export declare function easeLinear(t: number): number;
export declare function easeInCubic(t: number): number;
export declare function easeOutCubic(t: number): number;
export declare function easeInOutCubic(t: number): number;
export declare function easeSpring(t: number): number;
export declare function getEasingFn(name?: string): (t: number) => number;
export declare function interpolateColor(color1: string, color2: string, progress: number): string;
export declare function hashFraction(str: string, salt?: number): number;
export declare function getFloatAnimName(direction: string, seed: string): string;
export declare function computeFloatAmp(cfg: {
    amplitude: number;
    amplitudeRandomness?: number;
}, seed: string): number;
export declare function computeFloatSpeed(cfg: {
    speed: number;
    speedRandomness?: number;
}, seed: string): number;
export declare function getBackgroundStyle(bg: {
    type: string;
    color?: string;
    gradient?: {
        type: string;
        angle?: number;
        colors: string[];
    };
    image?: string;
}): string;
