iOS developer Steve Troughton-Smith found code in iOS 11.3 that contains a mysterious display output codenamed Tatl. The CoreUI framework can now request UI assets in meters, leading some to speculate that this might be referring to Apple AR glasses.

Tatl

Tatl refers to a fairy in the game The Legend of Zelda: Majora’s Mask. In the game, Tatl helps the main character Link interact with the environment. She can provide information when you look at certain objects, people, and enemies.

What the heck is a 'Tatl' display 🤨 And why does CoreUI want to know asset sizes in meters? Can haz iOS AR goggles pls? pic.twitter.com/4iWZF8UUi9 — Steve Troughton-Smith (@stroughtonsmith) March 30, 2018

This sounds like it could be a feature for augmented reality: giving you information when you look at things like landmarks, people, products in stores, etc. The specific code looks like this:

isTatlDisplay (mysterious device)

(mysterious device) isCarDisplay (CarPlay)

(CarPlay) isExternal (AirPlay)

(AirPlay) isMainDisplay (main display of iOS device)

This wasn’t present in iOS 11.2, but it was added in iOS 11.3. Could Apple be slowly adding functionality to iOS to allow for AR glasses? Or, the code could be part of ARKit 1.5 that has been added to iOS 11.3. Sizes in meters are used for ARKit reference images in asset catalogs, as Guilherme Rambo‏ pointed out in reply on Twitter.

Apple also has its own microLED manufacturing plant for a different type of display screen that is designed for mobile devices. However, it’s roughly 3-5 years before we’ll see this technology in a physical product, whether it be an Apple Watch or Apple AR glasses.