/**
 * Octahedron and Quantization encodings based on work by:
 *
 * @link https://github.com/tsherif/mesh-quantization-example
 *
 */

import {
	BufferAttribute,
	Matrix3,
	Matrix4,
	MeshPhongMaterial,
	ShaderChunk,
	ShaderLib,
	UniformsUtils,
	Vector3
} from '../../../build/three.module.js';

class GeometryCompressionUtils {

	/**
		 * Make the input mesh.geometry's normal attribute encoded and compressed by 3 different methods.
		 * Also will change the mesh.material to `PackedPhongMaterial` which let the vertex shader program decode the normal data.
		 *
		 * @param {THREE.Mesh} mesh
		 * @param {String} encodeMethod		"DEFAULT" || "OCT1Byte" || "OCT2Byte" || "ANGLES"
		 *
		 */
	static compressNormals( mesh, encodeMethod ) {

		if ( ! mesh.geometry ) {

			console.error( 'Mesh must contain geometry. ' );

		}

		const normal = mesh.geometry.attributes.normal;

		if ( ! normal ) {

			console.error( 'Geometry must contain normal attribute. ' );

		}

		if ( normal.isPacked ) return;

		if ( normal.itemSize != 3 ) {

			console.error( 'normal.itemSize is not 3, which cannot be encoded. ' );

		}

		const array = normal.array;
		const count = normal.count;

		let result;
		if ( encodeMethod == 'DEFAULT' ) {

			// TODO: Add 1 byte to the result, making the encoded length to be 4 bytes.
			result = new Uint8Array( count * 3 );

			for ( let idx = 0; idx < array.length; idx += 3 ) {

				const encoded = EncodingFuncs.defaultEncode( array[ idx ], array[ idx + 1 ], array[ idx + 2 ], 1 );

				result[ idx + 0 ] = encoded[ 0 ];
				result[ idx + 1 ] = encoded[ 1 ];
				result[ idx + 2 ] = encoded[ 2 ];

			}

			mesh.geometry.setAttribute( 'normal', new BufferAttribute( result, 3, true ) );
			mesh.geometry.attributes.normal.bytes = result.length * 1;

		} else if ( encodeMethod == 'OCT1Byte' ) {

			/**
			* It is not recommended to use 1-byte octahedron normals encoding unless you want to extremely reduce the memory usage
			* As it makes vertex data not aligned to a 4 byte boundary which may harm some WebGL implementations and sometimes the normal distortion is visible
			* Please refer to @zeux 's comments in https://github.com/mrdoob/three.js/pull/18208
			*/

			result = new Int8Array( count * 2 );

			for ( let idx = 0; idx < array.length; idx += 3 ) {

				const encoded = EncodingFuncs.octEncodeBest( array[ idx ], array[ idx + 1 ], array[ idx + 2 ], 1 );

				result[ idx / 3 * 2 + 0 ] = encoded[ 0 ];
				result[ idx / 3 * 2 + 1 ] = encoded[ 1 ];

			}

			mesh.geometry.setAttribute( 'normal', new BufferAttribute( result, 2, true ) );
			mesh.geometry.attributes.normal.bytes = result.length * 1;

		} else if ( encodeMethod == 'OCT2Byte' ) {

			result = new Int16Array( count * 2 );

			for ( let idx = 0; idx < array.length; idx += 3 ) {

				const encoded = EncodingFuncs.octEncodeBest( array[ idx ], array[ idx + 1 ], array[ idx + 2 ], 2 );

				result[ idx / 3 * 2 + 0 ] = encoded[ 0 ];
				result[ idx / 3 * 2 + 1 ] = encoded[ 1 ];

			}

			mesh.geometry.setAttribute( 'normal', new BufferAttribute( result, 2, true ) );
			mesh.geometry.attributes.normal.bytes = result.length * 2;

		} else if ( encodeMethod == 'ANGLES' ) {

			result = new Uint16Array( count * 2 );

			for ( let idx = 0; idx < array.length; idx += 3 ) {

				const encoded = EncodingFuncs.anglesEncode( array[ idx ], array[ idx + 1 ], array[ idx + 2 ] );

				result[ idx / 3 * 2 + 0 ] = encoded[ 0 ];
				result[ idx / 3 * 2 + 1 ] = encoded[ 1 ];

