( function () {

	/**
 * UnrealBloomPass is inspired by the bloom pass of Unreal Engine. It creates a
 * mip map chain of bloom textures and blurs them with different radii. Because
 * of the weighted combination of mips, and because larger blurs are done on
 * higher mips, this effect provides good quality and performance.
 *
 * Reference:
 * - https://docs.unrealengine.com/latest/INT/Engine/Rendering/PostProcessEffects/Bloom/
 */

	class UnrealBloomPass extends THREE.Pass {

		constructor( resolution, strength, radius, threshold ) {

			super();
			this.strength = strength !== undefined ? strength : 1;
			this.radius = radius;
			this.threshold = threshold;
			this.resolution = resolution !== undefined ? new THREE.Vector2( resolution.x, resolution.y ) : new THREE.Vector2( 256, 256 ); // create color only once here, reuse it later inside the render function

			this.clearColor = new THREE.Color( 0, 0, 0 ); // render targets

			this.renderTargetsHorizontal = [];
			this.renderTargetsVertical = [];
			this.nMips = 5;
			let resx = Math.round( this.resolution.x / 2 );
			let resy = Math.round( this.resolution.y / 2 );
			this.renderTargetBright = new THREE.WebGLRenderTarget( resx, resy );
			this.renderTargetBright.texture.name = 'UnrealBloomPass.bright';
			this.renderTargetBright.texture.generateMipmaps = false;

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

				const renderTargetHorizonal = new THREE.WebGLRenderTarget( resx, resy );
				renderTargetHorizonal.texture.name = 'UnrealBloomPass.h' + i;
				renderTargetHorizonal.texture.generateMipmaps = false;
				this.renderTargetsHorizontal.push( renderTargetHorizonal );
				const renderTargetVertical = new THREE.WebGLRenderTarget( resx, resy );
				renderTargetVertical.texture.name = 'UnrealBloomPass.v' + i;
				renderTargetVertical.texture.generateMipmaps = false;
				this.renderTargetsVertical.push( renderTargetVertical );
				resx = Math.round( resx / 2 );
				resy = Math.round( resy / 2 );

			} // luminosity high pass material


			if ( THREE.LuminosityHighPassShader === undefined ) console.error( 'THREE.UnrealBloomPass relies on THREE.LuminosityHighPassShader' );
			const highPassShader = THREE.LuminosityHighPassShader;
			this.highPassUniforms = THREE.UniformsUtils.clone( highPassShader.uniforms );
			this.highPassUniforms[ 'luminosityThreshold' ].value = threshold;
			this.highPassUniforms[ 'smoothWidth' ].value = 0.01;
			this.materialHighPassFilter = new THREE.ShaderMaterial( {
				uniforms: this.highPassUniforms,
				vertexShader: highPassShader.vertexShader,
				fragmentShader: highPassShader.fragmentShader,
				defines: {}
			} ); // Gaussian Blur Materials

			this.separableBlurMaterials = [];
			const kernelSizeArray = [ 3, 5, 7, 9, 11 ];
			resx = Math.round( this.resolution.x / 2 );
			resy = Math.round( this.resolution.y / 2 );

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

				this.separableBlurMaterials.push( this.getSeperableBlurMaterial( kernelSizeArray[ i ] ) );
				this.separableBlurMaterials[ i ].uniforms[ 'texSize' ].value = new THREE.Vector2( resx, resy );
				resx = Math.round( resx / 2 );
				resy = Math.round( resy / 2 );

			} // Composite material


			this.compositeMaterial = this.getCompositeMaterial( this.nMips );
			this.compositeMaterial.uniforms[ 'blurTexture1' ].value = this.renderTargetsVertical[ 0 ].texture;
			this.compositeMaterial.uniforms[ 'blurTexture2' ].value = this.renderTargetsVertical[ 1 ].texture;
			this.compositeMaterial.uniforms[ 'blurTexture3' ].value = this.renderTargetsVertical[ 2 ].texture;
			this.compositeMaterial.uniforms[ 'blurTexture4' ].value = this.renderTargetsVertical[ 3 ].texture;
			this.compositeMaterial.uniforms[ 'blurTexture5' ].value = this.renderTargetsVertical[ 4 ].texture;
			this.compositeMaterial.uniforms[ 'bloomStrength' ].value = strength;
			this.compositeMaterial.uniforms[ 'bloomRadius' ].value = 0.1;
			this.compositeMaterial.needsUpdate = true;
			const bloomFactors = [ 1.0, 0.8, 0.6, 0.4, 0.2 ];
			this.compositeMaterial.uniforms[ 'bloomFactors' ].value = bloomFactors;
			this.bloomTintColors = [ new THREE.Vector3( 1, 1, 1 ), new THREE.Vector3( 1, 1, 1 ), new THREE.Vector3( 1, 1, 1 ), new THREE.Vector3( 1, 1, 1 ), new THREE.Vector3( 1, 1, 1 ) ];
			this.compositeMaterial.uniforms[ 'bloomTintColors' ].value = this.bloomTintColors; // copy material

