import { BufferAttribute, BufferGeometry, FileLoader, Loader } from '../../../build/three.module.js'; /** * See https://github.com/kchapelier/PRWM for more informations about this file format */ let bigEndianPlatform = null; /** * Check if the endianness of the platform is big-endian (most significant bit first) * @returns {boolean} True if big-endian, false if little-endian */ function isBigEndianPlatform() { if ( bigEndianPlatform === null ) { const buffer = new ArrayBuffer( 2 ), uint8Array = new Uint8Array( buffer ), uint16Array = new Uint16Array( buffer ); uint8Array[ 0 ] = 0xAA; // set first byte uint8Array[ 1 ] = 0xBB; // set second byte bigEndianPlatform = ( uint16Array[ 0 ] === 0xAABB ); } return bigEndianPlatform; } // match the values defined in the spec to the TypedArray types const InvertedEncodingTypes = [ null, Float32Array, null, Int8Array, Int16Array, null, Int32Array, Uint8Array, Uint16Array, null, Uint32Array ]; // define the method to use on a DataView, corresponding the TypedArray type const getMethods = { Uint16Array: 'getUint16', Uint32Array: 'getUint32', Int16Array: 'getInt16', Int32Array: 'getInt32', Float32Array: 'getFloat32', Float64Array: 'getFloat64' }; function copyFromBuffer( sourceArrayBuffer, viewType, position, length, fromBigEndian ) { const bytesPerElement = viewType.BYTES_PER_ELEMENT; let result; if ( fromBigEndian === isBigEndianPlatform() || bytesPerElement === 1 ) { result = new viewType( sourceArrayBuffer, position, length ); } else { const readView = new DataView( sourceArrayBuffer, position, length * bytesPerElement ), getMethod = getMethods[ viewType.name ], littleEndian = ! fromBigEndian; result = new viewType( length ); for ( let i = 0; i < length; i ++ ) { result[ i ] = readView[ getMethod ]( i * bytesPerElement, littleEndian ); } } return result; } function decodePrwm( buffer ) { const array = new Uint8Array( buffer ), version = array[ 0 ]; let flags = array[ 1 ]; const indexedGeometry = !! ( flags >> 7 & 0x01 ), indicesType = flags >> 6 & 0x01, bigEndian = ( flags >> 5 & 0x01 ) === 1, attributesNumber = flags & 0x1F; let valuesNumber = 0, indicesNumber = 0; if ( bigEndian ) { valuesNumber = ( array[ 2 ] << 16 ) + ( array[ 3 ] << 8 ) + array[ 4 ]; indicesNumber = ( array[ 5 ] << 16 ) + ( array[ 6 ] << 8 ) + array[ 7 ]; } else { valuesNumber = array[ 2 ] + ( array[ 3 ] << 8 ) + ( array[ 4 ] << 16 ); indicesNumber = array[ 5 ] + ( array[ 6 ] << 8 ) + ( array[ 7 ] << 16 ); } /** PRELIMINARY CHECKS **/ if ( version === 0 ) { throw new Error( 'PRWM decoder: Invalid format version: 0' ); } else if ( version !== 1 ) { throw new Error( 'PRWM decoder: Unsupported format version: ' + version ); } if ( ! indexedGeometry ) { if ( indicesType !== 0 ) { throw new Error( 'PRWM decoder: Indices type must be set to 0 for non-indexed geometries' ); } else if ( indicesNumber !== 0 ) { throw new Error( 'PRWM decoder: Number of indices must be set to 0 for non-indexed geometries' ); } } /** PARSING **/ let pos = 8; const attributes = {}; for ( let i = 0; i < attributesNumber; i ++ ) { let attributeName = ''; while ( pos < array.length ) { const char = array[ pos ]; pos ++; if ( char === 0 ) { break; } else { attributeName += String.fromCharCode( char ); } } flags = array[ pos ]; const attributeType = flags >> 7 & 0x01; const cardinality = ( flags >> 4 & 0x03 ) + 1; const encodingType = flags & 0x0F; const arrayType = InvertedEncodingTypes[ encodingType ]; pos ++; // padding to next multiple of 4 pos = Math.ceil( pos / 4 ) * 4; const values = copyFromBuffer( buffer, arrayType, pos, cardinality * valuesNumber, bigEndian ); pos += arrayType.BYTES_PER_ELEMENT * cardinality * valuesNumber; attributes[ attributeName ] = { type: attributeType, cardinality: cardinality, values: values }; } pos = Math.ceil( pos / 4 ) * 4; let indices = null; if ( indexedGeometry ) { indices = copyFromBuffer( buffer, indicesType === 1 ? Uint32Array : Uint16Array, pos, indicesNumber, bigEndian ); } return { version: version, attributes: attributes, indices: indices }; } // Define the public interface class PRWMLoader 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 ); url = url.replace( /\*/g, isBigEndianPlatform() ? 'be' : 'le' ); loader.load( url, function ( arrayBuffer ) { try { onLoad( scope.parse( arrayBuffer ) ); } catch ( e ) { if ( onError ) { onError( e ); } else { console.error( e ); } scope.manager.itemError( url ); } }, onProgress, onError ); } parse( arrayBuffer ) { const data = decodePrwm( arrayBuffer ), attributesKey = Object.keys( data.attributes ), bufferGeometry = new BufferGeometry(); for ( let i = 0; i < attributesKey.length; i ++ ) { const attribute = data.attributes[ attributesKey[ i ] ]; bufferGeometry.setAttribute( attributesKey[ i ], new BufferAttribute( attribute.values, attribute.cardinality, attribute.normalized ) ); } if ( data.indices !== null ) { bufferGeometry.setIndex( new BufferAttribute( data.indices, 1 ) ); } return bufferGeometry; } static isBigEndianPlatform() { return isBigEndianPlatform(); } } export { PRWMLoader };