TGALoader.js

( function () {

	class TGALoader extends THREE.DataTextureLoader {

		constructor( manager ) {

			super( manager );

		}

		parse( buffer ) {

			// reference from vthibault, https://github.com/vthibault/roBrowser/blob/master/src/Loaders/Targa.js
			function tgaCheckHeader( header ) {

				switch ( header.image_type ) {

					// check indexed type
					case TGA_TYPE_INDEXED:
					case TGA_TYPE_RLE_INDEXED:
						if ( header.colormap_length > 256 || header.colormap_size !== 24 || header.colormap_type !== 1 ) {

							console.error( 'THREE.TGALoader: Invalid type colormap data for indexed type.' );

						}

						break;
						// check colormap type

					case TGA_TYPE_RGB:
					case TGA_TYPE_GREY:
					case TGA_TYPE_RLE_RGB:
					case TGA_TYPE_RLE_GREY:
						if ( header.colormap_type ) {

							console.error( 'THREE.TGALoader: Invalid type colormap data for colormap type.' );

						}

						break;
						// What the need of a file without data ?

					case TGA_TYPE_NO_DATA:
						console.error( 'THREE.TGALoader: No data.' );
						// Invalid type ?

					default:
						console.error( 'THREE.TGALoader: Invalid type "%s".', header.image_type );

				} // check image width and height


				if ( header.width <= 0 || header.height <= 0 ) {

					console.error( 'THREE.TGALoader: Invalid image size.' );

				} // check image pixel size


				if ( header.pixel_size !== 8 && header.pixel_size !== 16 && header.pixel_size !== 24 && header.pixel_size !== 32 ) {

					console.error( 'THREE.TGALoader: Invalid pixel size "%s".', header.pixel_size );

				}

			} // parse tga image buffer


			function tgaParse( use_rle, use_pal, header, offset, data ) {

				let pixel_data, palettes;
				const pixel_size = header.pixel_size >> 3;
				const pixel_total = header.width * header.height * pixel_size; // read palettes

				if ( use_pal ) {

					palettes = data.subarray( offset, offset += header.colormap_length * ( header.colormap_size >> 3 ) );

				} // read RLE


				if ( use_rle ) {

					pixel_data = new Uint8Array( pixel_total );
					let c, count, i;
					let shift = 0;
					const pixels = new Uint8Array( pixel_size );

					while ( shift < pixel_total ) {

						c = data[ offset ++ ];
						count = ( c & 0x7f ) + 1; // RLE pixels

						if ( c & 0x80 ) {

							// bind pixel tmp array
							for ( i = 0; i < pixel_size; ++ i ) {

								pixels[ i ] = data[ offset ++ ];

							} // copy pixel array


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

								pixel_data.set( pixels, shift + i * pixel_size );

							}

							shift += pixel_size * count;

						} else {

							// raw pixels
							count *= pixel_size;

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

								pixel_data[ shift + i ] = data[ offset ++ ];

							}

							shift += count;

						}

					}

				} else {

					// raw pixels
					pixel_data = data.subarray( offset, offset += use_pal ? header.width * header.height : pixel_total );

				}

				return {
					pixel_data: pixel_data,
					palettes: palettes
				};

			}

			function tgaGetImageData8bits( imageData, y_start, y_step, y_end, x_start, x_step, x_end, image, palettes ) {

				const colormap = palettes;
				let color,
					i = 0,
					x,
					y;
				const width = header.width;

				for ( y = y_start; y !== y_end; y += y_step ) {

					for ( x = x_start; x !== x_end; x += x_step, i ++ ) {

						color = image[ i ];
						imageData[ ( x + width * y ) * 4 + 3 ] = 255;
						imageData[ ( x + width * y ) * 4 + 2 ] = colormap[ color * 3 + 0 ];
						imageData[ ( x + width * y ) * 4 + 1 ] = colormap[ color * 3 + 1 ];
						imageData[ ( x + width * y ) * 4 + 0 ] = colormap[ color * 3 + 2 ];

					}

				}

				return imageData;

