text: import {
  	FloatType,
  	HalfFloatType,
  	LinearEncoding,
  	LinearFilter,
  	NearestFilter,
  	RGBEEncoding,
  	RGBEFormat,
  	RGBFormat,
  	UnsignedByteType
  } from '../../../src/constants';
  import {
  	DataTextureLoader
  } from '../../../src/loaders/DataTextureLoader'
  
  import {
  	DataUtils
  } from '../../../src/extras/DataUtils'
  
  // https://github.com/mrdoob/three.js/issues/5552
  // http://en.wikipedia.org/wiki/RGBE_image_format
  
  class RGBELoader extends DataTextureLoader {
  
  	constructor( manager ) {
  
  		super( manager );
  
  		this.type = HalfFloatType;
  
  	}
  
  	// adapted from http://www.graphics.cornell.edu/~bjw/rgbe.html
  
  	parse( buffer ) {
  
  		const
  			/* return codes for rgbe routines */
  			//RGBE_RETURN_SUCCESS = 0,
  			RGBE_RETURN_FAILURE = - 1,
  
  			/* default error routine.  change this to change error handling */
  			rgbe_read_error = 1,
  			rgbe_write_error = 2,
  			rgbe_format_error = 3,
  			rgbe_memory_error = 4,
  			rgbe_error = function ( rgbe_error_code, msg ) {
  
  				switch ( rgbe_error_code ) {
  
  					case rgbe_read_error: console.error( 'THREE.RGBELoader Read Error: ' + ( msg || '' ) );
  						break;
  					case rgbe_write_error: console.error( 'THREE.RGBELoader Write Error: ' + ( msg || '' ) );
  						break;
  					case rgbe_format_error: console.error( 'THREE.RGBELoader Bad File Format: ' + ( msg || '' ) );
  						break;
  					default:
  					case rgbe_memory_error: console.error( 'THREE.RGBELoader: Error: ' + ( msg || '' ) );
  
  				}
  
  				return RGBE_RETURN_FAILURE;
  
  			},
  
  			/* offsets to red, green, and blue components in a data (float) pixel */
  			//RGBE_DATA_RED = 0,
  			//RGBE_DATA_GREEN = 1,
  			//RGBE_DATA_BLUE = 2,
  
  			/* number of floats per pixel, use 4 since stored in rgba image format */
  			//RGBE_DATA_SIZE = 4,
  
  			/* flags indicating which fields in an rgbe_header_info are valid */
  			RGBE_VALID_PROGRAMTYPE = 1,
  			RGBE_VALID_FORMAT = 2,
  			RGBE_VALID_DIMENSIONS = 4,
  
  			NEWLINE = '\n',
  
  			fgets = function ( buffer, lineLimit, consume ) {
  
  				const chunkSize = 128;
  
  				lineLimit = ! lineLimit ? 1024 : lineLimit;
  				let p = buffer.pos,
  					i = - 1, len = 0, s = '',
  					chunk = String.fromCharCode.apply( null, new Uint16Array( buffer.subarray( p, p + chunkSize ) ) );
  
  				while ( ( 0 > ( i = chunk.indexOf( NEWLINE ) ) ) && ( len < lineLimit ) && ( p < buffer.byteLength ) ) {
  
  					s += chunk; len += chunk.length;
  					p += chunkSize;
  					chunk += String.fromCharCode.apply( null, new Uint16Array( buffer.subarray( p, p + chunkSize ) ) );
  
  				}
  
  				if ( - 1 < i ) {
  
  					/*for (i=l-1; i>=0; i--) {
  						byteCode = m.charCodeAt(i);
  						if (byteCode > 0x7f && byteCode <= 0x7ff) byteLen++;
  						else if (byteCode > 0x7ff && byteCode <= 0xffff) byteLen += 2;
  						if (byteCode >= 0xDC00 && byteCode <= 0xDFFF) i--; //trail surrogate
  					}*/
  					if ( false !== consume ) buffer.pos += len + i + 1;
  					return s + chunk.slice( 0, i );
  
  				}
  
  				return false;
  
