import type { IEventContainer } from "../../collection/EventContainer";
export declare class PhysicsMaterial2D {
    private readonly _onChangedEvent;
    private _friction;
    private _bounciness;
    constructor(friction?: number, bounciness?: number);
    get friction(): number;
    set friction(value: number);
    get bounciness(): number;
    set bounciness(value: number);
    get onChanged(): IEventContainer<() => void>;
    copy(other: PhysicsMaterial2D): void;
    clone(): PhysicsMaterial2D;
}