TXTR (Tropical Freeze)

See TXTR (File Format) for the other revisions of this format.

The TXTR format is Tropical Freeze's texture format. The image data in the GPU buffer is compressed using LZSS compression.

This file format needs a lot of research Most everything in the header + image compression formats needs to be cracked + documented.

Format

The format starts with the typical form descriptor found in every Tropical Freeze format. Following that, there's a HEAD header section that contains most of the texture parameters, then the GPU section containing the actual compressed image data. This is the structure of the HEAD section:

Offset	Type	Size	Description	Notes
0x0	Chunk Descriptor	0x18	HEAD Chunk Descriptor
0x18	u32	4	Unknown
0x1C	u32	4	Image Format
0x20	u32	4	Width
0x24	u32	4	Height
0x28	u32	4	Depth
0x2C	u32	4	Unknown
0x30	u32	4	Swizzle
0x34	u32	4	Unknown	Mipmap count? (MC)
0x38	u32[MC]	4 × MC	Unknown array	Appears to be mipmap sizes, but it doesn't match the size of the image data (unless there's 1)...
-	u32	4	Unknown
-	u8	1	Unknown
-	u8	1	Unknown
-	u8	1	Unknown
-	u8	1	Unknown

Image Formats

ID	Name
0xC	RGBA8888
0x14	DXT1
0x18	DXT5
0x1C	ATI2

PAK Metadata

The pak metadata for the TXTR format primarily contains compression-related information and provides the values required to decompress it.

Offset	Type	Size	Description	Notes
0x0	u32	4	Unknown
0x4	u32	4	Unknown
0x8	u32	4	GPU section offset	Relative to the start of the file
0xC	u32	4	Unknown
0x10	u32	4	GPU data start	This is the offset to the start of the GPU data, immediately after the GPU section header.
0x14	u32	4	GPU section size	Matches the size from the GPU section header.
0x18	u32	4	Compressed buffer count (BC)
0x1C	Compressed Buffer[BC]	0xC × BC	Compressed buffer metadata

Compressed Buffer

This is a small struct that defines a compressed data buffer within the GPU section.

Offset	Type	Description	Notes
0x0	u32	Decompressed Size
0x4	u32	Compressed Size
0x8	u32	Offset	Relative to after the GPU section header