  			},
  
  			/* minimal header reading.  modify if you want to parse more information */
  			RGBE_ReadHeader = function ( buffer ) {
  
  
  				// regexes to parse header info fields
  				const magic_token_re = /^#\?(\S+)/,
  					gamma_re = /^\s*GAMMA\s*=\s*(\d+(\.\d+)?)\s*$/,
  					exposure_re = /^\s*EXPOSURE\s*=\s*(\d+(\.\d+)?)\s*$/,
  					format_re = /^\s*FORMAT=(\S+)\s*$/,
  					dimensions_re = /^\s*\-Y\s+(\d+)\s+\+X\s+(\d+)\s*$/,
  
  					// RGBE format header struct
  					header = {
  
  						valid: 0, /* indicate which fields are valid */
  
  						string: '', /* the actual header string */
  
  						comments: '', /* comments found in header */
  
  						programtype: 'RGBE', /* listed at beginning of file to identify it after "#?". defaults to "RGBE" */
  
  						format: '', /* RGBE format, default 32-bit_rle_rgbe */
  
  						gamma: 1.0, /* image has already been gamma corrected with given gamma. defaults to 1.0 (no correction) */
  
  						exposure: 1.0, /* a value of 1.0 in an image corresponds to <exposure> watts/steradian/m^2. defaults to 1.0 */
  
  						width: 0, height: 0 /* image dimensions, width/height */
  
  					};
  
  				let line, match;
  
  				if ( buffer.pos >= buffer.byteLength || ! ( line = fgets( buffer ) ) ) {
  
  					return rgbe_error( rgbe_read_error, 'no header found' );
  
  				}
  
  				/* if you want to require the magic token then uncomment the next line */
  				if ( ! ( match = line.match( magic_token_re ) ) ) {
  
  					return rgbe_error( rgbe_format_error, 'bad initial token' );
  
  				}
  
  				header.valid |= RGBE_VALID_PROGRAMTYPE;
  				header.programtype = match[ 1 ];
  				header.string += line + '\n';
  
  				while ( true ) {
  
  					line = fgets( buffer );
  					if ( false === line ) break;
  					header.string += line + '\n';
  
  					if ( '#' === line.charAt( 0 ) ) {
  
  						header.comments += line + '\n';
  						continue; // comment line
  
  					}
  
  					if ( match = line.match( gamma_re ) ) {
  
  						header.gamma = parseFloat( match[ 1 ], 10 );
  
  					}
  
  					if ( match = line.match( exposure_re ) ) {
  
  						header.exposure = parseFloat( match[ 1 ], 10 );
  
  					}
  
  					if ( match = line.match( format_re ) ) {
  
  						header.valid |= RGBE_VALID_FORMAT;
  						header.format = match[ 1 ];//'32-bit_rle_rgbe';
  
  					}
  
  					if ( match = line.match( dimensions_re ) ) {
  
  						header.valid |= RGBE_VALID_DIMENSIONS;
  						header.height = parseInt( match[ 1 ], 10 );
  						header.width = parseInt( match[ 2 ], 10 );
  
  					}
  
  					if ( ( header.valid & RGBE_VALID_FORMAT ) && ( header.valid & RGBE_VALID_DIMENSIONS ) ) break;
  
  				}
  
  				if ( ! ( header.valid & RGBE_VALID_FORMAT ) ) {
  
  					return rgbe_error( rgbe_format_error, 'missing format specifier' );
  
  				}
  
  				if ( ! ( header.valid & RGBE_VALID_DIMENSIONS ) ) {
  
  					return rgbe_error( rgbe_format_error, 'missing image size specifier' );
  
  				}
  
  				return header;
  
  			},
  
  			RGBE_ReadPixels_RLE = function ( buffer, w, h ) {
  
  				const scanline_width = w;
  
  				if (
  					// run length encoding is not allowed so read flat
  					( ( scanline_width < 8 ) || ( scanline_width > 0x7fff ) ) ||
  					// this file is not run length encoded
  					( ( 2 !== buffer[ 0 ] ) || ( 2 !== buffer[ 1 ] ) || ( buffer[ 2 ] & 0x80 ) )
  				) {
  
