three.js/examples/js/loaders/VTKLoader.js

/**
 * @author mrdoob / http://mrdoob.com/
 * @author Alex Pletzer
 * 
 * Updated on 22.03.2017
 * VTK header is now parsed and used to extract all the compressed data
 * @author Andrii Iudin https://github.com/andreyyudin
 * @author Paul Kibet Korir https://github.com/polarise
 * @author Sriram Somasundharam https://github.com/raamssundar
 */

THREE.VTKLoader = function( manager ) {

	this.manager = ( manager !== undefined ) ? manager : THREE.DefaultLoadingManager;

};

Object.assign( THREE.VTKLoader.prototype, THREE.EventDispatcher.prototype, {

	load: function ( url, onLoad, onProgress, onError ) {

		var scope = this;

		var loader = new THREE.FileLoader( scope.manager );
		loader.setResponseType( 'arraybuffer' );
		loader.load( url, function( text ) {

			onLoad( scope.parse( text ) );

		}, onProgress, onError );

	},

	parse: function ( data ) {

		function parseASCII( data ) {

			// connectivity of the triangles
			var indices = [];

			// triangles vertices
			var positions = [];

			// red, green, blue colors in the range 0 to 1
			var colors = [];

			// normal vector, one per vertex
			var normals = [];

			var result;

			// pattern for reading vertices, 3 floats or integers
			var pat3Floats = /(\-?\d+\.?[\d\-\+e]*)\s+(\-?\d+\.?[\d\-\+e]*)\s+(\-?\d+\.?[\d\-\+e]*)/g;

			// pattern for connectivity, an integer followed by any number of ints
			// the first integer is the number of polygon nodes
			var patConnectivity = /^(\d+)\s+([\s\d]*)/;

			// indicates start of vertex data section
			var patPOINTS = /^POINTS /;

			// indicates start of polygon connectivity section
			var patPOLYGONS = /^POLYGONS /;

			// indicates start of triangle strips section
			var patTRIANGLE_STRIPS = /^TRIANGLE_STRIPS /;

			// POINT_DATA number_of_values
			var patPOINT_DATA = /^POINT_DATA[ ]+(\d+)/;

			// CELL_DATA number_of_polys
			var patCELL_DATA = /^CELL_DATA[ ]+(\d+)/;

			// Start of color section
			var patCOLOR_SCALARS = /^COLOR_SCALARS[ ]+(\w+)[ ]+3/;

			// NORMALS Normals float
			var patNORMALS = /^NORMALS[ ]+(\w+)[ ]+(\w+)/;

			var inPointsSection = false;
			var inPolygonsSection = false;
			var inTriangleStripSection = false;
			var inPointDataSection = false;
			var inCellDataSection = false;
			var inColorSection = false;
			var inNormalsSection = false;

			var lines = data.split( '\n' );

			for ( var i in lines ) {

				var line = lines[ i ];

				if ( inPointsSection ) {

					// get the vertices
					while ( ( result = pat3Floats.exec( line ) ) !== null ) {

						var x = parseFloat( result[ 1 ] );
						var y = parseFloat( result[ 2 ] );
						var z = parseFloat( result[ 3 ] );
						positions.push( x, y, z );

					}

				} else if ( inPolygonsSection ) {

					if ( ( result = patConnectivity.exec( line ) ) !== null ) {

						// numVertices i0 i1 i2 ...
						var numVertices = parseInt( result[ 1 ] );
						var inds = result[ 2 ].split( /\s+/ );

						if ( numVertices >= 3 ) {

							var i0 = parseInt( inds[ 0 ] );
							var i1, i2;
							var k = 1;
							// split the polygon in numVertices - 2 triangles
							for ( var j = 0; j < numVertices - 2; ++ j ) {

								i1 = parseInt( inds[ k ] );
								i2 = parseInt( inds[ k + 1 ] );
								indices.push( i0, i1, i2 );
								k ++;

