three.js/examples/jsm/loaders/EXRLoader.js

/**
 * @author Richard M. / https://github.com/richardmonette
 * @author ScieCode / http://github.com/sciecode
 *
 * OpenEXR loader currently supports uncompressed, ZIP(S), RLE, PIZ and DWA/B compression.
 * Supports reading as UnsignedByte, HalfFloat and Float type data texture.
 *
 * Referred to the original Industrial Light & Magic OpenEXR implementation and the TinyEXR / Syoyo Fujita
 * implementation, so I have preserved their copyright notices.
 */

import {
	DataTextureLoader,
	FloatType,
	HalfFloatType,
	LinearEncoding,
	LinearFilter,
	NearestFilter,
	RGBAFormat,
	RGBEEncoding,
	RGBEFormat,
	RGBFormat,
	UnsignedByteType
} from "../../../build/three.module.js";
import { Zlib } from "../libs/inflate.module.min.js";

// /*
// Copyright (c) 2014 - 2017, Syoyo Fujita
// All rights reserved.

// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright
//       notice, this list of conditions and the following disclaimer in the
//       documentation and/or other materials provided with the distribution.
//     * Neither the name of the Syoyo Fujita nor the
//       names of its contributors may be used to endorse or promote products
//       derived from this software without specific prior written permission.

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
// DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// */

// // TinyEXR contains some OpenEXR code, which is licensed under ------------

// ///////////////////////////////////////////////////////////////////////////
// //
// // Copyright (c) 2002, Industrial Light & Magic, a division of Lucas
// // Digital Ltd. LLC
// //
// // All rights reserved.
// //
// // Redistribution and use in source and binary forms, with or without
// // modification, are permitted provided that the following conditions are
// // met:
// // *       Redistributions of source code must retain the above copyright
// // notice, this list of conditions and the following disclaimer.
// // *       Redistributions in binary form must reproduce the above
// // copyright notice, this list of conditions and the following disclaimer
// // in the documentation and/or other materials provided with the
// // distribution.
// // *       Neither the name of Industrial Light & Magic nor the names of
// // its contributors may be used to endorse or promote products derived
// // from this software without specific prior written permission.
// //
// // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// //
// ///////////////////////////////////////////////////////////////////////////

// // End of OpenEXR license -------------------------------------------------

var EXRLoader = function ( manager ) {

	DataTextureLoader.call( this, manager );

	this.type = FloatType;

};

EXRLoader.prototype = Object.assign( Object.create( DataTextureLoader.prototype ), {

	constructor: EXRLoader,

	parse: function ( buffer ) {

		const USHORT_RANGE = ( 1 << 16 );
		const BITMAP_SIZE = ( USHORT_RANGE >> 3 );

		const HUF_ENCBITS = 16; // literal (value) bit length
		const HUF_DECBITS = 14; // decoding bit size (>= 8)

		const HUF_ENCSIZE = ( 1 << HUF_ENCBITS ) + 1; // encoding table size
		const HUF_DECSIZE = 1 << HUF_DECBITS; // decoding table size
		const HUF_DECMASK = HUF_DECSIZE - 1;

		const SHORT_ZEROCODE_RUN = 59;
		const LONG_ZEROCODE_RUN = 63;
		const SHORTEST_LONG_RUN = 2 + LONG_ZEROCODE_RUN - SHORT_ZEROCODE_RUN;

		const ULONG_SIZE = 8;
		const FLOAT32_SIZE = 4;
		const INT32_SIZE = 4;
		const INT16_SIZE = 2;
		const INT8_SIZE = 1;

		const STATIC_HUFFMAN = 0;
		const DEFLATE = 1;

		const UNKNOWN = 0;
		const LOSSY_DCT = 1;
		const RLE = 2;

		const logBase = Math.pow( 2.7182818, 2.2 );

		var tmpDataView = new DataView( new ArrayBuffer( 8 ) );

		function frexp( value ) {

			if ( value === 0 ) return [ value, 0 ];

			tmpDataView.setFloat64( 0, value );

			var bits = ( tmpDataView.getUint32( 0 ) >>> 20 ) & 0x7FF;
			if ( bits === 0 ) { // denormal

				tmpDataView.setFloat64( 0, value * Math.pow( 2, 64 ) ); // exp + 64
				bits = ( ( tmpDataView.getUint32( 0 ) >>> 20 ) & 0x7FF ) - 64;

			}
			var exponent = bits - 1022;
			var mantissa = ldexp( value, - exponent );

			return [ mantissa, exponent ];

		}

		function ldexp( mantissa, exponent ) {

			var steps = Math.min( 3, Math.ceil( Math.abs( exponent ) / 1023 ) );
			var result = mantissa;

			for ( var i = 0; i < steps; i ++ )
				result *= Math.pow( 2, Math.floor( ( exponent + i ) / steps ) );

			return result;

		}

		function reverseLutFromBitmap( bitmap, lut ) {

			var k = 0;

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

				if ( ( i == 0 ) || ( bitmap[ i >> 3 ] & ( 1 << ( i & 7 ) ) ) ) {

					lut[ k ++ ] = i;

				}

			}

			var n = k - 1;

			while ( k < USHORT_RANGE ) lut[ k ++ ] = 0;

			return n;

		}

		function hufClearDecTable( hdec ) {

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

				hdec[ i ] = {};
				hdec[ i ].len = 0;
				hdec[ i ].lit = 0;
				hdec[ i ].p = null;

			}

		}

		const getBitsReturn = { l: 0, c: 0, lc: 0 };

		function getBits( nBits, c, lc, uInt8Array, inOffset ) {

			while ( lc < nBits ) {

				c = ( c << 8 ) | parseUint8Array( uInt8Array, inOffset );
				lc += 8;

			}

			lc -= nBits;

			getBitsReturn.l = ( c >> lc ) & ( ( 1 << nBits ) - 1 );
			getBitsReturn.c = c;
			getBitsReturn.lc = lc;

		}

		const hufTableBuffer = new Array( 59 );

		function hufCanonicalCodeTable( hcode ) {

			for ( var i = 0; i <= 58; ++ i ) hufTableBuffer[ i ] = 0;
			for ( var i = 0; i < HUF_ENCSIZE; ++ i ) hufTableBuffer[ hcode[ i ] ] += 1;

			var c = 0;

			for ( var i = 58; i > 0; -- i ) {

				var nc = ( ( c + hufTableBuffer[ i ] ) >> 1 );
				hufTableBuffer[ i ] = c;
				c = nc;

			}

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

				var l = hcode[ i ];
				if ( l > 0 ) hcode[ i ] = l | ( hufTableBuffer[ l ] ++ << 6 );

			}

		}

		function hufUnpackEncTable( uInt8Array, inDataView, inOffset, ni, im, iM, hcode ) {

			var p = inOffset;
			var c = 0;
			var lc = 0;

			for ( ; im <= iM; im ++ ) {

				if ( p.value - inOffset.value > ni ) return false;

				getBits( 6, c, lc, uInt8Array, p );

				var l = getBitsReturn.l;
				c = getBitsReturn.c;
				lc = getBitsReturn.lc;

				hcode[ im ] = l;

				if ( l == LONG_ZEROCODE_RUN ) {

					if ( p.value - inOffset.value > ni ) {

						throw 'Something wrong with hufUnpackEncTable';

					}

					getBits( 8, c, lc, uInt8Array, p );

					var zerun = getBitsReturn.l + SHORTEST_LONG_RUN;
					c = getBitsReturn.c;
					lc = getBitsReturn.lc;

					if ( im + zerun > iM + 1 ) {

						throw 'Something wrong with hufUnpackEncTable';

					}

					while ( zerun -- ) hcode[ im ++ ] = 0;

					im --;

				} else if ( l >= SHORT_ZEROCODE_RUN ) {

					var zerun = l - SHORT_ZEROCODE_RUN + 2;

					if ( im + zerun > iM + 1 ) {

						throw 'Something wrong with hufUnpackEncTable';

					}

					while ( zerun -- ) hcode[ im ++ ] = 0;

					im --;

