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

import {
	DataTextureLoader,
	DataUtils,
	FloatType,
	HalfFloatType,
	LinearFilter,
	LinearSRGBColorSpace,
	RedFormat,
	RGFormat,
	RGBAFormat
} from 'three';
import { unzlibSync } from '../libs/fflate.module.js';

// Referred to the original Industrial Light & Magic OpenEXR implementation and the TinyEXR / Syoyo Fujita
// implementation, so I have preserved their copyright notices.

// /*
// 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 -------------------------------------------------


/**
 * A loader for the OpenEXR texture format.
 *
 * `EXRLoader` currently supports uncompressed, ZIP(S), RLE, PIZ, B44/A and DWA/B compression.
 * Supports reading as UnsignedByte, HalfFloat and Float type data texture.
 *
 * ```js
 * const loader = new EXRLoader();
 * const texture = await loader.loadAsync( 'textures/memorial.exr' );
 * ```
 *
 * @augments DataTextureLoader
 * @three_import import { EXRLoader } from 'three/addons/loaders/EXRLoader.js';
 */
class EXRLoader extends DataTextureLoader {

	/**
	 * Constructs a new EXR loader.
	 *
	 * @param {LoadingManager} [manager] - The loading manager.
	 */
	constructor( manager ) {

		super( manager );

		/**
		 * The texture type.
		 *
		 * @type {(HalfFloatType|FloatType)}
		 * @default HalfFloatType
		 */
		this.type = HalfFloatType;

		/**
		 * Texture output format.
		 *
		 * @type {(RGBAFormat|RGFormat|RedFormat)}
		 * @default RGBAFormat
		 */
		this.outputFormat = RGBAFormat;

		/**
		 * For multi-part EXR files, the index of the part to load.
		 *
		 * @type {number}
		 * @default 0
		 */
		this.part = 0;

	}

	/**
	 * Parses the given EXR texture data.
	 *
	 * @param {ArrayBuffer} buffer - The raw texture data.
	 * @return {DataTextureLoader~TexData} An object representing the parsed texture data.
	 */
	parse( 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 NBITS = 16;
		const A_OFFSET = 1 << ( NBITS - 1 );
		const MOD_MASK = ( 1 << NBITS ) - 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 );

		let b44LogTable = null; // lazily initialized for pLinear B44 channels

		function reverseLutFromBitmap( bitmap, lut ) {

			let k = 0;

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

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

					lut[ k ++ ] = i;

				}

			}

			const n = k - 1;

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

			return n;

		}

		function hufClearDecTable( hdec ) {

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

			let c = 0;

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

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

			}

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

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

			}

		}

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

			const p = inOffset;
			let c = 0;
			let lc = 0;

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

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

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

				const l = getBitsReturn.l;
				c = getBitsReturn.c;
				lc = getBitsReturn.lc;

				hcode[ im ] = l;

				if ( l == LONG_ZEROCODE_RUN ) {

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

						throw new Error( 'THREE.EXRLoader: Something wrong with hufUnpackEncTable' );

					}

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

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

					if ( im + zerun > iM + 1 ) {

						throw new Error( 'THREE.EXRLoader: Something wrong with hufUnpackEncTable' );

					}

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

					im --;

				} else if ( l >= SHORT_ZEROCODE_RUN ) {

					let zerun = l - SHORT_ZEROCODE_RUN + 2;

					if ( im + zerun > iM + 1 ) {

						throw new Error( 'THREE.EXRLoader: 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 ++ ) {

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

				if ( c >> l ) {

					throw new Error( 'THREE.EXRLoader: Invalid table entry' );

				}

				if ( l > HUF_DECBITS ) {

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

					if ( pl.len ) {

						throw new Error( 'THREE.EXRLoader: Invalid table entry' );

					}

					pl.lit ++;

					if ( pl.p ) {

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

						for ( let 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 ) {

					let plOffset = 0;

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

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

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

							throw new Error( 'THREE.EXRLoader: 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, inOffset, outBuffer, outBufferOffset, outBufferEndOffset ) {

			if ( po == rlc ) {

				if ( lc < 8 ) {

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

				}

				lc -= 8;

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

				if ( outBufferOffset.value + cs > outBufferEndOffset ) {

					return false;

				}

				const 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 ) {

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

		}

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

		function wdec14( l, h ) {

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

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

			const as = ai;
			const bs = ai - hi;

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

		}

		function wdec16( l, h ) {

			const m = UInt16( l );
			const d = UInt16( h );

			const bb = ( m - ( d >> 1 ) ) & MOD_MASK;
			const aa = ( d + bb - A_OFFSET ) & MOD_MASK;

			wdec14Return.a = aa;
			wdec14Return.b = bb;

		}

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

			const w14 = mx < ( 1 << 14 );
			const n = ( nx > ny ) ? ny : nx;
			let p = 1;
			let p2;
			let py;

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

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

			while ( p >= 1 ) {

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

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

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

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

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

						if ( w14 ) {

							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;

						} else {

							wdec16( buffer[ px + j ], buffer[ p10 + j ] );

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

							wdec16( buffer[ p01 + j ], buffer[ p11 + j ] );

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

							wdec16( i00, i01 );

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

							wdec16( i10, i11 );

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


						}

					}

					if ( nx & p ) {

						const p10 = px + oy1;

						if ( w14 )
							wdec14( buffer[ px + j ], buffer[ p10 + j ] );
						else
							wdec16( buffer[ px + j ], buffer[ p10 + j ] );

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

						buffer[ px + j ] = i00;

					}

				}

				if ( ny & p ) {

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

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

						const p01 = px + ox1;

						if ( w14 )
							wdec14( buffer[ px + j ], buffer[ p01 + j ] );
						else
							wdec16( 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, inOffset, ni, rlc, no, outBuffer, outOffset ) {

			let c = 0;
			let lc = 0;
			const outBufferEndOffset = no;
			const 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 ) {

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

					if ( pl.len ) {

						lc -= pl.len;

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

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

					} else {

						if ( ! pl.p ) {

							throw new Error( 'THREE.EXRLoader: hufDecode issues' );

						}

						let j;

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

							const 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, inOffset, outBuffer, outOffset, outBufferEndOffset );

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

									break;

								}

							}

						}

						if ( j == pl.lit ) {

							throw new Error( 'THREE.EXRLoader: hufDecode issues' );

						}

					}

				}

			}

			const i = ( 8 - ni ) & 7;

			c >>= i;
			lc -= i;

			while ( lc > 0 ) {

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

				if ( pl.len ) {

					lc -= pl.len;

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

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

				} else {

					throw new Error( 'THREE.EXRLoader: hufDecode issues' );

				}

			}

			return true;

		}

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

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

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

			inOffset.value += 4;

			const nBits = parseUint32( inDataView, inOffset );

			inOffset.value += 4;

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

				throw new Error( 'THREE.EXRLoader: Something wrong with HUF_ENCSIZE' );

			}

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

			hufClearDecTable( hdec );

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

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

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

				throw new Error( 'THREE.EXRLoader: Something wrong with hufUncompress' );

			}

			hufBuildDecTable( freq, im, iM, hdec );

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

		}

		function applyLut( lut, data, nData ) {

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

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

			}

		}

		function predictor( source ) {

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

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

			}

		}

		function interleaveScalar( source, out ) {

			let t1 = 0;
			let t2 = Math.floor( ( source.length + 1 ) / 2 );
			let s = 0;
			const 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 ) {

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

			const reader = new DataView( source );

			while ( size > 0 ) {

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

				if ( l < 0 ) {

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

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

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

					}


				} else {

					const count = l;
					size -= 2;

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

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

						out.push( value );

					}

				}

			}

			return out;

		}

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

			let dataView = new DataView( outBuffer.buffer );

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

			const numComp = 3;

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

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

				let maxY = 8;