							}

						}

					}

				} else if ( inTriangleStripSection ) {

					if ( ( result = patConnectivity.exec( line ) ) !== null ) {

						// numVertices i0 i1 i2 ...
						var numVertices = parseInt( result[ 1 ] );
						var inds = result[ 2 ].split( /\s+/ );

						if ( numVertices >= 3 ) {

							var i0, i1, i2;
							// split the polygon in numVertices - 2 triangles
							for ( var j = 0; j < numVertices - 2; j ++ ) {

								if ( j % 2 === 1 ) {

									i0 = parseInt( inds[ j ] );
									i1 = parseInt( inds[ j + 2 ] );
									i2 = parseInt( inds[ j + 1 ] );
									indices.push( i0, i1, i2 );

								} else {

									i0 = parseInt( inds[ j ] );
									i1 = parseInt( inds[ j + 1 ] );
									i2 = parseInt( inds[ j + 2 ] );
									indices.push( i0, i1, i2 );

								}

							}

						}

					}

				} else if ( inPointDataSection || inCellDataSection ) {

					if ( inColorSection ) {

						// Get the colors

						while ( ( result = pat3Floats.exec( line ) ) !== null ) {

							var r = parseFloat( result[ 1 ] );
							var g = parseFloat( result[ 2 ] );
							var b = parseFloat( result[ 3 ] );
							colors.push( r, g, b );

						}

					} else if ( inNormalsSection ) {

						// Get the normal vectors

						while ( ( result = pat3Floats.exec( line ) ) !== null ) {

							var nx = parseFloat( result[ 1 ] );
							var ny = parseFloat( result[ 2 ] );
							var nz = parseFloat( result[ 3 ] );
							normals.push( nx, ny, nz );

						}

					}

				}

				if ( patPOLYGONS.exec( line ) !== null ) {

					inPolygonsSection = true;
					inPointsSection = false;
					inTriangleStripSection = false;

				} else if ( patPOINTS.exec( line ) !== null ) {

					inPolygonsSection = false;
					inPointsSection = true;
					inTriangleStripSection = false;

				} else if ( patTRIANGLE_STRIPS.exec( line ) !== null ) {

					inPolygonsSection = false;
					inPointsSection = false;
					inTriangleStripSection = true;

				} else if ( patPOINT_DATA.exec( line ) !== null ) {

					inPointDataSection = true;
					inPointsSection = false;
					inPolygonsSection = false;
					inTriangleStripSection = false;

				} else if ( patCELL_DATA.exec( line ) !== null ) {

					inCellDataSection = true;
					inPointsSection = false;
					inPolygonsSection = false;
					inTriangleStripSection = false;

				} else if ( patCOLOR_SCALARS.exec( line ) !== null ) {

					inColorSection = true;
					inNormalsSection = false;
					inPointsSection = false;
					inPolygonsSection = false;
					inTriangleStripSection = false;

				} else if ( patNORMALS.exec( line ) !== null ) {

					inNormalsSection = true;
					inColorSection = false;
					inPointsSection = false;
					inPolygonsSection = false;
					inTriangleStripSection = false;

				}

			}

			var geometry;
			var stagger = 'point';

			if ( colors.length == indices.length ) {

				stagger = 'cell';

			}

			if ( stagger == 'point' ) {

				// Nodal. Use BufferGeometry
				geometry = new THREE.BufferGeometry();
				geometry.setIndex( new THREE.BufferAttribute( new Uint32Array( indices ), 1 ) );
				geometry.addAttribute( 'position', new THREE.BufferAttribute( new Float32Array( positions ), 3 ) );

				if ( colors.length == positions.length ) {

					geometry.addAttribute( 'color', new THREE.BufferAttribute( new Float32Array( colors ), 3 ) );

				}

				if ( normals.length == positions.length ) {

					geometry.addAttribute( 'normal', new THREE.BufferAttribute( new Float32Array( normals ), 3 ) );