				}

			}

			hufCanonicalCodeTable( hcode );

		}

		function hufLength( code ) {

			return code & 63;

		}

		function hufCode( code ) {

			return code >> 6;

		}

		function hufBuildDecTable( hcode, im, iM, hdecod ) {

			for ( ; im <= iM; im ++ ) {

				var c = hufCode( hcode[ im ] );
				var l = hufLength( hcode[ im ] );

				if ( c >> l ) {

					throw 'Invalid table entry';

				}

				if ( l > HUF_DECBITS ) {

					var pl = hdecod[ ( c >> ( l - HUF_DECBITS ) ) ];

					if ( pl.len ) {

						throw 'Invalid table entry';

					}

					pl.lit ++;

					if ( pl.p ) {

						var p = pl.p;
						pl.p = new Array( pl.lit );

						for ( var i = 0; i < pl.lit - 1; ++ i ) {

							pl.p[ i ] = p[ i ];

						}

					} else {

						pl.p = new Array( 1 );

					}

					pl.p[ pl.lit - 1 ] = im;

				} else if ( l ) {

					var plOffset = 0;

					for ( var i = 1 << ( HUF_DECBITS - l ); i > 0; i -- ) {

						var pl = hdecod[ ( c << ( HUF_DECBITS - l ) ) + plOffset ];

						if ( pl.len || pl.p ) {

							throw 'Invalid table entry';

						}

						pl.len = l;
						pl.lit = im;

						plOffset ++;

					}

				}

			}

			return true;

		}

		const getCharReturn = { c: 0, lc: 0 };

		function getChar( c, lc, uInt8Array, inOffset ) {

			c = ( c << 8 ) | parseUint8Array( uInt8Array, inOffset );
			lc += 8;

			getCharReturn.c = c;
			getCharReturn.lc = lc;

		}

		const getCodeReturn = { c: 0, lc: 0 };

		function getCode( po, rlc, c, lc, uInt8Array, inDataView, inOffset, outBuffer, outBufferOffset, outBufferEndOffset ) {

			if ( po == rlc ) {

				if ( lc < 8 ) {

					getChar( c, lc, uInt8Array, inOffset );
					c = getCharReturn.c;
					lc = getCharReturn.lc;

				}

				lc -= 8;

				var cs = ( c >> lc );
				var cs = new Uint8Array( [ cs ] )[ 0 ];

				if ( outBufferOffset.value + cs > outBufferEndOffset ) {

					return false;

				}

				var s = outBuffer[ outBufferOffset.value - 1 ];

				while ( cs -- > 0 ) {

					outBuffer[ outBufferOffset.value ++ ] = s;

				}

			} else if ( outBufferOffset.value < outBufferEndOffset ) {

				outBuffer[ outBufferOffset.value ++ ] = po;

			} else {

				return false;

			}

			getCodeReturn.c = c;
			getCodeReturn.lc = lc;

		}

		function UInt16( value ) {

			return ( value & 0xFFFF );

		}

		function Int16( value ) {

			var ref = UInt16( value );
			return ( ref > 0x7FFF ) ? ref - 0x10000 : ref;

		}

		const wdec14Return = { a: 0, b: 0 };

		function wdec14( l, h ) {

			var ls = Int16( l );
			var hs = Int16( h );

			var hi = hs;
			var ai = ls + ( hi & 1 ) + ( hi >> 1 );

			var as = ai;
			var bs = ai - hi;

			wdec14Return.a = as;
			wdec14Return.b = bs;

		}

		function wav2Decode( buffer, j, nx, ox, ny, oy ) {

			var n = ( nx > ny ) ? ny : nx;
			var p = 1;
			var p2;

			while ( p <= n ) p <<= 1;

			p >>= 1;
			p2 = p;
			p >>= 1;

			while ( p >= 1 ) {

				var py = 0;
				var ey = py + oy * ( ny - p2 );
				var oy1 = oy * p;
				var oy2 = oy * p2;
				var ox1 = ox * p;
				var ox2 = ox * p2;
				var i00, i01, i10, i11;

				for ( ; py <= ey; py += oy2 ) {

					var px = py;
					var ex = py + ox * ( nx - p2 );

					for ( ; px <= ex; px += ox2 ) {

						var p01 = px + ox1;
						var p10 = px + oy1;
						var p11 = p10 + ox1;

						wdec14( buffer[ px + j ], buffer[ p10 + j ] );

						i00 = wdec14Return.a;
						i10 = wdec14Return.b;

						wdec14( buffer[ p01 + j ], buffer[ p11 + j ] );

						i01 = wdec14Return.a;
						i11 = wdec14Return.b;

						wdec14( i00, i01 );

						buffer[ px + j ] = wdec14Return.a;
						buffer[ p01 + j ] = wdec14Return.b;

						wdec14( i10, i11 );

						buffer[ p10 + j ] = wdec14Return.a;
						buffer[ p11 + j ] = wdec14Return.b;

					}

					if ( nx & p ) {

						var p10 = px + oy1;

						wdec14( buffer[ px + j ], buffer[ p10 + j ] );

						i00 = wdec14Return.a;
						buffer[ p10 + j ] = wdec14Return.b;

						buffer[ px + j ] = i00;

					}

				}

				if ( ny & p ) {

					var px = py;
					var ex = py + ox * ( nx - p2 );

					for ( ; px <= ex; px += ox2 ) {

						var p01 = px + ox1;

						wdec14( buffer[ px + j ], buffer[ p01 + j ] );

						i00 = wdec14Return.a;
						buffer[ p01 + j ] = wdec14Return.b;

						buffer[ px + j ] = i00;

					}

				}

				p2 = p;
				p >>= 1;

			}

			return py;

		}

		function hufDecode( encodingTable, decodingTable, uInt8Array, inDataView, inOffset, ni, rlc, no, outBuffer, outOffset ) {

			var c = 0;
			var lc = 0;
			var outBufferEndOffset = no;
			var inOffsetEnd = Math.trunc( inOffset.value + ( ni + 7 ) / 8 );

			while ( inOffset.value < inOffsetEnd ) {

				getChar( c, lc, uInt8Array, inOffset );

				c = getCharReturn.c;
				lc = getCharReturn.lc;

				while ( lc >= HUF_DECBITS ) {

					var index = ( c >> ( lc - HUF_DECBITS ) ) & HUF_DECMASK;
					var pl = decodingTable[ index ];

					if ( pl.len ) {

						lc -= pl.len;

						getCode( pl.lit, rlc, c, lc, uInt8Array, inDataView, inOffset, outBuffer, outOffset, outBufferEndOffset );

						c = getCodeReturn.c;
						lc = getCodeReturn.lc;

					} else {

						if ( ! pl.p ) {

							throw 'hufDecode issues';

						}

						var j;

						for ( j = 0; j < pl.lit; j ++ ) {

							var l = hufLength( encodingTable[ pl.p[ j ] ] );

							while ( lc < l && inOffset.value < inOffsetEnd ) {

								getChar( c, lc, uInt8Array, inOffset );

								c = getCharReturn.c;
								lc = getCharReturn.lc;

							}

							if ( lc >= l ) {

								if ( hufCode( encodingTable[ pl.p[ j ] ] ) == ( ( c >> ( lc - l ) ) & ( ( 1 << l ) - 1 ) ) ) {

									lc -= l;

									getCode( pl.p[ j ], rlc, c, lc, uInt8Array, inDataView, inOffset, outBuffer, outOffset, outBufferEndOffset );

									c = getCodeReturn.c;
									lc = getCodeReturn.lc;

									break;

								}

							}

						}

						if ( j == pl.lit ) {

							throw 'hufDecode issues';

						}

					}

				}

			}

			var i = ( 8 - ni ) & 7;

			c >>= i;
			lc -= i;

			while ( lc > 0 ) {

				var pl = decodingTable[ ( c << ( HUF_DECBITS - lc ) ) & HUF_DECMASK ];

				if ( pl.len ) {

					lc -= pl.len;

					getCode( pl.lit, rlc, c, lc, uInt8Array, inDataView, inOffset, outBuffer, outOffset, outBufferEndOffset );

					c = getCodeReturn.c;
					lc = getCodeReturn.lc;

