CLYT (.bclyt) is the layout format used on the 3DS. It stands for (Binary) CTR Layout, and is similar to the RLYT format used on the Wii.

Header

Offset Size Type Description
0x00 0x4 String Signature (CLYT)
0x04 0x2 UInt16 Byte Order Mark
0x06 0x2 UInt16 Header Length
0x08 0x4 UInt32 Revision
0x0C 0x4 UInt32 File Size
0x10 0x4 UInt32 Nr Sections

lyt1 (Layout 1)

Offset Size Type Description
0x00 0x4 String Signature (lyt1)
0x04 0x4 UInt32 Section Size
0x08 0x4 UInt32 Origin type
Value Meaning
0 Classic
1 Normal
0x0C 0x8 Vector2 Canvas Size

txl1 (Texture List 1)

Offset Size Type Description
0x00 0x4 String Signature (txl1)
0x04 0x4 UInt32 Section Size
0x08 0x4 UInt32 Nr Textures = N
0x0C N * 4 UInt32[] Texture Name Offsets (relative to the start of this array)

After this, the null terminated names follow.

fnl1 (Font List 1)

Offset Size Type Description
0x00 0x4 String Signature (fnl1)
0x04 0x4 UInt32 Section Size
0x08 0x4 UInt32 Nr Fonts = N
0x0C N * 4 UInt32[] Font Name Offsets (relative to the start of this array)

After this, the null terminated names follow.

mat1 (Materials 1)

Offset Size Type Description
0x00 0x4 String Signature (mat1)
0x04 0x4 UInt32 Section Size
0x08 0x4 UInt32 Nr Materials = N
0x0C N * 4 UInt32[] Material Entry Offsets (relative to the start of this section)

After this, the material entries follow.

Offset Size Type Description
0x00 0x14 String Material Name
0x14 0x4 RGBA8 Tev Color (Buffer Color?)
0x18 0x18 RGBA8[6] Tev Constant Colors
0x30 0x4 UInt32 Flags / bitfield
Bit Flag / data
0-1 Nr texMap
2-3 Nr texMatrix
4-5 Nr texCoordGen
6-8 Nr tevStage
9 Has alphaCompare
10 Has blendMode
11 Use Texture Only
12 Separate Blend Mode
14 Has Indirect Parameter
15-16 Nr projectionTexGenParameter
17 Has Font Shadow Parameter

Texture Map Entry

Offset Size Type Description
0x00 0x2 UInt16 Texture Index
0x02 0x1 Byte Bitfield
Bit Data
0-1 Wrap S (Clamp = 0, Repeat = 1, Mirror = 2)
2-3 Min Filter (0 = Near, 1 = Linear)
0x02 0x1 Byte Bitfield
Bit Data
0-1 Wrap T (Clamp = 0, Repeat = 1, Mirror = 2)
2-3 Mag Filter (0 = Near, 1 = Linear)

Texture Matrix Entry

Offset Size Type Description
0x00 0x8 Vector2 Translation
0x08 0x4 Single Rotation
0x0C 0x8 Vector2 Scale

TODO: texCoordGen, tevStage, alphaCompare, blendMode, etc...

pan1 (Pane 1)

Offset Size Type Description
0x00 0x4 String Signature (pan1)
0x04 0x4 UInt32 Section Size
0x08 0x1 UInt8 Flags
Bit Flag
0 Visible
1 InfluencedAlpha
2 LocationAdjust
0x09 0x1 UInt8 Origin
0x0A 0x1 UInt8 Alpha
0x0B 0x1 UInt8 Pane magnification flags
Bit Flag
0 IgnorePartsMagnify
1 AdjustToPartsBounds
0x0C 0x18 String Pane name
0x24 0xC Vector3 Translation
0x30 0xC Vector3 Rotation
0x3C 0x8 Vector2 Scale
0x48 0x8 Vector2 Size

pic1 (Picture 1)

Offset Size Type Description
0x00 0x4 String Signature (pic1)
0x04 0x4 UInt32 Section Size
0x08 0x4 RGBA8 Top left vertex color
0x0C 0x4 RGBA8 Top right vertex color
0x10 0x4 RGBA8 Bottom left vertex color
0x14 0x4 RGBA8 Bottom right vertex color
0x18 0x2 UInt16 Material ID
0x1A 0x2 UInt16 Nr texture coordinates = N
Texture coordinates entry
0x1C + N*0x20 0x8 Vector2 Top left vertex texture coordinate
0x24 + N*0x20 0x8 Vector2 Top right vertex texture coordinate
0x2C + N*0x20 0x8 Vector2 Bottom left vertex texture coordinate
0x34 + N*0x20 0x8 Vector2 Bottom right vertex texture coordinate

txt1 (Text 1)

wnd1 (Window 1)

bnd1 (Bounding 1)

Offset Size Type Description
0x00 0x4 String Signature (bnd1)
0x04 0x4 UInt32 Section Size
0x08 0x2 UInt16? ?
0x0A 0x2 UInt16? ?
0x0C ? (0x10 up to 0x30) String Bounding name
0x3C 0x8 Vector2 ?
0x44 0x4 Vector2 ?

pts1 (Parts 1)

pas1 (Pane Start 1)

Starts a pane.

Offset Size Type Description
0x00 0x4 String Signature (pas1)
0x04 0x4 UInt32 Section Size

pae1 (Pane End 1)

Ends a pane.

Offset Size Type Description
0x00 0x4 String Signature (pae1)
0x04 0x4 UInt32 Section Size

grp1 (Group 1)

Offset Size Type Description
0x00 0x4 String Signature (grp1)
0x04 0x4 UInt32 Section Size
0x08 0x10 String Group Name
0x18 0x4 UInt32 Nr Pane References (=N)
0x1C 0x10 * N String[N] Pane References

grs1 (Group Start 1)

Starts a group.

Offset Size Type Description
0x00 0x4 String Signature (grs1)
0x04 0x4 UInt32 Section Size

gre1 (Group End 1)

Ends a group.

Offset Size Type Description
0x00 0x4 String Signature (gre1)
0x04 0x4 UInt32 Section Size

Tools

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See also

http://florian.nouwt.com/wiki/index.php/CLYT_%28File_Format%29 https://github.com/Gericom/EveryFileExplorer/tree/master/3DS/NintendoWare/LYT1