			}

			mesh.geometry.setAttribute( 'normal', new BufferAttribute( result, 2, true ) );
			mesh.geometry.attributes.normal.bytes = result.length * 2;

		} else {

			console.error( 'Unrecognized encoding method, should be `DEFAULT` or `ANGLES` or `OCT`. ' );

		}

		mesh.geometry.attributes.normal.needsUpdate = true;
		mesh.geometry.attributes.normal.isPacked = true;
		mesh.geometry.attributes.normal.packingMethod = encodeMethod;

		// modify material
		if ( ! ( mesh.material instanceof PackedPhongMaterial ) ) {

			mesh.material = new PackedPhongMaterial().copy( mesh.material );

		}

		if ( encodeMethod == 'ANGLES' ) {

			mesh.material.defines.USE_PACKED_NORMAL = 0;

		}

		if ( encodeMethod == 'OCT1Byte' ) {

			mesh.material.defines.USE_PACKED_NORMAL = 1;

		}

		if ( encodeMethod == 'OCT2Byte' ) {

			mesh.material.defines.USE_PACKED_NORMAL = 1;

		}

		if ( encodeMethod == 'DEFAULT' ) {

			mesh.material.defines.USE_PACKED_NORMAL = 2;

		}

	}


	/**
		 * Make the input mesh.geometry's position attribute encoded and compressed.
		 * Also will change the mesh.material to `PackedPhongMaterial` which let the vertex shader program decode the position data.
		 *
		 * @param {THREE.Mesh} mesh
		 *
		 */
	static compressPositions( mesh ) {

		if ( ! mesh.geometry ) {

			console.error( 'Mesh must contain geometry. ' );

		}

		const position = mesh.geometry.attributes.position;

		if ( ! position ) {

			console.error( 'Geometry must contain position attribute. ' );

		}

		if ( position.isPacked ) return;

		if ( position.itemSize != 3 ) {

			console.error( 'position.itemSize is not 3, which cannot be packed. ' );

		}

		const array = position.array;
		const encodingBytes = 2;

		const result = EncodingFuncs.quantizedEncode( array, encodingBytes );

		const quantized = result.quantized;
		const decodeMat = result.decodeMat;

		// IMPORTANT: calculate original geometry bounding info first, before updating packed positions
		if ( mesh.geometry.boundingBox == null ) mesh.geometry.computeBoundingBox();
		if ( mesh.geometry.boundingSphere == null ) mesh.geometry.computeBoundingSphere();

		mesh.geometry.setAttribute( 'position', new BufferAttribute( quantized, 3 ) );
		mesh.geometry.attributes.position.isPacked = true;
		mesh.geometry.attributes.position.needsUpdate = true;
		mesh.geometry.attributes.position.bytes = quantized.length * encodingBytes;

		// modify material
		if ( ! ( mesh.material instanceof PackedPhongMaterial ) ) {

			mesh.material = new PackedPhongMaterial().copy( mesh.material );

		}

		mesh.material.defines.USE_PACKED_POSITION = 0;

		mesh.material.uniforms.quantizeMatPos.value = decodeMat;
		mesh.material.uniforms.quantizeMatPos.needsUpdate = true;

	}

	/**
		 * Make the input mesh.geometry's uv attribute encoded and compressed.
		 * Also will change the mesh.material to `PackedPhongMaterial` which let the vertex shader program decode the uv data.
		 *
		 * @param {THREE.Mesh} mesh
		 *
		 */
	static compressUvs( mesh ) {

		if ( ! mesh.geometry ) {

			console.error( 'Mesh must contain geometry property. ' );

		}

		const uvs = mesh.geometry.attributes.uv;

		if ( ! uvs ) {

			console.error( 'Geometry must contain uv attribute. ' );

		}

		if ( uvs.isPacked ) return;

		const range = { min: Infinity, max: - Infinity };

		const array = uvs.array;

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

			range.min = Math.min( range.min, array[ i ] );
			range.max = Math.max( range.max, array[ i ] );

