export declare class SimplexNoise2D {
    private readonly _NORM_2D;
    private readonly _SQUISH_2D;
    private readonly _STRETCH_2D;
    private readonly _base2D;
    private readonly _gradients2D;
    private _lookup;
    private readonly _lookupPairs2D;
    private readonly _p2D;
    private _perm;
    private _perm2D;
    constructor();
    noise(x: number, y: number): number;
    seed(clientSeed: number): void;
    private _contribution2D;
}