High CPU usage (167%) just by scrolling canvasView in the sample project

In the sample project "Drawing with PencilKit", even scrolling by 1 pixel can cause my iPad Pro to use 167% CPU and keep this usage for 2-5 seconds. My iPad got too hot after few minutes that I can't barely put my palm on it.

This a serious problem and could be reprocedure easily:

  • Run the sample "Drawing with PencilKit" on your iPad
  • Open the sample note
  • Select all strokes in the note and duplicate about 7 times (it is just an average number of strokes I write in a page on a note-taking app like GoodNotes).
  • Scroll and watch the CPU usage jumps in Xcode

It is not matter how long you scroll or how many strokes are visible on the screen. If the drawing has that much strokes, the CoreHandwriting objects will eat all the CPU.

I hope it got fixed soon because it make apps with PencilKit consume too much baterry, getting too hot and we receive many bad review because of it :(

Many thank to Pencil and Paperteam for developing this Framework btw, this framework is awesome, but it could be better, I believe.

High CPU usage (167%) just by scrolling canvasView in the sample project
 
 
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