency of the Apple Pencil, but with certain limits, as it objects.
Apple has reduced the latency of the Apple Pencil from 20ms to 9ms, and developers making apps for the stylus will be able to access statistics about its latency in iOS 13. Although Apple provides access to this information, developers will not see what happens at the 9ms latency , but at 13ms, because Apple could not have provided access to what it has without exposing other "sensitive" information.
Apple says it has managed to substantially reduce the latency of the Apple Pencil using optimizations for graphics rendering using Metal, by better predicting tingers, and processing in the middle of events. Third-party apps will be able to offer latency almost as good as Apple's apps for the Apple pencil, and it will be interesting to see what they manage to offer for customers.
"Note that we achieve low latency through a combination of several techniques: Metal rendering optimizations, touch prediction, and mid-frame event processing. Third-party developers can achieve similar low-latency drawing experiences by taking advantage of Metal rendering and touch prediction best practices covered in the WWDC Sessions I've referenced below. With these you can achieve almost all of the improvements you've seen in PencilKit drawing with your own renderer. (There does remain a small gap: 4 ms of our improvement comes from a technique called mid-frame event processing; we are looking for ways to expose this capability to third party engines in the future, but for this year this one was only safely achievable through tight integration within our frameworks)."