				} else {

					throw 'hufDecode issues';

				}

			}

			return true;

		}

		function hufUncompress( uInt8Array, inDataView, inOffset, nCompressed, outBuffer, nRaw ) {

			var outOffset = { value: 0 };
			var initialInOffset = inOffset.value;

			var im = parseUint32( inDataView, inOffset );
			var iM = parseUint32( inDataView, inOffset );

			inOffset.value += 4;

			var nBits = parseUint32( inDataView, inOffset );

			inOffset.value += 4;

			if ( im < 0 || im >= HUF_ENCSIZE || iM < 0 || iM >= HUF_ENCSIZE ) {

				throw 'Something wrong with HUF_ENCSIZE';

			}

			var freq = new Array( HUF_ENCSIZE );
			var hdec = new Array( HUF_DECSIZE );

			hufClearDecTable( hdec );

			var ni = nCompressed - ( inOffset.value - initialInOffset );

			hufUnpackEncTable( uInt8Array, inDataView, inOffset, ni, im, iM, freq );

			if ( nBits > 8 * ( nCompressed - ( inOffset.value - initialInOffset ) ) ) {

				throw 'Something wrong with hufUncompress';

			}

			hufBuildDecTable( freq, im, iM, hdec );

			hufDecode( freq, hdec, uInt8Array, inDataView, inOffset, nBits, iM, nRaw, outBuffer, outOffset );

		}

		function applyLut( lut, data, nData ) {

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

				data[ i ] = lut[ data[ i ] ];

			}

		}

		function predictor( source ) {

			for ( var t = 1; t < source.length; t ++ ) {

				var d = source[ t - 1 ] + source[ t ] - 128;
				source[ t ] = d;

			}

		}

		function interleaveScalar( source, out ) {

			var t1 = 0;
			var t2 = Math.floor( ( source.length + 1 ) / 2 );
			var s = 0;
			var stop = source.length - 1;

			while ( true ) {

				if ( s > stop ) break;
				out[ s ++ ] = source[ t1 ++ ];

				if ( s > stop ) break;
				out[ s ++ ] = source[ t2 ++ ];

			}

		}

		function decodeRunLength( source ) {

			var size = source.byteLength;
			var out = new Array();
			var p = 0;

			var reader = new DataView( source );

			while ( size > 0 ) {

				var l = reader.getInt8( p ++ );

				if ( l < 0 ) {

					var count = - l;
					size -= count + 1;

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

						out.push( reader.getUint8( p ++ ) );

					}


				} else {

					var count = l;
					size -= 2;

					var value = reader.getUint8( p ++ );

					for ( var i = 0; i < count + 1; i ++ ) {

						out.push( value );

					}

				}

			}

			return out;

		}

		function lossyDctDecode( cscSet, rowPtrs, channelData, acBuffer, dcBuffer, outBuffer ) {

			var dataView = new DataView( outBuffer.buffer );

			var width = channelData[ cscSet.idx[ 0 ] ].width;
			var height = channelData[ cscSet.idx[ 0 ] ].height;

			var numComp = 3;

			var numFullBlocksX = Math.floor( width / 8.0 );
			var numBlocksX = Math.ceil( width / 8.0 );
			var numBlocksY = Math.ceil( height / 8.0 );
			var leftoverX = width - ( numBlocksX - 1 ) * 8;
			var leftoverY = height - ( numBlocksY - 1 ) * 8;

			var currAcComp = { value: 0 };
			var currDcComp = new Array( numComp );
			var dctData = new Array( numComp );
			var halfZigBlock = new Array( numComp );
			var rowBlock = new Array( numComp );
			var rowOffsets = new Array( numComp );

			for ( let comp = 0; comp < numComp; ++ comp ) {

				rowOffsets[ comp ] = rowPtrs[ cscSet.idx[ comp ] ];
				currDcComp[ comp ] = ( comp < 1 ) ? 0 : currDcComp[ comp - 1 ] + numBlocksX * numBlocksY;
				dctData[ comp ] = new Float32Array( 64 );
				halfZigBlock[ comp ] = new Uint16Array( 64 );
				rowBlock[ comp ] = new Uint16Array( numBlocksX * 64 );

			}

			for ( let blocky = 0; blocky < numBlocksY; ++ blocky ) {

				var maxY = 8;

				if ( blocky == numBlocksY - 1 )
					maxY = leftoverY;

				var maxX = 8;

				for ( let blockx = 0; blockx < numBlocksX; ++ blockx ) {

					if ( blockx == numBlocksX - 1 )
						maxX = leftoverX;

					for ( let comp = 0; comp < numComp; ++ comp ) {

						halfZigBlock[ comp ].fill( 0 );

						// set block DC component
						halfZigBlock[ comp ][ 0 ] = dcBuffer[ currDcComp[ comp ] ++ ];
						// set block AC components
						unRleAC( currAcComp, acBuffer, halfZigBlock[ comp ] );

						// UnZigZag block to float
						unZigZag( halfZigBlock[ comp ], dctData[ comp ] );
						// decode float dct
						dctInverse( dctData[ comp ] );

					}

					if ( numComp == 3 ) {

						csc709Inverse( dctData );

					}

					for ( let comp = 0; comp < numComp; ++ comp ) {

						convertToHalf( dctData[ comp ], rowBlock[ comp ], blockx * 64 );

					}

				} // blockx

				let offset = 0;

				for ( let comp = 0; comp < numComp; ++ comp ) {

					let type = channelData[ cscSet.idx[ comp ] ].type;

					for ( let y = 8 * blocky; y < 8 * blocky + maxY; ++ y ) {

						offset = rowOffsets[ comp ][ y ];

						for ( let blockx = 0; blockx < numFullBlocksX; ++ blockx ) {

							let src = blockx * 64 + ( ( y & 0x7 ) * 8 );

							dataView.setUint16( offset + 0 * INT16_SIZE * type, rowBlock[ comp ][ src + 0 ], true );
							dataView.setUint16( offset + 1 * INT16_SIZE * type, rowBlock[ comp ][ src + 1 ], true );
							dataView.setUint16( offset + 2 * INT16_SIZE * type, rowBlock[ comp ][ src + 2 ], true );
							dataView.setUint16( offset + 3 * INT16_SIZE * type, rowBlock[ comp ][ src + 3 ], true );

							dataView.setUint16( offset + 4 * INT16_SIZE * type, rowBlock[ comp ][ src + 4 ], true );
							dataView.setUint16( offset + 5 * INT16_SIZE * type, rowBlock[ comp ][ src + 5 ], true );
							dataView.setUint16( offset + 6 * INT16_SIZE * type, rowBlock[ comp ][ src + 6 ], true );
							dataView.setUint16( offset + 7 * INT16_SIZE * type, rowBlock[ comp ][ src + 7 ], true );

							offset += 8 * INT16_SIZE * type;

						}

					}

					// handle partial X blocks
					if ( numFullBlocksX != numBlocksX ) {

						for ( let y = 8 * blocky; y < 8 * blocky + maxY; ++ y ) {

							let offset = rowOffsets[ comp ][ y ] + 8 * numFullBlocksX * INT16_SIZE * type;
							let src = numFullBlocksX * 64 + ( ( y & 0x7 ) * 8 );

							for ( let x = 0; x < maxX; ++ x ) {

								dataView.setUint16( offset + x * INT16_SIZE * type, rowBlock[ comp ][ src + x ], true );

							}

						}

					}

				} // comp

			} // blocky

			var halfRow = new Uint16Array( width );
			var dataView = new DataView( outBuffer.buffer );

