import { Step } from './Step';
import { Timeline } from './Timeline';
export type OnTickHandler = (elapsedTime: number, step: Step, deltaTime: number) => void;
export type OnStepHandler = (elapsedTime: number, step: Step, deltaTime: number) => void;
export declare class Animator {
    private _pausedTime;
    private _startTime;
    private _lastTime;
    private _timelines;
    private _animationFrame;
    private _onTick?;
    private _onStep?;
    constructor(timelines: Timeline[]);
    get isRunning(): boolean;
    get startTime(): number;
    set startTime(startTime: number);
    onTick(onTick: OnTickHandler): void;
    onStep(onStep: OnStepHandler): void;
    computeFrameAt(time: number): void;
    private loop;
    start(): void;
    stop(): void;
    pause(): void;
    getDuration(): number;
}