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

				let 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 ) {

					const 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 ) {

							const 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 ) {

							const offset = rowOffsets[ comp ][ y ] + 8 * numFullBlocksX * INT16_SIZE * type;
							const 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

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

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

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

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

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

					const offset = rowOffsets[ comp ][ y ];

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

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

					}

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

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

					}

				}

			}

		}

		function lossyDctChannelDecode( channelIndex, rowPtrs, channelData, acBuffer, dcBuffer, outBuffer ) {

			const dataView = new DataView( outBuffer.buffer );
			const cd = channelData[ channelIndex ];
			const width = cd.width;
			const height = cd.height;

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

			const currAcComp = { value: 0 };
			let currDcComp = 0;
			const dctData = new Float32Array( 64 );
			const halfZigBlock = new Uint16Array( 64 );
			const rowBlock = new Uint16Array( numBlocksX * 64 );

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

				let maxY = 8;

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

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

					halfZigBlock.fill( 0 );
					halfZigBlock[ 0 ] = dcBuffer[ currDcComp ++ ];
					unRleAC( currAcComp, acBuffer, halfZigBlock );
					unZigZag( halfZigBlock, dctData );
					dctInverse( dctData );
					convertToHalf( dctData, rowBlock, blockx * 64 );

				}

				// Write decoded data to output buffer
				for ( let y = 8 * blocky; y < 8 * blocky + maxY; ++ y ) {

					let offset = rowPtrs[ channelIndex ][ y ];

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

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

						for ( let x = 0; x < 8; ++ x ) {

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

						}

						offset += 8 * INT16_SIZE * cd.type;

					}

					if ( numBlocksX != numFullBlocksX ) {

						const src = numFullBlocksX * 64 + ( ( y & 0x7 ) * 8 );

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

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

						}

					}

				}

			}

			cd.decoded = true;

		}

		function unRleAC( currAcComp, acBuffer, halfZigBlock ) {

			let acValue;
			let 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 );

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

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

				const 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 ( let 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 ( let i = 0; i < 64; ++ i ) {

				const y = data[ 0 ][ i ];
				const cb = data[ 1 ][ i ];
				const 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 ( let i = 0; i < 64; ++ i ) {

				dst[ idx + i ] = DataUtils.toHalfFloat( 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 ) {

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

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

			predictor( rawBuffer ); // revert predictor

			interleaveScalar( rawBuffer, tmpBuffer ); // interleave pixels

			return new DataView( tmpBuffer.buffer );

		}

		function uncompressZIP( info ) {

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

			const rawBuffer = unzlibSync( compressed );
			const tmpBuffer = new Uint8Array( rawBuffer.length );

			predictor( rawBuffer ); // revert predictor

			interleaveScalar( rawBuffer, tmpBuffer ); // interleave pixels

			return new DataView( tmpBuffer.buffer );

		}

		function uncompressPIZ( info ) {

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

			const outBuffer = new Uint16Array( info.columns * info.lines * ( info.inputChannels.length * info.type ) );
			const bitmap = new Uint8Array( BITMAP_SIZE );

			// Setup channel info
			let outBufferEnd = 0;
			const pizChannelData = new Array( info.inputChannels.length );
			for ( let i = 0, il = info.inputChannels.length; i < il; i ++ ) {

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

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

			}

			// Read range compression data

			const minNonZero = parseUint16( inDataView, inOffset );
			const maxNonZero = parseUint16( inDataView, inOffset );

			if ( maxNonZero >= BITMAP_SIZE ) {

				throw new Error( 'THREE.EXRLoader: Something is wrong with PIZ_COMPRESSION BITMAP_SIZE' );

			}

			if ( minNonZero <= maxNonZero ) {

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

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

				}

			}

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

			const length = parseUint32( inDataView, inOffset );

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

			// Wavelet decoding
			for ( let i = 0; i < info.inputChannels.length; ++ i ) {

				const cd = pizChannelData[ i ];

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

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

				}

			}

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

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

				for ( let c = 0; c < info.inputChannels.length; c ++ ) {

					const cd = pizChannelData[ c ];

					const n = cd.nx * cd.size;
					const 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 uncompressPXR( info ) {

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

			const rawBuffer = unzlibSync( compressed );

			const byteSize = info.inputChannels.length * info.lines * info.columns * info.totalBytes;
			const tmpBuffer = new ArrayBuffer( byteSize );
			const viewer = new DataView( tmpBuffer );

			let tmpBufferEnd = 0;
			let writePtr = 0;
			const ptr = new Array( 4 );

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

				for ( let c = 0; c < info.inputChannels.length; c ++ ) {

					let pixel = 0;

					const type = info.inputChannels[ c ].pixelType;
					switch ( type ) {

						case 1:

							ptr[ 0 ] = tmpBufferEnd;
							ptr[ 1 ] = ptr[ 0 ] + info.columns;
							tmpBufferEnd = ptr[ 1 ] + info.columns;

							for ( let j = 0; j < info.columns; ++ j ) {

								const diff = ( rawBuffer[ ptr[ 0 ] ++ ] << 8 ) | rawBuffer[ ptr[ 1 ] ++ ];

								pixel += diff;

								viewer.setUint16( writePtr, pixel, true );
								writePtr += 2;

							}

							break;

						case 2:

							ptr[ 0 ] = tmpBufferEnd;
							ptr[ 1 ] = ptr[ 0 ] + info.columns;
							ptr[ 2 ] = ptr[ 1 ] + info.columns;
							tmpBufferEnd = ptr[ 2 ] + info.columns;

							for ( let j = 0; j < info.columns; ++ j ) {

								const diff = ( rawBuffer[ ptr[ 0 ] ++ ] << 24 ) | ( rawBuffer[ ptr[ 1 ] ++ ] << 16 ) | ( rawBuffer[ ptr[ 2 ] ++ ] << 8 );

								pixel += diff;

								viewer.setUint32( writePtr, pixel, true );
								writePtr += 4;

							}

							break;

					}

				}

			}

			return viewer;

		}

		function uncompressB44( info ) {

			const src = info.array;
			let srcOffset = info.offset.value;

			const width = info.columns;
			const height = info.lines;
			const channels = info.inputChannels;
			const totalBytes = info.totalBytes;

			// B44A allows 3-byte flat blocks; B44 always uses 14-byte blocks
			const isB44A = EXRHeader.compression === 'B44A_COMPRESSION';

			// Output buffer organised as:
			// for each scanline y: [ ch0 pixels (w×2 bytes) | ch1 pixels | … ]
			const outBuffer = new Uint8Array( height * width * totalBytes );

			// Reusable 4×4 block buffer
			const block = new Uint16Array( 16 );

			// chByteOffset mirrors channelByteOffsets accumulation in setupDecoder
			let chByteOffset = 0;

			for ( let c = 0; c < channels.length; c ++ ) {

				const channel = channels[ c ];
				const pixelSize = channel.pixelType * 2; // HALF=2, FLOAT=4

				// Effective dimensions for this channel (subsampled channels are smaller)
				const chanWidth = Math.ceil( width / channel.xSampling );
				const chanHeight = Math.ceil( height / channel.ySampling );
				const isFullRes = channel.xSampling === 1 && channel.ySampling === 1;

				if ( channel.pixelType !== 1 ) {

					// Non-HALF channels are stored raw, scanline by scanline
					for ( let y = 0; y < chanHeight; y ++ ) {

						if ( isFullRes ) {

							const lineBase = y * width * totalBytes + chByteOffset * width;
							for ( let x = 0; x < chanWidth * pixelSize; x ++ ) {

								outBuffer[ lineBase + x ] = src[ srcOffset ++ ];

							}

						} else {

							srcOffset += chanWidth * pixelSize;

						}

					}

					chByteOffset += pixelSize;
					continue;