		}

		let result;

		if ( range.min >= - 1.0 && range.max <= 1.0 ) {

			// use default encoding method
			result = new Uint16Array( array.length );

			for ( let i = 0; i < array.length; i += 2 ) {

				const encoded = EncodingFuncs.defaultEncode( array[ i ], array[ i + 1 ], 0, 2 );

				result[ i ] = encoded[ 0 ];
				result[ i + 1 ] = encoded[ 1 ];

			}

			mesh.geometry.setAttribute( 'uv', new BufferAttribute( result, 2, true ) );
			mesh.geometry.attributes.uv.isPacked = true;
			mesh.geometry.attributes.uv.needsUpdate = true;
			mesh.geometry.attributes.uv.bytes = result.length * 2;

			if ( ! ( mesh.material instanceof PackedPhongMaterial ) ) {

				mesh.material = new PackedPhongMaterial().copy( mesh.material );

			}

			mesh.material.defines.USE_PACKED_UV = 0;

		} else {

			// use quantized encoding method
			result = EncodingFuncs.quantizedEncodeUV( array, 2 );

			mesh.geometry.setAttribute( 'uv', new BufferAttribute( result.quantized, 2 ) );
			mesh.geometry.attributes.uv.isPacked = true;
			mesh.geometry.attributes.uv.needsUpdate = true;
			mesh.geometry.attributes.uv.bytes = result.quantized.length * 2;

			if ( ! ( mesh.material instanceof PackedPhongMaterial ) ) {

				mesh.material = new PackedPhongMaterial().copy( mesh.material );

			}

			mesh.material.defines.USE_PACKED_UV = 1;

			mesh.material.uniforms.quantizeMatUV.value = result.decodeMat;
			mesh.material.uniforms.quantizeMatUV.needsUpdate = true;

		}

	}

}

class EncodingFuncs {

	static defaultEncode( x, y, z, bytes ) {

		if ( bytes == 1 ) {

			const tmpx = Math.round( ( x + 1 ) * 0.5 * 255 );
			const tmpy = Math.round( ( y + 1 ) * 0.5 * 255 );
			const tmpz = Math.round( ( z + 1 ) * 0.5 * 255 );
			return new Uint8Array( [ tmpx, tmpy, tmpz ] );

		} else if ( bytes == 2 ) {

			const tmpx = Math.round( ( x + 1 ) * 0.5 * 65535 );
			const tmpy = Math.round( ( y + 1 ) * 0.5 * 65535 );
			const tmpz = Math.round( ( z + 1 ) * 0.5 * 65535 );
			return new Uint16Array( [ tmpx, tmpy, tmpz ] );

		} else {

			console.error( 'number of bytes must be 1 or 2' );

		}

	}

	static defaultDecode( array, bytes ) {

		if ( bytes == 1 ) {

			return [
				( ( array[ 0 ] / 255 ) * 2.0 ) - 1.0,
				( ( array[ 1 ] / 255 ) * 2.0 ) - 1.0,
				( ( array[ 2 ] / 255 ) * 2.0 ) - 1.0,
			];

		} else if ( bytes == 2 ) {

			return [
				( ( array[ 0 ] / 65535 ) * 2.0 ) - 1.0,
				( ( array[ 1 ] / 65535 ) * 2.0 ) - 1.0,
				( ( array[ 2 ] / 65535 ) * 2.0 ) - 1.0,
			];

		} else {

			console.error( 'number of bytes must be 1 or 2' );

		}

	}

	// for `Angles` encoding
	static anglesEncode( x, y, z ) {

		const normal0 = parseInt( 0.5 * ( 1.0 + Math.atan2( y, x ) / Math.PI ) * 65535 );
		const normal1 = parseInt( 0.5 * ( 1.0 + z ) * 65535 );
		return new Uint16Array( [ normal0, normal1 ] );

	}

	// for `Octahedron` encoding
	static octEncodeBest( x, y, z, bytes ) {

		let oct, dec, best, currentCos, bestCos;

		// Test various combinations of ceil and floor
		// to minimize rounding errors
		best = oct = octEncodeVec3( x, y, z, 'floor', 'floor' );
		dec = octDecodeVec2( oct );
		bestCos = dot( x, y, z, dec );

		oct = octEncodeVec3( x, y, z, 'ceil', 'floor' );
		dec = octDecodeVec2( oct );
		currentCos = dot( x, y, z, dec );

		if ( currentCos > bestCos ) {

			best = oct;
			bestCos = currentCos;