  					// return the flat buffer
  					return new Uint8Array( buffer );
  
  				}
  
  				if ( scanline_width !== ( ( buffer[ 2 ] << 8 ) | buffer[ 3 ] ) ) {
  
  					return rgbe_error( rgbe_format_error, 'wrong scanline width' );
  
  				}
  
  				const data_rgba = new Uint8Array( 4 * w * h );
  
  				if ( ! data_rgba.length ) {
  
  					return rgbe_error( rgbe_memory_error, 'unable to allocate buffer space' );
  
  				}
  
  				let offset = 0, pos = 0;
  
  				const ptr_end = 4 * scanline_width;
  				const rgbeStart = new Uint8Array( 4 );
  				const scanline_buffer = new Uint8Array( ptr_end );
  				let num_scanlines = h;
  
  				// read in each successive scanline
  				while ( ( num_scanlines > 0 ) && ( pos < buffer.byteLength ) ) {
  
  					if ( pos + 4 > buffer.byteLength ) {
  
  						return rgbe_error( rgbe_read_error );
  
  					}
  
  					rgbeStart[ 0 ] = buffer[ pos ++ ];
  					rgbeStart[ 1 ] = buffer[ pos ++ ];
  					rgbeStart[ 2 ] = buffer[ pos ++ ];
  					rgbeStart[ 3 ] = buffer[ pos ++ ];
  
  					if ( ( 2 != rgbeStart[ 0 ] ) || ( 2 != rgbeStart[ 1 ] ) || ( ( ( rgbeStart[ 2 ] << 8 ) | rgbeStart[ 3 ] ) != scanline_width ) ) {
  
  						return rgbe_error( rgbe_format_error, 'bad rgbe scanline format' );
  
  					}
  
  					// read each of the four channels for the scanline into the buffer
  					// first red, then green, then blue, then exponent
  					let ptr = 0, count;
  
  					while ( ( ptr < ptr_end ) && ( pos < buffer.byteLength ) ) {
  
  						count = buffer[ pos ++ ];
  						const isEncodedRun = count > 128;
  						if ( isEncodedRun ) count -= 128;
  
  						if ( ( 0 === count ) || ( ptr + count > ptr_end ) ) {
  
  							return rgbe_error( rgbe_format_error, 'bad scanline data' );
  
  						}
  
  						if ( isEncodedRun ) {
  
  							// a (encoded) run of the same value
  							const byteValue = buffer[ pos ++ ];
  							for ( let i = 0; i < count; i ++ ) {
  
  								scanline_buffer[ ptr ++ ] = byteValue;
  
  							}
  							//ptr += count;
  
  						} else {
  
  							// a literal-run
  							scanline_buffer.set( buffer.subarray( pos, pos + count ), ptr );
  							ptr += count; pos += count;
  
  						}
  
  					}
  
  
  					// now convert data from buffer into rgba
  					// first red, then green, then blue, then exponent (alpha)
  					const l = scanline_width; //scanline_buffer.byteLength;
  					for ( let i = 0; i < l; i ++ ) {
  
  						let off = 0;
  						data_rgba[ offset ] = scanline_buffer[ i + off ];
  						off += scanline_width; //1;
  						data_rgba[ offset + 1 ] = scanline_buffer[ i + off ];
  						off += scanline_width; //1;
  						data_rgba[ offset + 2 ] = scanline_buffer[ i + off ];
  						off += scanline_width; //1;
  						data_rgba[ offset + 3 ] = scanline_buffer[ i + off ];
  						offset += 4;
  
  					}
  
  					num_scanlines --;
  
  				}
  
  				return data_rgba;
  
  			};
  
  		const RGBEByteToRGBFloat = function ( sourceArray, sourceOffset, destArray, destOffset ) {
  
  			const e = sourceArray[ sourceOffset + 3 ];
  			const scale = Math.pow( 2.0, e - 128.0 ) / 255.0;
  
  			destArray[ destOffset + 0 ] = sourceArray[ sourceOffset + 0 ] * scale;
  			destArray[ destOffset + 1 ] = sourceArray[ sourceOffset + 1 ] * scale;
  			destArray[ destOffset + 2 ] = sourceArray[ sourceOffset + 2 ] * scale;
  
