export declare class PerlinNoise {
    private readonly _grad4;
    private readonly _gradP;
    private readonly _p;
    private readonly _perm;
    constructor();
    noise2d(x: number, y: number): number;
    noise3d(x: number, y: number, z: number): number;
    noise4d(x: number, y: number, z: number, w: number): number;
    seed(inputSeed: number): void;
    private _fade;
    private _lerp;
}