export type SwingVec3 = readonly [number, number, number];
export interface GrappleSwingConfig {
    /** Rope shortens by this many units/s while `reeling`. Default `0` (fixed length). */
    reelSpeed?: number;
    minLength?: number;
    /** Extra spring pull toward the anchor when the rope is taut (elastic feel); default `0` (hard constraint only). */
    stiffness?: number;
    /** Velocity damping per second while attached; default `0.1`. */
    damping?: number;
}
export interface GrappleSwingState {
    attached: boolean;
    anchor: SwingVec3 | null;
    ropeLength: number;
}
export interface GrappleSwingStep {
    position: SwingVec3;
    velocity: SwingVec3;
}
/**
 * A rope-swing constraint for kinematic controllers (#282.5) — the walk-controller-compatible
 * sibling of `physics/traversal`'s rigid-body `Grapple`. Fire at an anchor, feed each frame's
 * integrated position/velocity through `step`, and commit what comes back (via `beforeCommit`
 * or `setPose`): positions beyond the rope clamp to its sphere and velocity loses its outward
 * radial component, which is exactly a pendulum swing.
 */
export interface GrappleSwing {
    fire(anchor: SwingVec3, from: SwingVec3): void;
    release(): void;
    state(): GrappleSwingState;
    /** Puts a {@link GrappleSwing.state} back; `anchor: null` detaches. */
    restore(next: GrappleSwingState): void;
    /** Constrain one frame. `reeling` shortens the rope; returns the corrected position/velocity. */
    step(position: SwingVec3, velocity: SwingVec3, dt: number, reeling?: boolean): GrappleSwingStep;
}
/**
 * Grappling-hook rope swing physics with anchor, pendulum motion, and reel-in.
 *
 * @capability grapple-swing grappling-hook rope swing physics with reel-in
 */
export declare function createGrappleSwing(config?: GrappleSwingConfig): GrappleSwing;