			if ( THREE.CopyShader === undefined ) {

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

			}

			const copyShader = THREE.CopyShader;
			this.copyUniforms = THREE.UniformsUtils.clone( copyShader.uniforms );
			this.copyUniforms[ 'opacity' ].value = 1.0;
			this.materialCopy = new THREE.ShaderMaterial( {
				uniforms: this.copyUniforms,
				vertexShader: copyShader.vertexShader,
				fragmentShader: copyShader.fragmentShader,
				blending: THREE.AdditiveBlending,
				depthTest: false,
				depthWrite: false,
				transparent: true
			} );
			this.enabled = true;
			this.needsSwap = false;
			this._oldClearColor = new THREE.Color();
			this.oldClearAlpha = 1;
			this.basic = new THREE.MeshBasicMaterial();
			this.fsQuad = new THREE.FullScreenQuad( null );

		}

		dispose() {

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

				this.renderTargetsHorizontal[ i ].dispose();

			}

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

				this.renderTargetsVertical[ i ].dispose();

			}

			this.renderTargetBright.dispose();

		}

		setSize( width, height ) {

			let resx = Math.round( width / 2 );
			let resy = Math.round( height / 2 );
			this.renderTargetBright.setSize( resx, resy );

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

				this.renderTargetsHorizontal[ i ].setSize( resx, resy );
				this.renderTargetsVertical[ i ].setSize( resx, resy );
				this.separableBlurMaterials[ i ].uniforms[ 'texSize' ].value = new THREE.Vector2( resx, resy );
				resx = Math.round( resx / 2 );
				resy = Math.round( resy / 2 );

			}

		}

		render( renderer, writeBuffer, readBuffer, deltaTime, maskActive ) {

			renderer.getClearColor( this._oldClearColor );
			this.oldClearAlpha = renderer.getClearAlpha();
			const oldAutoClear = renderer.autoClear;
			renderer.autoClear = false;
			renderer.setClearColor( this.clearColor, 0 );
			if ( maskActive ) renderer.state.buffers.stencil.setTest( false ); // Render input to screen

			if ( this.renderToScreen ) {

				this.fsQuad.material = this.basic;
				this.basic.map = readBuffer.texture;
				renderer.setRenderTarget( null );
				renderer.clear();
				this.fsQuad.render( renderer );

			} // 1. Extract Bright Areas


			this.highPassUniforms[ 'tDiffuse' ].value = readBuffer.texture;
			this.highPassUniforms[ 'luminosityThreshold' ].value = this.threshold;
			this.fsQuad.material = this.materialHighPassFilter;
			renderer.setRenderTarget( this.renderTargetBright );
			renderer.clear();
			this.fsQuad.render( renderer ); // 2. Blur All the mips progressively

			let inputRenderTarget = this.renderTargetBright;

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

				this.fsQuad.material = this.separableBlurMaterials[ i ];
				this.separableBlurMaterials[ i ].uniforms[ 'colorTexture' ].value = inputRenderTarget.texture;
				this.separableBlurMaterials[ i ].uniforms[ 'direction' ].value = UnrealBloomPass.BlurDirectionX;
				renderer.setRenderTarget( this.renderTargetsHorizontal[ i ] );
				renderer.clear();
				this.fsQuad.render( renderer );
				this.separableBlurMaterials[ i ].uniforms[ 'colorTexture' ].value = this.renderTargetsHorizontal[ i ].texture;
				this.separableBlurMaterials[ i ].uniforms[ 'direction' ].value = UnrealBloomPass.BlurDirectionY;
				renderer.setRenderTarget( this.renderTargetsVertical[ i ] );
				renderer.clear();
				this.fsQuad.render( renderer );
				inputRenderTarget = this.renderTargetsVertical[ i ];

			} // Composite All the mips


			this.fsQuad.material = this.compositeMaterial;
			this.compositeMaterial.uniforms[ 'bloomStrength' ].value = this.strength;
			this.compositeMaterial.uniforms[ 'bloomRadius' ].value = this.radius;
			this.compositeMaterial.uniforms[ 'bloomTintColors' ].value = this.bloomTintColors;
			renderer.setRenderTarget( this.renderTargetsHorizontal[ 0 ] );
			renderer.clear();
			this.fsQuad.render( renderer ); // Blend it additively over the input texture

			this.fsQuad.material = this.materialCopy;
			this.copyUniforms[ 'tDiffuse' ].value = this.renderTargetsHorizontal[ 0 ].texture;
			if ( maskActive ) renderer.state.buffers.stencil.setTest( true );

			if ( this.renderToScreen ) {

				renderer.setRenderTarget( null );
				this.fsQuad.render( renderer );

