User:G-lander/NCCS

NCCS (extension being .ncss) is the file format used for storing NotCC level scores and solutions, similar to the TWS file format.

The file is a binary file consisting of several sections one after the other, terminated by the END section. Each section begins with a section header, which is followed by the section's data.

All data in the file is little-endian.

Format

Section header

Bytes	Content
4	Four character code identifying the section, see table below. Codes shorter than 4 characters (such as "END") are padded with spaces (making "END " in this case).
4	The length of the section's data

Section types

Section ID	Content Type	Content
NCCS	Null-terminated string	The file's version. The latest version is "0.2".
FILE	Null-terminated string	The level's (or level set's) file name
TYPE	Null-terminated string	Usually the name of the levelset. For the base CC2 set it's "Chips Challenge 2". If the level does not have a proper set name (eg. DATs, C2Ms outside of sets), excluded.
NAME	Null-terminated string	The level's title, excluded if the level has no title.
MISC	100 bytes	Level miscellaneous data. The format is identical to the format of the SAVE section in C2H files.
SLN /PSLN	See SLN section below	The recorded level solution. The PSLN section is compressed, the SLN section is not.
STAT	See STAT section below	The state for some level variables
END	No content (length is 0)	Signifies end of file

Section packing

"PSLN" sections are packed via the same packing algorithm as C2M.

SLN Section

The SLN section stores the solution for the specified level. It is similar to the REPL section of C2M files, but they are not the same.

The contents of this section are as follows:

Bytes	Content
1	The number of the player
Varies	A sequence of input changes

Multiple SLN sections can be set for a single level for multiple players.

Input change

Specifies a change in input:

Bytes	Content
1	An input bitmask specifying the new input
1	Number of frames this input is held for. Last input must have length 0xff, specifying infinite length. Otherwise <= 0xfc. Larger delays are specified via multiple input changes

Input bitmask

Specifies which keys are pressed, any number of bits can be combined:

Bitmask	Meaning
0x1	Up
0x2	Right
0x4	Down
0x8	Left
0x10	Drop item
0x20	Cycle items
0x40	Switch player

STAT section

The STAT section contains variables which are most likely to cause a change on the level outcome, contrary to some data in the MISC section, which can only be vital in obscure scenarios.

This section is made up of many sub-sections, each for a single variable, for extensibility.

A single subsection looks like this:

Bytes	Content
1	The ID of the section
1	Length of the section, in bytes. (Multiple sub-sections should be used for larger data)
Varies	The sub-section data itself

Here is a list of existing sub-section types:

ID	Length	Data description
0x01	1	Random force floor initial direction
0x02	1	Blob randomness seed