Hello, I have a question about something mentioned in the Human Interface Guidelines in the section on image size and resolution ( https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/image-size-and-resolution/ ). It says to use an 8x8 pixel grid when creating images. What does it mean by this exactly - to ensure that the width and height of the image are multiples of 8, or to ensure that all image details have a size of at least 8x8? What kind of image could I create to see the effect of not doing it right? (I have placeholder artwork in my app, which is not 8x8 in either sense, and I don't notice it looking any different on different resolution iOS simulators. The placeholder artwork isn't meant to be very good anyway though).

Hello,In the simulator (iOS 12.2, multiple phone versions tried), I had some code which presented one view on top of another, usingpresent(childVC, animated: false, completion: nil)where childVC is the view controller for the new view. Even though this view had had its windowframe set to the same frame as the window that contained the original view, the new view appeared smaller (in the upper left corner of the screen) with the old view taking up the rest of the space behind it. I couldn't figure out the cause of this, so I worked around it by setting the rootViewController of the window of the application delegate to the new view, which worked fine, except that when going back to the original view (dismissing childVC) and presenting another new view on top of it, I would get the message "Presenting view controllers on detached view controllers is discouraged".Now working on iOS 13.1, this workaround does not work. It results in a blank screen, after the view pops up briefly; viewWillDisappear is getting called for some reason. If I take out the part setting rootViewController of the window to childVC, then it works fine.I will note that these errors affect only the first view controller presented (after the original view controller that was originally the rootViewController of the window). If I move on to another view by pressing one of the buttons in my new view (in the case of the black screen, this can be done by setting a break point before the screen goes black and clicking on one of the buttons before continuing), then everything works as expected.I am looking for some insight into these errors; any help appreciated.