three#RGB_ETC1_Format JavaScript Examples

The following examples show how to use three#RGB_ETC1_Format. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.
Example #1
Source File: DDSLoader.js    From threejs-tutorial with MIT License 4 votes vote down vote up
DDSLoader.prototype = Object.assign( Object.create( CompressedTextureLoader.prototype ), {

	constructor: DDSLoader,

	parse: function ( buffer, loadMipmaps ) {

		var dds = { mipmaps: [], width: 0, height: 0, format: null, mipmapCount: 1 };

		// Adapted from @toji's DDS utils
		// https://github.com/toji/webgl-texture-utils/blob/master/texture-util/dds.js

		// All values and structures referenced from:
		// http://msdn.microsoft.com/en-us/library/bb943991.aspx/

		var DDS_MAGIC = 0x20534444;

		var DDSD_CAPS = 0x1,
			DDSD_HEIGHT = 0x2,
			DDSD_WIDTH = 0x4,
			DDSD_PITCH = 0x8,
			DDSD_PIXELFORMAT = 0x1000,
			DDSD_MIPMAPCOUNT = 0x20000,
			DDSD_LINEARSIZE = 0x80000,
			DDSD_DEPTH = 0x800000;

		var DDSCAPS_COMPLEX = 0x8,
			DDSCAPS_MIPMAP = 0x400000,
			DDSCAPS_TEXTURE = 0x1000;

		var DDSCAPS2_CUBEMAP = 0x200,
			DDSCAPS2_CUBEMAP_POSITIVEX = 0x400,
			DDSCAPS2_CUBEMAP_NEGATIVEX = 0x800,
			DDSCAPS2_CUBEMAP_POSITIVEY = 0x1000,
			DDSCAPS2_CUBEMAP_NEGATIVEY = 0x2000,
			DDSCAPS2_CUBEMAP_POSITIVEZ = 0x4000,
			DDSCAPS2_CUBEMAP_NEGATIVEZ = 0x8000,
			DDSCAPS2_VOLUME = 0x200000;

		var DDPF_ALPHAPIXELS = 0x1,
			DDPF_ALPHA = 0x2,
			DDPF_FOURCC = 0x4,
			DDPF_RGB = 0x40,
			DDPF_YUV = 0x200,
			DDPF_LUMINANCE = 0x20000;

		function fourCCToInt32( value ) {

			return value.charCodeAt( 0 ) +
				( value.charCodeAt( 1 ) << 8 ) +
				( value.charCodeAt( 2 ) << 16 ) +
				( value.charCodeAt( 3 ) << 24 );

		}

		function int32ToFourCC( value ) {

			return String.fromCharCode(
				value & 0xff,
				( value >> 8 ) & 0xff,
				( value >> 16 ) & 0xff,
				( value >> 24 ) & 0xff
			);

		}

		function loadARGBMip( buffer, dataOffset, width, height ) {

			var dataLength = width * height * 4;
			var srcBuffer = new Uint8Array( buffer, dataOffset, dataLength );
			var byteArray = new Uint8Array( dataLength );
			var dst = 0;
			var src = 0;
			for ( var y = 0; y < height; y ++ ) {

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

					var b = srcBuffer[ src ]; src ++;
					var g = srcBuffer[ src ]; src ++;
					var r = srcBuffer[ src ]; src ++;
					var a = srcBuffer[ src ]; src ++;
					byteArray[ dst ] = r; dst ++;	//r
					byteArray[ dst ] = g; dst ++;	//g
					byteArray[ dst ] = b; dst ++;	//b
					byteArray[ dst ] = a; dst ++;	//a

				}

			}
			return byteArray;

		}

		var FOURCC_DXT1 = fourCCToInt32( "DXT1" );
		var FOURCC_DXT3 = fourCCToInt32( "DXT3" );
		var FOURCC_DXT5 = fourCCToInt32( "DXT5" );
		var FOURCC_ETC1 = fourCCToInt32( "ETC1" );

		var headerLengthInt = 31; // The header length in 32 bit ints

		// Offsets into the header array

		var off_magic = 0;

		var off_size = 1;
		var off_flags = 2;
		var off_height = 3;
		var off_width = 4;

		var off_mipmapCount = 7;

		var off_pfFlags = 20;
		var off_pfFourCC = 21;
		var off_RGBBitCount = 22;
		var off_RBitMask = 23;
		var off_GBitMask = 24;
		var off_BBitMask = 25;
		var off_ABitMask = 26;

		var off_caps = 27;
		var off_caps2 = 28;
		var off_caps3 = 29;
		var off_caps4 = 30;

