MIX

Description

.mix is the archive/container format used by OpenW3D runtime and tools for packaged game content.

This is not a chunkio format. It uses its own header + file table layout.

References

• wwlib/mixfile.h

• wwlib/mixfile.cpp

• wwlib/realcrc.h

• Tools/LevelEdit/Export.cpp

Specification

Header

OpenW3D writer emits a MIX1 file with this leading data:

Offset	Bytes	Field
0	4	Signature (MIX1)
4	4	HeaderOffset
8	4	NamesOffset
12	4	Reserved/unused

File data area

Embedded file bytes are written before the directory tables.

• Each stored file is padded to 8-byte alignment.

• Directory Offset values point into this file data area.

Directory table at HeaderOffset

Seq	Bytes	Field
1	4	FileCount
N	12	File entry x N

Each file entry:

• uint32 CRC (case-insensitive CRC of stored filename).

• uint32 Offset (archive-relative file start).

• uint32 Size (file size in bytes).

Entries are sorted by CRC and looked up with binary search.

Name table at NamesOffset

Seq	Bytes	Field
1	4	FileCount
N	1+L	Name record x N

Each name record:

• uint8 NameLength.

• char Name[NameLength] (includes null terminator in writer output).

Runtime lookup

MixFileFactoryClass::Get_File computes CRC_Stringi(filename) and binary-searches the file table. On hit, it returns a biased file view into the archive data.