This is such a fantastic post on how Apple sweats certain almost unnoticeable design details.
I picked up a whole bunch of nuggets reading this article:
…iPhone X rounded screen corners don’t use the classic rounding method where you move in a straight line and then arc using a single quadrant of a circle. Instead, the math is a bit more complicated. Commonly called a squircle, the slope starts sooner, but is more gentle.
Here' the wikipedia link to the mathematical shape Squircle.
The aforementioned article follows another link which has more gems:
Apple doesn’t have the patent on this. Any company can bring their surfaces to this degree of quality. So why don’t they? Companies used to have more excuses. It used to be that engineering CAD tools weren’t as concerned about this sort of thing. Or engineers might not have been expert in that module of their CAD tools. Or surface design tools and engineering tools didn’t play well together. Or its importance to the bottom line wasn’t recognized.
I got to admit, once I learnt of this shape —and how beautiful it looks when applied to hardware— I can’t stop seeing the absence of this shape in competing products.
Keep your friends close ;)