				}

			} else {

				// Cell centered colors. The only way to attach a solid color to each triangle
				// is to use Geometry, which is less efficient than BufferGeometry
				geometry = new THREE.Geometry();

				var numTriangles = indices.length / 3;
				var numPoints = positions.length / 3;
				var va, vb, vc;
				var face;
				var ia, ib, ic;
				var x, y, z;
				var r, g, b;

				for ( var j = 0; j < numPoints; ++ j ) {

					x = positions[ 3 * j + 0 ];
					y = positions[ 3 * j + 1 ];
					z = positions[ 3 * j + 2 ];
					geometry.vertices.push( new THREE.Vector3( x, y, z ) );

				}

				for ( var i = 0; i < numTriangles; ++ i ) {

					ia = indices[ 3 * i + 0 ];
					ib = indices[ 3 * i + 1 ];
					ic = indices[ 3 * i + 2 ];
					geometry.faces.push( new THREE.Face3( ia, ib, ic ) );

				}

				if ( colors.length == numTriangles * 3 ) {

					for ( var i = 0; i < numTriangles; ++ i ) {

						face = geometry.faces[ i ];
						r = colors[ 3 * i + 0 ];
						g = colors[ 3 * i + 1 ];
						b = colors[ 3 * i + 2 ];
						face.color = new THREE.Color().setRGB( r, g, b );

					}

				}

			}

			return geometry;

		}

		function parseBinary( data ) {

			var count, pointIndex, i, numberOfPoints, pt, s;
			var buffer = new Uint8Array ( data );
			var dataView = new DataView ( data );

			// Points and normals, by default, are empty
			var points = [];
			var normals = [];
			var indices = [];

			// Going to make a big array of strings
			var vtk = [];
			var index = 0;

			function findString( buffer, start ) {

				var index = start;
				var c = buffer[ index ];
				var s = [];
				while ( c != 10 ) {

					s.push ( String.fromCharCode ( c ) );
					index ++;
					c = buffer[ index ];

				}

				return { start: start,
						end: index,
						next: index + 1,
						parsedString: s.join( '' ) };

			}

			var state, line;

			while ( true ) {

				// Get a string
				state = findString ( buffer, index );
				line = state.parsedString;

				if ( line.indexOf ( 'POINTS' ) === 0 ) {

					vtk.push ( line );
					// Add the points
					numberOfPoints = parseInt ( line.split( ' ' )[ 1 ], 10 );

					// Each point is 3 4-byte floats
					count = numberOfPoints * 4 * 3;

					points = new Float32Array( numberOfPoints * 3 );

					pointIndex = state.next;
					for ( i = 0; i < numberOfPoints; i ++ ) {

						points[ 3 * i ] = dataView.getFloat32( pointIndex, false );
						points[ 3 * i + 1 ] = dataView.getFloat32( pointIndex + 4, false );
						points[ 3 * i + 2 ] = dataView.getFloat32( pointIndex + 8, false );
						pointIndex = pointIndex + 12;

					}
					// increment our next pointer
					state.next = state.next + count + 1;

				} else if ( line.indexOf ( 'TRIANGLE_STRIPS' ) === 0 ) {

					var numberOfStrips = parseInt ( line.split( ' ' )[ 1 ], 10 );
					var size = parseInt ( line.split ( ' ' )[ 2 ], 10 );
					// 4 byte integers
					count = size * 4;

					indices = new Uint32Array( 3 * size - 9 * numberOfStrips );
					var indicesIndex = 0;

					pointIndex = state.next;
					for ( i = 0; i < numberOfStrips; i ++ ) {

						// For each strip, read the first value, then record that many more points
						var indexCount = dataView.getInt32( pointIndex, false );
						var strip = [];
						pointIndex += 4;
						for ( s = 0; s < indexCount; s ++ ) {

							strip.push ( dataView.getInt32( pointIndex, false ) );
							pointIndex += 4;

						}

						// retrieves the n-2 triangles from the triangle strip
						for ( var j = 0; j < indexCount - 2; j ++ ) {

							if ( j % 2 ) {

								indices[ indicesIndex ++ ] = strip[ j ];
								indices[ indicesIndex ++ ] = strip[ j + 2 ];
								indices[ indicesIndex ++ ] = strip[ j + 1 ];