			// convert channels back to float, if needed
			for ( var comp = 0; comp < numComp; ++ comp ) {

				channelData[ cscSet.idx[ comp ] ].decoded = true;
				var type = channelData[ cscSet.idx[ comp ] ].type;

				if ( channelData[ comp ].type != 2 ) continue;

				for ( var y = 0; y < height; ++ y ) {

					let offset = rowOffsets[ comp ][ y ];

					for ( var x = 0; x < width; ++ x ) {

						halfRow[ x ] = dataView.getUint16( offset + x * INT16_SIZE * type, true );

					}

					for ( var x = 0; x < width; ++ x ) {

						dataView.setFloat32( offset + x * INT16_SIZE * type, decodeFloat16( halfRow[ x ] ), true );

					}

				}

			}

		}

		function unRleAC( currAcComp, acBuffer, halfZigBlock ) {

			var acValue;
			var dctComp = 1;

			while ( dctComp < 64 ) {

				acValue = acBuffer[ currAcComp.value ];

				if ( acValue == 0xff00 ) {

					dctComp = 64;

				} else if ( acValue >> 8 == 0xff ) {

					dctComp += acValue & 0xff;

				} else {

					halfZigBlock[ dctComp ] = acValue;
					dctComp ++;

				}

				currAcComp.value ++;

			}

		}

		function unZigZag( src, dst ) {

			dst[ 0 ] = decodeFloat16( src[ 0 ] );
			dst[ 1 ] = decodeFloat16( src[ 1 ] );
			dst[ 2 ] = decodeFloat16( src[ 5 ] );
			dst[ 3 ] = decodeFloat16( src[ 6 ] );
			dst[ 4 ] = decodeFloat16( src[ 14 ] );
			dst[ 5 ] = decodeFloat16( src[ 15 ] );
			dst[ 6 ] = decodeFloat16( src[ 27 ] );
			dst[ 7 ] = decodeFloat16( src[ 28 ] );
			dst[ 8 ] = decodeFloat16( src[ 2 ] );
			dst[ 9 ] = decodeFloat16( src[ 4 ] );

			dst[ 10 ] = decodeFloat16( src[ 7 ] );
			dst[ 11 ] = decodeFloat16( src[ 13 ] );
			dst[ 12 ] = decodeFloat16( src[ 16 ] );
			dst[ 13 ] = decodeFloat16( src[ 26 ] );
			dst[ 14 ] = decodeFloat16( src[ 29 ] );
			dst[ 15 ] = decodeFloat16( src[ 42 ] );
			dst[ 16 ] = decodeFloat16( src[ 3 ] );
			dst[ 17 ] = decodeFloat16( src[ 8 ] );
			dst[ 18 ] = decodeFloat16( src[ 12 ] );
			dst[ 19 ] = decodeFloat16( src[ 17 ] );

			dst[ 20 ] = decodeFloat16( src[ 25 ] );
			dst[ 21 ] = decodeFloat16( src[ 30 ] );
			dst[ 22 ] = decodeFloat16( src[ 41 ] );
			dst[ 23 ] = decodeFloat16( src[ 43 ] );
			dst[ 24 ] = decodeFloat16( src[ 9 ] );
			dst[ 25 ] = decodeFloat16( src[ 11 ] );
			dst[ 26 ] = decodeFloat16( src[ 18 ] );
			dst[ 27 ] = decodeFloat16( src[ 24 ] );
			dst[ 28 ] = decodeFloat16( src[ 31 ] );
			dst[ 29 ] = decodeFloat16( src[ 40 ] );

			dst[ 30 ] = decodeFloat16( src[ 44 ] );
			dst[ 31 ] = decodeFloat16( src[ 53 ] );
			dst[ 32 ] = decodeFloat16( src[ 10 ] );
			dst[ 33 ] = decodeFloat16( src[ 19 ] );
			dst[ 34 ] = decodeFloat16( src[ 23 ] );
			dst[ 35 ] = decodeFloat16( src[ 32 ] );
			dst[ 36 ] = decodeFloat16( src[ 39 ] );
			dst[ 37 ] = decodeFloat16( src[ 45 ] );
			dst[ 38 ] = decodeFloat16( src[ 52 ] );
			dst[ 39 ] = decodeFloat16( src[ 54 ] );

			dst[ 40 ] = decodeFloat16( src[ 20 ] );
			dst[ 41 ] = decodeFloat16( src[ 22 ] );
			dst[ 42 ] = decodeFloat16( src[ 33 ] );
			dst[ 43 ] = decodeFloat16( src[ 38 ] );
			dst[ 44 ] = decodeFloat16( src[ 46 ] );
			dst[ 45 ] = decodeFloat16( src[ 51 ] );
			dst[ 46 ] = decodeFloat16( src[ 55 ] );
			dst[ 47 ] = decodeFloat16( src[ 60 ] );
			dst[ 48 ] = decodeFloat16( src[ 21 ] );
			dst[ 49 ] = decodeFloat16( src[ 34 ] );

			dst[ 50 ] = decodeFloat16( src[ 37 ] );
			dst[ 51 ] = decodeFloat16( src[ 47 ] );
			dst[ 52 ] = decodeFloat16( src[ 50 ] );
			dst[ 53 ] = decodeFloat16( src[ 56 ] );
			dst[ 54 ] = decodeFloat16( src[ 59 ] );
			dst[ 55 ] = decodeFloat16( src[ 61 ] );
			dst[ 56 ] = decodeFloat16( src[ 35 ] );
			dst[ 57 ] = decodeFloat16( src[ 36 ] );
			dst[ 58 ] = decodeFloat16( src[ 48 ] );
			dst[ 59 ] = decodeFloat16( src[ 49 ] );

			dst[ 60 ] = decodeFloat16( src[ 57 ] );
			dst[ 61 ] = decodeFloat16( src[ 58 ] );
			dst[ 62 ] = decodeFloat16( src[ 62 ] );
			dst[ 63 ] = decodeFloat16( src[ 63 ] );

		}

		function dctInverse( data ) {

			const a = 0.5 * Math.cos( 3.14159 / 4.0 );
			const b = 0.5 * Math.cos( 3.14159 / 16.0 );
			const c = 0.5 * Math.cos( 3.14159 / 8.0 );
			const d = 0.5 * Math.cos( 3.0 * 3.14159 / 16.0 );
			const e = 0.5 * Math.cos( 5.0 * 3.14159 / 16.0 );
			const f = 0.5 * Math.cos( 3.0 * 3.14159 / 8.0 );
			const g = 0.5 * Math.cos( 7.0 * 3.14159 / 16.0 );

			var alpha = new Array( 4 );
			var beta = new Array( 4 );
			var theta = new Array( 4 );
			var gamma = new Array( 4 );

			for ( var row = 0; row < 8; ++ row ) {

				var rowPtr = row * 8;

				alpha[ 0 ] = c * data[ rowPtr + 2 ];
				alpha[ 1 ] = f * data[ rowPtr + 2 ];
				alpha[ 2 ] = c * data[ rowPtr + 6 ];
				alpha[ 3 ] = f * data[ rowPtr + 6 ];

				beta[ 0 ] = b * data[ rowPtr + 1 ] + d * data[ rowPtr + 3 ] + e * data[ rowPtr + 5 ] + g * data[ rowPtr + 7 ];
				beta[ 1 ] = d * data[ rowPtr + 1 ] - g * data[ rowPtr + 3 ] - b * data[ rowPtr + 5 ] - e * data[ rowPtr + 7 ];
				beta[ 2 ] = e * data[ rowPtr + 1 ] - b * data[ rowPtr + 3 ] + g * data[ rowPtr + 5 ] + d * data[ rowPtr + 7 ];
				beta[ 3 ] = g * data[ rowPtr + 1 ] - e * data[ rowPtr + 3 ] + d * data[ rowPtr + 5 ] - b * data[ rowPtr + 7 ];

				theta[ 0 ] = a * ( data[ rowPtr + 0 ] + data[ rowPtr + 4 ] );
				theta[ 3 ] = a * ( data[ rowPtr + 0 ] - data[ rowPtr + 4 ] );
				theta[ 1 ] = alpha[ 0 ] + alpha[ 3 ];
				theta[ 2 ] = alpha[ 1 ] - alpha[ 2 ];

				gamma[ 0 ] = theta[ 0 ] + theta[ 1 ];
				gamma[ 1 ] = theta[ 3 ] + theta[ 2 ];
				gamma[ 2 ] = theta[ 3 ] - theta[ 2 ];
				gamma[ 3 ] = theta[ 0 ] - theta[ 1 ];

				data[ rowPtr + 0 ] = gamma[ 0 ] + beta[ 0 ];
				data[ rowPtr + 1 ] = gamma[ 1 ] + beta[ 1 ];
				data[ rowPtr + 2 ] = gamma[ 2 ] + beta[ 2 ];
				data[ rowPtr + 3 ] = gamma[ 3 ] + beta[ 3 ];

				data[ rowPtr + 4 ] = gamma[ 3 ] - beta[ 3 ];
				data[ rowPtr + 5 ] = gamma[ 2 ] - beta[ 2 ];
				data[ rowPtr + 6 ] = gamma[ 1 ] - beta[ 1 ];
				data[ rowPtr + 7 ] = gamma[ 0 ] - beta[ 0 ];