		// Parse header

		var header = new Int32Array( buffer, 0, headerLengthInt );

		if ( header[ off_magic ] !== DDS_MAGIC ) {

			console.error( 'THREE.DDSLoader.parse: Invalid magic number in DDS header.' );
			return dds;

		}

		if ( ! header[ off_pfFlags ] & DDPF_FOURCC ) {

			console.error( 'THREE.DDSLoader.parse: Unsupported format, must contain a FourCC code.' );
			return dds;

		}

		var blockBytes;

		var fourCC = header[ off_pfFourCC ];

		var isRGBAUncompressed = false;

		switch ( fourCC ) {

			case FOURCC_DXT1:

				blockBytes = 8;
				dds.format = RGB_S3TC_DXT1_Format;
				break;

			case FOURCC_DXT3:

				blockBytes = 16;
				dds.format = RGBA_S3TC_DXT3_Format;
				break;

			case FOURCC_DXT5:

				blockBytes = 16;
				dds.format = RGBA_S3TC_DXT5_Format;
				break;

			case FOURCC_ETC1:

				blockBytes = 8;
				dds.format = RGB_ETC1_Format;
				break;

			default:

				if ( header[ off_RGBBitCount ] === 32
					&& header[ off_RBitMask ] & 0xff0000
					&& header[ off_GBitMask ] & 0xff00
					&& header[ off_BBitMask ] & 0xff
					&& header[ off_ABitMask ] & 0xff000000 ) {

					isRGBAUncompressed = true;
					blockBytes = 64;
					dds.format = RGBAFormat;

				} else {

					console.error( 'THREE.DDSLoader.parse: Unsupported FourCC code ', int32ToFourCC( fourCC ) );
					return dds;

				}

		}

		dds.mipmapCount = 1;

		if ( header[ off_flags ] & DDSD_MIPMAPCOUNT && loadMipmaps !== false ) {

			dds.mipmapCount = Math.max( 1, header[ off_mipmapCount ] );

		}

		var caps2 = header[ off_caps2 ];
		dds.isCubemap = caps2 & DDSCAPS2_CUBEMAP ? true : false;
		if ( dds.isCubemap && (
			! ( caps2 & DDSCAPS2_CUBEMAP_POSITIVEX ) ||
			! ( caps2 & DDSCAPS2_CUBEMAP_NEGATIVEX ) ||
			! ( caps2 & DDSCAPS2_CUBEMAP_POSITIVEY ) ||
			! ( caps2 & DDSCAPS2_CUBEMAP_NEGATIVEY ) ||
			! ( caps2 & DDSCAPS2_CUBEMAP_POSITIVEZ ) ||
			! ( caps2 & DDSCAPS2_CUBEMAP_NEGATIVEZ )
		) ) {

			console.error( 'THREE.DDSLoader.parse: Incomplete cubemap faces' );
			return dds;

		}

		dds.width = header[ off_width ];
		dds.height = header[ off_height ];

		var dataOffset = header[ off_size ] + 4;

		// Extract mipmaps buffers

		var faces = dds.isCubemap ? 6 : 1;

		for ( var face = 0; face < faces; face ++ ) {

			var width = dds.width;
			var height = dds.height;

			for ( var i = 0; i < dds.mipmapCount; i ++ ) {

				if ( isRGBAUncompressed ) {

					var byteArray = loadARGBMip( buffer, dataOffset, width, height );
					var dataLength = byteArray.length;

				} else {

					var dataLength = Math.max( 4, width ) / 4 * Math.max( 4, height ) / 4 * blockBytes;
					var byteArray = new Uint8Array( buffer, dataOffset, dataLength );

				}

				var mipmap = { "data": byteArray, "width": width, "height": height };
				dds.mipmaps.push( mipmap );

				dataOffset += dataLength;

				width = Math.max( width >> 1, 1 );
				height = Math.max( height >> 1, 1 );

			}

		}

		return dds;

	}

} );