							} else {


								indices[ indicesIndex ++ ] = strip[ j ];
								indices[ indicesIndex ++ ] = strip[ j + 1 ];
								indices[ indicesIndex ++ ] = strip[ j + 2 ];

							}

						}

					}
					// increment our next pointer
					state.next = state.next + count + 1;

				} else if ( line.indexOf ( 'POLYGONS' ) === 0 ) {

					var numberOfStrips = parseInt ( line.split( ' ' )[ 1 ], 10 );
					var size = parseInt ( line.split ( ' ' )[ 2 ], 10 );
					// 4 byte integers
					count = size * 4;

					indices = new Uint32Array( 3 * size - 9 * numberOfStrips );
					var indicesIndex = 0;

					pointIndex = state.next;
					for ( i = 0; i < numberOfStrips; i ++ ) {

						// For each strip, read the first value, then record that many more points
						var indexCount = dataView.getInt32( pointIndex, false );
						var strip = [];
						pointIndex += 4;
						for ( s = 0; s < indexCount; s ++ ) {

							strip.push ( dataView.getInt32( pointIndex, false ) );
							pointIndex += 4;

						}
						var i0 = strip[ 0 ];
						// divide the polygon in n-2 triangle
						for ( var j = 1; j < indexCount - 1; j ++ ) {

							indices[ indicesIndex ++ ] = strip[ 0 ];
							indices[ indicesIndex ++ ] = strip[ j ];
							indices[ indicesIndex ++ ] = strip[ j + 1 ];

						}

					}
					// increment our next pointer
					state.next = state.next + count + 1;

				} else if ( line.indexOf ( 'POINT_DATA' ) === 0 ) {

					numberOfPoints = parseInt ( line.split( ' ' )[ 1 ], 10 );

					// Grab the next line
					state = findString ( buffer, state.next );

					// Now grab the binary data
					count = numberOfPoints * 4 * 3;

					normals = new Float32Array( numberOfPoints * 3 );
					pointIndex = state.next;
					for ( i = 0; i < numberOfPoints; i ++ ) {

						normals[ 3 * i ] = dataView.getFloat32( pointIndex, false );
						normals[ 3 * i + 1 ] = dataView.getFloat32( pointIndex + 4, false );
						normals[ 3 * i + 2 ] = dataView.getFloat32( pointIndex + 8, false );
						pointIndex += 12;

					}

					// Increment past our data
					state.next = state.next + count;

				}

				// Increment index
				index = state.next;

				if ( index >= buffer.byteLength ) {

					break;

				}

			}

			var geometry = new THREE.BufferGeometry();
			geometry.setIndex( new THREE.BufferAttribute( indices, 1 ) );
			geometry.addAttribute( 'position', new THREE.BufferAttribute( points, 3 ) );

			if ( normals.length == points.length ) {

				geometry.addAttribute( 'normal', new THREE.BufferAttribute( normals, 3 ) );

			}

			return geometry;

		}

		function Float32Concat(first, second) {
		    var firstLength = first.length,
		        result = new Float32Array(firstLength + second.length);

		    result.set(first);
		    result.set(second, firstLength);

		    return result;
		}

		function Int32Concat(first, second) {
		    var firstLength = first.length,
		        result = new Int32Array(firstLength + second.length);

		    result.set(first);
		    result.set(second, firstLength);

		    return result;
		}

		function parseXML( stringFile ) {

			// Changes XML to JSON, based on https://davidwalsh.name/convert-xml-json

			function xmlToJson( xml ) {

				// Create the return object
				var obj = {};

				if ( xml.nodeType == 1 ) { // element

					// do attributes

					if ( xml.attributes ) {

						if ( xml.attributes.length > 0 ) {

							obj[ 'attributes' ] = {};

							for ( var j = 0; j < xml.attributes.length; j ++ ) {

								var attribute = xml.attributes.item( j );
								obj[ 'attributes' ][ attribute.nodeName ] = attribute.nodeValue.trim();