			}

			for ( var column = 0; column < 8; ++ column ) {

				alpha[ 0 ] = c * data[ 16 + column ];
				alpha[ 1 ] = f * data[ 16 + column ];
				alpha[ 2 ] = c * data[ 48 + column ];
				alpha[ 3 ] = f * data[ 48 + column ];

				beta[ 0 ] = b * data[ 8 + column ] + d * data[ 24 + column ] + e * data[ 40 + column ] + g * data[ 56 + column ];
				beta[ 1 ] = d * data[ 8 + column ] - g * data[ 24 + column ] - b * data[ 40 + column ] - e * data[ 56 + column ];
				beta[ 2 ] = e * data[ 8 + column ] - b * data[ 24 + column ] + g * data[ 40 + column ] + d * data[ 56 + column ];
				beta[ 3 ] = g * data[ 8 + column ] - e * data[ 24 + column ] + d * data[ 40 + column ] - b * data[ 56 + column ];

				theta[ 0 ] = a * ( data[ column ] + data[ 32 + column ] );
				theta[ 3 ] = a * ( data[ column ] - data[ 32 + column ] );

				theta[ 1 ] = alpha[ 0 ] + alpha[ 3 ];
				theta[ 2 ] = alpha[ 1 ] - alpha[ 2 ];

				gamma[ 0 ] = theta[ 0 ] + theta[ 1 ];
				gamma[ 1 ] = theta[ 3 ] + theta[ 2 ];
				gamma[ 2 ] = theta[ 3 ] - theta[ 2 ];
				gamma[ 3 ] = theta[ 0 ] - theta[ 1 ];

				data[ 0 + column ] = gamma[ 0 ] + beta[ 0 ];
				data[ 8 + column ] = gamma[ 1 ] + beta[ 1 ];
				data[ 16 + column ] = gamma[ 2 ] + beta[ 2 ];
				data[ 24 + column ] = gamma[ 3 ] + beta[ 3 ];

				data[ 32 + column ] = gamma[ 3 ] - beta[ 3 ];
				data[ 40 + column ] = gamma[ 2 ] - beta[ 2 ];
				data[ 48 + column ] = gamma[ 1 ] - beta[ 1 ];
				data[ 56 + column ] = gamma[ 0 ] - beta[ 0 ];

			}

		}

		function csc709Inverse( data ) {

			for ( var i = 0; i < 64; ++ i ) {

				var y = data[ 0 ][ i ];
				var cb = data[ 1 ][ i ];
				var cr = data[ 2 ][ i ];

				data[ 0 ][ i ] = y + 1.5747 * cr;
				data[ 1 ][ i ] = y - 0.1873 * cb - 0.4682 * cr;
				data[ 2 ][ i ] = y + 1.8556 * cb;

			}

		}

		function convertToHalf( src, dst, idx ) {

			for ( var i = 0; i < 64; ++ i ) {

				dst[ idx + i ] = encodeFloat16( toLinear( src[ i ] ) );

			}

		}

		function toLinear( float ) {

			if ( float <= 1 ) {

				return Math.sign( float ) * Math.pow( Math.abs( float ), 2.2 );

			} else {

				return Math.sign( float ) * Math.pow( logBase, Math.abs( float ) - 1.0 );

			}

		}

		function uncompressRAW( info ) {

			return new DataView( info.array.buffer, info.offset.value, info.size );

		}

		function uncompressRLE( info ) {

			var compressed = info.viewer.buffer.slice( info.offset.value, info.offset.value + info.size );

			var rawBuffer = new Uint8Array( decodeRunLength( compressed ) );
			var tmpBuffer = new Uint8Array( rawBuffer.length );

			predictor( rawBuffer ); // revert predictor

			interleaveScalar( rawBuffer, tmpBuffer ); // interleave pixels

			return new DataView( tmpBuffer.buffer );

		}

		function uncompressZIP( info ) {

			var compressed = info.array.slice( info.offset.value, info.offset.value + info.size );

			if ( typeof Zlib === 'undefined' ) {

				console.error( 'THREE.EXRLoader: External library Inflate.min.js required, obtain or import from https://github.com/imaya/zlib.js' );

			}

			var inflate = new Zlib.Inflate( compressed, { resize: true, verify: true } ); // eslint-disable-line no-undef

			var rawBuffer = new Uint8Array( inflate.decompress().buffer );
			var tmpBuffer = new Uint8Array( rawBuffer.length );

			predictor( rawBuffer ); // revert predictor

			interleaveScalar( rawBuffer, tmpBuffer ); // interleave pixels

			return new DataView( tmpBuffer.buffer );

		}

		function uncompressPIZ( info ) {

			var inDataView = info.viewer;
			var inOffset = { value: info.offset.value };

			var tmpBufSize = info.width * scanlineBlockSize * ( EXRHeader.channels.length * info.type );
			var outBuffer = new Uint16Array( tmpBufSize );
			var bitmap = new Uint8Array( BITMAP_SIZE );

			// Setup channel info
			var outBufferEnd = 0;
			var pizChannelData = new Array( info.channels );
			for ( var i = 0; i < info.channels; i ++ ) {

				pizChannelData[ i ] = {};
				pizChannelData[ i ][ 'start' ] = outBufferEnd;
				pizChannelData[ i ][ 'end' ] = pizChannelData[ i ][ 'start' ];
				pizChannelData[ i ][ 'nx' ] = info.width;
				pizChannelData[ i ][ 'ny' ] = info.lines;
				pizChannelData[ i ][ 'size' ] = info.type;

				outBufferEnd += pizChannelData[ i ].nx * pizChannelData[ i ].ny * pizChannelData[ i ].size;

			}

			// Read range compression data
			var minNonZero = parseUint16( inDataView, inOffset );
			var maxNonZero = parseUint16( inDataView, inOffset );

			if ( maxNonZero >= BITMAP_SIZE ) {

				throw 'Something is wrong with PIZ_COMPRESSION BITMAP_SIZE';

			}

			if ( minNonZero <= maxNonZero ) {

				for ( var i = 0; i < maxNonZero - minNonZero + 1; i ++ ) {

					bitmap[ i + minNonZero ] = parseUint8( inDataView, inOffset );

				}

			}

			// Reverse LUT
			var lut = new Uint16Array( USHORT_RANGE );
			reverseLutFromBitmap( bitmap, lut );

			var length = parseUint32( inDataView, inOffset );

			// Huffman decoding
			hufUncompress( info.array, inDataView, inOffset, length, outBuffer, outBufferEnd );

			// Wavelet decoding
			for ( var i = 0; i < info.channels; ++ i ) {

				var cd = pizChannelData[ i ];

				for ( var j = 0; j < pizChannelData[ i ].size; ++ j ) {

					wav2Decode(
						outBuffer,
						cd.start + j,
						cd.nx,
						cd.size,
						cd.ny,
						cd.nx * cd.size
					);

				}

			}

			// Expand the pixel data to their original range
			applyLut( lut, outBuffer, outBufferEnd );

