A full decompilation of Sonic CD 2011, based on the PC remake with improvements & tweaks from the mobile remakes. Ported to the Switch.

SUPPORT THE OFFICIAL RELEASE OF SONIC CD

• Without assets from the official release, this decompilation will not run.

• You can get the official release of Sonic CD from:

  • Windows (Via Steam)
  • iOS (Via the App Store)
  • Android (Via Google Play)
  • Android (Via Amazon)

Installation Instructions

You can find downloads in releases.

1. Make sure your Switch can run homebrew.
2. Extract the contents of the zip to the root of your SD card.
3. Copy the assets to /switch/scd2011 on your Switch's SD card. You will need the following files/folders:
   • help (folder, optional as How to Play is broken)
   • videos (folder)
   • Data.rsdk
   • fonts.arc
   • images.arc
   • sounds.arc
   • Strings.str
4. Start Sonic CD via hbmenu (or whatever method you prefer).

NOTE: It is recommended to give the game full RAM access. This means you shouldn't launch hbmenu from the album applet when running this. With the latest Atmosphere build and its default config, you can hold R while starting any game to open hbmenu with full RAM access. If you have any issues make sure the game has full RAM access before reporting them; launching as an applet will not be supported.

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Sections below are lifted directly from the source repository.

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Even if your platform isn't supported by the official releases, you must buy or officially download it for the assets (you don't need to run the official release, you just need the game assets)

Advantages over the PC version of Sonic CD

• Sharp, pixel-perfect display
• Controls are completely remappable via the settings.ini file
• The window allows windows shortcuts to be used
• Complete support for using mobile/updated scripts, allowing for features the official PC version never got to be played on PC
• Native Windows x64 version, as well as an x86 version

Advantages over the Mobile versions of Sonic CD

• The rendering backend is based off the PC version by default, so palettes are fully supported (Tidal Tempest water in particular)

Additional Tweaks

• Added a built in mod loader and API allowing to easily create and play mods with features such as save file redirection and XML GameConfig data.
• There is now a settings.ini file that the game uses to load all settings, similar to Sonic Mania
• Dev menu can now be accessed from anywhere by pressing ESC if enabled in the config
• The F12 pause, F11 step over & fast forward debug features from Sonic Mania have all been ported and are enabled if devMenu is enabled in the config
• If devMenu is enabled in the config, pressing F9 will visualize hitboxes, and F10 will activate a palette overlay that shows the game's 8 internal palettes in real time
• If useSteamDir is set in the config, and the user is on Windows, the game will try to load savedata from Steam's userdata directory (where the Steam version saves to)
• Added the idle screen dimming feature from Sonic Mania Plus, as well as allowing the user to disable it or set how long it takes for the screen to dim

How to build

Windows

• Clone the repo, then follow the instructions in the dependencies readme for Windows to setup dependencies, then build via the Visual Studio solution (or just grab a prebuilt executable from the releases section.)

Windows via MSYS2 (64-bit only)

• Download the newest version of the MSYS2 installer from here and install it.
• Run the MINGW64 prompt (from the windows Start Menu/MSYS2 64-bit/MSYS2 MinGW 64-bit), when the program starts enter pacman -Syuu in the prompt and hit Enter. Press Y when it asks if you want to update packages. If it asks you to close the prompt, do so, then restart it and run the same command again. This updates the packages to their latest versions.
• Now install the dependencies with the following command: pacman -S pkg-config make git mingw-w64-x86_64-gcc mingw-w64-x86_64-SDL2 mingw-w64-x86_64-libogg mingw-w64-x86_64-libvorbis mingw-w64-x86_64-libtheora mingw-w64-x86_64-glew.
• Clone the repo with the following command: git clone https://github.com/Rubberduckycooly/Sonic-CD-11-Decompilation.git.
• Go into the repo you just cloned with cd Sonic-CD-11-Decompilation.
• Then run make -f Makefile.msys2 CXXFLAGS=-O2 CXX=x86_64-w64-mingw32-g++ STATIC=1 -j5.
  • The CXXFLAGS option can be removed if you do not want optimizations.
  • -j switch is optional, but will make building faster by running it parallel on multiple cores (8 cores would be -j9.)

Windows UWP (Phone, Xbox, etc.)

• Clone the repo, then follow the instructions in the dependencies readme for Windows and dependencies readme for UWP to setup dependencies, then build and deploy via the UWP Visual Studio solution.
• After install, copy your Data.rsdk and videos folder into the apps localstate folder.