							}

						}

					}

				} else if ( xml.nodeType == 3 ) { // text

					obj = xml.nodeValue.trim();

				}

				// do children
				if ( xml.hasChildNodes() ) {

					for ( var i = 0; i < xml.childNodes.length; i ++ ) {

						var item = xml.childNodes.item( i );
						var nodeName = item.nodeName;

						if ( typeof( obj[ nodeName ] ) === 'undefined' ) {

							var tmp = xmlToJson( item );

							if ( tmp !== '' ) obj[ nodeName ] = tmp;

						} else {

							if ( typeof( obj[ nodeName ].push ) === 'undefined' ) {

								var old = obj[ nodeName ];
								obj[ nodeName ] = [ old ];

							}

							var tmp = xmlToJson( item );

							if ( tmp !== '' ) obj[ nodeName ].push( tmp );

						}

					}

				}

				return obj;

			}

			// Taken from Base64-js
			function Base64toByteArray( b64 ) {

				var Arr = typeof Uint8Array !== 'undefined' ? Uint8Array : Array;
				var i;
				var lookup = [];
				var revLookup = [];
				var code = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
				var len = code.length;

				for ( i = 0; i < len; i ++ ) {

					lookup[ i ] = code[ i ];

				}

				for ( i = 0; i < len; ++ i ) {

					revLookup[ code.charCodeAt( i ) ] = i;

				}

				revLookup[ '-'.charCodeAt( 0 ) ] = 62;
				revLookup[ '_'.charCodeAt( 0 ) ] = 63;

				var j, l, tmp, placeHolders, arr;
				var len = b64.length;

				if ( len % 4 > 0 ) {

					throw new Error( 'Invalid string. Length must be a multiple of 4' );

				}

				placeHolders = b64[ len - 2 ] === '=' ? 2 : b64[ len - 1 ] === '=' ? 1 : 0;
				arr = new Arr( len * 3 / 4 - placeHolders );
				l = placeHolders > 0 ? len - 4 : len;

				var L = 0;

				for ( i = 0, j = 0; i < l; i += 4, j += 3 ) {

					tmp = ( revLookup[ b64.charCodeAt( i ) ] << 18 ) | ( revLookup[ b64.charCodeAt( i + 1 ) ] << 12 ) | ( revLookup[ b64.charCodeAt( i + 2 ) ] << 6 ) | revLookup[ b64.charCodeAt( i + 3 ) ];
					arr[ L ++ ] = ( tmp & 0xFF0000 ) >> 16;
					arr[ L ++ ] = ( tmp & 0xFF00 ) >> 8;
					arr[ L ++ ] = tmp & 0xFF;

				}

				if ( placeHolders === 2 ) {

					tmp = ( revLookup[ b64.charCodeAt( i ) ] << 2 ) | ( revLookup[ b64.charCodeAt( i + 1 ) ] >> 4 );
					arr[ L ++ ] = tmp & 0xFF;

				} else if ( placeHolders === 1 ) {

					tmp = ( revLookup[ b64.charCodeAt( i ) ] << 10 ) | ( revLookup[ b64.charCodeAt( i + 1 ) ] << 4 ) | ( revLookup[ b64.charCodeAt( i + 2 ) ] >> 2 );
					arr[ L ++ ] = ( tmp >> 8 ) & 0xFF;
					arr[ L ++ ] = tmp & 0xFF;

				}

				return arr;

			}

			function parseDataArray( ele, compressed ) {
				var numBytes = 0;
				if ( json.attributes.header_type == 'UInt64' )
					numBytes = 8;
				else if( json.attributes.header_type == 'UInt32' )
					numBytes = 4;

				// Check the format
				if ( ele.attributes.format == 'binary' && compressed ) {
						var rawData, content, byteData, blocks, cSizeStart, headerSize, padding, dataOffsets, currentOffset;

						if ( ele.attributes.type == 'Float32' ) {
							var txt = new Float32Array( );
						} else if ( ele.attributes.type === 'Int64' ) {
							var txt = new Int32Array( );
						}