		}

		oct = octEncodeVec3( x, y, z, 'floor', 'ceil' );
		dec = octDecodeVec2( oct );
		currentCos = dot( x, y, z, dec );

		if ( currentCos > bestCos ) {

			best = oct;
			bestCos = currentCos;

		}

		oct = octEncodeVec3( x, y, z, 'ceil', 'ceil' );
		dec = octDecodeVec2( oct );
		currentCos = dot( x, y, z, dec );

		if ( currentCos > bestCos ) {

			best = oct;

		}

		return best;

		function octEncodeVec3( x0, y0, z0, xfunc, yfunc ) {

			let x = x0 / ( Math.abs( x0 ) + Math.abs( y0 ) + Math.abs( z0 ) );
			let y = y0 / ( Math.abs( x0 ) + Math.abs( y0 ) + Math.abs( z0 ) );

			if ( z < 0 ) {

				const tempx = ( 1 - Math.abs( y ) ) * ( x >= 0 ? 1 : - 1 );
				const tempy = ( 1 - Math.abs( x ) ) * ( y >= 0 ? 1 : - 1 );

				x = tempx;
				y = tempy;

				let diff = 1 - Math.abs( x ) - Math.abs( y );
				if ( diff > 0 ) {

					diff += 0.001;
					x += x > 0 ? diff / 2 : - diff / 2;
					y += y > 0 ? diff / 2 : - diff / 2;

				}

			}

			if ( bytes == 1 ) {

				return new Int8Array( [
					Math[ xfunc ]( x * 127.5 + ( x < 0 ? 1 : 0 ) ),
					Math[ yfunc ]( y * 127.5 + ( y < 0 ? 1 : 0 ) )
				] );

			}

			if ( bytes == 2 ) {

				return new Int16Array( [
					Math[ xfunc ]( x * 32767.5 + ( x < 0 ? 1 : 0 ) ),
					Math[ yfunc ]( y * 32767.5 + ( y < 0 ? 1 : 0 ) )
				] );

			}


		}

		function octDecodeVec2( oct ) {

			let x = oct[ 0 ];
			let y = oct[ 1 ];

			if ( bytes == 1 ) {

				x /= x < 0 ? 127 : 128;
				y /= y < 0 ? 127 : 128;

			} else if ( bytes == 2 ) {

				x /= x < 0 ? 32767 : 32768;
				y /= y < 0 ? 32767 : 32768;

			}


			const z = 1 - Math.abs( x ) - Math.abs( y );

			if ( z < 0 ) {

				const tmpx = x;
				x = ( 1 - Math.abs( y ) ) * ( x >= 0 ? 1 : - 1 );
				y = ( 1 - Math.abs( tmpx ) ) * ( y >= 0 ? 1 : - 1 );

			}

			const length = Math.sqrt( x * x + y * y + z * z );

			return [
				x / length,
				y / length,
				z / length
			];

		}

		function dot( x, y, z, vec3 ) {

			return x * vec3[ 0 ] + y * vec3[ 1 ] + z * vec3[ 2 ];

		}

	}

	static quantizedEncode( array, bytes ) {

		let quantized, segments;

		if ( bytes == 1 ) {

			quantized = new Uint8Array( array.length );
			segments = 255;

		} else if ( bytes == 2 ) {

			quantized = new Uint16Array( array.length );
			segments = 65535;

		} else {

			console.error( 'number of bytes error! ' );

		}

		const decodeMat = new Matrix4();

		const min = new Float32Array( 3 );
		const max = new Float32Array( 3 );

		min[ 0 ] = min[ 1 ] = min[ 2 ] = Number.MAX_VALUE;
		max[ 0 ] = max[ 1 ] = max[ 2 ] = - Number.MAX_VALUE;

		for ( let i = 0; i < array.length; i += 3 ) {

			min[ 0 ] = Math.min( min[ 0 ], array[ i + 0 ] );
			min[ 1 ] = Math.min( min[ 1 ], array[ i + 1 ] );
			min[ 2 ] = Math.min( min[ 2 ], array[ i + 2 ] );
			max[ 0 ] = Math.max( max[ 0 ], array[ i + 0 ] );
			max[ 1 ] = Math.max( max[ 1 ], array[ i + 1 ] );
			max[ 2 ] = Math.max( max[ 2 ], array[ i + 2 ] );