  		};
  
  		const RGBEByteToRGBHalf = function ( sourceArray, sourceOffset, destArray, destOffset ) {
  
  			const e = sourceArray[ sourceOffset + 3 ];
  			const scale = Math.pow( 2.0, e - 128.0 ) / 255.0;
  
  			// clamping to 65504, the maximum representable value in float16
  			destArray[ destOffset + 0 ] = DataUtils.toHalfFloat( Math.min( sourceArray[ sourceOffset + 0 ] * scale, 65504 ) );
  			destArray[ destOffset + 1 ] = DataUtils.toHalfFloat( Math.min( sourceArray[ sourceOffset + 1 ] * scale, 65504 ) );
  			destArray[ destOffset + 2 ] = DataUtils.toHalfFloat( Math.min( sourceArray[ sourceOffset + 2 ] * scale, 65504 ) );
  
  		};
  
  		const byteArray = new Uint8Array( buffer );
  		byteArray.pos = 0;
  		const rgbe_header_info = RGBE_ReadHeader( byteArray );
  
  		if ( RGBE_RETURN_FAILURE !== rgbe_header_info ) {
  
  			const w = rgbe_header_info.width,
  				h = rgbe_header_info.height,
  				image_rgba_data = RGBE_ReadPixels_RLE( byteArray.subarray( byteArray.pos ), w, h );
  
  			if ( RGBE_RETURN_FAILURE !== image_rgba_data ) {
  
  				let data, format, type;
  				let numElements;
  
  				switch ( this.type ) {
  
  					case UnsignedByteType:
  
  						data = image_rgba_data;
  						format = RGBEFormat; // handled as THREE.RGBAFormat in shaders
  						type = UnsignedByteType;
  						break;
  
  					case FloatType:
  
  						numElements = image_rgba_data.length / 4;
  						const floatArray = new Float32Array( numElements * 3 );
  
  						for ( let j = 0; j < numElements; j ++ ) {
  
  							RGBEByteToRGBFloat( image_rgba_data, j * 4, floatArray, j * 3 );
  
  						}
  
  						data = floatArray;
  						format = RGBFormat;
  						type = FloatType;
  						break;
  
  					case HalfFloatType:
  
  						numElements = image_rgba_data.length / 4;
  						const halfArray = new Uint16Array( numElements * 3 );
  
  						for ( let j = 0; j < numElements; j ++ ) {
  
  							RGBEByteToRGBHalf( image_rgba_data, j * 4, halfArray, j * 3 );
  
  						}
  
  						data = halfArray;
  						format = RGBFormat;
  						type = HalfFloatType;
  						break;
  
  					default:
  
  						console.error( 'THREE.RGBELoader: unsupported type: ', this.type );
  						break;
  
  				}
  
  				return {
  					width: w, height: h,
  					data: data,
  					header: rgbe_header_info.string,
  					gamma: rgbe_header_info.gamma,
  					exposure: rgbe_header_info.exposure,
  					format: format,
  					type: type
  				};
  
  			}
  
  		}
  
  		return null;
  
  	}
  
  	setDataType( value ) {
  
  		this.type = value;
  		return this;
  
  	}
  
  	load( 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:
  
  					texture.encoding = LinearEncoding;
  					texture.minFilter = LinearFilter;
  					texture.magFilter = LinearFilter;
  					texture.generateMipmaps = false;
  					texture.flipY = true;
  					break;
  
  				case HalfFloatType:
  
  					texture.encoding = LinearEncoding;
  					texture.minFilter = LinearFilter;
  					texture.magFilter = LinearFilter;
  					texture.generateMipmaps = false;
  					texture.flipY = true;
  					break;
  
  			}
  
  			if ( onLoad ) onLoad( texture, texData );
  
  		}
  
  		return super.load( url, onLoadCallback, onProgress, onError );
  
  	}
  
  }
  
  export { RGBELoader };
  