mrdoob/three.js

View on GitHub
examples/jsm/loaders/VTKLoader.js

Summary

Maintainability
F
3 wks
Test Coverage
import {
    BufferAttribute,
    BufferGeometry,
    Color,
    FileLoader,
    Float32BufferAttribute,
    Loader
} from 'three';
import * as fflate from '../libs/fflate.module.js';

class VTKLoader extends Loader {

    constructor( manager ) {

        super( manager );

    }

    load( url, onLoad, onProgress, onError ) {

        const scope = this;

        const loader = new FileLoader( scope.manager );
        loader.setPath( scope.path );
        loader.setResponseType( 'arraybuffer' );
        loader.setRequestHeader( scope.requestHeader );
        loader.setWithCredentials( scope.withCredentials );
        loader.load( url, function ( text ) {

            try {

                onLoad( scope.parse( text ) );

            } catch ( e ) {

                if ( onError ) {

                    onError( e );

                } else {

                    console.error( e );

                }

                scope.manager.itemError( url );

            }

        }, onProgress, onError );

    }

    parse( data ) {

        function parseASCII( data ) {

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

            // triangles vertices
            const positions = [];

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

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

            let result;

            // pattern for detecting the end of a number sequence
            const patWord = /^[^\d.\s-]+/;

            // pattern for reading vertices, 3 floats or integers
            const 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
            const patConnectivity = /^(\d+)\s+([\s\d]*)/;

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

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

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

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

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

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

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

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

            const color = new Color();

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

            for ( const i in lines ) {

                const line = lines[ i ].trim();

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

                    const dataset = line.split( ' ' )[ 1 ];

                    if ( dataset !== 'POLYDATA' ) throw new Error( 'Unsupported DATASET type: ' + dataset );

                } else if ( inPointsSection ) {

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

                        if ( patWord.exec( line ) !== null ) break;

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

                    }

                } else if ( inPolygonsSection ) {

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

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

                        if ( numVertices >= 3 ) {

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

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

                            }

                        }

                    }

                } else if ( inTriangleStripSection ) {

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

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

                        if ( numVertices >= 3 ) {

                            // split the polygon in numVertices - 2 triangles
                            for ( let j = 0; j < numVertices - 2; j ++ ) {

                                if ( j % 2 === 1 ) {

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

                                } else {

                                    const i0 = parseInt( inds[ j ] );
                                    const i1 = parseInt( inds[ j + 1 ] );
                                    const 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 ) {

                            if ( patWord.exec( line ) !== null ) break;

                            const r = parseFloat( result[ 1 ] );
                            const g = parseFloat( result[ 2 ] );
                            const b = parseFloat( result[ 3 ] );

                            color.set( r, g, b ).convertSRGBToLinear();

                            colors.push( color.r, color.g, color.b );

                        }

                    } else if ( inNormalsSection ) {

                        // Get the normal vectors

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

                            if ( patWord.exec( line ) !== null ) break;

                            const nx = parseFloat( result[ 1 ] );
                            const ny = parseFloat( result[ 2 ] );
                            const 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;

                }

            }

            let geometry = new BufferGeometry();
            geometry.setIndex( indices );
            geometry.setAttribute( 'position', new Float32BufferAttribute( positions, 3 ) );

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

                geometry.setAttribute( 'normal', new Float32BufferAttribute( normals, 3 ) );

            }

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

                // stagger

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

                    geometry.setAttribute( 'color', new Float32BufferAttribute( colors, 3 ) );

                }

            } else {

                // cell

                geometry = geometry.toNonIndexed();
                const numTriangles = geometry.attributes.position.count / 3;

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

                    const newColors = [];

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

                        const r = colors[ 3 * i + 0 ];
                        const g = colors[ 3 * i + 1 ];
                        const b = colors[ 3 * i + 2 ];

                        color.set( r, g, b ).convertSRGBToLinear();

                        newColors.push( color.r, color.g, color.b );
                        newColors.push( color.r, color.g, color.b );
                        newColors.push( color.r, color.g, color.b );

