3D:CTXB format
From CloudModding OoT Wiki
The CTXB format (CTR Texture Binary) is an image format used in Ocarina of Time 3D, Majora's Mask 3D, Luigi's Mansion 3D, and Ever Oasis
Note: Nearly all this information was gathered from the source code of Scarlet.
Contents
CTXB chunk
The CTXB chunk is first chunk encountered in the file. It encompasses the entire file and contains a TEX chunk.
| Offset | Type | Description |
|---|---|---|
| 0000 | char[4] | magic "ctxb" ("CTR Texture Binary") |
| 0004 | u32 | FileSize |
| 0008 | u32 | Number of TEX chunks |
| 000C | u32 | Unknown |
| 0010 | u32 | Offset to TEX chunk |
| 0014 | u32 | Offset to texture data |
TEX chunk
The TEX chunk contains textures.
| Offset | Type | Description |
|---|---|---|
| 0000 | char[4] | magic "tex " ("Textures?") |
| 0004 | u32 | size of chunk |
| 0008 | u32 | # of textures |
| 000C | Texture[# of textures] | array of textures |
Texture
Each Texture is:
| Offset | Type | Description |
|---|---|---|
| 0000 | u32 | Length of texture data in bytes |
| 0004 | u16 | Mipmap Count |
| 0006 | u8 | IsETC1 (if TextureFormat is ETC1RGB8NativeDMP or ETC1AlphaRGB8A4NativeDMP) |
| 0007 | u8 | IsCubemap (see CubemapData) |
| 0008 | u16 | Width |
| 000A | u16 | Height |
| 000C | u16 (PicaTextureFormat) | Texture color format |
| 000E | u16 (PicaDataType) | Texture data type (If 0, just use the texture color format by itself. Also see PicaTextureFormat) |
| 0010 | u32 | Texture data offset, relative to the Texture data pointer from the CMB chunk |
| 0014 | char[16] | Texture name |
CubemapData
Note: Cubemap entries come after all texture entries
Each Cubemap entry is:
| Offset | Type | Description | Coordinate |
|---|---|---|---|
| 0000 | u32 | Right DataOffset | (+X) |
| 0004 | u32 | Left DataOffset | (-X) |
| 0008 | u32 | Bottom DataOffset | (-Y) |
| 000C | u32 | Top DataOffset | (+Y) |
| 0010 | u32 | Front DataOffset | (-Z) |
| 0014 | u32 | Back DataOffset | (+Z) |
PicaTextureFormat
PicaTextureFormat can be:
| Value | Description |
|---|---|
| 0x6752 | RGBANativeDMP |
| 0x6754 | RGBNativeDMP |
| 0x6756 | AlphaNativeDMP |
| 0x6757 | LuminanceNativeDMP |
| 0x6758 | LuminanceAlphaNativeDMP |
| 0x675A | ETC1RGB8NativeDMP |
| 0x675B | ETC1AlphaRGB8A4NativeDMP |
PicaTextureFormat interacts with PicaDataType as follows:
| PicaTextureFormat | PicaDataType | Resulting texture data format |
|---|---|---|
| ETC1RGB8NativeDMP | 0 | ETC1 |
| ETC1AlphaRGB8A4NativeDMP | 0 | ETC1A4 |
| RGBANativeDMP | u8 (unsigned byte) | RGBA8 |
| RGBNativeDMP | u8 (unsigned byte) | RGB8 |
| RGBANativeDMP | UnsignedShort4444 | RGBA4 |
| RGBANativeDMP | UnsignedShort5551 | RGBA5551 |
| RGBNativeDMP | UnsignedShort565 | RGB565 |
| LuminanceAlphaNativeDMP | UnsignedByte44DMP | LA4 |
| LuminanceAlphaNativeDMP | u8 (unsigned byte) | LA8 |
| AlphaNativeDMP | u8 (unsigned byte) | A8 |
| LuminanceNativeDMP | u8 (unsigned byte) | L8 |
| LuminanceNativeDMP | Unsigned4BitsDMP | L4 |
PicaDataType
PicaDataType can be:
| Value | Description |
|---|---|
| 0x1400 | s8 (byte) |
| 0x1401 | u8 (unsigned byte) |
| 0x1402 | s16 (short) |
| 0x1403 | u16 unsigned short |
| 0x1404 | s32 (int) |
| 0x1405 | u32 (unsigned int) |
| 0x1406 | f32 (float) |
| 0x6760 | UnsignedByte44DMP |
| 0x6761 | Unsigned4BitsDMP |
| 0x8033 | UnsignedShort4444 |
| 0x8034 | UnsignedShort5551 |
| 0x8363 | UnsignedShort565 |