			// Rearrange the pixel data into the format expected by the caller.
			var tmpOffset = 0;
			var tmpBuffer = new Uint8Array( outBuffer.buffer.byteLength );
			for ( var y = 0; y < info.lines; y ++ ) {

				for ( var c = 0; c < info.channels; c ++ ) {

					var cd = pizChannelData[ c ];

					var n = cd.nx * cd.size;
					var cp = new Uint8Array( outBuffer.buffer, cd.end * INT16_SIZE, n * INT16_SIZE );

					tmpBuffer.set( cp, tmpOffset );
					tmpOffset += n * INT16_SIZE;
					cd.end += n;

				}

			}

			return new DataView( tmpBuffer.buffer );

		}

		function uncompressDWA( info ) {

			var inDataView = info.viewer;
			var inOffset = { value: info.offset.value };
			var outBuffer = new Uint8Array( info.width * info.lines * ( EXRHeader.channels.length * info.type * INT16_SIZE ) );

			// Read compression header information
			var dwaHeader = {

				version: parseInt64( inDataView, inOffset ),
				unknownUncompressedSize: parseInt64( inDataView, inOffset ),
				unknownCompressedSize: parseInt64( inDataView, inOffset ),
				acCompressedSize: parseInt64( inDataView, inOffset ),
				dcCompressedSize: parseInt64( inDataView, inOffset ),
				rleCompressedSize: parseInt64( inDataView, inOffset ),
				rleUncompressedSize: parseInt64( inDataView, inOffset ),
				rleRawSize: parseInt64( inDataView, inOffset ),
				totalAcUncompressedCount: parseInt64( inDataView, inOffset ),
				totalDcUncompressedCount: parseInt64( inDataView, inOffset ),
				acCompression: parseInt64( inDataView, inOffset )

			};

			if ( dwaHeader.version < 2 )
				throw 'EXRLoader.parse: ' + EXRHeader.compression + ' version ' + dwaHeader.version + ' is unsupported';

			// Read channel ruleset information
			var channelRules = new Array();
			var ruleSize = parseUint16( inDataView, inOffset ) - INT16_SIZE;

			while ( ruleSize > 0 ) {

				var name = parseNullTerminatedString( inDataView.buffer, inOffset );
				var value = parseUint8( inDataView, inOffset );
				var compression = ( value >> 2 ) & 3;
				var csc = ( value >> 4 ) - 1;
				var index = new Int8Array( [ csc ] )[ 0 ];
				var type = parseUint8( inDataView, inOffset );

				channelRules.push( {
					name: name,
					index: index,
					type: type,
					compression: compression,
				} );

				ruleSize -= name.length + 3;

			}

			// Classify channels
			var channels = EXRHeader.channels;
			var channelData = new Array( info.channels );

			for ( var i = 0; i < info.channels; ++ i ) {

				var cd = channelData[ i ] = {};
				var channel = channels[ i ];

				cd.name = channel.name;
				cd.compression = UNKNOWN;
				cd.decoded = false;
				cd.type = channel.pixelType;
				cd.pLinear = channel.pLinear;
				cd.width = info.width;
				cd.height = info.lines;

			}

			var cscSet = {
				idx: new Array( 3 )
			};

			for ( var offset = 0; offset < info.channels; ++ offset ) {

				var cd = channelData[ offset ];

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

					var rule = channelRules[ i ];

					if ( cd.name == rule.name ) {

						cd.compression = rule.compression;

						if ( rule.index >= 0 ) {

							cscSet.idx[ rule.index ] = offset;

						}

						cd.offset = offset;

					}

				}

			}

			// Read DCT - AC component data
			if ( dwaHeader.acCompressedSize > 0 ) {

				switch ( dwaHeader.acCompression ) {

					case STATIC_HUFFMAN:

						var acBuffer = new Uint16Array( dwaHeader.totalAcUncompressedCount );
						hufUncompress( info.array, inDataView, inOffset, dwaHeader.acCompressedSize, acBuffer, dwaHeader.totalAcUncompressedCount );
						break;

					case DEFLATE:

						var compressed = info.array.slice( inOffset.value, inOffset.value + dwaHeader.totalAcUncompressedCount );
						var inflate = new Zlib.Inflate( compressed, { resize: true, verify: true } );
						var acBuffer = new Uint16Array( inflate.decompress().buffer );
						inOffset.value += dwaHeader.totalAcUncompressedCount;
						break;

				}


			}

			// Read DCT - DC component data
			if ( dwaHeader.dcCompressedSize > 0 ) {

				var zlibInfo = {
					array: info.array,
					offset: inOffset,
					size: dwaHeader.dcCompressedSize
				};
				var dcBuffer = new Uint16Array( uncompressZIP( zlibInfo ).buffer );
				inOffset.value += dwaHeader.dcCompressedSize;

			}

			// Read RLE compressed data
			if ( dwaHeader.rleRawSize > 0 ) {

				var compressed = info.array.slice( inOffset.value, inOffset.value + dwaHeader.rleCompressedSize );
				var inflate = new Zlib.Inflate( compressed, { resize: true, verify: true } );
				var rleBuffer = decodeRunLength( inflate.decompress().buffer );

				inOffset.value += dwaHeader.rleCompressedSize;

			}

			// Prepare outbuffer data offset
			var outBufferEnd = 0;
			var rowOffsets = new Array( channelData.length );
			for ( var i = 0; i < rowOffsets.length; ++ i ) {

				rowOffsets[ i ] = new Array();

			}

			for ( var y = 0; y < info.lines; ++ y ) {

				for ( var chan = 0; chan < channelData.length; ++ chan ) {

					rowOffsets[ chan ].push( outBufferEnd );
					outBufferEnd += channelData[ chan ].width * info.type * INT16_SIZE;

				}

			}

			// Lossy DCT decode RGB channels
			lossyDctDecode( cscSet, rowOffsets, channelData, acBuffer, dcBuffer, outBuffer );

			// Decode other channels
			for ( var i = 0; i < channelData.length; ++ i ) {

				var cd = channelData[ i ];

				if ( cd.decoded ) continue;

				switch ( cd.compression ) {

					case RLE:

						var row = 0;
						var rleOffset = 0;

						for ( var y = 0; y < info.lines; ++ y ) {

							var rowOffsetBytes = rowOffsets[ i ][ row ];

							for ( var x = 0; x < cd.width; ++ x ) {

								for ( var byte = 0; byte < INT16_SIZE * cd.type; ++ byte ) {

									outBuffer[ rowOffsetBytes ++ ] = rleBuffer[ rleOffset + byte * cd.width * cd.height ];

								}

								rleOffset ++;

							}

							row ++;

						}

						break;

					case LOSSY_DCT: // skip

					default:
						throw 'EXRLoader.parse: unsupported channel compression';

				}

			}

			return new DataView( outBuffer.buffer );

		}

		function parseNullTerminatedString( buffer, offset ) {

			var uintBuffer = new Uint8Array( buffer );
			var endOffset = 0;

			while ( uintBuffer[ offset.value + endOffset ] != 0 ) {

				endOffset += 1;

			}

			var stringValue = new TextDecoder().decode(
				uintBuffer.slice( offset.value, offset.value + endOffset )
			);

			offset.value = offset.value + endOffset + 1;

			return stringValue;

		}

		function parseFixedLengthString( buffer, offset, size ) {

			var stringValue = new TextDecoder().decode(
				new Uint8Array( buffer ).slice( offset.value, offset.value + size )
			);

			offset.value = offset.value + size;

			return stringValue;

		}

		function parseUlong( dataView, offset ) {

			var uLong = dataView.getUint32( 0, true );

			offset.value = offset.value + ULONG_SIZE;

			return uLong;

		}

		function parseRational( dataView, offset ) {

			var x = parseUint32( dataView, offset );
			var y = parseUint32( dataView, offset );

			return [ x, y ];

		}

		function parseTimecode( dataView, offset ) {

			var x = parseUint32( dataView, offset );
			var y = parseUint32( dataView, offset );

			return [ x, y ];