			}

			function tgaGetImageData16bits( imageData, y_start, y_step, y_end, x_start, x_step, x_end, image ) {

				let color,
					i = 0,
					x,
					y;
				const width = header.width;

				for ( y = y_start; y !== y_end; y += y_step ) {

					for ( x = x_start; x !== x_end; x += x_step, i += 2 ) {

						color = image[ i + 0 ] + ( image[ i + 1 ] << 8 );
						imageData[ ( x + width * y ) * 4 + 0 ] = ( color & 0x7C00 ) >> 7;
						imageData[ ( x + width * y ) * 4 + 1 ] = ( color & 0x03E0 ) >> 2;
						imageData[ ( x + width * y ) * 4 + 2 ] = ( color & 0x001F ) << 3;
						imageData[ ( x + width * y ) * 4 + 3 ] = color & 0x8000 ? 0 : 255;

					}

				}

				return imageData;

			}

			function tgaGetImageData24bits( imageData, y_start, y_step, y_end, x_start, x_step, x_end, image ) {

				let i = 0,
					x,
					y;
				const width = header.width;

				for ( y = y_start; y !== y_end; y += y_step ) {

					for ( x = x_start; x !== x_end; x += x_step, i += 3 ) {

						imageData[ ( x + width * y ) * 4 + 3 ] = 255;
						imageData[ ( x + width * y ) * 4 + 2 ] = image[ i + 0 ];
						imageData[ ( x + width * y ) * 4 + 1 ] = image[ i + 1 ];
						imageData[ ( x + width * y ) * 4 + 0 ] = image[ i + 2 ];

					}

				}

				return imageData;

			}

			function tgaGetImageData32bits( imageData, y_start, y_step, y_end, x_start, x_step, x_end, image ) {

				let i = 0,
					x,
					y;
				const width = header.width;

				for ( y = y_start; y !== y_end; y += y_step ) {

					for ( x = x_start; x !== x_end; x += x_step, i += 4 ) {

						imageData[ ( x + width * y ) * 4 + 2 ] = image[ i + 0 ];
						imageData[ ( x + width * y ) * 4 + 1 ] = image[ i + 1 ];
						imageData[ ( x + width * y ) * 4 + 0 ] = image[ i + 2 ];
						imageData[ ( x + width * y ) * 4 + 3 ] = image[ i + 3 ];

					}

				}

				return imageData;

			}

			function tgaGetImageDataGrey8bits( imageData, y_start, y_step, y_end, x_start, x_step, x_end, image ) {

				let color,
					i = 0,
					x,
					y;
				const width = header.width;

				for ( y = y_start; y !== y_end; y += y_step ) {

					for ( x = x_start; x !== x_end; x += x_step, i ++ ) {

						color = image[ i ];
						imageData[ ( x + width * y ) * 4 + 0 ] = color;
						imageData[ ( x + width * y ) * 4 + 1 ] = color;
						imageData[ ( x + width * y ) * 4 + 2 ] = color;
						imageData[ ( x + width * y ) * 4 + 3 ] = 255;

					}

				}

				return imageData;

			}

			function tgaGetImageDataGrey16bits( imageData, y_start, y_step, y_end, x_start, x_step, x_end, image ) {

				let i = 0,
					x,
					y;
				const width = header.width;

				for ( y = y_start; y !== y_end; y += y_step ) {

					for ( x = x_start; x !== x_end; x += x_step, i += 2 ) {

						imageData[ ( x + width * y ) * 4 + 0 ] = image[ i + 0 ];
						imageData[ ( x + width * y ) * 4 + 1 ] = image[ i + 0 ];
						imageData[ ( x + width * y ) * 4 + 2 ] = image[ i + 0 ];
						imageData[ ( x + width * y ) * 4 + 3 ] = image[ i + 1 ];

					}

				}

				return imageData;

			}

			function getTgaRGBA( data, width, height, image, palette ) {

				let x_start, y_start, x_step, y_step, x_end, y_end;

				switch ( ( header.flags & TGA_ORIGIN_MASK ) >> TGA_ORIGIN_SHIFT ) {

					default:
					case TGA_ORIGIN_UL:
						x_start = 0;
						x_step = 1;
						x_end = width;
						y_start = 0;
						y_step = 1;
						y_end = height;
						break;

					case TGA_ORIGIN_BL:
						x_start = 0;
						x_step = 1;
						x_end = width;
						y_start = height - 1;
						y_step = - 1;
						y_end = - 1;
						break;

					case TGA_ORIGIN_UR:
						x_start = width - 1;
						x_step = - 1;
						x_end = - 1;
						y_start = 0;
						y_step = 1;
						y_end = height;
						break;

					case TGA_ORIGIN_BR:
						x_start = width - 1;
						x_step = - 1;
						x_end = - 1;
						y_start = height - 1;
						y_step = - 1;
						y_end = - 1;
						break;

