Which Way is Up? Normalized Coordinates in Swift

AKA my struggles with Vision

Photo by Stefan Steinbauer on Unsplash

You know what. It is really annoying being an iOS developer sometimes. People laugh at you in the street (probably, I’m not sure as I don’t go outside that much), usually because you don’t know which way is up.

The Core Issue

I simply didn’t understand which coordinate space vision worked in. Yeah, the documentation presupposes that you understand “normalized coordinate space” but I didn’t. A great deal of pain then occurred.

The outcome is this article.

UIKit

Most of my experience in Swift is with UIKit. This means that the top-left hand corner of the screen is the origin point.

The origin point for UIKit’s UIView subclasses

The paradigm at play here is one that has existed for decades, perhaps because in western countries people read from left-right in a downwards…