						// VTP data with the header has the following structure:
						// [#blocks][#u-size][#p-size][#c-size-1][#c-size-2]...[#c-size-#blocks][DATA]
						//
						// Each token is an integer value whose type is specified by "header_type" at the top of the file (UInt32 if no type specified). The token meanings are:
						// [#blocks] = Number of blocks
						// [#u-size] = Block size before compression
						// [#p-size] = Size of last partial block (zero if it not needed)
						// [#c-size-i] = Size in bytes of block i after compression
						//
						// The [DATA] portion stores contiguously every block appended together. The offset from the beginning of the data section to the beginning of a block is 
						// computed by summing the compressed block sizes from preceding blocks according to the header. 

						rawData = ele[ '#text' ];

						byteData = Base64toByteArray( rawData );

						blocks = byteData[0]
						for ( var i = 1; i<numBytes-1; i++ ) {
							blocks = blocks | ( byteData[i] << (i*numBytes) );
						}

						headerSize = (blocks + 3) * numBytes;
						padding = ( (headerSize % 3) > 0 ) ? 3 - (headerSize % 3) : 0;
						headerSize = headerSize + padding;
						
						dataOffsets = [];
						currentOffset = headerSize;
						dataOffsets.push( currentOffset );

						// Get the blocks sizes after the compression.
						// There are three blocks before c-size-i, so we skip 3*numBytes
						cSizeStart = 3*numBytes;
						for ( var i = 0; i<blocks; i++ ) {
							var currentBlockSize = byteData[i*numBytes + cSizeStart];
							for ( var j = 1; j<numBytes-1; j++ ) {
								currentBlockSize = currentBlockSize | ( byteData[i*numBytes + cSizeStart + j] << (j*numBytes) );
							}
							
							currentOffset = currentOffset + currentBlockSize;
							dataOffsets.push( currentOffset );
						}

						for ( var i=0; i<dataOffsets.length-1; i++ ) {
							var inflate = new Zlib.Inflate( byteData.slice( dataOffsets[i], dataOffsets[i+1] ), { resize: true, verify: true } );
							content = inflate.decompress();
							content = content.buffer;

							if ( ele.attributes.type == 'Float32' ) {
								content = new Float32Array( content );
								txt = Float32Concat(txt, content);
							} else if ( ele.attributes.type === 'Int64' ) {
								content = new Int32Array( content );
								txt = Int32Concat(txt, content);
							}
						}

						delete ele[ '#text' ];

						// Get the content and optimize it
						if ( ele.attributes.type == 'Float32' ) {
							if ( ele.attributes.format == 'binary' ) {
								if ( ! compressed ) {
									txt = txt.filter( function( el, idx, arr ) {
										if ( idx !== 0 ) return true;
									} );
								}
							}

						} else if ( ele.attributes.type === 'Int64' ) {
							if ( ele.attributes.format == 'binary' ) {
								if ( ! compressed ) {
									txt = txt.filter( function ( el, idx, arr ) {
										if ( idx !== 0 ) return true;
									} );
								}

								txt = txt.filter( function ( el, idx, arr ) {
									if ( idx % 2 !== 1 ) return true;
								} );
							}
						}

				} else {
					if ( ele.attributes.format == 'binary' && ! compressed ) {

						var content = Base64toByteArray( ele[ '#text' ] );

						//  VTP data for the uncompressed case has the following structure:
						// [#bytes][DATA]
						// where "[#bytes]" is an integer value specifying the number of bytes in the block of data following it.
						content = content.slice(numBytes).buffer;

					} else {

						if ( ele[ '#text' ] ) {
							var content = ele[ '#text' ].replace( /\n/g, ' ' ).split( ' ' ).filter( function ( el, idx, arr ) {
								if ( el !== '' ) return el;
							} );
						} else {
							var content = new Int32Array( 0 ).buffer;
						}

