three.js/examples/js/postprocessing/Pass.js

( function () {

	class Pass {

		constructor() {

			// if set to true, the pass is processed by the composer
			this.enabled = true;

			// if set to true, the pass indicates to swap read and write buffer after rendering
			this.needsSwap = true;

			// if set to true, the pass clears its buffer before rendering
			this.clear = false;

			// if set to true, the result of the pass is rendered to screen. This is set automatically by EffectComposer.
			this.renderToScreen = false;

		}
		setSize() {}
		render() {

			console.error( 'THREE.Pass: .render() must be implemented in derived pass.' );

		}
		dispose() {}

	}

	// Helper for passes that need to fill the viewport with a single quad.

	const _camera = new THREE.OrthographicCamera( - 1, 1, 1, - 1, 0, 1 );

	// https://github.com/mrdoob/three.js/pull/21358

	const _geometry = new THREE.BufferGeometry();
	_geometry.setAttribute( 'position', new THREE.Float32BufferAttribute( [ - 1, 3, 0, - 1, - 1, 0, 3, - 1, 0 ], 3 ) );
	_geometry.setAttribute( 'uv', new THREE.Float32BufferAttribute( [ 0, 2, 0, 0, 2, 0 ], 2 ) );
	class FullScreenQuad {

		constructor( material ) {

			this._mesh = new THREE.Mesh( _geometry, material );

		}
		dispose() {

			this._mesh.geometry.dispose();

		}
		render( renderer ) {

			renderer.render( this._mesh, _camera );

		}
		get material() {

			return this._mesh.material;

		}
		set material( value ) {

			this._mesh.material = value;

		}

	}

	THREE.FullScreenQuad = FullScreenQuad;
	THREE.Pass = Pass;

} )();