Coordinate Transforms in iOS using Swift, Part 0: The Problems

“Hi, my name is Gary, and I get flustered figuring out coordinate transforms in iOS.”

“Hi, Gary!” the crowd replies. Some smile. Some grimace, reminded of their own struggles.

Side-by-side illustrations of the coordinate systems of UIKit and CoreGraphics. CoreGraphics is also labeled as Quartz.
UIKit (UIView) and CoreGraphics (CGImage) coordinate systems, copied from https://medium.com/mobile-app-development-publication/access-cgcontext-in-ios-for-drawing-154d7d02fc04

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