/**
 * Live config for the cursor "bend" effect — a local liquid dent.
 *
 * The cursor carries a blob of displacement that rides the ring: moving
 * toward the button's centre dents the edge inward, moving away drags it
 * outward, and on release the bulge springs back. Implemented as an SVG
 * `feDisplacementMap` over the whole MetalFx root (button, ring, glow), with
 * the vector field regenerated each frame into a small canvas.
 *
 * Mutable singleton, read every frame by `useBend`.
 */
export interface BendConfig {
    enabled: boolean;
    /** What deforms. `ring` = the metal canvas only; button content and glow
     *  stay rigid. `all` = the whole MetalFx root. */
    applyTo: 'ring' | 'all';
    /** Global amplitude multiplier on the whole displacement field. */
    strength: number;
    /** Time for the effect to ease in after the cursor arrives, ms. Without
     *  this the directional spring lands the dent in 2–3 frames — a pop. */
    fadeInMs: number;
    /** Time for the effect to ease out after the cursor leaves, ms. */
    fadeOutMs: number;
    /** Low-pass on the field's *target* before the spring sees it, ms. A fast
     *  sweep across the ring flips press→pull and swings the direction vector
     *  within a frame; this keeps the dent from snapping to each new target. */
    smoothMs: number;
    /** How far beyond the element's edge the cursor is still felt, CSS px. */
    reach: number;
    /** Area of the directional bend (gaussian σ), CSS px. */
    blob: number;
    /** Area of the liquid push (gaussian σ), CSS px. Independent of `blob`. */
    liquidBlob: number;
    /** Displacement cap, CSS px. Also sets the filter's `scale`. */
    maxDisp: number;
    /** Displacement px produced per 100 px/s of cursor speed — a transient
     *  kick on fast moves. 0 disables. */
    gain: number;
    /** Position-based press: dent px per px the cursor sits inside the ring's
     *  edge, pushing toward the centre. Holds while the cursor stays. */
    pressGain: number;
    /** Position-based pull: bulge px per px the cursor sits outside the edge
     *  (within `reach`), dragging the ring toward the cursor — the sticky part. */
    pullGain: number;
    /** Extra inward dent (toward element centre) while pressed, px. */
    press: number;
    /** Radial push away from the contact point, px at full pressure. This is
     *  the divergent part of the field — it *stretches* material rather than
     *  sliding it, so the stroke thins under the cursor and bulges around it.
     *  Pressure is 1 with the cursor on the ring, fading to 0 at `reach`. */
    liquid: number;
    /** Distance from the ring (either side) over which liquid pressure fades
     *  to zero, px. Keep this small — a large value lets a cursor sitting
     *  inside the button push the whole ring outward, which reads as a scale. */
    liquidReach: number;
    /** Spring constant for the liquid push. Lower = slower swell. */
    liquidStiffness: number;
    /** Damping for the liquid push. Below 2·√k it overshoots on release. */
    liquidDamping: number;
    /** Spring on the displacement vector — snap back speed. */
    stiffness: number;
    /** Below 2·√(k·m) the surface wobbles after release. */
    damping: number;
    mass: number;
    /** Blob-centre tracking, as a per-frame lerp at 60 Hz (0..1); applied
     *  time-based so 120 Hz pointers don't track twice as hard. Lower = the
     *  blob lags and stretches behind the cursor — stickier. */
    follow: number;
    /** Map resolution multiplier. 1 = one texel per CSS px, 2 = device parity
     *  on a 2× display. Steps in the field are visible below device parity. */
    mapRes: number;
    /** Post-displacement blur, CSS px. `feDisplacementMap` samples the source
     *  nearest-neighbour, which shows as stepping where material is stretched;
     *  a quarter-pixel blur hides it. 0 disables. */
    smooth: number;
}
export declare const BEND_DEFAULTS: Readonly<BendConfig>;
export declare const BEND: BendConfig;
export declare function setBendConfig(patch: Partial<BendConfig>): void;
export declare function resetBendConfig(): void;