LEX (File Format)

LEX (LE-CODE Extension) is a file format defined by Wiimm. A LEX file is usually stored as part of a track SZS under the name course.lex. It's like KMP's course.kmp, but it provides additional settings and modifications outside of a KMP. LEX is designed to be open for future extension by third persons. Anyway, each new section identifier (a 4 byte ASCII magic) should be requested to Wiimm. He will guarantee unique identifiers.

At least LE-CODE will support LEX. Maybe CTGP will do it too.

Design Notes

There were some prerequisites before the definition of the file format:

• The format should be open for future extensions.
• Extensions are menages by sections. Each section is identified by an unique ID (magic).
• ID should be 4 ASCII characters to make viewing by a hex-dumper easier.
• Old implementation should work, event if new unknown subtypes were added. Therefore, the code needs an easy skip mechanism.
• The order must be stable to support sections, that depend on other prior defined sections.
• Fast and easy scanning support.

File Format

Each file starts with a LEX header, followed by a sequence of LEX elements. The chain of elements is closed by a special termination element.

All values are stored in network byte order (big endian). Each element is aligned to 4 bytes.

File header of LEX files

Offset	Type	Description
0x00	char[4]	File magic, always »LE-X«
0x04	uint16	The major version number. Usually 1. It is incremented, if the data structure changes in an incompatible way. This is not expected.
0x06	uint16	The minor version number. It starts with 0 and is incremented, if this header is expanded in a compatible way.
0x08	uint32	Total size of file. use it for sanity cheeks.
0x0c	uint32	Offset of first element of the chain relative to the beginning of this structure.
0x10	End of file header

Notes

• The version number is printed as »%u.%u«. At the moment it is 1.0.
• Don't expect the first element at offset 0x10. Use Offset of first element instead.

The list of elements is managed as chain. The header of each element contains a magic to identify it, and a size:

Element header of LEX files

Offset	Type	Description
0x00	uint32	A magic to identify the element (type of element). An alternative datatype is char[4].
0x04	uint32	Size of the element data. It is an offset to the next element relative to the data member too. The size is always a multiple of 4.
0x08	u8[SIZE]	Binary data of the element.
0x08+SIZE	The next element

Notes

• Duplicates of the same element are forbidden.
• The chain of elements is well ordered. Tools should usually not change this order, except they know exactly what they do.
• The offset of the next element is: current_offset + 8 + element_size
• Magic and size of the final element (terminator) are 0.

Example Implementation

For example code in C, see »LEX (File Format)/C example«.

Elements

Each element has its own identity (magic). This magic is an integer of 4 bytes. It can be interpreted as 4 characters. So it created by printable ASCII characters. At the moment, the identities are manged by Wiimm to guarantee unique values.

List of defined elements

Identity / Magic		Date of definition	Description
ASCII	uint32
	0	2019-02-28	Termintor of chain.
----	0x2d2d2d2d	2019-02-28	Invalidated element. Ignore it.
CANN	0x43414e4e	2019-02-28	Cannon settings.

CANN : Cannon settings

Data of velement "CANN" (ID 0x43414e4e)

Offset	Type	Description
0x00	uint32	N = Number of defined cannon types
0x04	float[4]	4 settings for a cannon type #0
0x14	float[4]	4 settings for a cannon type #1
0x24	...
4+N*16	End of data

See »Cannon Characteristics« for details about the settings.