/**
 * Inertia → spring handoff utilities (axis-only, pure, testable).
 *
 * Implements exponential velocity decay until crossing a bound, then hands off
 * to a damped spring targeting the nearest boundary. If out-of-bounds at t=0,
 * spring starts immediately.
 *
 * This module is SSR-safe and holds no references to the DOM or timers.
 */
/** Current position and velocity on a single axis. */
export type AxisState = {
    value: number;
    velocity: number;
};
/** Min/max boundary pair for clamping an axis. */
export type Bounds = {
    min: number;
    max: number;
};
/**
 * Parameters controlling the inertia decay and boundary spring phases.
 *
 * @see deriveBoundaryPhysics
 */
export type InertiaHandoffOptions = {
    timeConstantMs: number;
    restDelta: number;
    restSpeed: number;
    bounceStiffness: number;
    bounceDamping: number;
};
/** Value returned by each step of the inertia/spring simulation. */
export type StepResult = {
    value: number;
    done: boolean;
};
/**
 * Create a stepper that yields a value at each elapsed time. Handoff from
 * inertia to spring when crossing the bounds.
 *
 * @param initial Starting position and velocity on the axis.
 * @param bounds Min/max boundaries for the axis.
 * @param opts Physics parameters for decay and boundary spring.
 * @returns A function that accepts elapsed time in ms and returns the current `StepResult`.
 *
 * @example
 * ```ts
 * const step = createInertiaToBoundary(
 *     { value: 50, velocity: 200 },
 *     { min: 0, max: 300 },
 *     { timeConstantMs: 350, restDelta: 0.5, restSpeed: 10, bounceStiffness: 500, bounceDamping: 25 }
 * )
 * const { value, done } = step(16) // advance 16 ms
 * ```
 */
export declare const createInertiaToBoundary: (initial: AxisState, bounds: Bounds, opts: InertiaHandoffOptions) => ((tMs: number) => StepResult);