SWEyeball Saga

Every complex shape starts somewhere simple. Eye 1 is that starting point for the SWEyeball Saga: two plain white disks on a grid — nothing more. No pupils, no glints, no interaction. Just the question: what is the minimum structure needed to place an eye-shaped object in space?

Big Picture — What This Stage Establishes

The answer turns out to be three things working together:

1. A coordinate system (SWGrid) — The canvas is mapped to a user-unit space (−10 to +10 on both axes). All positions and sizes are expressed in those units, not pixels. This means the sketch is resolution-independent from the very first line of code, and the math stays intuitive: a radius of 2 means 2 user-units, not 2 pixels.
2. A center anchor (SWPoint) — Each disk owns a named, colored center point. In Eye 1, the left eye center is a green SWPoint labeled “A” at (−3, 6); the right is a red SWPoint labeled “B” at (3, 6). Giving the center point its own identity matters: later stages will move it independently to make the pupil look around.
3. A styled disk (SWDisk) — Each sclera is a SWDisk with a white fill, a black (or gray) stroke, and a radius of 2 user-units. The disk delegates all color management to SWColor, so HSB values and alpha are handled cleanly even at this earliest stage.

Why Start Here?

Starting with just the sclera — and nothing else — forces clear answers to foundational design questions before complexity arrives:

• What unit system will the whole eyeball use? → Grid user-units, decided here.
• What object owns the center position? → An SWPoint, decided here.
• How are colors passed and stored? → As SWColor instances, decided here.
• Should the disk show its center point? → Yes (shouldShowCenter = true), useful for debugging placement in early stages.

These decisions carry through every subsequent stage unchanged. Eye 2 adds a pupil disk; Eye 3 adds glints; later stages add drag and the look-at constraint — but all of them build directly on the structure laid out here.

What to Notice in the Sketch

• The two disks differ only in their stroke color (swBlack vs swLightGray) — a preview of how easily SWColor variations will style individual eye components.
• Each center point is visible and labeled. In later stages these center points move; watching them here with no motion makes their role as positional anchors obvious.
• A second test point (testPt2) is created as a SWPoint.copy() of the first and then repositioned — demonstrating the copy-then-move pattern that the pupil will use in Eye 2.
• Clicking the canvas toggles the grid on and off — the coordinate axes and grid lines are part of SWGrid, not drawn manually.

The Road Ahead

Eye 1 → Eye 2 adds a second SWDisk as the pupil, offset from the sclera center.
Eye 3 → introduces glint disks computed from polar offsets.
Eyes 4–6 → wire up mouse drag and the sclera-boundary constraint.
Eyes 7–9 → refine geometry and add programmatic look-at control.
Eye 10 → encapsulates everything into the reusable SWEyeball class.