TXD

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Renderware TeXture Dictionary. Used by the Renderware Game Engine, which is used by games like Grand Theft Auto: San Andreas, Sonic The Hedgehog and NRL Rugby League. The format has undergone some changes over the years. The one described here is that in use by Grand Theft Auto: San Andreas. Other versions might be slightly different.

Generic chunk lay-out

TXD files consist of chunks and sub-chunks, which are really just chunks encapsulated in the data field of other chunks. All chunks have the following basic structure:

typedef struct txd_chunk_s {
 uint32_t id;
 uint32_t chunk_size;       // does not include id, chunk_size and marker
 uint32_t rw_version;
 uint8_t  data[chunk_size];
} txd_chunk_t;

Known chunks

typedef struct txd_file_s {
 uint32_t id;               // 0x16 (22)
 uint32_t chunk_size        // file_size - 12
 uint32_t rw_version;
 uint8_t  data[chunk_size];
} txd_file_t;
typedef struct txd_info_s {
 uint32_t id;               // 0x01 (1)
 uint32_t chunk_size;       // 0x04 (4)
 uint32_t rw_version;
 uint16_t count;            // number of textures in the dictionary
 uint16_t unknown;
} txd_info_t;
typedef struct txd_texture_s {
 uint32_t id;               // 0x15 (21)
 uint32_t chunk_size;
 uint32_t rw_version;
 uint8_t  data[chunk_size];
} txd_texture_t;
typedef struct txd_texture_data_s {
 uint32_t id;                         // 0x01 (1)
 uint32_t chunk_size;
 uint32_t rw_version;
 uint32_t version;                    // 0x08 (8) or 0x09 (9)
 uint32_t filter_flags;
 uint8_t  texture_name[32];           // treat as a char array, but make sure 8-bit chars are specified
 uint8_t  alpha_name[32];             // ^
 uint32_t alpha_flags;
 uint32_t direct3d_texture_format;    // see below
 uint16_t width;
 uint16_t height;
 uint8_t  depth;
 uint8_t  mipmap_count;
 uint8_t  texcode_type;
 uint8_t  flags;
 uint8_t  palette[depth == 8 ? 256 * 4 : 0];
 uint32_t data_size;
 uint8_t  data[data_size];
 struct mipmaps_s {
  uint32_t data_size;
  uint8_t  data[data_size];
 } mipmaps[mipmap_count - 1];
} txd_texture_data_t;
typedef struct txd_extra_info_s {
 uint32_t id;               // 0x03 (3)
 uint32_t chunk_size;
 uint32_t rw_version;
 uint8_t  data[chunk_size];
} txd_extra_info_t;

direct3d_texture_format

This is the format of the texture data found in txd_texture_data_t::data. This value must be known if the textures are to be extracted. It can be one of:

  • 0x21 - RGBA32
  • 0x22 - RGB32
  • 0x00 and flags & 1 is set - S3TC DXT1 compression (used in old version 8 files)

Additionally, direct3d_texture_format may be a four character code ("FourCC") relating to a DXT format. In such cases, the unsigned integer value is actually the concatenated bytes of the FourCC. For example, 0x44585431 is "DXT1" (44 58 54 31).

rw_version

This is the identifier of the version of the RenderWare engine that the file is for. It can be found in many types of RenderWare binary stream file.

rw_version Hex RenderWare Version
0x0003FFFF 3.0.0.3
0x0800FFFF 3.?.?.?
0x00000310 3.1.0.0
0x0C02FFFF 3.3.0.2
0x1003FFFF 3.4.0.3
0x1803FFFF 3.6.0.3

Basic file structure

Chunks other than txd_file_t (which has no parent chunk) are nested within the parent chunk's data array. For example, txd_info_t is found within txd_file_t::data.

txd_file_t

txd_info_t
txd_texture_t
txd_texture_data_t
txd_extra_info_t
txd_texture_t
txd_texture_data_t
txd_extra_info_t
txd_texture_t
txd_texture_data_t
txd_extra_info_t
txd_texture_t...*
txd_extra_info_t


*txd_texture_t... blocks repeated. The number of repetitions differs between files, and is dictated by the value of txd_info_t::count.

Notes

  • Chunk IDs are scope-dependent. For example, within the txd_file_t chunk, a chunk with id 0x01 is a txd_info_t chunk, but within a txd_texture_t chunk, id 0x01 is used by txd_texture_data_t chunks.
  • The C structures on this page should be assumed to be packed (as if with #pragma pack or __attribute__((packed))) if they are to be read directly from a file.
  • All values are stored in little endian format for both bits and bytes. (Therefore, for multi-byte values, the least significant byte goes in the lowest addressed memory slot.)