S3D

All values are little endian.

Header

• u32 offset -- Absolute file offset to Index
• byte[4] magic -- "PFS " (50 46 53 20)

Index

• u32 count -- Number of chunks in archive
• Chunk[count] chunks -- Contiguous array of chunks

Chunk

• u32 crc -- Checksum of data in chunk (TODO: document checksum), unless it's a Directory Chunk
• u32 offset -- Absolute file offset to Compressed Data
• u32 size -- Total uncompressed size of data

Compressed Data

This structure repeats until the total uncompressed size matches the size field in the Chunk.

• u32 deflateLength -- Length of compressed data
• u32 inflateLength -- Length of uncompressed data
• byte[deflateLength] -- Data compressed with zlib compress method (Note: This differs from deflate. See https://stackoverflow.com/questions/10166122/zlib-differences-between-the-deflate-and-compress-functions)

Directory Chunk

This chunk has the same format as the others, but its CRC value is always 0x61580AC9. The below fields describe the uncompressed data:

• u32 fileCount -- This will match the total number of chunks in the archive, minus one (the directory chunk is not counted)
• FileName[fileCount] fileNames -- List of filenames for chunks

Note: The list of filenames will only match the chunks if the chunk list is sorted by offset ascending. This is not the default order of most (any?) real-world archive files.

File Name

• u32 length -- Length in bytes of filename, including null terminator
• byte[length] filename -- Filename, ASCII encoded, includes null terminator