Crate decart

Encode and decode Octo cartridges or “Octocarts”, CHIP-8 game cartridges for the Octo environment.

Use cases:

• Decoding: You can extract the program source code and runtime settings from an Octocart file. The source code can be assembled into CHIP-8 bytecode with Octo or decasm. The runtime settings can be given to a CHIP-8 interpreter like Octo or deca, or saved as JSON for the CHIP-8 Archive, as an .octo.rc file for C-Octo or termin-8, etc.
• Encoding: TODO

Octo cartridge files are GIF89a images with a payload steganographically embedded in one or more animation frames. Data is stored in the least significant bits of colors, 1 from the red/blue channels and 2 from the green channel, allowing us to pack a hidden byte into every 2 successive pixels.

The payload consists of a 32-bit length, followed by a sequence of ASCII bytes consisting of the JSON-encoded options dictionary and source text.

An Octo cartridge contains the source code of an Octo program, and a set of options for the Octo runtime on how to run the program.

• To compile/assemble the source code, check out the decasm crate.
• To interpret an assembled program, check out the deca crate (backend) or a program like termin-8 (frontend and graphics).

Structs

OctoCart

Representation of the payload in the Octo cartridge.

Enums

Error

Represents the types of errors that can occur during decoding of an Octocart.

Functions

decode_octocart

Decodes an Octocart, and returns the decoded JSON payload as a string.

from_file

Read and decode Octocart from a file path