three.js/examples/js/postprocessing/TexturePass.js

( function () {

	class TexturePass extends THREE.Pass {

		constructor( map, opacity ) {

			super();
			if ( THREE.CopyShader === undefined ) console.error( 'THREE.TexturePass relies on THREE.CopyShader' );
			const shader = THREE.CopyShader;
			this.map = map;
			this.opacity = opacity !== undefined ? opacity : 1.0;
			this.uniforms = THREE.UniformsUtils.clone( shader.uniforms );
			this.material = new THREE.ShaderMaterial( {
				uniforms: this.uniforms,
				vertexShader: shader.vertexShader,
				fragmentShader: shader.fragmentShader,
				depthTest: false,
				depthWrite: false
			} );
			this.needsSwap = false;
			this.fsQuad = new THREE.FullScreenQuad( null );

		}
		render( renderer, writeBuffer, readBuffer /*, deltaTime, maskActive */ ) {

			const oldAutoClear = renderer.autoClear;
			renderer.autoClear = false;
			this.fsQuad.material = this.material;
			this.uniforms[ 'opacity' ].value = this.opacity;
			this.uniforms[ 'tDiffuse' ].value = this.map;
			this.material.transparent = this.opacity < 1.0;
			renderer.setRenderTarget( this.renderToScreen ? null : readBuffer );
			if ( this.clear ) renderer.clear();
			this.fsQuad.render( renderer );
			renderer.autoClear = oldAutoClear;

		}
		dispose() {

			this.material.dispose();
			this.fsQuad.dispose();

		}

	}

	THREE.TexturePass = TexturePass;

} )();