refpack-rs

A very overengineered rust crate for compressing and decompressing data in the RefPack format utilized by many EA games of the early 2000s

RefPack is a nonstandardized format that varied greatly in exact encoding and implementation. refpack uses a Format system to specify different encoding formats. This is implemented via generic trait parameters that get monomorphized down to static dispatch.

Put simply, this means that you get the benefit of being able to use any format however you like without any performance overhead from dynamic dispatch, as well as being able to implement your own arbitrary formats that are still compatible with the same compression algorithms.

More details on the refpack format can be found at the niotso wiki. The short explanation is that RefPack is a compression scheme loosely based on LZ77 compression.

The Original Refpack Implementation was referenced to ensure proper compatibility

Usage

refpack-rs exposes two functions: compress and decompress, along with easy variants with easier but less flexible of usage.

compress and decompress take mutable references to a buffer to read and write from, that implements std::io::Read and std::io::Write, respectively.

decompress will read from the buffer until it encounters a stopcode (byte within (0xFC..=0xFF)), while compress will read in the provided length.

all compression and decompression functions accept one generic argument constrained to the Format trait. Implementations should be a unit or "unconstructable" (one inaccessible () member to prevent construction), and define a pair of how to interpret

Implementations

| Format | Games | Control | Header | |--------|-------|---------|--------| | Reference | Various 90s Origin Software and EA games | Reference | Reference | | TheSims12 | The Sims, The Sims Online, The Sims 2 | Reference | Maxis | | Simcity4 | Simcity 4 | Simcity4 | Maxis |

Example

```rust use std::io::Cursor; use std::io::Seek; use refpack::format::Reference;

let mut sourcereader = Cursor::new(b"Hello World!".tovec()); let mut outbuf = Cursor::new(vec![]); refpack::compress::(sourcereader.getref().len(), &mut sourcereader, &mut out_buf).unwrap(); ```

The easy variants are compress_easy and decompress_easy, which take a &[u8] and return a Result<Vec<u8>, RefPackError>.

Internally they simply call compress and decompress with a Cursor to the input and output buffers, however they are more convenient to use in many cases.