		}

		function parseUint32( dataView, offset ) {

			var Uint32 = dataView.getUint32( offset.value, true );

			offset.value = offset.value + INT32_SIZE;

			return Uint32;

		}

		function parseUint8Array( uInt8Array, offset ) {

			var Uint8 = uInt8Array[ offset.value ];

			offset.value = offset.value + INT8_SIZE;

			return Uint8;

		}

		function parseUint8( dataView, offset ) {

			var Uint8 = dataView.getUint8( offset.value );

			offset.value = offset.value + INT8_SIZE;

			return Uint8;

		}

		function parseInt64( dataView, offset ) {

			var int = Number( dataView.getBigInt64( offset.value, true ) );

			offset.value += ULONG_SIZE;

			return int;

		}

		function parseFloat32( dataView, offset ) {

			var float = dataView.getFloat32( offset.value, true );

			offset.value += FLOAT32_SIZE;

			return float;

		}

		function decodeFloat32( dataView, offset ) {

			return encodeFloat16( parseFloat32( dataView, offset ) );

		}

		// https://stackoverflow.com/questions/5678432/decompressing-half-precision-floats-in-javascript
		function decodeFloat16( binary ) {

			var exponent = ( binary & 0x7C00 ) >> 10,
				fraction = binary & 0x03FF;

			return ( binary >> 15 ? - 1 : 1 ) * (
				exponent ?
					(
						exponent === 0x1F ?
							fraction ? NaN : Infinity :
							Math.pow( 2, exponent - 15 ) * ( 1 + fraction / 0x400 )
					) :
					6.103515625e-5 * ( fraction / 0x400 )
			);

		}

		// http://gamedev.stackexchange.com/questions/17326/conversion-of-a-number-from-single-precision-floating-point-representation-to-a/17410#17410
		function encodeFloat16( val ) {

			/* This method is faster than the OpenEXR implementation (very often
			 * used, eg. in Ogre), with the additional benefit of rounding, inspired
			 * by James Tursa?s half-precision code.
			*/

			tmpDataView.setFloat32( 0, val );
			var x = tmpDataView.getInt32( 0 );

			var bits = ( x >> 16 ) & 0x8000; /* Get the sign */
			var m = ( x >> 12 ) & 0x07ff; /* Keep one extra bit for rounding */
			var e = ( x >> 23 ) & 0xff; /* Using int is faster here */

			/* If zero, or denormal, or exponent underflows too much for a denormal
				* half, return signed zero. */
			if ( e < 103 ) return bits;

			/* If NaN, return NaN. If Inf or exponent overflow, return Inf. */
			if ( e > 142 ) {

				bits |= 0x7c00;
				/* If exponent was 0xff and one mantissa bit was set, it means NaN,
							* not Inf, so make sure we set one mantissa bit too. */
				bits |= ( ( e == 255 ) ? 0 : 1 ) && ( x & 0x007fffff );
				return bits;

			}

			/* If exponent underflows but not too much, return a denormal */
			if ( e < 113 ) {

				m |= 0x0800;
				/* Extra rounding may overflow and set mantissa to 0 and exponent
					* to 1, which is OK. */
				bits |= ( m >> ( 114 - e ) ) + ( ( m >> ( 113 - e ) ) & 1 );
				return bits;

			}

			bits |= ( ( e - 112 ) << 10 ) | ( m >> 1 );
			/* Extra rounding. An overflow will set mantissa to 0 and increment
				* the exponent, which is OK. */
			bits += m & 1;
			return bits;

		}

		function parseUint16( dataView, offset ) {

			var Uint16 = dataView.getUint16( offset.value, true );

			offset.value += INT16_SIZE;

			return Uint16;

		}

		function parseFloat16( buffer, offset ) {

			return decodeFloat16( parseUint16( buffer, offset ) );

		}

		function parseChlist( dataView, buffer, offset, size ) {

			var startOffset = offset.value;
			var channels = [];

			while ( offset.value < ( startOffset + size - 1 ) ) {

				var name = parseNullTerminatedString( buffer, offset );
				var pixelType = parseUint32( dataView, offset ); // TODO: Cast this to UINT, HALF or FLOAT
				var pLinear = parseUint8( dataView, offset );
				offset.value += 3; // reserved, three chars
				var xSampling = parseUint32( dataView, offset );
				var ySampling = parseUint32( dataView, offset );

				channels.push( {
					name: name,
					pixelType: pixelType,
					pLinear: pLinear,
					xSampling: xSampling,
					ySampling: ySampling
				} );

			}

			offset.value += 1;

			return channels;

		}

		function parseChromaticities( dataView, offset ) {

			var redX = parseFloat32( dataView, offset );
			var redY = parseFloat32( dataView, offset );
			var greenX = parseFloat32( dataView, offset );
			var greenY = parseFloat32( dataView, offset );
			var blueX = parseFloat32( dataView, offset );
			var blueY = parseFloat32( dataView, offset );
			var whiteX = parseFloat32( dataView, offset );
			var whiteY = parseFloat32( dataView, offset );

			return { redX: redX, redY: redY, greenX: greenX, greenY: greenY, blueX: blueX, blueY: blueY, whiteX: whiteX, whiteY: whiteY };

		}

		function parseCompression( dataView, offset ) {

			var compressionCodes = [
				'NO_COMPRESSION',
				'RLE_COMPRESSION',
				'ZIPS_COMPRESSION',
				'ZIP_COMPRESSION',
				'PIZ_COMPRESSION',
				'PXR24_COMPRESSION',
				'B44_COMPRESSION',
				'B44A_COMPRESSION',
				'DWAA_COMPRESSION',
				'DWAB_COMPRESSION'
			];

			var compression = parseUint8( dataView, offset );

			return compressionCodes[ compression ];

		}

		function parseBox2i( dataView, offset ) {

			var xMin = parseUint32( dataView, offset );
			var yMin = parseUint32( dataView, offset );
			var xMax = parseUint32( dataView, offset );
			var yMax = parseUint32( dataView, offset );

			return { xMin: xMin, yMin: yMin, xMax: xMax, yMax: yMax };

		}

		function parseLineOrder( dataView, offset ) {

			var lineOrders = [
				'INCREASING_Y'
			];

			var lineOrder = parseUint8( dataView, offset );

			return lineOrders[ lineOrder ];

		}

		function parseV2f( dataView, offset ) {

			var x = parseFloat32( dataView, offset );
			var y = parseFloat32( dataView, offset );

			return [ x, y ];

		}

		function parseValue( dataView, buffer, offset, type, size ) {

			if ( type === 'string' || type === 'stringvector' || type === 'iccProfile' ) {

				return parseFixedLengthString( buffer, offset, size );

			} else if ( type === 'chlist' ) {

				return parseChlist( dataView, buffer, offset, size );

			} else if ( type === 'chromaticities' ) {

				return parseChromaticities( dataView, offset );

			} else if ( type === 'compression' ) {

				return parseCompression( dataView, offset );

			} else if ( type === 'box2i' ) {

				return parseBox2i( dataView, offset );

			} else if ( type === 'lineOrder' ) {

				return parseLineOrder( dataView, offset );

			} else if ( type === 'float' ) {

				return parseFloat32( dataView, offset );

			} else if ( type === 'v2f' ) {

				return parseV2f( dataView, offset );

			} else if ( type === 'int' ) {

				return parseUint32( dataView, offset );

			} else if ( type === 'rational' ) {

				return parseRational( dataView, offset );

			} else if ( type === 'timecode' ) {

				return parseTimecode( dataView, offset );

			} else {

				throw 'Cannot parse value for unsupported type: ' + type;

			}

		}

		var bufferDataView = new DataView( buffer );
		var uInt8Array = new Uint8Array( buffer );

		var EXRHeader = {};

		bufferDataView.getUint32( 0, true ); // magic
		bufferDataView.getUint8( 4, true ); // versionByteZero
		bufferDataView.getUint8( 5, true ); // fullMask