				}

				// HALF channel — process 4×4 blocks at effective channel dimensions
				const numBlocksX = Math.ceil( chanWidth / 4 );
				const numBlocksY = Math.ceil( chanHeight / 4 );

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

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

						// B44A only: flat-block when shift ≥ 13 (byte[2] ≥ 52)
						if ( isB44A && src[ srcOffset + 2 ] >= 52 ) {

							// 3-byte flat block — all 16 pixels share one value
							const t = ( src[ srcOffset ] << 8 ) | src[ srcOffset + 1 ];
							const h = ( t & 0x8000 ) ? ( t & 0x7fff ) : ( ( ~ t ) & 0xffff );
							block.fill( h );
							srcOffset += 3;

						} else {

							// 14-byte B44 block
							const s0 = ( src[ srcOffset ] << 8 ) | src[ srcOffset + 1 ];
							const shift = src[ srcOffset + 2 ] >> 2;
							const bias = 0x20 << shift;

							// Reconstruct 16 ordered-magnitude values from 6-bit running deltas.
							// Prediction structure (row = 4 pixels wide):
							//   column 0 top-to-bottom: s0 → s4 → s8  → s12
							//   then row-wise:          s0 → s1 → s2  → s3
							//                           s4 → s5 → s6  → s7  etc.

							const s4 = ( s0 + ( ( ( src[ srcOffset + 2 ] << 4 ) | ( src[ srcOffset + 3 ] >> 4 ) ) & 0x3f ) * ( 1 << shift ) - bias ) & 0xffff;
							const s8 = ( s4 + ( ( ( src[ srcOffset + 3 ] << 2 ) | ( src[ srcOffset + 4 ] >> 6 ) ) & 0x3f ) * ( 1 << shift ) - bias ) & 0xffff;
							const s12 = ( s8 + ( src[ srcOffset + 4 ] & 0x3f ) * ( 1 << shift ) - bias ) & 0xffff;

							const s1 = ( s0 + ( ( src[ srcOffset + 5 ] >> 2 ) & 0x3f ) * ( 1 << shift ) - bias ) & 0xffff;
							const s5 = ( s4 + ( ( ( src[ srcOffset + 5 ] << 4 ) | ( src[ srcOffset + 6 ] >> 4 ) ) & 0x3f ) * ( 1 << shift ) - bias ) & 0xffff;
							const s9 = ( s8 + ( ( ( src[ srcOffset + 6 ] << 2 ) | ( src[ srcOffset + 7 ] >> 6 ) ) & 0x3f ) * ( 1 << shift ) - bias ) & 0xffff;
							const s13 = ( s12 + ( src[ srcOffset + 7 ] & 0x3f ) * ( 1 << shift ) - bias ) & 0xffff;

							const s2 = ( s1 + ( ( src[ srcOffset + 8 ] >> 2 ) & 0x3f ) * ( 1 << shift ) - bias ) & 0xffff;
							const s6 = ( s5 + ( ( ( src[ srcOffset + 8 ] << 4 ) | ( src[ srcOffset + 9 ] >> 4 ) ) & 0x3f ) * ( 1 << shift ) - bias ) & 0xffff;
							const s10 = ( s9 + ( ( ( src[ srcOffset + 9 ] << 2 ) | ( src[ srcOffset + 10 ] >> 6 ) ) & 0x3f ) * ( 1 << shift ) - bias ) & 0xffff;
							const s14 = ( s13 + ( src[ srcOffset + 10 ] & 0x3f ) * ( 1 << shift ) - bias ) & 0xffff;

							const s3 = ( s2 + ( ( src[ srcOffset + 11 ] >> 2 ) & 0x3f ) * ( 1 << shift ) - bias ) & 0xffff;
							const s7 = ( s6 + ( ( ( src[ srcOffset + 11 ] << 4 ) | ( src[ srcOffset + 12 ] >> 4 ) ) & 0x3f ) * ( 1 << shift ) - bias ) & 0xffff;
							const s11 = ( s10 + ( ( ( src[ srcOffset + 12 ] << 2 ) | ( src[ srcOffset + 13 ] >> 6 ) ) & 0x3f ) * ( 1 << shift ) - bias ) & 0xffff;
							const s15 = ( s14 + ( src[ srcOffset + 13 ] & 0x3f ) * ( 1 << shift ) - bias ) & 0xffff;

							// Convert ordered-magnitude → half-float:
							// positive (bit15=1): clear sign bit; negative (bit15=0): invert all bits
							const t = [ s0, s1, s2, s3, s4, s5, s6, s7, s8, s9, s10, s11, s12, s13, s14, s15 ];
							for ( let i = 0; i < 16; i ++ ) {

								block[ i ] = ( t[ i ] & 0x8000 ) ? ( t[ i ] & 0x7fff ) : ( ( ~ t[ i ] ) & 0xffff );

							}

							srcOffset += 14;

						}

						// pLinear channels: data was stored as exp(x/8), convert back with 8·log(x)
						if ( channel.pLinear ) {

							if ( b44LogTable === null ) {

								b44LogTable = new Uint16Array( 65536 );
								for ( let i = 0; i < 65536; i ++ ) {

									if ( ( i & 0x7c00 ) === 0x7c00 || i > 0x8000 ) {

										b44LogTable[ i ] = 0;

									} else {

										const f = decodeFloat16( i );
										b44LogTable[ i ] = ( f <= 0 ) ? 0 : DataUtils.toHalfFloat( 8 * Math.log( f ) );

									}

								}

							}

							for ( let i = 0; i < 16; i ++ ) block[ i ] = b44LogTable[ block[ i ] ];

						}

						// Scatter the 16 pixels into the scanline-interleaved output buffer.
						// For subsampled channels (e.g. RY/BY with xSampling=ySampling=2) each decoded
						// pixel is replicated across its xSampling×ySampling footprint so the output
						// buffer has uniform full-resolution scanlines that parseScanline can read directly.
						for ( let py = 0; py < 4; py ++ ) {

							const chanY = by * 4 + py;
							if ( chanY >= chanHeight ) continue;

							for ( let px = 0; px < 4; px ++ ) {

								const chanX = bx * 4 + px;
								if ( chanX >= chanWidth ) continue;

								const val = block[ py * 4 + px ];

								for ( let dy = 0; dy < channel.ySampling; dy ++ ) {

									const fullY = chanY * channel.ySampling + dy;
									if ( fullY >= height ) continue;

									for ( let dx = 0; dx < channel.xSampling; dx ++ ) {

										const fullX = chanX * channel.xSampling + dx;
										if ( fullX >= width ) continue;

										const outIdx = fullY * width * totalBytes + chByteOffset * width + fullX * 2;
										outBuffer[ outIdx ] = val & 0xff;
										outBuffer[ outIdx + 1 ] = ( val >> 8 ) & 0xff;

									}

								}

							}

						}

					}

				}

				chByteOffset += 2; // HALF = 2 bytes per pixel

			}

			return new DataView( outBuffer.buffer );

		}

		function uncompressDWA( info ) {

			const inDataView = info.viewer;
			const inOffset = { value: info.offset.value };
			const outBuffer = new Uint8Array( info.columns * info.lines * ( info.inputChannels.length * info.type * INT16_SIZE ) );

			// Read compression header information
			const 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 new Error( 'THREE.EXRLoader: ' + EXRHeader.compression + ' version ' + dwaHeader.version + ' is unsupported' );

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

			while ( ruleSize > 0 ) {

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

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

				ruleSize -= name.length + 3;

			}

			// Classify channels
			const channels = EXRHeader.channels;
			const channelData = new Array( info.inputChannels.length );

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

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

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

			}

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

			for ( let offset = 0; offset < info.inputChannels.length; ++ offset ) {

				const cd = channelData[ offset ];

				const dotIndex = cd.name.lastIndexOf( '.' );
				const suffix = dotIndex >= 0 ? cd.name.substring( dotIndex + 1 ) : cd.name;

