/**
 * 缓动函数
 * https://aaron-bird.github.io/2019/03/30/%E7%BC%93%E5%8A%A8%E5%87%BD%E6%95%B0(easing%20function)/
 */
export declare function easeInOutQuad({ currentTime, targetTime, startValue, endValue, }: {
    currentTime: number;
    targetTime: number;
    startValue: number;
    endValue: number;
}): number;