		// start of header

		var offset = { value: 8 }; // start at 8, after magic stuff

		var keepReading = true;

		while ( keepReading ) {

			var attributeName = parseNullTerminatedString( buffer, offset );

			if ( attributeName == 0 ) {

				keepReading = false;

			} else {

				var attributeType = parseNullTerminatedString( buffer, offset );
				var attributeSize = parseUint32( bufferDataView, offset );
				var attributeValue = parseValue( bufferDataView, buffer, offset, attributeType, attributeSize );

				EXRHeader[ attributeName ] = attributeValue;

			}

		}

		// offsets
		var dataWindowHeight = EXRHeader.dataWindow.yMax + 1;

		var uncompress;
		var scanlineBlockSize;

		switch ( EXRHeader.compression ) {

			case 'NO_COMPRESSION':

				scanlineBlockSize = 1;
				uncompress = uncompressRAW;
				break;

			case 'RLE_COMPRESSION':

				scanlineBlockSize = 1;
				uncompress = uncompressRLE;
				break;

			case 'ZIPS_COMPRESSION':

				scanlineBlockSize = 1;
				uncompress = uncompressZIP;
				break;

			case 'ZIP_COMPRESSION':

				scanlineBlockSize = 16;
				uncompress = uncompressZIP;
				break;

			case 'PIZ_COMPRESSION':

				scanlineBlockSize = 32;
				uncompress = uncompressPIZ;
				break;

			case 'DWAA_COMPRESSION':

				scanlineBlockSize = 32;
				uncompress = uncompressDWA;
				break;

			case 'DWAB_COMPRESSION':

				scanlineBlockSize = 256;
				uncompress = uncompressDWA;
				break;

			default:

				throw 'EXRLoader.parse: ' + EXRHeader.compression + ' is unsupported';

		}

		var size_t;
		var getValue;

		// mixed pixelType not supported
		var pixelType = EXRHeader.channels[ 0 ].pixelType;

		if ( pixelType === 1 ) { // half

			switch ( this.type ) {

				case UnsignedByteType:
				case FloatType:

					getValue = parseFloat16;
					size_t = INT16_SIZE;
					break;

				case HalfFloatType:

					getValue = parseUint16;
					size_t = INT16_SIZE;
					break;

			}

		} else if ( pixelType === 2 ) { // float

			switch ( this.type ) {

				case UnsignedByteType:
				case FloatType:

					getValue = parseFloat32;
					size_t = FLOAT32_SIZE;
					break;

				case HalfFloatType:

					getValue = decodeFloat32;
					size_t = FLOAT32_SIZE;

			}

		} else {

			throw 'EXRLoader.parse: unsupported pixelType ' + pixelType + ' for ' + EXRHeader.compression + '.';

		}

		var numBlocks = dataWindowHeight / scanlineBlockSize;

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

			parseUlong( bufferDataView, offset ); // scanlineOffset

		}

		// we should be passed the scanline offset table, start reading pixel data

		var width = EXRHeader.dataWindow.xMax - EXRHeader.dataWindow.xMin + 1;
		var height = EXRHeader.dataWindow.yMax - EXRHeader.dataWindow.yMin + 1;
		// Firefox only supports RGBA (half) float textures
		// var numChannels = EXRHeader.channels.length;
		var numChannels = 4;
		var size = width * height * numChannels;

		// Fill initially with 1s for the alpha value if the texture is not RGBA, RGB values will be overwritten
		switch ( this.type ) {

			case UnsignedByteType:
			case FloatType:

				var byteArray = new Float32Array( size );

				if ( EXRHeader.channels.length < numChannels ) {

					byteArray.fill( 1, 0, size );

				}

				break;

			case HalfFloatType:

				var byteArray = new Uint16Array( size );

				if ( EXRHeader.channels.length < numChannels ) {

					byteArray.fill( 0x3C00, 0, size ); // Uint16Array holds half float data, 0x3C00 is 1

				}

				break;

			default:

				console.error( 'THREE.EXRLoader: unsupported type: ', this.type );
				break;

		}

		var channelOffsets = {
			R: 0,
			G: 1,
			B: 2,
			A: 3
		};

		var compressionInfo = {

			size: 0,
			width: width,
			lines: scanlineBlockSize,

			offset: offset,
			array: uInt8Array,
			viewer: bufferDataView,

			type: pixelType,
			channels: EXRHeader.channels.length,

		};

		var line;
		var size;
		var viewer;
		var tmpOffset = { value: 0 };

		for ( var scanlineBlockIdx = 0; scanlineBlockIdx < height / scanlineBlockSize; scanlineBlockIdx ++ ) {

			line = parseUint32( bufferDataView, offset ); // line_no
			size = parseUint32( bufferDataView, offset ); // data_len

			compressionInfo.lines = ( line + scanlineBlockSize > height ) ? height - line : scanlineBlockSize;
			compressionInfo.offset = offset;
			compressionInfo.size = size;

			viewer = uncompress( compressionInfo );

			offset.value += size;

			for ( var line_y = 0; line_y < scanlineBlockSize; line_y ++ ) {

				var true_y = line_y + ( scanlineBlockIdx * scanlineBlockSize );

				if ( true_y >= height ) break;

				for ( var channelID = 0; channelID < EXRHeader.channels.length; channelID ++ ) {

					var cOff = channelOffsets[ EXRHeader.channels[ channelID ].name ];

					for ( var x = 0; x < width; x ++ ) {

						var idx = ( line_y * ( EXRHeader.channels.length * width ) ) + ( channelID * width ) + x;
						tmpOffset.value = idx * size_t;

						var val = getValue( viewer, tmpOffset );

						byteArray[ ( ( ( height - 1 - true_y ) * ( width * numChannels ) ) + ( x * numChannels ) ) + cOff ] = val;

					}

				}

			}

		}

		if ( this.type === UnsignedByteType ) {

			let v, i, j;
			const size = byteArray.length;
			const RGBEArray = new Uint8Array( size );

			for ( let h = 0; h < height; ++ h ) {

				for ( let w = 0; w < width; ++ w ) {

					i = h * width * 4 + w * 4;
					j = ( height - 1 - h ) * width * 4 + w * 4;

					const red = byteArray[ j ];
					const green = byteArray[ j + 1 ];
					const blue = byteArray[ j + 2 ];

					v = ( red > green ) ? red : green;
					v = ( blue > v ) ? blue : v;

					if ( v < 1e-32 ) {

						RGBEArray[ i ] = RGBEArray[ i + 1 ] = RGBEArray[ i + 2 ] = RGBEArray[ i + 3 ] = 0;

					} else {

						const res = frexp( v );
						v = res[ 0 ] * 256 / v;

						RGBEArray[ i ] = red * v;
						RGBEArray[ i + 1 ] = green * v;
						RGBEArray[ i + 2 ] = blue * v;
						RGBEArray[ i + 3 ] = res[ 1 ] + 128;

					}

				}

			}

			byteArray = RGBEArray;

		}

		let format = ( this.type === UnsignedByteType ) ? RGBEFormat : ( numChannels === 4 ) ? RGBAFormat : RGBFormat;

		return {
			header: EXRHeader,
			width: width,
			height: height,
			data: byteArray,
			format: format,
			type: this.type
		};

	},

	setDataType: function ( value ) {

		this.type = value;
		return this;

	},

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

		function onLoadCallback( texture, texData ) {

			switch ( texture.type ) {

				case UnsignedByteType:

					texture.encoding = RGBEEncoding;
					texture.minFilter = NearestFilter;
					texture.magFilter = NearestFilter;
					texture.generateMipmaps = false;
					texture.flipY = true;
					break;

				case FloatType:
				case HalfFloatType:

					texture.encoding = LinearEncoding;
					texture.minFilter = LinearFilter;
					texture.magFilter = LinearFilter;
					texture.generateMipmaps = false;
					texture.flipY = false;
					break;

			}

			if ( onLoad ) onLoad( texture, texData );

		}

		return DataTextureLoader.prototype.load.call( this, url, onLoadCallback, onProgress, onError );

	}

} );

export { EXRLoader };