Mac

• Clone the repo, follow the instructions in the dependencies readme for Mac to setup dependencies, then build via the Xcode project (or grab a prebuilt executable from the releases section.)

Linux

• To setup your build enviroment and library dependecies run the following commands:
  • Ubuntu (Mint, Pop!_OS, etc...): sudo apt install build-essential git libsdl2-dev libvorbis-dev libogg-dev libtheora-dev libglew-dev libtinyxml2-dev
  • Fedora Linux: sudo rpm install g++ SDL2-devel libvorbis-devel libogg-devel libtheora-devel glew-devel tinyxml2-devel
  • Arch Linux: sudo pacman -S base-devel git sdl2 libvorbis libogg libtheora glew tinyxml2
• Clone the repo with the following command: git clone https://github.com/Rubberduckycooly/Sonic-CD-11-Decompilation.git.
• Go into the repo you just cloned with cd Sonic-CD-11-Decompilation.
• Run make CXXFLAGS=-O2 -j5.
  • If your distro is using gcc 8.x.x, then add the argument LIBS=-lstdc++fs.
  • The CXXFLAGS option can be removed if you do not want optimizations.
  • -j switch is optional, but will make building faster by running it parallel on multiple cores (8 cores would be -j9.)

iOS

• Clone the repo, follow the instructions in the dependencies readme for iOS to setup dependencies, then build via the Xcode project

Android

• Clone the repo, then follow the instructions in the dependencies readme for Android.
• Ensure the symbolic links in android/app/jni are correct. If not, fix them with the following on Windows:
  • mklink /D src ..\..\..
  • mklink /D SDL ..\..\..\dependencies\android\SDL
• Open android/ in Android Studio, install the NDK and everything else that it asks for, and build.

PlayStation Vita

• Ensure you have Docker installed and run the script build.sh from RSDKv3.vita. If you are on Windows, WSL2 is recommended.
  • NOTE: You would need to copy Sonic CD game data into ux0:data/RSDKv3 to boot the game.

Unofficial Branches

Follow the installation instructions in the readme of each branch.

• For the Nintendo Switch, go to heyjoeway's fork.
• For the Nintendo 3DS, go to SaturnSH2x2's fork.
  • A New Nintendo 3DS is required for the game to run smoothly.

Because these branches are unofficial, we can't provide support for them and they may not be up-to-date.

Other Platforms

Currently the only supported platforms are the ones listed above, however the backend uses libogg, libvorbis, libtheora & SDL2 to power it, so the codebase is very multiplatform. If you're able to, you can clone this repo and port it to a platform not on the list.

FAQ

Q: Why don't some buttons in the menu work?

A: Buttons like leaderboards & achievements require code to be added to support online functionality & menus (though they are saved anyways), and other buttons like the controls button on PC or privacy button on mobile have no game code and are instead hardcoded through callback. I just didnt feel like going through the effort to decompile all that, since its not really worth it.

Q: Is the titlecard text slightly offset when using a PC datafile?

A: Unfortunately, it's an error with the scripts. If you wanna go into TitleCards/R[X]\_TitleCard.txt and fix it, be my guest, but the best fix is to set screenWidth to 400, instead of 424 in the settings.ini file to match the PC version's resolution.

Q: There's a weird spot on the title screen, how do I fix it?

A: See above.

Q: The screen is tearing, how do I fix it?

A: Try turning on VSync in settings.ini.

Q: I found a bug!

A: Submit an issue in the issues tab and we might fix it in the master branch. Don't expect any future releases, however.

Q: Will you do a decompilation for Sonic 1/Sonic 2?

A: Yes! I've done a decompilation of RSDKv4 (the engine version that S1/S2 run on) and it can be found here!

Q: Will you do a decompilation for Sonic Mania?

A: No. Sonic Mania is much bigger and requires that I'd decompile not only how the (far more complex) RSDKv5 works, but also all 600+ objects work.

Special Thanks

• Xeeynamo: for creating the RSDK Animation editor & an early version of the script unpacker, both of which got me into RSDK modding.
• Sappharad: for making a decompilation of the Windows Phone 7 version of Sonic CD (found here) which gave me the idea & motivation to decompile the PC/IOS/Android versions.
• SuperSonic16: for creating & adding some stuff to the Sonic CD mod loader that I asked for.
• The Weigman for creating the header you see up here along with similar assets.
• Everyone in the Retro Engine Modding Server: for being supportive of me and for giving me a place to show off these things that I've found.

Contact:

Join the Retro Engine Modding Discord Server for any extra questions you may need to know about the decompilation or modding it.