import type { ArrayVector4D } from "./types.js";
/**
 * Projects one 4D vector onto another.
 * @param {ArrayVector4D} xyzw1 - First vector as `[x, y, z, w]`
 * @param {ArrayVector4D} xyzw2 - Second vector as `[x, y, z, w]` to project onto
 * @param {number} [m1] - Optional current magnitude (default: `magnitude4D(xyzw1)`)
 * @param {number} [m2] - Optional current magnitude (default: `magnitude4D(xyzw2)`)
 * @returns {ArrayVector4D} The projected vector
 */
export declare const project4D: (xyzw1: ArrayVector4D, xyzw2: ArrayVector4D, m1?: number, m2?: number) => ArrayVector4D;