( function () {

	class EffectComposer {

		constructor( renderer, renderTarget ) {

			this.renderer = renderer;

			if ( renderTarget === undefined ) {

				const parameters = {
					minFilter: THREE.LinearFilter,
					magFilter: THREE.LinearFilter,
					format: THREE.RGBAFormat
				};
				const size = renderer.getSize( new THREE.Vector2() );
				this._pixelRatio = renderer.getPixelRatio();
				this._width = size.width;
				this._height = size.height;
				renderTarget = new THREE.WebGLRenderTarget( this._width * this._pixelRatio, this._height * this._pixelRatio, parameters );
				renderTarget.texture.name = 'EffectComposer.rt1';

			} else {

				this._pixelRatio = 1;
				this._width = renderTarget.width;
				this._height = renderTarget.height;

			}

			this.renderTarget1 = renderTarget;
			this.renderTarget2 = renderTarget.clone();
			this.renderTarget2.texture.name = 'EffectComposer.rt2';
			this.writeBuffer = this.renderTarget1;
			this.readBuffer = this.renderTarget2;
			this.renderToScreen = true;
			this.passes = []; // dependencies

			if ( THREE.CopyShader === undefined ) {

				console.error( 'THREE.EffectComposer relies on THREE.CopyShader' );

			}

			if ( THREE.ShaderPass === undefined ) {

				console.error( 'THREE.EffectComposer relies on THREE.ShaderPass' );

			}

			this.copyPass = new THREE.ShaderPass( THREE.CopyShader );
			this.clock = new THREE.Clock();

		}

		swapBuffers() {

			const tmp = this.readBuffer;
			this.readBuffer = this.writeBuffer;
			this.writeBuffer = tmp;

		}

		addPass( pass ) {

			this.passes.push( pass );
			pass.setSize( this._width * this._pixelRatio, this._height * this._pixelRatio );

		}

		insertPass( pass, index ) {

			this.passes.splice( index, 0, pass );
			pass.setSize( this._width * this._pixelRatio, this._height * this._pixelRatio );

		}

		removePass( pass ) {

			const index = this.passes.indexOf( pass );

			if ( index !== - 1 ) {

				this.passes.splice( index, 1 );

			}

		}

		isLastEnabledPass( passIndex ) {

			for ( let i = passIndex + 1; i < this.passes.length; i ++ ) {

				if ( this.passes[ i ].enabled ) {

					return false;

				}

			}

			return true;

		}

		render( deltaTime ) {

			// deltaTime value is in seconds
			if ( deltaTime === undefined ) {

				deltaTime = this.clock.getDelta();

			}

			const currentRenderTarget = this.renderer.getRenderTarget();
			let maskActive = false;

			for ( let i = 0, il = this.passes.length; i < il; i ++ ) {

				const pass = this.passes[ i ];
				if ( pass.enabled === false ) continue;
				pass.renderToScreen = this.renderToScreen && this.isLastEnabledPass( i );
				pass.render( this.renderer, this.writeBuffer, this.readBuffer, deltaTime, maskActive );

				if ( pass.needsSwap ) {

					if ( maskActive ) {

						const context = this.renderer.getContext();
						const stencil = this.renderer.state.buffers.stencil; //context.stencilFunc( context.NOTEQUAL, 1, 0xffffffff );

						stencil.setFunc( context.NOTEQUAL, 1, 0xffffffff );
						this.copyPass.render( this.renderer, this.writeBuffer, this.readBuffer, deltaTime ); //context.stencilFunc( context.EQUAL, 1, 0xffffffff );

						stencil.setFunc( context.EQUAL, 1, 0xffffffff );

					}

					this.swapBuffers();

				}

				if ( THREE.MaskPass !== undefined ) {

					if ( pass instanceof THREE.MaskPass ) {

						maskActive = true;

					} else if ( pass instanceof THREE.ClearMaskPass ) {

						maskActive = false;

					}

				}

			}

			this.renderer.setRenderTarget( currentRenderTarget );

		}

		reset( renderTarget ) {

			if ( renderTarget === undefined ) {

				const size = this.renderer.getSize( new THREE.Vector2() );
				this._pixelRatio = this.renderer.getPixelRatio();
				this._width = size.width;
				this._height = size.height;
				renderTarget = this.renderTarget1.clone();
				renderTarget.setSize( this._width * this._pixelRatio, this._height * this._pixelRatio );

			}

			this.renderTarget1.dispose();
			this.renderTarget2.dispose();
			this.renderTarget1 = renderTarget;
			this.renderTarget2 = renderTarget.clone();
			this.writeBuffer = this.renderTarget1;
			this.readBuffer = this.renderTarget2;

		}

		setSize( width, height ) {

			this._width = width;
			this._height = height;
			const effectiveWidth = this._width * this._pixelRatio;
			const effectiveHeight = this._height * this._pixelRatio;
			this.renderTarget1.setSize( effectiveWidth, effectiveHeight );
			this.renderTarget2.setSize( effectiveWidth, effectiveHeight );

			for ( let i = 0; i < this.passes.length; i ++ ) {

				this.passes[ i ].setSize( effectiveWidth, effectiveHeight );

			}

		}

		setPixelRatio( pixelRatio ) {

			this._pixelRatio = pixelRatio;
			this.setSize( this._width, this._height );

		}

	}

	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.' );

		}

	} // 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.EffectComposer = EffectComposer;
	THREE.FullScreenQuad = FullScreenQuad;
	THREE.Pass = Pass;

} )();
