Format: CsMO Scene

Format: CsMO Scene

CsMO is the predecessor of the newer CST Scene script format. Both formats use the .cst extension.

CsMO was present in the earlier half of CatSystem 1's life. Primarily found in CsPack1 Archives over the newer CsPack2 version, which hold CST Scene scripts instead.

File Structure

Data Type	Value	Description
char[4]	"CsMO"	File Signature
uint32	" ‍ ‍ "	Unknown, possibly part of file signature, always 3 spaces
uint32	CompressedInputsLength	Compressed length of InputOffsets table
uint32	DecompressedInputsLength	Decompressed length of InputOffsets table
bytes[CompressedInputsLength]	InputOffsets	Array of uint32 that point to the offsets I'd message inputs in LinesData
uint32	CompressedLinesLength	Compressed length of LinesData region
uint32	DecompressedLinesLength	Decompressed length of LinesData region
bytes[CompressedLinesLength]	LinesData	Sequential script lines (messages, commands, etc.)

Input Offset Table

These values are not necessary to read when parsing the file. They possibly mark the offsets of the script line after every Input line and most likely aid the game engine in skipping and loading game saves.

N = DecompressedInputsLength / 4

Data Type	Value	Description
uint32[N]	Offsets	Offset to start of each 'input' line in LinesData

Note: The first (and second?) offset in InputOffsets points to byte offset 0, and byte offset 1 respectively in the Lines Table data. These first two bytes are not fully understood, as described in the following section.

Lines Table

The string data table for script lines. Each line has a type that determines what it does, and content that is either used to parse a command or display a message or name.

Script lines must be read sequentially, or from a known offset supplied by InputOffsets.

Data Type	Value	Description
Line[>]	Lines	Script lines in a scene, which can be commands, names, etc

Note: The first two bytes of the Script Data are 0x00 0x01, their usage is unclear, but skipping forward 2 bytes to start reading the script seems to work.

Theories on 0x00 byte

1. Byte 0x00 May be a LineType denoting an Input (waiting for the user to press a button to continue). This would coincide with the inconsistent appearance of null terminators after Scene Line content, based on the Line Type.
2. Byte 0x00 is simply padding to align to a byte boundary.
3. Byte 0x00 is just a special handler case. The null terminators at the end of Monologue and Dialogue Line Types may be a runtime optimization.

Scene Line

An individual script line.

Important: When Type is 0x00 or 0x01, the remaining structure is skipped (does not exist). These Type codes may serve a different purpose, but this method works well enough for reading scene lines.

Note: The Monologue and Dialogue line types always have zero byte (null terminator?) after the string content. This byte is not included in the Length field.

Data Type	Value	Description
uint8	Type	Action performed by the line (see Line Types)
uint16	Length	Length of content string
char[Length]	Content	Content string of the line
char	'\0'	Appears only at end of Monologue / Dialogue line types (?)

Line Types

(There may be more unknown values that are not listed here)

Name	Value	Description
None	0x00	Seen at end and beginning of script, possibly Input: Wait for input after message
Unknown	0x01	Seen once as second byte in script, possibly Page: Novel page break and wait for input after message
Monologue	0x02	Display a message as internal monologue
Name	0x03	Change speaker of the message
Dialogue	0x04	Display a message with a speaker
Command	0x08	Perform any other command

Note: Unlike in CST Scene scripts, the Name line type only changes the stored speaker name. It does not need to be redeclared after every message, and... due to the Monologue line type, does not need to be unset for monologue.

See Also

• CST Scene
• File Formats