|
|
| (50 intermediate revisions by 6 users not shown) |
| Line 1: |
Line 1: |
| − | {{RW Section|Struct|0x0001}} | + | {{request-delete}} |
| − | | |
| − | ''This article is about the [[Struct (RW Section)|Struct]] section accompanied by a [[Texture Native (RW Section)|Texture Native]] parent section.''
| |
| − | | |
| − | The '''Texture Native Struct''' section can usually be found in [[texture archive]]s used by the PC and XBOX versions of the GTA III game trilogy. They are the most important sections inside a <code>.txd</code> file since they contain the names, dimensions and the actual image data for textures. The typical location in the file's section hierarchy is ''[[Texture Dictionary (RW Section)|Texture Dictionary]] > [[Texture Native (RW Section)|Texture Native]] > Struct''.
| |
| − | | |
| − | ==File Header==
| |
| − | | |
| − | It takes ''52 byte'' to store some still unknown data:
| |
| − | | |
| − | 2b - WORD - Texture Count (+ 18b)
| |
| − | | |
| − | ==Images Header==
| |
| − | | |
| − | There is a ''88 byte'' header with general image information:
| |
| − | | |
| − | 4b - DWORD - Platform ID
| |
| − | 2b - WORD - Filter Flags
| |
| − | 1b - BYTE - Texture Wrap V
| |
| − | 1b - BYTE - Texture Wrap U
| |
| − | 32b - CHAR[32] - Diffuse Texture Name (null-terminated string)
| |
| − | 32b - CHAR[32] - Alpha Texture Name (null-terminated string)
| |
| − | 4b - DWORD - Raster Format
| |
| − | 4b - DWORD - Alpha/FOURCC
| |
| − | 2b - WORD - Image Width
| |
| − | 2b - WORD - Image Height
| |
| − | 1b - BYTE - Bits Per Pixel (BPP)
| |
| − | 1b - BYTE - Mipmap Count
| |
| − | 1b - BYTE - Raster Type, always 0x04 ("Texture")
| |
| − | 1b - BYTE - DXT Compression Type/Alpha
| |
| − | 4b - DWORD - Image Data Size
| |
| − | | |
| − | ;Platform ID: This is '''8''' for GTA3 and VC on the PC, '''9''' for GTA SA on the PC, and '''5''' for GTA3/VC/SA on the XBOX.
| |
| − | ;Filter Flags:
| |
| − | FILTER_NONE 0x00
| |
| − | FILTER_NEAREST 0x01
| |
| − | FILTER_LINEAR 0x02
| |
| − | FILTER_MIP_NEAREST 0x03
| |
| − | FILTER_MIP_LINEAR 0x04
| |
| − | FILTER_LINEAR_MIP_NEAREST 0x05
| |
| − | FILTER_LINEAR_MIP_LINEAR 0x06
| |
| − | FILTER_??? 0x1101
| |
| − | | |
| − | ;Texture Wrap:
| |
| − | WRAP_NONE 0x00
| |
| − | WRAP_WRAP 0x01
| |
| − | WRAP_MIRROR 0x02
| |
| − | WRAP_CLAMP 0x03
| |
| − | | |
| − | ;Raster Format:
| |
| − | FORMAT_DEFAULT 0x0000
| |
| − | FORMAT_1555 0x0100 (1 bit alpha, RGB 5 bits each; also used for DXT1 with alpha)
| |
| − | FORMAT_565 0x0200 (5 bits red, 6 bits green, 5 bits blue; also used for DXT1 without alpha)
| |
| − | FORMAT_4444 0x0300 (RGBA 4 bits each; also used for DXT3)
| |
| − | FORMAT_LUM8 0x0400 (gray scale)
| |
| − | FORMAT_8888 0x0500 (RGBA 8 bits each)
| |
| − | FORMAT_888 0x0600 (RGB 8 bits each)
| |
| − | FORMAT_555 0x0A00 (RGB 5 bits each - rare, use 565 instead)
| |
| − |
| |
| − | FORMAT_EXT_AUTO_MIPMAP 0x1000 (RW generates mipmaps)
| |
| − | FORMAT_EXT_PAL8 0x2000 (2^8 = 256 palette colors)
| |
| − | FORMAT_EXT_PAL4 0x4000 (2^4 = 16 palette colors)
| |
| − | FORMAT_EXT_MIPMAP 0x8000 (mipmaps included)
| |
| − | | |
| − | ;Alpha/FOURCC: Usually this defines if the alpha channel is used (0: no, 1: yes), but for platform 9 this is the FOURCC of the used DXTn compression type or something else for other formats (currently unknown).
| |
| − | ;BPP: 8, 16 or 32; 8 usually comes with palette
| |
| − | ;DXT Compression Type/Alpha: If greater than 0 the raster data is DXT compressed. This value directly defines the DXT compression (e.g. 3 means DXT3). For more information, refer to [[Wikipedia:S3 Texture Compression|S3 Texture Compression]].
| |
| − | :However, for GTA SA (platform ID 9) this is slightly different. The DXT version is derived from the FOURCC, while this seems to be 9 for textures with alpha channel and 8 for those without. If there's no compression applied, these values will respectively look like 1 and 0.
| |
| − | ;Image Data Size: It is constantly changed based on the image size and its own bits.
| |
| − | | |
| − | ==Raster Data==
| |
| − | | |
| − | The header is followed by an optional palette and the raster data (pixels), according to the Raster Format flags.
| |
| − | | |
| − | If Raster Format is <code>FORMAT_EXT_PAL8 | FORMAT_8888</code> or <code>FORMAT_EXT_PAL8 | FORMAT_888</code>, then a ''color palette'' of (up to) 256 RGBA colors is included. This is used in GTA3 quite often. The raster's one byte for each pixel is an index into the palette.
| |
| − | | |
| − | 1024 byte - BYTE[256][4] - palette of RGBA colors
| |
| − | 4 byte - DWORD - raster size
| |
| − | w*h*1 byte - BYTE[w*h] - pixels, 1 byte each
| |
| − | | |
| − | If no palette is included, the header is followed by raster size and data. If ''[[Wikipedia:mipmap|mipmap]]s'' are included (<code>FORMAT_EXT_MIPMAP</code>) then this is repeated for each mipmap. With increasing mipmap levels the raster size is decreased by the factor 4 (side lengths halved). Small initial textures can result in mipmaps of the size 0. For ''uncompressed'' images:
| |
| − | | |
| − | 4 byte - DWORD - raster size
| |
| − | w*h*bpp/8 byte - BYTE[w*h][bpp/8] - pixels
| |
| − | | |
| − | '''Note:''' FORMAT_888(8) rasters use BGRA colors!
| |
| − | | |
| − | If DXT compression is used, blocks of 4x4 pixels occupy only 8 or 16 bytes (depending on the type).
| |
