Open source
Retina
A SwiftUI spirograph — three trochoid curves, drawn by hand, animated, and pinched.
What it is
A small, hand-written SwiftUI toy: three Shapes — a hypotrochoid, an epitrochoid and a hypocycloid — built from raw CGPoint loops, animated on a timer, zoomed with a pinch, regenerated from a menu of buttons. Every curve is a standard trochoid parametric equation with a reveal parameter that decides how far around the circle to draw.
Why it is here
It is the direct ancestor of this site's masthead. The same three formulas, the same rotation multipliers, the same habit of letting the curves spin at different rates relative to each other — the spirograph on the home page is Retina's drawing model ported to a canvas. Publishing the original is publishing the sketchbook.
Status
Builds clean on current Xcode with zero warnings and zero code changes. The pending hygiene pass is exactly what the audit found and no more: untracked user data in the repo, a leading-zero literal in an unused colour file, and a README that describes the app as it is.