		}

		decodeMat.scale( new Vector3(
			( max[ 0 ] - min[ 0 ] ) / segments,
			( max[ 1 ] - min[ 1 ] ) / segments,
			( max[ 2 ] - min[ 2 ] ) / segments
		) );

		decodeMat.elements[ 12 ] = min[ 0 ];
		decodeMat.elements[ 13 ] = min[ 1 ];
		decodeMat.elements[ 14 ] = min[ 2 ];

		decodeMat.transpose();


		const multiplier = new Float32Array( [
			max[ 0 ] !== min[ 0 ] ? segments / ( max[ 0 ] - min[ 0 ] ) : 0,
			max[ 1 ] !== min[ 1 ] ? segments / ( max[ 1 ] - min[ 1 ] ) : 0,
			max[ 2 ] !== min[ 2 ] ? segments / ( max[ 2 ] - min[ 2 ] ) : 0
		] );

		for ( let i = 0; i < array.length; i += 3 ) {

			quantized[ i + 0 ] = Math.floor( ( array[ i + 0 ] - min[ 0 ] ) * multiplier[ 0 ] );
			quantized[ i + 1 ] = Math.floor( ( array[ i + 1 ] - min[ 1 ] ) * multiplier[ 1 ] );
			quantized[ i + 2 ] = Math.floor( ( array[ i + 2 ] - min[ 2 ] ) * multiplier[ 2 ] );

		}

		return {
			quantized: quantized,
			decodeMat: decodeMat
		};

	}

	static quantizedEncodeUV( array, bytes ) {

		let quantized, segments;

		if ( bytes == 1 ) {

			quantized = new Uint8Array( array.length );
			segments = 255;

		} else if ( bytes == 2 ) {

			quantized = new Uint16Array( array.length );
			segments = 65535;

		} else {

			console.error( 'number of bytes error! ' );

		}

		const decodeMat = new Matrix3();

		const min = new Float32Array( 2 );
		const max = new Float32Array( 2 );

		min[ 0 ] = min[ 1 ] = Number.MAX_VALUE;
		max[ 0 ] = max[ 1 ] = - Number.MAX_VALUE;

		for ( let i = 0; i < array.length; i += 2 ) {

			min[ 0 ] = Math.min( min[ 0 ], array[ i + 0 ] );
			min[ 1 ] = Math.min( min[ 1 ], array[ i + 1 ] );
			max[ 0 ] = Math.max( max[ 0 ], array[ i + 0 ] );
			max[ 1 ] = Math.max( max[ 1 ], array[ i + 1 ] );

		}

		decodeMat.scale(
			( max[ 0 ] - min[ 0 ] ) / segments,
			( max[ 1 ] - min[ 1 ] ) / segments
		);

		decodeMat.elements[ 6 ] = min[ 0 ];
		decodeMat.elements[ 7 ] = min[ 1 ];

		decodeMat.transpose();

		const multiplier = new Float32Array( [
			max[ 0 ] !== min[ 0 ] ? segments / ( max[ 0 ] - min[ 0 ] ) : 0,
			max[ 1 ] !== min[ 1 ] ? segments / ( max[ 1 ] - min[ 1 ] ) : 0
		] );

		for ( let i = 0; i < array.length; i += 2 ) {

			quantized[ i + 0 ] = Math.floor( ( array[ i + 0 ] - min[ 0 ] ) * multiplier[ 0 ] );
			quantized[ i + 1 ] = Math.floor( ( array[ i + 1 ] - min[ 1 ] ) * multiplier[ 1 ] );

		}

		return {
			quantized: quantized,
			decodeMat: decodeMat
		};

	}

}



/**
 * `PackedPhongMaterial` inherited from THREE.MeshPhongMaterial
 *
 * @param {Object} parameters
 */
class PackedPhongMaterial extends MeshPhongMaterial {

	constructor( parameters ) {

		super();

		this.defines = {};
		this.type = 'PackedPhongMaterial';
		this.uniforms = UniformsUtils.merge( [