					}

					delete ele[ '#text' ];

					// Get the content and optimize it
					if ( ele.attributes.type == 'Float32' ) {

						var txt = new Float32Array( content );

					} else if ( ele.attributes.type === 'Int64' ) {
						var txt = new Int32Array( content );

						if ( ele.attributes.format == 'binary' ) {
							txt = txt.filter( function ( el, idx, arr ) {
								if ( idx % 2 !== 1 ) return true;
							} );
						}
					}

				} // endif ( ele.attributes.format == 'binary' && compressed )

				return txt;

			}

			// Main part
			// Get Dom
			var dom = null;

			if ( window.DOMParser ) {

				try {

					dom = ( new DOMParser() ).parseFromString( stringFile, 'text/xml' );

				} catch ( e ) {

					dom = null;

				}

			} else if ( window.ActiveXObject ) {

				try {

					dom = new ActiveXObject( 'Microsoft.XMLDOM' );
					dom.async = false;

					if ( ! dom.loadXML( xml ) ) {

						throw new Error( dom.parseError.reason + dom.parseError.srcText );

					}

				} catch ( e ) {

					dom = null;

				}

			} else {

				throw new Error( 'Cannot parse xml string!' );

			}

			// Get the doc
			var doc = dom.documentElement;
			// Convert to json
			var json = xmlToJson( doc );
			var points = [];
			var normals = [];
			var indices = [];

			if ( json.PolyData ) {

				var piece = json.PolyData.Piece;
				var compressed = json.attributes.hasOwnProperty( 'compressor' );

				// Can be optimized
				// Loop through the sections
				var sections = [ 'PointData', 'Points', 'Strips', 'Polys' ];// +['CellData', 'Verts', 'Lines'];
				var sectionIndex = 0, numberOfSections = sections.length;

				while ( sectionIndex < numberOfSections ) {

					var section = piece[ sections[ sectionIndex ] ];

					// If it has a DataArray in it

					if ( section.DataArray ) {

						// Depending on the number of DataArrays

						if ( Object.prototype.toString.call( section.DataArray ) === '[object Array]' ) {

							var arr = section.DataArray;

						} else {

							var arr = [ section.DataArray ];

						}

						var dataArrayIndex = 0, numberOfDataArrays = arr.length;

						while ( dataArrayIndex < numberOfDataArrays ) {

							// Parse the DataArray
							if ( ('#text' in arr[ dataArrayIndex ]) && (arr[ dataArrayIndex ][ '#text' ].length > 0) ) {
								arr[ dataArrayIndex ].text = parseDataArray( arr[ dataArrayIndex ], compressed );
							}
								dataArrayIndex ++;

						}

						switch ( sections[ sectionIndex ] ) {

							// if iti is point data
							case 'PointData':

								var numberOfPoints = parseInt( piece.attributes.NumberOfPoints );
								var normalsName = section.attributes.Normals;

								if ( numberOfPoints > 0 ) {

									for ( var i = 0, len = arr.length; i < len; i ++ ) {

										if ( normalsName == arr[ i ].attributes.Name ) {

											var components = arr[ i ].attributes.NumberOfComponents;
											normals = new Float32Array( numberOfPoints * components );
											normals.set( arr[ i ].text, 0 );

										}

									}

								}

								break;

							// if it is points
							case 'Points':

								var numberOfPoints = parseInt( piece.attributes.NumberOfPoints );

								if ( numberOfPoints > 0 ) {

									var components = section.DataArray.attributes.NumberOfComponents;
									points = new Float32Array( numberOfPoints * components );
									points.set( section.DataArray.text, 0 );

								}

								break;