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

					const rule = channelRules[ i ];

					if ( suffix === rule.name && cd.type === rule.type ) {

						cd.compression = rule.compression;

						if ( rule.index >= 0 ) {

							cscSet.idx[ rule.index ] = offset;

						}

						cd.offset = offset;

					}

				}

			}

			let acBuffer, dcBuffer, rleBuffer;

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

				switch ( dwaHeader.acCompression ) {

					case STATIC_HUFFMAN:

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

					case DEFLATE:

						const compressed = info.array.slice( inOffset.value, inOffset.value + dwaHeader.totalAcUncompressedCount );
						const data = unzlibSync( compressed );
						acBuffer = new Uint16Array( data.buffer );
						inOffset.value += dwaHeader.totalAcUncompressedCount;
						break;

				}


			}

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

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

			}

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

				const compressed = info.array.slice( inOffset.value, inOffset.value + dwaHeader.rleCompressedSize );
				const data = unzlibSync( compressed );
				rleBuffer = decodeRunLength( data.buffer );

				inOffset.value += dwaHeader.rleCompressedSize;

			}

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

				rowOffsets[ i ] = new Array();

			}

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

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

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

				}

			}

			// Decode lossy DCT data if we have a valid color space conversion set with the first RGB channel present
			if ( cscSet.idx[ 0 ] !== undefined && channelData[ cscSet.idx[ 0 ] ] ) {

				lossyDctDecode( cscSet, rowOffsets, channelData, acBuffer, dcBuffer, outBuffer );

			}

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

				const cd = channelData[ i ];

				if ( cd.decoded ) continue;

				switch ( cd.compression ) {

					case RLE:

						let row = 0;
						let rleOffset = 0;

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

							let rowOffsetBytes = rowOffsets[ i ][ row ];

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

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

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

								}

								rleOffset ++;

							}

							row ++;

						}

						break;

					case LOSSY_DCT:

						lossyDctChannelDecode( i, rowOffsets, channelData, acBuffer, dcBuffer, outBuffer );

						break;

					default:
						throw new Error( 'THREE.EXRLoader: unsupported channel compression' );

				}

			}

			return new DataView( outBuffer.buffer );

		}

		function parseNullTerminatedString( buffer, offset ) {

			const uintBuffer = new Uint8Array( buffer );
			let endOffset = 0;

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

				endOffset += 1;

			}

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

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

			return stringValue;

		}

		function parseFixedLengthString( buffer, offset, size ) {

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

			offset.value = offset.value + size;

			return stringValue;

		}

		function parseRational( dataView, offset ) {

			const x = parseInt32( dataView, offset );
			const y = parseUint32( dataView, offset );

			return [ x, y ];

		}

		function parseTimecode( dataView, offset ) {

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

			return [ x, y ];

		}

		function parseInt32( dataView, offset ) {

			const Int32 = dataView.getInt32( offset.value, true );

			offset.value = offset.value + INT32_SIZE;

			return Int32;

		}

		function parseUint32( dataView, offset ) {

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

			offset.value = offset.value + INT32_SIZE;

			return Uint32;

		}

		function parseUint8Array( uInt8Array, offset ) {

			const Uint8 = uInt8Array[ offset.value ];

			offset.value = offset.value + INT8_SIZE;

			return Uint8;

		}

		function parseUint8( dataView, offset ) {

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

			offset.value = offset.value + INT8_SIZE;

			return Uint8;

		}

		const parseInt64 = function ( dataView, offset ) {

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

			offset.value += ULONG_SIZE;

			return int;

		};

		function parseFloat32( dataView, offset ) {

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

			offset.value += FLOAT32_SIZE;

			return float;

		}

		function decodeFloat32( dataView, offset ) {

			return DataUtils.toHalfFloat( parseFloat32( dataView, offset ) );

		}

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

			const 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 )
			);

		}

		function parseUint16( dataView, offset ) {

			const 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 ) {

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

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

				const name = parseNullTerminatedString( buffer, offset );
				const pixelType = parseInt32( dataView, offset );
				const pLinear = parseUint8( dataView, offset );
				offset.value += 3; // reserved, three chars
				const xSampling = parseInt32( dataView, offset );
				const ySampling = parseInt32( dataView, offset );

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

			}

			offset.value += 1;

			return channels;

		}

		function parseChromaticities( dataView, offset ) {

			const redX = parseFloat32( dataView, offset );
			const redY = parseFloat32( dataView, offset );
			const greenX = parseFloat32( dataView, offset );
			const greenY = parseFloat32( dataView, offset );
			const blueX = parseFloat32( dataView, offset );
			const blueY = parseFloat32( dataView, offset );
			const whiteX = parseFloat32( dataView, offset );
			const 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 ) {

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

			const compression = parseUint8( dataView, offset );

			return compressionCodes[ compression ];

		}

		function parseBox2i( dataView, offset ) {

			const xMin = parseInt32( dataView, offset );
			const yMin = parseInt32( dataView, offset );
			const xMax = parseInt32( dataView, offset );
			const yMax = parseInt32( dataView, offset );

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

		}

		function parseLineOrder( dataView, offset ) {

			const lineOrders = [
				'INCREASING_Y',
				'DECREASING_Y',
				'RANDOM_Y',
			];

			const lineOrder = parseUint8( dataView, offset );

			return lineOrders[ lineOrder ];

		}

		function parseEnvmap( dataView, offset ) {

			const envmaps = [
				'ENVMAP_LATLONG',
				'ENVMAP_CUBE'
			];

			const envmap = parseUint8( dataView, offset );

			return envmaps[ envmap ];

		}

		function parseTiledesc( dataView, offset ) {

			const levelModes = [
				'ONE_LEVEL',
				'MIPMAP_LEVELS',
				'RIPMAP_LEVELS',
			];

			const roundingModes = [
				'ROUND_DOWN',
				'ROUND_UP',
			];

			const xSize = parseUint32( dataView, offset );
			const ySize = parseUint32( dataView, offset );
			const modes = parseUint8( dataView, offset );

			return {
				xSize: xSize,
				ySize: ySize,
				levelMode: levelModes[ modes & 0xf ],
				roundingMode: roundingModes[ modes >> 4 ]
			};

		}

		function parseV2f( dataView, offset ) {

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

			return [ x, y ];

		}

		function parseV3f( dataView, offset ) {

			const x = parseFloat32( dataView, offset );
			const y = parseFloat32( dataView, offset );
			const z = parseFloat32( dataView, offset );

			return [ x, y, z ];

		}

		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 === 'envmap' ) {

				return parseEnvmap( dataView, offset );

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

				return parseTiledesc( 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 === 'v3f' ) {

				return parseV3f( dataView, offset );

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

				return parseInt32( dataView, offset );

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

				return parseRational( dataView, offset );

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

				return parseTimecode( dataView, offset );

			} else if ( type === 'preview' || type === 'deepImageState' || type === 'idmanifest' ) {

				// Known metadata-only types: silently skip, they carry no pixel data.
				offset.value += size;
				return 'skipped';

			} else {

				offset.value += size;
				return undefined;

			}

		}

		function roundLog2( x, mode ) {

			const log2 = Math.log2( x );
			return mode == 'ROUND_DOWN' ? Math.floor( log2 ) : Math.ceil( log2 );

		}

		function calculateTileLevels( tiledesc, w, h ) {

			let num = 0;

			switch ( tiledesc.levelMode ) {

				case 'ONE_LEVEL':
					num = 1;
					break;

				case 'MIPMAP_LEVELS':
					num = roundLog2( Math.max( w, h ), tiledesc.roundingMode ) + 1;
					break;

				case 'RIPMAP_LEVELS':
					throw new Error( 'THREE.EXRLoader: RIPMAP_LEVELS tiles currently unsupported.' );

			}

			return num;