			ShaderLib.phong.uniforms,

			{
				quantizeMatPos: { value: null },
				quantizeMatUV: { value: null }
			}

		] );

		this.vertexShader = [
			'#define PHONG',

			'varying vec3 vViewPosition;',

			'#ifndef FLAT_SHADED',
			'varying vec3 vNormal;',
			'#endif',

			ShaderChunk.common,
			ShaderChunk.uv_pars_vertex,
			ShaderChunk.uv2_pars_vertex,
			ShaderChunk.displacementmap_pars_vertex,
			ShaderChunk.envmap_pars_vertex,
			ShaderChunk.color_pars_vertex,
			ShaderChunk.fog_pars_vertex,
			ShaderChunk.morphtarget_pars_vertex,
			ShaderChunk.skinning_pars_vertex,
			ShaderChunk.shadowmap_pars_vertex,
			ShaderChunk.logdepthbuf_pars_vertex,
			ShaderChunk.clipping_planes_pars_vertex,

			`#ifdef USE_PACKED_NORMAL
					#if USE_PACKED_NORMAL == 0
						vec3 decodeNormal(vec3 packedNormal)
						{
							float x = packedNormal.x * 2.0 - 1.0;
							float y = packedNormal.y * 2.0 - 1.0;
							vec2 scth = vec2(sin(x * PI), cos(x * PI));
							vec2 scphi = vec2(sqrt(1.0 - y * y), y);
							return normalize( vec3(scth.y * scphi.x, scth.x * scphi.x, scphi.y) );
						}
					#endif

					#if USE_PACKED_NORMAL == 1
						vec3 decodeNormal(vec3 packedNormal)
						{
							vec3 v = vec3(packedNormal.xy, 1.0 - abs(packedNormal.x) - abs(packedNormal.y));
							if (v.z < 0.0)
							{
								v.xy = (1.0 - abs(v.yx)) * vec2((v.x >= 0.0) ? +1.0 : -1.0, (v.y >= 0.0) ? +1.0 : -1.0);
							}
							return normalize(v);
						}
					#endif

					#if USE_PACKED_NORMAL == 2
						vec3 decodeNormal(vec3 packedNormal)
						{
							vec3 v = (packedNormal * 2.0) - 1.0;
							return normalize(v);
						}
					#endif
				#endif`,

			`#ifdef USE_PACKED_POSITION
					#if USE_PACKED_POSITION == 0
						uniform mat4 quantizeMatPos;
					#endif
				#endif`,

			`#ifdef USE_PACKED_UV
					#if USE_PACKED_UV == 1
						uniform mat3 quantizeMatUV;
					#endif
				#endif`,

			`#ifdef USE_PACKED_UV
					#if USE_PACKED_UV == 0
						vec2 decodeUV(vec2 packedUV)
						{
							vec2 uv = (packedUV * 2.0) - 1.0;
							return uv;
						}
					#endif

					#if USE_PACKED_UV == 1
						vec2 decodeUV(vec2 packedUV)
						{
							vec2 uv = ( vec3(packedUV, 1.0) * quantizeMatUV ).xy;
							return uv;
						}
					#endif
				#endif`,

			'void main() {',

			ShaderChunk.uv_vertex,

			`#ifdef USE_UV
					#ifdef USE_PACKED_UV
						vUv = decodeUV(vUv);
					#endif
				#endif`,

			ShaderChunk.uv2_vertex,
			ShaderChunk.color_vertex,
			ShaderChunk.beginnormal_vertex,

			`#ifdef USE_PACKED_NORMAL
					objectNormal = decodeNormal(objectNormal);
				#endif

				#ifdef USE_TANGENT
					vec3 objectTangent = vec3( tangent.xyz );
				#endif
				`,

			ShaderChunk.morphnormal_vertex,
			ShaderChunk.skinbase_vertex,
			ShaderChunk.skinnormal_vertex,
			ShaderChunk.defaultnormal_vertex,

			'#ifndef FLAT_SHADED',
			'	vNormal = normalize( transformedNormal );',
			'#endif',

