import { SpringPreset } from '../core/spring';
import { IconInput } from '../core/types';
/** Target element, structurally typed: any object with setAttribute works
 *  (a real SVGPathElement, or a fake in tests). */
export interface PathEl {
    setAttribute: (name: string, value: string) => void;
}
/** Morph physics: named preset or custom spring. */
export interface MorphOptions {
    stiffness?: number;
    damping?: number;
}
/** Reduced-motion policy. `"never"` (default): morphs always animate,
 *  ignoring the OS setting. `"user"`: while the OS reduce-motion setting is
 *  on, `morphTo` degrades to an instant `set`. `"always"`: every `morphTo`
 *  jumps (tests, screenshots). */
export type ReducedMotionMode = 'never' | 'user' | 'always';
export interface CreateMorphOptions {
    /** Reduced-motion policy; also live via the `reducedMotion` property. */
    reducedMotion?: ReducedMotionMode;
}
export interface Morph {
    /** Animates toward the icon with spring physics. Interruptible: mid-flight
     *  it re-plans from the intermediate shape while preserving velocity. */
    morphTo: (icon: IconInput, spring?: SpringPreset | MorphOptions) => void;
    /** Jumps to the icon without animating (canonical d, no frames). */
    set: (icon: IconInput) => void;
    /** Renders the morph toward `icon` frozen at t (no spring) — the
     *  controlled-mode primitive: scrubbing, gestures, scroll. A later
     *  morphTo takes off from that intermediate shape. */
    seek: (icon: IconInput, t: number) => void;
    /** Current progress (t of the last frame; 1 at rest). Assigning it is
     *  equivalent to seek(target, t) on the active target. */
    progress: number;
    /** Reduced-motion policy, live: assigning it applies to the next morphTo. */
    reducedMotion: ReducedMotionMode;
    /** Unregisters the instance; later calls are no-ops. */
    destroy: () => void;
}
/** Canonical `d` of an icon: the input string verbatim, or the real cubics
 *  quantized to 4 decimals (the at-rest snap; engine-stable bytes so SSR
 *  hydration matches, see fmtCanon in core/serialize). Exported because it
 *  is what a binding renders at SSR/rest before any runtime exists. */
export declare function canonicalD(icon: IconInput): string;
/** Creates the morph instance over a `<path>` and paints the initial icon. */
export declare function createMorph(el: PathEl, icon: IconInput, options?: CreateMorphOptions): Morph;