			} else {

				renderer.setRenderTarget( readBuffer );
				this.fsQuad.render( renderer );

			} // Restore renderer settings


			renderer.setClearColor( this._oldClearColor, this.oldClearAlpha );
			renderer.autoClear = oldAutoClear;

		}

		getSeperableBlurMaterial( kernelRadius ) {

			return new THREE.ShaderMaterial( {
				defines: {
					'KERNEL_RADIUS': kernelRadius,
					'SIGMA': kernelRadius
				},
				uniforms: {
					'colorTexture': {
						value: null
					},
					'texSize': {
						value: new THREE.Vector2( 0.5, 0.5 )
					},
					'direction': {
						value: new THREE.Vector2( 0.5, 0.5 )
					}
				},
				vertexShader: `varying vec2 vUv;
				void main() {
					vUv = uv;
					gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
				}`,
				fragmentShader: `#include <common>
				varying vec2 vUv;
				uniform sampler2D colorTexture;
				uniform vec2 texSize;
				uniform vec2 direction;

				float gaussianPdf(in float x, in float sigma) {
					return 0.39894 * exp( -0.5 * x * x/( sigma * sigma))/sigma;
				}
				void main() {
					vec2 invSize = 1.0 / texSize;
					float fSigma = float(SIGMA);
					float weightSum = gaussianPdf(0.0, fSigma);
					vec3 diffuseSum = texture2D( colorTexture, vUv).rgb * weightSum;
					for( int i = 1; i < KERNEL_RADIUS; i ++ ) {
						float x = float(i);
						float w = gaussianPdf(x, fSigma);
						vec2 uvOffset = direction * invSize * x;
						vec3 sample1 = texture2D( colorTexture, vUv + uvOffset).rgb;
						vec3 sample2 = texture2D( colorTexture, vUv - uvOffset).rgb;
						diffuseSum += (sample1 + sample2) * w;
						weightSum += 2.0 * w;
					}
					gl_FragColor = vec4(diffuseSum/weightSum, 1.0);
				}`
			} );

		}

		getCompositeMaterial( nMips ) {

			return new THREE.ShaderMaterial( {
				defines: {
					'NUM_MIPS': nMips
				},
				uniforms: {
					'blurTexture1': {
						value: null
					},
					'blurTexture2': {
						value: null
					},
					'blurTexture3': {
						value: null
					},
					'blurTexture4': {
						value: null
					},
					'blurTexture5': {
						value: null
					},
					'bloomStrength': {
						value: 1.0
					},
					'bloomFactors': {
						value: null
					},
					'bloomTintColors': {
						value: null
					},
					'bloomRadius': {
						value: 0.0
					}
				},
				vertexShader: `varying vec2 vUv;
				void main() {
					vUv = uv;
					gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
				}`,
				fragmentShader: `varying vec2 vUv;
				uniform sampler2D blurTexture1;
				uniform sampler2D blurTexture2;
				uniform sampler2D blurTexture3;
				uniform sampler2D blurTexture4;
				uniform sampler2D blurTexture5;
				uniform float bloomStrength;
				uniform float bloomRadius;
				uniform float bloomFactors[NUM_MIPS];
				uniform vec3 bloomTintColors[NUM_MIPS];

				float lerpBloomFactor(const in float factor) {
					float mirrorFactor = 1.2 - factor;
					return mix(factor, mirrorFactor, bloomRadius);
				}

				void main() {
					gl_FragColor = bloomStrength * ( lerpBloomFactor(bloomFactors[0]) * vec4(bloomTintColors[0], 1.0) * texture2D(blurTexture1, vUv) +
						lerpBloomFactor(bloomFactors[1]) * vec4(bloomTintColors[1], 1.0) * texture2D(blurTexture2, vUv) +
						lerpBloomFactor(bloomFactors[2]) * vec4(bloomTintColors[2], 1.0) * texture2D(blurTexture3, vUv) +
						lerpBloomFactor(bloomFactors[3]) * vec4(bloomTintColors[3], 1.0) * texture2D(blurTexture4, vUv) +
						lerpBloomFactor(bloomFactors[4]) * vec4(bloomTintColors[4], 1.0) * texture2D(blurTexture5, vUv) );
				}`
			} );

		}

	}

	UnrealBloomPass.BlurDirectionX = new THREE.Vector2( 1.0, 0.0 );
	UnrealBloomPass.BlurDirectionY = new THREE.Vector2( 0.0, 1.0 );

	THREE.UnrealBloomPass = UnrealBloomPass;

} )();