import type { ArrayVector2D } from "./types.js";
/**
 * Reflects the vector across a normal vector.
 * The normal vector should be normalized (unit length).
 * @param {ArrayVector2D} xy - Vector as `[x, y]` to reflect
 * @param {ArrayVector2D} normal - Normal vector to reflect across (must be normalized)
 * @returns {ArrayVector2D} The reflected vector
 */
export declare const reflect2D: (xy: ArrayVector2D, normal: ArrayVector2D) => ArrayVector2D;