import { EasingFunction } from "../easing";
import { Module, ModuleObject } from "../module";
import { Particle } from "../particle";
import { ParticleEffect } from "../particleEffect";
import { Velocity } from "../types";
declare type ParticleWithInitialVelocity = Particle & {
    /**
     * Saved initial velocity of particle. This is cached when particle is added.
     */
    _velocityOverLifetime_initialVelocity?: Velocity;
};
/**
 * Module that deaccelerates particle velocity over its lifetime.
 *
 * The direction of the deacceleration is based on the initial velocity of each particle.
 * For this reason, you should ensure that the module that initializes particle velocity is listed BEFORE this module!
 *
 * Deacceleration animation can be customized with `easing` property.
 *
 * This module modifies `Particle.velocity` property, but does not reassign it so this can be combined with other modules which affect particle velocity.
 *
 * @module
 * @category    Modifier
 * easing {
 *      @tooltip        TODO
 *      @type           EasingFunction
 *      @defaultValue   easeOutSine
 * }
 */
export declare class DeaccelerationOverLifetime extends Module {
    /**
     * Easing function that controls the animation of velocity.
     *
     * Assign via `EasingFunctions` export.
     */
    easing: EasingFunction;
    init(): void;
    handleParticleAdd: (particle: ParticleWithInitialVelocity) => void;
    update(dt: number): void;
    /**
     * Wrap the properties of the module into a JSON containing only primitive JavaScript data types
     * (such as numbers, strings, etc.) that can be serialized into strings natively.
     */
    toObject(): ModuleObject;
    static fromObject(particleEffect: ParticleEffect, object: ModuleObject, hideWarnings: boolean): DeaccelerationOverLifetime;
    /**
     * Serializable identifier for the module.
     *
     * This must be unique between all existing Modules in the library.
     */
    static moduleTypeId: string;
}
export {};