自分用pingpong buffer

import * as THREE from 'three';
import { Scene, OrthographicCamera, WebGLRenderer, Vector3, MeshBasicMaterial, Texture } from 'three';


export class FilpFlopSceneBase{

    scene                 :Scene;
    camera                :OrthographicCamera;
    renderTarget1         :THREE.WebGLRenderTarget;
    renderTarget2         :THREE.WebGLRenderTarget;
    feedbackMaterial      :THREE.ShaderMaterial;
    feedbackBgMesh        :THREE.Mesh;
    pingpong:boolean = true;
    uniforms:{ [uniform: string]: THREE.IUniform } ;
    mainRenderer: THREE.WebGLRenderer;

    constructor(
        sizeX:number,
        sizeY:number,
        sharaderParams:THREE.ShaderMaterialParameters
    ){
        
        //super();
        
        this.scene = new THREE.Scene();
 
        //オフスクリーンレンダリング用のカメラ
        this.camera = new OrthographicCamera();
        
        this.camera.left    =   -1;
        this.camera.right   =   1;
        this.camera.top     =   1;
        this.camera.bottom  =   -1;

        this.camera.near = 0.1;
        this.camera.far = 10;
        this.camera.position.set(0,0,1);
        this.camera.lookAt(new Vector3());

        //レンダーターゲットオブジェクト
        this.renderTarget1 = new THREE.WebGLRenderTarget(sizeX,sizeY);
        this.renderTarget2 = new THREE.WebGLRenderTarget(sizeX,sizeY);
        /*
        this.renderTarget1.texture.minFilter = THREE.NearestFilter;
        this.renderTarget1.texture.magFilter = THREE.NearestFilter;
        this.renderTarget2.texture.minFilter = THREE.NearestFilter;
        this.renderTarget2.texture.magFilter = THREE.NearestFilter;               
        */
        //feedback用
        let planeGeometry = new THREE.PlaneGeometry(2,2,1,1);
        this.feedbackMaterial = new THREE.ShaderMaterial(sharaderParams);
        this.feedbackBgMesh = new THREE.Mesh(planeGeometry,this.feedbackMaterial);
        this.scene.add(this.feedbackBgMesh);

        //uniformを格納
        this.uniforms = sharaderParams.uniforms;
    }

    getTex():Texture{
        
        return this.pingpong?this.renderTarget2.texture:this.renderTarget1.texture;

    }

    clearTargets(){
        this.mainRenderer.setClearColor(0x000000,1.0);
        this.mainRenderer.setRenderTarget(this.renderTarget1);
        this.mainRenderer.clear();
        this.mainRenderer.setRenderTarget(this.renderTarget2);
        this.mainRenderer.clear();
        this.mainRenderer.setRenderTarget(null);
    }

    render(renderer:WebGLRenderer){
        
        this.mainRenderer = renderer;
        let tex = this.pingpong?this.renderTarget1:this.renderTarget2;
        renderer.setRenderTarget(tex);
        renderer.setClearColor(0x000000,0.0);
        renderer.render(this.scene,this.camera);
        renderer.setRenderTarget(null);
        this.pingpong = !this.pingpong;

    }

}