import type { Engine } from '../engine';
import { FilterMode, Framebuffer, RenderTextureFormat } from './framebuffer';
export declare class RenderTargetPool {
    engine: Engine;
    private temporaryRTs;
    private currentFrame;
    private readonly maxUnusedFrames;
    constructor(engine: Engine);
    /**
     * 清理 RenderTarget 池
     * @param force - 是否强制清理所有未占用的 RT
     * @param framesOffset - 自定义未使用帧数阈值，-1 表示使用默认值
     */
    flush(force?: boolean, framesOffset?: number): void;
    get(name: string, width: number, height: number, depthBuffer?: number, filter?: FilterMode, format?: RenderTextureFormat): Framebuffer;
    /**
     * 释放 RenderTarget，使其可以被复用
     * @param rt - 要释放的 Framebuffer
     */
    release(rt: Framebuffer): void;
    dispose(): void;
}