                    }

                    geometry.setAttribute( 'color', new Float32BufferAttribute( newColors, 3 ) );

                }

            }

            return geometry;

        }

        function parseBinary( data ) {

            const buffer = new Uint8Array( data );
            const dataView = new DataView( data );

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

            let index = 0;

            function findString( buffer, start ) {

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

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

                }

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

            }

            let state, line;

            while ( true ) {

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

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

                    const dataset = line.split( ' ' )[ 1 ];

                    if ( dataset !== 'POLYDATA' ) throw new Error( 'Unsupported DATASET type: ' + dataset );

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

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

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

                    points = new Float32Array( numberOfPoints * 3 );

                    let pointIndex = state.next;
                    for ( let 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 ) {

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

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

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

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

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

                        }

                        // retrieves the n-2 triangles from the triangle strip
                        for ( let 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 ) {

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

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

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

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

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

                        }

                        // divide the polygon in n-2 triangle
                        for ( let 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 ) {

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

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

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

                    normals = new Float32Array( numberOfPoints * 3 );
                    let pointIndex = state.next;
                    for ( let 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;

                }

            }

            const geometry = new BufferGeometry();
            geometry.setIndex( new BufferAttribute( indices, 1 ) );
            geometry.setAttribute( 'position', new BufferAttribute( points, 3 ) );

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

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

            }

            return geometry;

        }

        function Float32Concat( first, second ) {

            const firstLength = first.length, result = new Float32Array( firstLength + second.length );

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

            return result;

        }

        function Int32Concat( first, second ) {

            const 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
                let obj = {};

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

                    // do attributes

                    if ( xml.attributes ) {

                        if ( xml.attributes.length > 0 ) {

                            obj[ 'attributes' ] = {};

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

                                const 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 ( let i = 0; i < xml.childNodes.length; i ++ ) {

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

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

                            const tmp = xmlToJson( item );

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

                        } else {

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

                                const old = obj[ nodeName ];
                                obj[ nodeName ] = [ old ];

                            }

                            const tmp = xmlToJson( item );

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

                        }

                    }

                }

                return obj;

            }

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

                const Arr = typeof Uint8Array !== 'undefined' ? Uint8Array : Array;
                const revLookup = [];
                const code = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';

                for ( let i = 0, l = code.length; i < l; ++ i ) {

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

                }

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

                const len = b64.length;

                if ( len % 4 > 0 ) {

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

                }

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

                let L = 0;
                let i, j;

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

                    const 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 ) {

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

                } else if ( placeHolders === 1 ) {

                    const 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 ) {

                let numBytes = 0;

                if ( json.attributes.header_type === 'UInt64' ) {

                    numBytes = 8;

                }    else if ( json.attributes.header_type === 'UInt32' ) {

                    numBytes = 4;

                }

                let txt, content;

                // Check the format
                if ( ele.attributes.format === 'binary' && compressed ) {

                    if ( ele.attributes.type === 'Float32' ) {

                        txt = new Float32Array( );

                    } else if ( ele.attributes.type === 'Int32' || ele.attributes.type === 'Int64' ) {

                        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.

                    const textNode = ele[ '#text' ];
                    const rawData = Array.isArray( textNode ) ? textNode[ 0 ] : textNode;

                    const byteData = Base64toByteArray( rawData );

                    // Each data point consists of 8 bits regardless of the header type
                    const dataPointSize = 8;

                    let blocks = byteData[ 0 ];
                    for ( let i = 1; i < numBytes - 1; i ++ ) {

                        blocks = blocks | ( byteData[ i ] << ( i * dataPointSize ) );

                    }

                    let headerSize = ( blocks + 3 ) * numBytes;
                    const padding = ( ( headerSize % 3 ) > 0 ) ? 3 - ( headerSize % 3 ) : 0;
                    headerSize = headerSize + padding;

                    const dataOffsets = [];
                    let 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
                    const cSizeStart = 3 * numBytes;

                    for ( let i = 0; i < blocks; i ++ ) {

                        let currentBlockSize = byteData[ i * numBytes + cSizeStart ];

