Focus

Menu focus navigation for the cards of GREASEPAINT. A controller has no pointer, so every menu carries an ordered ring of focusable ids and exactly one of them is lit; this module walks that ring.

• Focus.open(list, prefer) — open a menu: the ids in stick order, and which starts lit.
• Focus.axis(v, dt) — feed the navigate axis; one flick is one step, a held stick repeats.
• Focus.point(id) — a mouse crossing a row or a finger tapping it moves the focus there.
• Focus.id() / Focus.isFocused(id) — read it.
• Focus.close() — nothing is focused until the next open.
• Focus.release() — let go of a held direction, so a stick held through a transition does not keep walking.

The ring is whatever the card offers, so an interval with three faces and a fourth row is a ring of four and needs nothing said about it here: open takes the list screens.itemIds returns for the phase.

A held stick repeats on a delay measured in seconds AND in frames. On a machine running long frames a single flick can be one frame carrying half a second of dt, and a delay measured only in time turns that flick into two steps.

Fed by game/input/console.inputMap; consumed by game.ui.Screens, which asks it which row to draw lit.