SWEyeball Saga

Eye 3 is where the sclera stops being a lone disk and becomes an eye. A second SWDisk is layered on top of each sclera to form the iris and pupil — using the exact same class, just with different parameters.

Big Idea 1 — One Class, Two Roles

Both the sclera and the pupil are SWDisk instances. The difference is entirely in the constructor arguments: a large radius and thin stroke for the sclera; a smaller radius and thick stroke for the pupil/iris disk. No new class needed — just reuse what you have.

Big Idea 2 — Thick Stroke Creates the Iris Ring

The iris ring is not a separate shape. It emerges from the stroke weight of the pupil disk (irisThickness = 8). A stroke that thick bleeds outward from the disk edge, forming a wide colored band — the iris — while the dark fill inside becomes the pupil. One disk does both jobs.

Big Idea 3 — pupilFactor Scales the Pupil Proportionally

Rather than hardcoding the pupil radius, it is computed as a fraction of the eye radius:

let pupilFactor = 0.4;
let pupilRadius = eyeRadius * pupilFactor;

This means the whole eye — sclera and pupil together — scales up or down by changing a single variable: eyeRadius.

Big Idea 4 — Shared SWPoint Center

Both the sclera disk and the pupil disk receive the same SWPoint as their center. The pupil is automatically centered on the sclera because they share the same anchor — no manual alignment needed. This shared-reference pattern will matter later when the pupil needs to move independently.

What to Notice

• Click the canvas to toggle the grid on/off and see the eyes unobstructed.
• The iris ring width is controlled by irisThickness — try imagining what happens if it were set to 2 vs. 20.
• Both eyes share the same parameter values (eyeRadius, pupilFactor, irisThickness) — one change propagates to both.

The Road Ahead

The pupils are currently locked to the sclera center. Coming stages will introduce glint highlights, then decouple the pupil's SWPoint from the eye center so it can move — eventually responding to the mouse.