Module anim 

Time-driven animation primitives: easing, tweens, and frame cycles. Time-driven animation primitives for retained and immediate paints.

Everything here is a pure function of a caller-supplied clock — a Duration since an arbitrary epoch — so animated paints stay deterministic and testable. Retained components read the clock from crate::PaintCtx::now and request a future repaint with crate::PaintCtx::wake; immediate-mode painters call the same types with their own elapsed time.

Three shapes cover terminal animation:

• Frames: periodic glyph cycles (spinners, pulses) that run while a state holds and never finish.
• Tween: finite eased interpolations (color fades, progress smoothing) that settle, and can be retargeted mid-flight without a visual jump.
• Reveal: a paced cursor chasing a growing unit total (streamed text), catching up smoothly and settling once even.

Components get all of this declaratively: the anim, ease, and spin properties tween fg/bg/bc colors, gradient endpoints, w/h sizes, and gradient rotation on any component without custom paint code — see crate::Props::anim, crate::Props::ease, and crate::Props::spin. The shimmer property sweeps a Shimmer brightness crest across <text>, the reveal property paces streamed <text> content through a [Reveal] cursor, and the hover and lift properties ride the same clock: pointer-driven border chrome and elevation ease through their declared anim/ease, and snap without one.

Structs

Frames

A periodic glyph cycle on a caller-supplied clock.

Reveal

A paced cursor over streamed units — grapheme clusters, rows, blocks — that chases a growing total and settles once even with it.

Shimmer

A brightness crest sweeping across one line of cells.

Tween

A finite eased interpolation between two values on a caller-supplied clock.

Enums

Easing

Easing curve applied to a tween’s normalized progress.

Constants

FRAME

Repaint cadence for continuously changing values (mid-flight tweens, gradient spins): fast enough to read as motion in a terminal, slow enough to stay cheap. Pass now + FRAME to crate::PaintCtx::wake.

Traits

Lerp

Values a Tween can interpolate.