		}

		function calculateTiles( count, dataSize, size, roundingMode ) {

			const tiles = new Array( count );

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

				const b = ( 1 << i );
				let s = ( dataSize / b ) | 0;

				if ( roundingMode == 'ROUND_UP' && s * b < dataSize ) s += 1;

				const l = Math.max( s, 1 );

				tiles[ i ] = ( ( l + size - 1 ) / size ) | 0;

			}

			return tiles;

		}

		function parseTiles() {

			const EXRDecoder = this;
			const offset = EXRDecoder.offset;
			const tmpOffset = { value: 0 };

			for ( let tile = 0; tile < EXRDecoder.tileCount; tile ++ ) {

				const tileX = parseInt32( EXRDecoder.viewer, offset );
				const tileY = parseInt32( EXRDecoder.viewer, offset );
				offset.value += 8; // skip levels - only parsing top-level
				EXRDecoder.size = parseUint32( EXRDecoder.viewer, offset );

				const startX = tileX * EXRDecoder.blockWidth;
				const startY = tileY * EXRDecoder.blockHeight;
				EXRDecoder.columns = ( startX + EXRDecoder.blockWidth > EXRDecoder.width ) ? EXRDecoder.width - startX : EXRDecoder.blockWidth;
				EXRDecoder.lines = ( startY + EXRDecoder.blockHeight > EXRDecoder.height ) ? EXRDecoder.height - startY : EXRDecoder.blockHeight;

				const bytesBlockLine = EXRDecoder.columns * EXRDecoder.totalBytes;
				const isCompressed = EXRDecoder.size < EXRDecoder.lines * bytesBlockLine;
				const viewer = isCompressed ? EXRDecoder.uncompress( EXRDecoder ) : uncompressRAW( EXRDecoder );

				offset.value += EXRDecoder.size;

				for ( let line = 0; line < EXRDecoder.lines; line ++ ) {

					const lineOffset = line * EXRDecoder.columns * EXRDecoder.totalBytes;

					for ( let channelID = 0; channelID < EXRDecoder.inputChannels.length; channelID ++ ) {

						const name = EXRHeader.channels[ channelID ].name;
						const lOff = EXRDecoder.channelByteOffsets[ name ] * EXRDecoder.columns;
						const cOff = EXRDecoder.decodeChannels[ name ];

						if ( cOff === undefined ) continue;

						tmpOffset.value = lineOffset + lOff;
						const outLineOffset = ( EXRDecoder.height - ( 1 + startY + line ) ) * EXRDecoder.outLineWidth;

						for ( let x = 0; x < EXRDecoder.columns; x ++ ) {

							const outIndex = outLineOffset + ( x + startX ) * EXRDecoder.outputChannels + cOff;
							EXRDecoder.byteArray[ outIndex ] = EXRDecoder.getter( viewer, tmpOffset );

						}

					}

				}

			}

		}

		function parseScanline() {

			const EXRDecoder = this;
			const offset = EXRDecoder.offset;
			const tmpOffset = { value: 0 };

			for ( let scanlineBlockIdx = 0; scanlineBlockIdx < EXRDecoder.height / EXRDecoder.blockHeight; scanlineBlockIdx ++ ) {

				const line = parseInt32( EXRDecoder.viewer, offset ) - EXRHeader.dataWindow.yMin; // line_no
				EXRDecoder.size = parseUint32( EXRDecoder.viewer, offset ); // data_len
				EXRDecoder.lines = ( ( line + EXRDecoder.blockHeight > EXRDecoder.height ) ? ( EXRDecoder.height - line ) : EXRDecoder.blockHeight );

				const bytesPerLine = EXRDecoder.columns * EXRDecoder.totalBytes;
				const isCompressed = EXRDecoder.size < EXRDecoder.lines * bytesPerLine;
				const viewer = isCompressed ? EXRDecoder.uncompress( EXRDecoder ) : uncompressRAW( EXRDecoder );

				offset.value += EXRDecoder.size;

				for ( let line_y = 0; line_y < EXRDecoder.lines; line_y ++ ) {

					const true_y = line + line_y;

					const lineOffset = line_y * bytesPerLine;
					const outLineOffset = ( EXRDecoder.height - 1 - true_y ) * EXRDecoder.outLineWidth;

					for ( let channelID = 0; channelID < EXRDecoder.inputChannels.length; channelID ++ ) {

						const name = EXRHeader.channels[ channelID ].name;
						const lOff = EXRDecoder.channelByteOffsets[ name ] * EXRDecoder.columns;
						const cOff = EXRDecoder.decodeChannels[ name ];

						if ( cOff === undefined ) continue;

						tmpOffset.value = lineOffset + lOff;

						for ( let x = 0; x < EXRDecoder.columns; x ++ ) {

							const outIndex = outLineOffset + x * EXRDecoder.outputChannels + cOff;
							EXRDecoder.byteArray[ outIndex ] = EXRDecoder.getter( viewer, tmpOffset );

						}

					}

				}

			}

		}

		function parseMultiPartScanline() {

			const EXRDecoder = this;
			const chunkOffsets = EXRDecoder.chunkOffsets;
			const tmpOffset = { value: 0 };

			for ( let chunkIdx = 0; chunkIdx < chunkOffsets.length; chunkIdx ++ ) {

				const offset = { value: chunkOffsets[ chunkIdx ] };

				offset.value += INT32_SIZE; // skip part number

				const line = parseInt32( EXRDecoder.viewer, offset ) - EXRHeader.dataWindow.yMin;
				EXRDecoder.size = parseUint32( EXRDecoder.viewer, offset );
				EXRDecoder.lines = ( ( line + EXRDecoder.blockHeight > EXRDecoder.height ) ? ( EXRDecoder.height - line ) : EXRDecoder.blockHeight );

				const bytesPerLine = EXRDecoder.columns * EXRDecoder.totalBytes;
				const isCompressed = EXRDecoder.size < EXRDecoder.lines * bytesPerLine;

				const savedOffset = EXRDecoder.offset;
				EXRDecoder.offset = offset;
				const viewer = isCompressed ? EXRDecoder.uncompress( EXRDecoder ) : uncompressRAW( EXRDecoder );
				EXRDecoder.offset = savedOffset;

				for ( let line_y = 0; line_y < EXRDecoder.lines; line_y ++ ) {

					const true_y = line + line_y;

					const lineOffset = line_y * bytesPerLine;
					const outLineOffset = ( EXRDecoder.height - 1 - true_y ) * EXRDecoder.outLineWidth;

					for ( let channelID = 0; channelID < EXRDecoder.inputChannels.length; channelID ++ ) {

						const name = EXRHeader.channels[ channelID ].name;
						const lOff = EXRDecoder.channelByteOffsets[ name ] * EXRDecoder.columns;
						const cOff = EXRDecoder.decodeChannels[ name ];

						if ( cOff === undefined ) continue;

						tmpOffset.value = lineOffset + lOff;

						for ( let x = 0; x < EXRDecoder.columns; x ++ ) {

							const outIndex = outLineOffset + x * EXRDecoder.outputChannels + cOff;
							EXRDecoder.byteArray[ outIndex ] = EXRDecoder.getter( viewer, tmpOffset );

						}

					}

				}

			}

		}

		function decompressDeepData( array, compressedOffset, compressedSize, compression ) {

			if ( compressedSize === 0 ) return null;

			const compressed = array.slice( compressedOffset, compressedOffset + compressedSize );

			switch ( compression ) {

				case 'NO_COMPRESSION':
					return new DataView( compressed.buffer, compressed.byteOffset, compressed.byteLength );

				case 'RLE_COMPRESSION': {

					const rawBuffer = new Uint8Array( decodeRunLength( compressed.buffer.slice( compressed.byteOffset, compressed.byteOffset + compressed.byteLength ) ) );
					const tmpBuffer = new Uint8Array( rawBuffer.length );
					predictor( rawBuffer );
					interleaveScalar( rawBuffer, tmpBuffer );
					return new DataView( tmpBuffer.buffer );

