OpenRayman/docs

This file attempts to document the Rayman 2: The Great Escape file formats and engine as best possible. Note: OpenRayman could not have been possible without the amazing szymski on GitHub (https://github.com/szymski/Rayman2Lib), who seems to have reverse engineered the encoding algorithm used in Rayman 2 and the file formats that are used within the engine. Most of this information was scrapped together from the Rayman2Lib repository.

Progress

Some progress have been made in decoding and reading files. Note: some of this information may not be incorrect, as i have not verified any of this information yet

Formats

.cnt = archive .gf (graphics file?) (TODO: rayman2lib has both gf3 and gf?) = textures .sna = ? scripts / events / level / everything?!?! (TODO: figure out what rayman2lib is doing with seeking) .dat = pointers to file?!? file database?!?! .dsb = same?!? scripts?!?! .gpt = ?!?!?!? .bnm = probably sound files (based off of rayman2lib)

Decoding

Some files used by the Rayman 2: The Great Escape engine are encoded via a simple encoding algorithm.

The general formula for decoding these files (as provided by Rayman2Lib) in psuedo code is

skip int32 (magic number)
magic = 1790299257
for each byte
	byte ^= (magic >> 8) & 255
	magic = 16807 * (magic ^ 0x75BD924) - 0x7FFFFFFF * ((magic ^ 0x75BD924u) / 0x1F31D)

.cnt files

.cnt files are archive files, used for storing textures (more?).

The structure of a .cnt file in psuedo code is as follows:

uint32 directory_count
uint32 file_count
uint16 signature
uint8 xor_key

directories
	uint32 name_length
	char[] name

uint8 version_id

files
	uint32 directory;
	uint32 name_length;
	char[] name
	uint32 unknown (TODO)
	uint32 pointer (in file)
	uint32 size

.gf files

.gf files are texture files (graphics file), in RGB24 or RGBA32 format.

The structure of a .gf file in psuedo code is as follows:

uint32 signature
uint32 width
uint32 height
uint8 channels
uint8 repeat_byte

for each pixel
	uint8 color
	if color equals repeat_byte
		uint8 color
		uint8 repeat_count