			ShaderChunk.begin_vertex,

			`#ifdef USE_PACKED_POSITION
					#if USE_PACKED_POSITION == 0
						transformed = ( vec4(transformed, 1.0) * quantizeMatPos ).xyz;
					#endif
				#endif`,

			ShaderChunk.morphtarget_vertex,
			ShaderChunk.skinning_vertex,
			ShaderChunk.displacementmap_vertex,
			ShaderChunk.project_vertex,
			ShaderChunk.logdepthbuf_vertex,
			ShaderChunk.clipping_planes_vertex,

			'vViewPosition = - mvPosition.xyz;',

			ShaderChunk.worldpos_vertex,
			ShaderChunk.envmap_vertex,
			ShaderChunk.shadowmap_vertex,
			ShaderChunk.fog_vertex,

			'}',
		].join( '\n' );

		// Use the original MeshPhongMaterial's fragmentShader.
		this.fragmentShader = [
			'#define PHONG',

			'uniform vec3 diffuse;',
			'uniform vec3 emissive;',
			'uniform vec3 specular;',
			'uniform float shininess;',
			'uniform float opacity;',

			ShaderChunk.common,
			ShaderChunk.packing,
			ShaderChunk.dithering_pars_fragment,
			ShaderChunk.color_pars_fragment,
			ShaderChunk.uv_pars_fragment,
			ShaderChunk.uv2_pars_fragment,
			ShaderChunk.map_pars_fragment,
			ShaderChunk.alphamap_pars_fragment,
			ShaderChunk.aomap_pars_fragment,
			ShaderChunk.lightmap_pars_fragment,
			ShaderChunk.emissivemap_pars_fragment,
			ShaderChunk.envmap_common_pars_fragment,
			ShaderChunk.envmap_pars_fragment,
			ShaderChunk.cube_uv_reflection_fragment,
			ShaderChunk.fog_pars_fragment,
			ShaderChunk.bsdfs,
			ShaderChunk.lights_pars_begin,
			ShaderChunk.lights_phong_pars_fragment,
			ShaderChunk.shadowmap_pars_fragment,
			ShaderChunk.bumpmap_pars_fragment,
			ShaderChunk.normalmap_pars_fragment,
			ShaderChunk.specularmap_pars_fragment,
			ShaderChunk.logdepthbuf_pars_fragment,
			ShaderChunk.clipping_planes_pars_fragment,

			'void main() {',

			ShaderChunk.clipping_planes_fragment,

			'vec4 diffuseColor = vec4( diffuse, opacity );',
			'ReflectedLight reflectedLight = ReflectedLight( vec3( 0.0 ), vec3( 0.0 ), vec3( 0.0 ), vec3( 0.0 ) );',
			'vec3 totalEmissiveRadiance = emissive;',

			ShaderChunk.logdepthbuf_fragment,
			ShaderChunk.map_fragment,
			ShaderChunk.color_fragment,
			ShaderChunk.alphamap_fragment,
			ShaderChunk.alphatest_fragment,
			ShaderChunk.specularmap_fragment,
			ShaderChunk.normal_fragment_begin,
			ShaderChunk.normal_fragment_maps,
			ShaderChunk.emissivemap_fragment,

			// accumulation
			ShaderChunk.lights_phong_fragment,
			ShaderChunk.lights_fragment_begin,
			ShaderChunk.lights_fragment_maps,
			ShaderChunk.lights_fragment_end,

			// modulation
			ShaderChunk.aomap_fragment,

			'vec3 outgoingLight = reflectedLight.directDiffuse + reflectedLight.indirectDiffuse + reflectedLight.directSpecular + reflectedLight.indirectSpecular + totalEmissiveRadiance;',

			ShaderChunk.envmap_fragment,

			'gl_FragColor = vec4( outgoingLight, diffuseColor.a );',

			ShaderChunk.tonemapping_fragment,
			ShaderChunk.encodings_fragment,
			ShaderChunk.fog_fragment,
			ShaderChunk.premultiplied_alpha_fragment,
			ShaderChunk.dithering_fragment,
			'}',
		].join( '\n' );

		this.setValues( parameters );

	}

}

export { GeometryCompressionUtils, PackedPhongMaterial };