                        for ( let j = 1; j < numBytes - 1; j ++ ) {

                            currentBlockSize = currentBlockSize | ( byteData[ i * numBytes + cSizeStart + j ] << ( j * dataPointSize ) );

                        }

                        currentOffset = currentOffset + currentBlockSize;
                        dataOffsets.push( currentOffset );

                    }

                    for ( let i = 0; i < dataOffsets.length - 1; i ++ ) {

                        const data = fflate.unzlibSync( byteData.slice( dataOffsets[ i ], dataOffsets[ i + 1 ] ) );
                        content = data.buffer;

                        if ( ele.attributes.type === 'Float32' ) {

                            content = new Float32Array( content );
                            txt = Float32Concat( txt, content );

                        } else if ( ele.attributes.type === 'Int32' || ele.attributes.type === 'Int64' ) {

                            content = new Int32Array( content );
                            txt = Int32Concat( txt, content );

                        }

                    }

                    delete ele[ '#text' ];

                    if ( ele.attributes.type === 'Int64' ) {

                        if ( ele.attributes.format === 'binary' ) {

                            txt = txt.filter( function ( el, idx ) {

                                if ( idx % 2 !== 1 ) return true;

                            } );

                        }

                    }

                } else {

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

                        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' ] ) {

                            content = ele[ '#text' ].split( /\s+/ ).filter( function ( el ) {

                                if ( el !== '' ) return el;

                            } );

                        } else {

                            content = new Int32Array( 0 ).buffer;

                        }

                    }

                    delete ele[ '#text' ];

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

                        txt = new Float32Array( content );

                    } else if ( ele.attributes.type === 'Int32' ) {

                        txt = new Int32Array( content );

                    } else if ( ele.attributes.type === 'Int64' ) {

                        txt = new Int32Array( content );

                        if ( ele.attributes.format === 'binary' ) {

                            txt = txt.filter( function ( el, idx ) {

                                if ( idx % 2 !== 1 ) return true;

                            } );

                        }

                    }

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

                return txt;

            }

            // Main part
            // Get Dom
            const dom = new DOMParser().parseFromString( stringFile, 'application/xml' );

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

            if ( json.PolyData ) {

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

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

                while ( sectionIndex < numberOfSections ) {

                    const section = piece[ sections[ sectionIndex ] ];

                    // If it has a DataArray in it

                    if ( section && section.DataArray ) {

                        // Depending on the number of DataArrays

                        let arr;

                        if ( Array.isArray( section.DataArray ) ) {

                            arr = section.DataArray;

                        } else {

                            arr = [ section.DataArray ];

                        }

                        let dataArrayIndex = 0;
                        const 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':

                                {

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

                                    if ( numberOfPoints > 0 ) {

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

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

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

                                            }

                                        }

                                    }

                                }

                                break;

                            // if it is points
                            case 'Points':

                                {

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

                                    if ( numberOfPoints > 0 ) {

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

                                    }

                                }

                                break;

                            // if it is strips
                            case 'Strips':

                                {

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

                                    if ( numberOfStrips > 0 ) {

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

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

                                        let indicesIndex = 0;

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

                                            const strip = [];

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

                                                strip.push( connectivity[ s ] );

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

                                            }

                                            for ( let 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':

                                {

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

                                    if ( numberOfPolys > 0 ) {

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

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

                                        while ( i < len ) {

                                            const poly = [];
                                            let s = 0;
                                            const len1 = offset[ i ];

                                            while ( s < len1 - len0 ) {

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

                                            }

                                            let 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 ++;

                }

                const geometry = new BufferGeometry();
                geometry.setIndex( new BufferAttribute( indices, 1 ) );
                geometry.setAttribute( 'position', new BufferAttribute( points, 3 ) );

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

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

                }

                return geometry;

            } else {

                throw new Error( 'Unsupported DATASET type' );

            }

        }

        const textDecoder = new TextDecoder();

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

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

            return parseXML( textDecoder.decode( data ) );

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

            return parseASCII( textDecoder.decode( data ) );

        } else {

            return parseBinary( data );

        }

    }

}

export { VTKLoader };