				}

				case 'ZIPS_COMPRESSION': {

					const rawBuffer = unzlibSync( compressed );
					const tmpBuffer = new Uint8Array( rawBuffer.length );
					predictor( rawBuffer );
					interleaveScalar( rawBuffer, tmpBuffer );
					return new DataView( tmpBuffer.buffer );

				}

				default:
					throw new Error( 'THREE.EXRLoader: ' + compression + ' is unsupported for deep data' );

			}

		}

		function parseDeepScanline() {

			const EXRDecoder = this;
			const chunkOffsets = EXRDecoder.chunkOffsets;
			const width = EXRDecoder.width;
			const height = EXRDecoder.height;
			const deepChannels = EXRDecoder.deepChannels;
			const compression = EXRHeader.compression;
			const isMultiPart = EXRDecoder.multiPart;

			// Build a map from channel name to decode output slot
			const decodeChannels = EXRDecoder.decodeChannels;
			const outputChannels = EXRDecoder.outputChannels;
			const isHalfOutput = EXRDecoder.byteArray instanceof Uint16Array;

			// Find the alpha channel index in deepChannels (for compositing)
			let alphaChannelIdx = - 1;

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

				if ( deepChannels[ i ].name === 'A' ) {

					alphaChannelIdx = i;
					break;

				}

			}

			for ( let chunkIdx = 0; chunkIdx < chunkOffsets.length; chunkIdx ++ ) {

				const chunkOffset = { value: chunkOffsets[ chunkIdx ] };

				// Multi-part files have a part number prefix per chunk
				if ( isMultiPart ) chunkOffset.value += INT32_SIZE;

				const line = parseInt32( EXRDecoder.viewer, chunkOffset ) - EXRHeader.dataWindow.yMin;

				// Read deep scanline sizes
				const sctCompressedSize = parseInt64( EXRDecoder.viewer, chunkOffset );
				const dataCompressedSize = parseInt64( EXRDecoder.viewer, chunkOffset );
				parseInt64( EXRDecoder.viewer, chunkOffset ); // uncompressed data size (unused)

				// Decompress sample count table
				const sctView = decompressDeepData( EXRDecoder.array, chunkOffset.value, sctCompressedSize, compression );
				chunkOffset.value += sctCompressedSize;

				if ( sctView === null ) continue;

				// Parse cumulative sample counts
				const cumulativeCounts = new Uint32Array( width );

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

					cumulativeCounts[ x ] = sctView.getUint32( x * 4, true );

				}

				const totalSamples = cumulativeCounts[ width - 1 ];

				if ( totalSamples === 0 ) {

					chunkOffset.value += dataCompressedSize;
					continue;

				}

				// Decompress pixel data
				const pixelView = decompressDeepData( EXRDecoder.array, chunkOffset.value, dataCompressedSize, compression );

				// Compute channel byte offsets within the decompressed pixel data.
				// Deep data layout: channels are contiguous, each has totalSamples values.
				const channelOffsets = [];
				let bytePos = 0;

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

					channelOffsets.push( bytePos );
					bytePos += totalSamples * deepChannels[ i ].bytesPerSample;

				}

				// Flatten deep samples: front-to-back composite with premultiplied alpha
				const outLineOffset = ( height - 1 - line ) * EXRDecoder.outLineWidth;

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

					const startSample = x === 0 ? 0 : cumulativeCounts[ x - 1 ];
					const endSample = cumulativeCounts[ x ];
					const numSamples = endSample - startSample;

					if ( numSamples === 0 ) continue;

					// Composite samples front-to-back (premultiplied alpha)
					const composited = new Float32Array( outputChannels );
					let compositedAlpha = 0;

					for ( let s = 0; s < numSamples; s ++ ) {

						const sampleIdx = startSample + s;
						const factor = 1 - compositedAlpha;

						if ( factor <= 0 ) break;

						// Read alpha for this sample
						let sampleAlpha = 1;

						if ( alphaChannelIdx >= 0 ) {

							const aBps = deepChannels[ alphaChannelIdx ].bytesPerSample;
							const aOff = channelOffsets[ alphaChannelIdx ] + sampleIdx * aBps;

							sampleAlpha = aBps === 2
								? decodeFloat16( pixelView.getUint16( aOff, true ) )
								: pixelView.getFloat32( aOff, true );

						}

						// Read and composite each output channel
						for ( let ci = 0; ci < deepChannels.length; ci ++ ) {

							const ch = deepChannels[ ci ];
							const cOff = decodeChannels[ ch.name ];

							if ( cOff === undefined ) continue;

							const bps = ch.bytesPerSample;
							const dataOff = channelOffsets[ ci ] + sampleIdx * bps;

							const value = bps === 2
								? decodeFloat16( pixelView.getUint16( dataOff, true ) )
								: pixelView.getFloat32( dataOff, true );

							composited[ cOff ] += value * factor;

						}

						compositedAlpha += sampleAlpha * factor;

					}

					// If alpha channel is being output, set it
					if ( decodeChannels[ 'A' ] !== undefined ) {

						composited[ decodeChannels[ 'A' ] ] = compositedAlpha;

					}

					// Write to output buffer
					const outIndex = outLineOffset + x * outputChannels;

					for ( let c = 0; c < outputChannels; c ++ ) {

						EXRDecoder.byteArray[ outIndex + c ] = isHalfOutput
							? DataUtils.toHalfFloat( composited[ c ] )
							: composited[ c ];

					}

				}

			}

		}

		function parsePartHeader( dataView, buffer, offset ) {

			const header = {};
			let hasAttributes = false;

			while ( true ) {

				const attributeName = parseNullTerminatedString( buffer, offset );

				if ( attributeName === '' ) break;

				hasAttributes = true;

				const attributeType = parseNullTerminatedString( buffer, offset );
				const attributeSize = parseUint32( dataView, offset );
				const attributeValue = parseValue( dataView, buffer, offset, attributeType, attributeSize );

				if ( attributeValue === undefined ) {

					console.warn( `THREE.EXRLoader: Skipped unknown header attribute type \'${attributeType}\'.` );

				} else {

					header[ attributeName ] = attributeValue;

				}

			}

			return hasAttributes ? header : null;

		}

		function parseHeader( dataView, buffer, offset ) {

			if ( dataView.getUint32( 0, true ) != 20000630 ) { // magic

				throw new Error( 'THREE.EXRLoader: Provided file doesn\'t appear to be in OpenEXR format.' );

			}

			const version = dataView.getUint8( 4 );

			const spec = dataView.getUint8( 5 ); // fullMask

			const flags = {
				singleTile: !! ( spec & 2 ),
				longName: !! ( spec & 4 ),
				deepFormat: !! ( spec & 8 ),
				multiPart: !! ( spec & 16 ),
			};

			// start of header

			offset.value = 8; // start at 8 - after pre-amble

			const headers = [];

			if ( flags.multiPart ) {

				// Multi-part files: parse all part headers.
				// Each part header ends with an empty attribute name (null byte).
				// The header section ends when a null byte is read with no preceding attributes.

				while ( true ) {

					const header = parsePartHeader( dataView, buffer, offset );
					if ( header === null ) break;

					header.version = version;
					header.spec = flags;
					headers.push( header );

				}

				if ( headers.length === 0 ) {

					throw new Error( 'THREE.EXRLoader: No valid part headers found.' );

				}

			} else {

				// Single-part (standard or deep): one header

				const header = parsePartHeader( dataView, buffer, offset );
				header.version = version;
				header.spec = flags;
				headers.push( header );

			}

			return headers;