							// if it is strips
							case 'Strips':

								var numberOfStrips = parseInt( piece.attributes.NumberOfStrips );

								if ( numberOfStrips > 0 ) {

									var connectivity = new Int32Array( section.DataArray[ 0 ].text.length );
									var offset = new Int32Array( section.DataArray[ 1 ].text.length );
									connectivity.set( section.DataArray[ 0 ].text, 0 );
									offset.set( section.DataArray[ 1 ].text, 0 );

									var size = numberOfStrips + connectivity.length;
									indices = new Uint32Array( 3 * size - 9 * numberOfStrips );

									var indicesIndex = 0;

									for ( var i = 0,len = numberOfStrips; i < len; i ++ ) {

										var strip = [];

										for ( var s = 0, len1 = offset[ i ], len0 = 0; s < len1 - len0; s ++ ) {

											strip.push ( connectivity[ s ] );

											if ( i > 0 ) len0 = offset[ i - 1 ];

										}

										for ( var j = 0, len1 = offset[ i ], len0 = 0; j < len1 - len0 - 2; j ++ ) {

											if ( j % 2 ) {

												indices[ indicesIndex ++ ] = strip[ j ];
												indices[ indicesIndex ++ ] = strip[ j + 2 ];
												indices[ indicesIndex ++ ] = strip[ j + 1 ];

											} else {

												indices[ indicesIndex ++ ] = strip[ j ];
												indices[ indicesIndex ++ ] = strip[ j + 1 ];
												indices[ indicesIndex ++ ] = strip[ j + 2 ];

											}

											if ( i > 0 ) len0 = offset[ i - 1 ];

										}

									}

								}

								break;

							// if it is polys
							case 'Polys':

								var numberOfPolys = parseInt( piece.attributes.NumberOfPolys );

								if ( numberOfPolys > 0 ) {

									var connectivity = new Int32Array( section.DataArray[ 0 ].text.length );
									var offset = new Int32Array( section.DataArray[ 1 ].text.length );
									connectivity.set( section.DataArray[ 0 ].text, 0 );
									offset.set( section.DataArray[ 1 ].text, 0 );

									var size = numberOfPolys + connectivity.length;
									indices = new Uint32Array( 3 * size - 9 * numberOfPolys );
									var indicesIndex = 0, connectivityIndex = 0;
									var i = 0,len = numberOfPolys, len0 = 0;

									while ( i < len ) {

										var poly = [];
										var s = 0, len1 = offset[ i ];

										while ( s < len1 - len0 ) {

											poly.push( connectivity[ connectivityIndex ++ ] );
											s ++;

										}

										var j = 1;

										while ( j < len1 - len0 - 1 ) {

											indices[ indicesIndex ++ ] = poly[ 0 ];
											indices[ indicesIndex ++ ] = poly[ j ];
											indices[ indicesIndex ++ ] = poly[ j + 1 ];
											j ++;

										}

										i ++;
										len0 = offset[ i - 1 ];

									}

								}

								break;

							default:
								break;

						}

					}

					sectionIndex ++;

				}

				var geometry = new THREE.BufferGeometry();
				geometry.setIndex( new THREE.BufferAttribute( indices, 1 ) );
				geometry.addAttribute( 'position', new THREE.BufferAttribute( points, 3 ) );

				if ( normals.length == points.length ) {

					geometry.addAttribute( 'normal', new THREE.BufferAttribute( normals, 3 ) );

				}

				return geometry;

			} else {

				// TODO for vtu,vti,and other xml formats

			}

		}

		function getStringFile( data ) {

			var stringFile = '';
			var charArray = new Uint8Array( data );
			var i = 0;
			var len = charArray.length;

			while ( len -- ) {

				stringFile += String.fromCharCode( charArray[ i ++ ] );

			}

			return stringFile;

		}

		// get the 5 first lines of the files to check if there is the key word binary
		var meta = String.fromCharCode.apply( null, new Uint8Array( data, 0, 250 ) ).split( '\n' );

		if ( meta[ 0 ].indexOf( 'xml' ) !== - 1 ) {

			return parseXML( getStringFile( data ) );

		} else if ( meta[ 2 ].includes( 'ASCII' ) ) {

			return parseASCII( getStringFile( data ) );

		} else {

			return parseBinary( data );

		}

	}

} );