Struct ZoomPath 

pub struct ZoomPath { /* private fields */ }

A smooth zoom-and-pan path between two viewport framings, after van Wijk & Nuij (Smooth and efficient zooming and panning, 2003) — the same path d3.interpolateZoom implements. A framing is (cx, cy, w): the content-space point at the viewport’s center and the content-space width the viewport shows (inner.w / zoom). The path zooms out, translates, and zooms back in along a hyperbolic arc, so mid-flight frames keep both endpoints’ context on screen instead of tunneling across the canvas at full magnification.

Pure math with no clock: sample with a progress fraction t ∈ [0, 1] and pace t however you like. length is the perceptual path length S — the natural basis for a duration. This is a Layer-3 primitive: the smooth ViewportRequests ride on it, and a custom host or widget can sample it directly.

Implementations

impl ZoomPath

pub fn new(start: (f32, f32, f32), end: (f32, f32, f32)) -> Self

The path from start to end, each a (cx, cy, w) framing with w > 0 (non-positive widths are clamped to a tiny epsilon).

pub fn length(&self) -> f32

The perceptual path length S, in ρ-normalized units: 0 for a no-op path, ~1 per zoom factor of e^√2 ≈ 4, growing with the translation distance relative to the viewport width.

pub fn sample(&self, t: f32) -> (f32, f32, f32)

The framing at progress t (clamped to [0, 1]). The endpoints return the constructor inputs bit-exactly, so arrival lands on the resolved target with no float drift.

Trait Implementations

impl Clone for ZoomPath

fn clone(&self) -> ZoomPath

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for ZoomPath

impl Debug for ZoomPath

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.