		}

		function setupDecoder( EXRHeader, dataView, uInt8Array, offset, outputType, outputFormat ) {

			const EXRDecoder = {
				size: 0,
				viewer: dataView,
				array: uInt8Array,
				offset: offset,
				width: EXRHeader.dataWindow.xMax - EXRHeader.dataWindow.xMin + 1,
				height: EXRHeader.dataWindow.yMax - EXRHeader.dataWindow.yMin + 1,
				inputChannels: EXRHeader.channels,
				channelByteOffsets: {},
				shouldExpand: false,
				yCbCr: false,
				totalBytes: null,
				columns: null,
				lines: null,
				type: null,
				uncompress: null,
				getter: null,
				format: null,
				colorSpace: LinearSRGBColorSpace,
			};

			switch ( EXRHeader.compression ) {

				case 'NO_COMPRESSION':
					EXRDecoder.blockHeight = 1;
					EXRDecoder.uncompress = uncompressRAW;
					break;

				case 'RLE_COMPRESSION':
					EXRDecoder.blockHeight = 1;
					EXRDecoder.uncompress = uncompressRLE;
					break;

				case 'ZIPS_COMPRESSION':
					EXRDecoder.blockHeight = 1;
					EXRDecoder.uncompress = uncompressZIP;
					break;

				case 'ZIP_COMPRESSION':
					EXRDecoder.blockHeight = 16;
					EXRDecoder.uncompress = uncompressZIP;
					break;

				case 'PIZ_COMPRESSION':
					EXRDecoder.blockHeight = 32;
					EXRDecoder.uncompress = uncompressPIZ;
					break;

				case 'PXR24_COMPRESSION':
					EXRDecoder.blockHeight = 16;
					EXRDecoder.uncompress = uncompressPXR;
					break;

				case 'B44_COMPRESSION':
				case 'B44A_COMPRESSION':
					EXRDecoder.blockHeight = 32;
					EXRDecoder.uncompress = uncompressB44;
					break;

				case 'DWAA_COMPRESSION':
					EXRDecoder.blockHeight = 32;
					EXRDecoder.uncompress = uncompressDWA;
					break;

				case 'DWAB_COMPRESSION':
					EXRDecoder.blockHeight = 256;
					EXRDecoder.uncompress = uncompressDWA;
					break;

				default:
					throw new Error( 'THREE.EXRLoader: ' + EXRHeader.compression + ' is unsupported' );

			}

			const channels = {};
			for ( const channel of EXRHeader.channels ) {

				switch ( channel.name ) {

					case 'BY':
					case 'RY':
					case 'Y':
					case 'R':
					case 'G':
					case 'B':
					case 'A':
						channels[ channel.name ] = true;
						EXRDecoder.type = channel.pixelType;

				}

			}

			// RGB images will be converted to RGBA format, preventing software emulation in select devices.
			let fillAlpha = false;
			let invalidOutput = false;

			// Validate if input texture contain supported channels
			if ( channels.Y && channels.RY && channels.BY ) {

				EXRDecoder.outputChannels = 4;
				EXRDecoder.yCbCr = true;

			} else if ( channels.R && channels.G && channels.B ) {

				EXRDecoder.outputChannels = 4;

			} else if ( channels.Y ) {

				EXRDecoder.outputChannels = 1;

			} else {

				throw new Error( 'THREE.EXRLoader: file contains unsupported data channels.' );

			}

			// Setup output texture configuration
			switch ( EXRDecoder.outputChannels ) {

				case 4:

					if ( outputFormat == RGBAFormat ) {

						fillAlpha = ! channels.A;
						EXRDecoder.format = RGBAFormat;
						EXRDecoder.colorSpace = LinearSRGBColorSpace;
						EXRDecoder.outputChannels = 4;
						EXRDecoder.decodeChannels = { R: 0, G: 1, B: 2, A: 3 };

					} else if ( outputFormat == RGFormat ) {

						EXRDecoder.format = RGFormat;
						EXRDecoder.colorSpace = LinearSRGBColorSpace;
						EXRDecoder.outputChannels = 2;
						EXRDecoder.decodeChannels = { R: 0, G: 1 };

					} else if ( outputFormat == RedFormat ) {

						EXRDecoder.format = RedFormat;
						EXRDecoder.colorSpace = LinearSRGBColorSpace;
						EXRDecoder.outputChannels = 1;
						EXRDecoder.decodeChannels = { R: 0 };

					} else {

						invalidOutput = true;

					}

					break;

				case 1:

					if ( outputFormat == RGBAFormat ) {

						fillAlpha = true;
						EXRDecoder.format = RGBAFormat;
						EXRDecoder.colorSpace = LinearSRGBColorSpace;
						EXRDecoder.outputChannels = 4;
						EXRDecoder.shouldExpand = true;
						EXRDecoder.decodeChannels = { Y: 0 };

					} else if ( outputFormat == RGFormat ) {

						EXRDecoder.format = RGFormat;
						EXRDecoder.colorSpace = LinearSRGBColorSpace;
						EXRDecoder.outputChannels = 2;
						EXRDecoder.shouldExpand = true;
						EXRDecoder.decodeChannels = { Y: 0 };

					} else if ( outputFormat == RedFormat ) {

						EXRDecoder.format = RedFormat;
						EXRDecoder.colorSpace = LinearSRGBColorSpace;
						EXRDecoder.outputChannels = 1;
						EXRDecoder.decodeChannels = { Y: 0 };

					} else {

						invalidOutput = true;

					}

					break;

				default:

					invalidOutput = true;

			}

			if ( invalidOutput ) throw new Error( 'THREE.EXRLoader: invalid output format for specified file.' );

			// Luminance/chroma images always decode to RGBA; override whatever the output-format switch selected.
			if ( EXRDecoder.yCbCr ) {

				EXRDecoder.format = RGBAFormat;
				EXRDecoder.outputChannels = 4;
				EXRDecoder.decodeChannels = { Y: 0, RY: 1, BY: 2 };
				fillAlpha = true;

			}

			if ( EXRDecoder.type == 1 ) {

				// half
				switch ( outputType ) {

					case FloatType:
						EXRDecoder.getter = parseFloat16;
						break;

					case HalfFloatType:
						EXRDecoder.getter = parseUint16;
						break;

				}

			} else if ( EXRDecoder.type == 2 ) {

				// float
				switch ( outputType ) {

					case FloatType:
						EXRDecoder.getter = parseFloat32;
						break;

					case HalfFloatType:
						EXRDecoder.getter = decodeFloat32;

				}

			} else {

				throw new Error( 'THREE.EXRLoader: unsupported pixelType ' + EXRDecoder.type + ' for ' + EXRHeader.compression + '.' );

			}

			EXRDecoder.columns = EXRDecoder.width;
			const size = EXRDecoder.width * EXRDecoder.height * EXRDecoder.outputChannels;

			switch ( outputType ) {

				case FloatType:
					EXRDecoder.byteArray = new Float32Array( size );

					// Fill initially with 1s for the alpha value if the texture is not RGBA, RGB values will be overwritten
					if ( fillAlpha )
						EXRDecoder.byteArray.fill( 1, 0, size );

					break;

				case HalfFloatType:
					EXRDecoder.byteArray = new Uint16Array( size );

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

					break;

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

			}

			let byteOffset = 0;
			for ( const channel of EXRHeader.channels ) {

				if ( EXRDecoder.decodeChannels[ channel.name ] !== undefined ) {

					EXRDecoder.channelByteOffsets[ channel.name ] = byteOffset;

				}

				byteOffset += channel.pixelType * 2;

			}

			EXRDecoder.totalBytes = byteOffset;
			EXRDecoder.outLineWidth = EXRDecoder.width * EXRDecoder.outputChannels;

			if ( EXRHeader.spec.deepFormat ) {

				// Deep format: offset tables are already parsed in the main flow.
				// Compute per-channel byte sizes for the deep pixel data layout.