				}

				if ( use_grey ) {

					switch ( header.pixel_size ) {

						case 8:
							tgaGetImageDataGrey8bits( data, y_start, y_step, y_end, x_start, x_step, x_end, image );
							break;

						case 16:
							tgaGetImageDataGrey16bits( data, y_start, y_step, y_end, x_start, x_step, x_end, image );
							break;

						default:
							console.error( 'THREE.TGALoader: Format not supported.' );
							break;

					}

				} else {

					switch ( header.pixel_size ) {

						case 8:
							tgaGetImageData8bits( data, y_start, y_step, y_end, x_start, x_step, x_end, image, palette );
							break;

						case 16:
							tgaGetImageData16bits( data, y_start, y_step, y_end, x_start, x_step, x_end, image );
							break;

						case 24:
							tgaGetImageData24bits( data, y_start, y_step, y_end, x_start, x_step, x_end, image );
							break;

						case 32:
							tgaGetImageData32bits( data, y_start, y_step, y_end, x_start, x_step, x_end, image );
							break;

						default:
							console.error( 'THREE.TGALoader: Format not supported.' );
							break;

					}

				} // Load image data according to specific method
				// let func = 'tgaGetImageData' + (use_grey ? 'Grey' : '') + (header.pixel_size) + 'bits';
				// func(data, y_start, y_step, y_end, x_start, x_step, x_end, width, image, palette );


				return data;

			} // TGA constants


			const TGA_TYPE_NO_DATA = 0,
				TGA_TYPE_INDEXED = 1,
				TGA_TYPE_RGB = 2,
				TGA_TYPE_GREY = 3,
				TGA_TYPE_RLE_INDEXED = 9,
				TGA_TYPE_RLE_RGB = 10,
				TGA_TYPE_RLE_GREY = 11,
				TGA_ORIGIN_MASK = 0x30,
				TGA_ORIGIN_SHIFT = 0x04,
				TGA_ORIGIN_BL = 0x00,
				TGA_ORIGIN_BR = 0x01,
				TGA_ORIGIN_UL = 0x02,
				TGA_ORIGIN_UR = 0x03;
			if ( buffer.length < 19 ) console.error( 'THREE.TGALoader: Not enough data to contain header.' );
			let offset = 0;
			const content = new Uint8Array( buffer ),
				header = {
					id_length: content[ offset ++ ],
					colormap_type: content[ offset ++ ],
					image_type: content[ offset ++ ],
					colormap_index: content[ offset ++ ] | content[ offset ++ ] << 8,
					colormap_length: content[ offset ++ ] | content[ offset ++ ] << 8,
					colormap_size: content[ offset ++ ],
					origin: [ content[ offset ++ ] | content[ offset ++ ] << 8, content[ offset ++ ] | content[ offset ++ ] << 8 ],
					width: content[ offset ++ ] | content[ offset ++ ] << 8,
					height: content[ offset ++ ] | content[ offset ++ ] << 8,
					pixel_size: content[ offset ++ ],
					flags: content[ offset ++ ]
				}; // check tga if it is valid format

			tgaCheckHeader( header );

			if ( header.id_length + offset > buffer.length ) {

				console.error( 'THREE.TGALoader: No data.' );

			} // skip the needn't data


			offset += header.id_length; // get targa information about RLE compression and palette

			let use_rle = false,
				use_pal = false,
				use_grey = false;

			switch ( header.image_type ) {

				case TGA_TYPE_RLE_INDEXED:
					use_rle = true;
					use_pal = true;
					break;

				case TGA_TYPE_INDEXED:
					use_pal = true;
					break;

				case TGA_TYPE_RLE_RGB:
					use_rle = true;
					break;

				case TGA_TYPE_RGB:
					break;

				case TGA_TYPE_RLE_GREY:
					use_rle = true;
					use_grey = true;
					break;

				case TGA_TYPE_GREY:
					use_grey = true;
					break;

			} //


			const imageData = new Uint8Array( header.width * header.height * 4 );
			const result = tgaParse( use_rle, use_pal, header, offset, content );
			getTgaRGBA( imageData, header.width, header.height, result.pixel_data, result.palettes );
			return {
				data: imageData,
				width: header.width,
				height: header.height,
				flipY: true,
				generateMipmaps: true,
				minFilter: THREE.LinearMipmapLinearFilter
			};

		}

	}

	THREE.TGALoader = TGALoader;

} )();