This is a work-in-progress decompilation of [*Sly Cooper and the Thievius Raccoonus*](https://en.wikipedia.org/wiki/Sly_Cooper_and_the_Thievius_Raccoonus) for the PlayStation 2. It builds the NTSC-U version of the game, `SCUS_971.98` (SHA1: `57dc305d`).
The goal of this project is to better understand the game engine. This repo does not contain any game assets or code from the game's executable; It requires your own copy of the game to build and run.
Documentation of the code can be found at [theonlyzac.github.io/sly1](https://theonlyzac.github.io/sly1). For further reading on the game's internal structures and mechanics, visit the [SlyMods Wiki][wiki-url].
New contributors are welcome and encouraged to make a pull request! If you would like to help but aren't sure where to start, check out [CONTRIBUTING.md](/docs/CONTRIBUTING.md) and feel free to [join our Discord server][discord-url] for guidance.
To build the ELF, you will need to extract the original ELF file from your own legally obtained copy of the game. Mount the disk on your PC and copy the file `SCUS_971.98` from the root directory of the disc to the `disc` directory of this project.
Running the executable requires [PCSX2 1.7](https://pcsx2.net/). You must have your own copy of the original game and the BIOS from your own PS2. They are not included in this repo and we cannot provide them for you.
The `run.sh` script in the `scripts` dir will automatically rebuild the executable and run it in the PCSX2 emulator. To use it, you must first edit the script to set the `PCSX2_PATH` and `ISO_PATH` variables to the correct paths on your system.
Replace `pcsx2-1.7.exe` with the path to your PCSX2 v1.7 executable (for Linux it will be an **.appimage** file).
- The `-elf` parameter specifies the path to the SCUS_971.98 you built from this project. Replace `...` with the path to this repository. The emulator will use this ELF to boot the game.
- The last argument is the path to your game ISO. Replace `/path/to/game/backup.iso` with the path to a backup of your own game disc. This is where the game will load the assets from.
Copy `SCUS_971.98` from the `out` dir to your PCSX2 Games folder and rename it to `SCUS_971.98.elf`. Right click on the game in PCSX2 and click "Properties...". Go to "Disc Path", click "Browse", and select the ISO of your game backup. Then click "Close" and start the game as normal.
When the developers created the game, they wrote source code and compiled it to assembly code that can run on the PS2. A decompilation involves reverse-engineering the assembly code to produce new, original code that compiles to matching assembly. This process leaves us with source code that is similar to and behaves the same as the source code (though not necessarily identical), which helps us understand what the programmers were thinking when they made the game.
We use a tool called [Splat](https://github.com/ethteck/splat/) to split the binary into assembly files representing each individual function. We then reimplement every function and data structure by writing C++ code that compiles to the same assembly code. We do not include any data or code from the original game binary in the decompilation.
This was one the first ever PS2 decompilations; Several other PS2 decompilations have been started since we began in 2020. Our main inspiration was other projects such as the [Super Mario 64 decomp](https://github.com/n64decomp/sm64) for the N64 and the [Breath of the Wild decomp](https://github.com/zeldaret/botw) for the Wii U (the latter being more similar in scope to this project). There is also a Jak & Daxter decomp/PC port called [OpenGOAL](https://github.com/open-goal/jak-project), though that game is 98% GOAL language rather than C/C++.
Yes. This was the first PS2 decompilation project that aimed to target the PS2 and utilize function matching, before it was even possible to produce a byte-matching executable. The ultimate goal is to match 100% of the game's functions.
If you want to contribute, check out [CONTRIBUTING.md](/docs/CONTRIBUTING.md) and feel free to [join our discord server](https://discord.gg/gh5xwfj) if you have any questions!