				EXRDecoder.deepChannels = [];
				let deepBytesPerSample = 0;

				for ( const channel of EXRHeader.channels ) {

					// UINT=0→4bytes, HALF=1→2bytes, FLOAT=2→4bytes
					const bytesPerSample = channel.pixelType === 0 ? 4 : channel.pixelType * 2;
					EXRDecoder.deepChannels.push( {
						name: channel.name,
						pixelType: channel.pixelType,
						bytesPerSample: bytesPerSample,
					} );
					deepBytesPerSample += bytesPerSample;

				}

				EXRDecoder.deepBytesPerSample = deepBytesPerSample;
				EXRDecoder.chunkOffsets = EXRHeader._chunkOffsets;
				EXRDecoder.multiPart = EXRHeader.spec.multiPart;
				EXRDecoder.decode = parseDeepScanline.bind( EXRDecoder );

			} else if ( EXRHeader.spec.singleTile ) {

				EXRDecoder.blockHeight = EXRHeader.tiles.ySize;
				EXRDecoder.blockWidth = EXRHeader.tiles.xSize;

				const numXLevels = calculateTileLevels( EXRHeader.tiles, EXRDecoder.width, EXRDecoder.height );
				// const numYLevels = calculateTileLevels( EXRHeader.tiles, EXRDecoder.width, EXRDecoder.height );

				const numXTiles = calculateTiles( numXLevels, EXRDecoder.width, EXRHeader.tiles.xSize, EXRHeader.tiles.roundingMode );
				const numYTiles = calculateTiles( numXLevels, EXRDecoder.height, EXRHeader.tiles.ySize, EXRHeader.tiles.roundingMode );

				EXRDecoder.tileCount = numXTiles[ 0 ] * numYTiles[ 0 ];

				for ( let l = 0; l < numXLevels; l ++ )
					for ( let y = 0; y < numYTiles[ l ]; y ++ )
						for ( let x = 0; x < numXTiles[ l ]; x ++ )
							parseInt64( dataView, offset ); // tileOffset

				EXRDecoder.decode = parseTiles.bind( EXRDecoder );

			} else if ( EXRHeader.spec.multiPart ) {

				// Multi-part scanline: offsets already parsed in main flow.
				EXRDecoder.blockWidth = EXRDecoder.width;
				EXRDecoder.chunkOffsets = EXRHeader._chunkOffsets;
				EXRDecoder.decode = parseMultiPartScanline.bind( EXRDecoder );

			} else {

				EXRDecoder.blockWidth = EXRDecoder.width;
				const blockCount = Math.ceil( EXRDecoder.height / EXRDecoder.blockHeight );

				for ( let i = 0; i < blockCount; i ++ )
					parseInt64( dataView, offset ); // scanlineOffset

				EXRDecoder.decode = parseScanline.bind( EXRDecoder );

			}

			return EXRDecoder;

		}

		// start parsing file [START]
		const offset = { value: 0 };
		const bufferDataView = new DataView( buffer );
		const uInt8Array = new Uint8Array( buffer );

		// get header information and validate format.
		const EXRHeaders = parseHeader( bufferDataView, buffer, offset );

		// select part to decode
		const partIndex = Math.max( 0, Math.min( this.part, EXRHeaders.length - 1 ) );
		const EXRHeader = EXRHeaders[ partIndex ];

		// for multi-part deep files, skip offset tables for other parts
		if ( EXRHeader.spec.multiPart || EXRHeader.spec.deepFormat ) {

			for ( let p = 0; p < EXRHeaders.length; p ++ ) {

				const chunkCount = EXRHeaders[ p ].chunkCount;

				if ( p === partIndex ) {

					// store offset table for the selected part
					EXRHeader._chunkOffsets = [];

					for ( let i = 0; i < chunkCount; i ++ )
						EXRHeader._chunkOffsets.push( parseInt64( bufferDataView, offset ) );

				} else {

					// skip other parts' offset tables
					for ( let i = 0; i < chunkCount; i ++ )
						parseInt64( bufferDataView, offset );

				}

			}

		}

		// get input compression information and prepare decoding.
		const EXRDecoder = setupDecoder( EXRHeader, bufferDataView, uInt8Array, offset, this.type, this.outputFormat );

		// parse input data
		EXRDecoder.decode();

		// output texture post-processing
		if ( EXRDecoder.shouldExpand ) {

			const byteArray = EXRDecoder.byteArray;

			if ( this.outputFormat == RGBAFormat ) {

				for ( let i = 0; i < byteArray.length; i += 4 )
					byteArray[ i + 2 ] = ( byteArray[ i + 1 ] = byteArray[ i ] );

			} else if ( this.outputFormat == RGFormat ) {

				for ( let i = 0; i < byteArray.length; i += 2 )
					byteArray[ i + 1 ] = byteArray[ i ];

			}

		}

		// Luminance/chroma → RGB conversion (second pass).
		// Y/RY/BY were decoded into output slots 0/1/2; convert in-place using Rec.709 coefficients:
		//   R = ( 1 + RY ) * Y,  B = ( 1 + BY ) * Y,  G = ( Y − R·0.2126 − B·0.0722 ) / 0.7152
		if ( EXRDecoder.yCbCr ) {

			const byteArray = EXRDecoder.byteArray;
			const nPixels = EXRDecoder.width * EXRDecoder.height;

			if ( this.type === HalfFloatType ) {

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

					const base = i * 4;
					const Y = decodeFloat16( byteArray[ base ] );
					const RY = decodeFloat16( byteArray[ base + 1 ] );
					const BY = decodeFloat16( byteArray[ base + 2 ] );
					const R = ( 1 + RY ) * Y;
					const B = ( 1 + BY ) * Y;
					const G = ( Y - R * 0.2126 - B * 0.0722 ) / 0.7152;
					byteArray[ base ] = DataUtils.toHalfFloat( Math.max( 0, R ) );
					byteArray[ base + 1 ] = DataUtils.toHalfFloat( Math.max( 0, G ) );
					byteArray[ base + 2 ] = DataUtils.toHalfFloat( Math.max( 0, B ) );

				}

			} else {

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

					const base = i * 4;
					const Y = byteArray[ base ];
					const RY = byteArray[ base + 1 ];
					const BY = byteArray[ base + 2 ];
					const R = ( 1 + RY ) * Y;
					const B = ( 1 + BY ) * Y;
					byteArray[ base ] = Math.max( 0, R );
					byteArray[ base + 1 ] = Math.max( 0, ( Y - R * 0.2126 - B * 0.0722 ) / 0.7152 );
					byteArray[ base + 2 ] = Math.max( 0, B );

				}

			}

		}

		return {
			header: EXRHeader,
			width: EXRDecoder.width,
			height: EXRDecoder.height,
			data: EXRDecoder.byteArray,
			format: EXRDecoder.format,
			colorSpace: EXRDecoder.colorSpace,
			type: this.type,
			minFilter: LinearFilter,
			magFilter: LinearFilter,
			generateMipmaps: false,
			flipY: false,
		};

	}

	/**
	 * Sets the texture type.
	 *
	 * @param {(HalfFloatType|FloatType)} value - The texture type to set.
	 * @return {EXRLoader} A reference to this loader.
	 */
	setDataType( value ) {

		this.type = value;
		return this;

	}

	/**
	 * Sets texture output format. Defaults to `RGBAFormat`.
	 *
	 * @param {(RGBAFormat|RGFormat|RedFormat)} value - Texture output format.
	 * @return {EXRLoader} A reference to this loader.
	 */
	setOutputFormat( value ) {

		this.outputFormat = value;
		return this;

	}

	/**
	 * For multi-part EXR files, sets which part to load.
	 *
	 * @param {number} value - The part index to load.
	 * @return {EXRLoader} A reference to this loader.
	 */
	setPart( value ) {

		this.part = value;
		return this;

	}

}

export { EXRLoader };