ym1234 / nitrosharp

Open-source N2System reimplementation

NitroSharp (codename Project Hoppy)

NitroSharp is an open-source reimplementation of N2System, a visual novel engine used in a number of games made by Nitroplus. The primary goal of the project is to make Chaos;Head Noah, a console-exclusive game, fully playable on PC (Windows, Linux) and possibly other platforms (listed below). Support for other N2System-based games may come later.

Status

NitroSharp is close to being feature-complete. You should be able to reach at least some of the endings in Chaos;Head Noah without crashes, if you're lucky. Please do not expect NitroSharp to be a viable drop-in replacement for N2System just yet.

• Do expect all sorts of bugs.
• Do not expect your saves to work after upgrading to a newer build of the engine or modifying the scripts.
• Do not use NitroSharp if you simply want to enjoy the game.

Missing features:

• Support for the archive formats
  • AFS
  • NPA
• Decent, reliable save system
• Graphical effects
  • Motion blur
  • Lens (partially implemented)
  • Box blur (currently disabled)
• Fullscreen mode
• Auto mode
• Backlog voice replay
• Controller support (partially implemented)

Supported games

• Chaos;Head Noah
• Chaos;Head

Supported platforms

The initial release will likely only support two major platforms:

• Windows x64
  • Direct3D 11
  • Vulkan
• Linux x64
  • Vulkan

The Linux version currently doesn't have sound.

It should be theoretically possible to add support for the following platforms:

• Windows x86
• Windows ARM64
• Linux ARM64
• macOS
• Android
• Nintendo Switch

Building

Required Software

• .NET 5 SDK
• PowerShell 7 (for AOT-compiled builds)
• Windows SDK might be required for producing Windows builds

Run

dotnet run --no-launch-profile --project ./src/NitroSharp.ShaderCompiler/NitroSharp.ShaderCompiler.csproj ./src/NitroSharp/Graphics/Shaders ./bin/obj/NitroSharp/Shaders.Generated
dotnet build NitroSharp.sln [-c Release]

OR

Run aot-build.ps1 in PowerShell 7 to produce an AOT-compiled build. Do not expect the build script to work in the old Windows PowerShell.

How do I play the game?

There is currently no support for AFS and NPA archives, which means you will have to extract the game files first. Before you start, make sure your game directory looks this way:

1. Get the tools for extracting the archives here.
2. Place them in the same directory as the game assets and run ./extract.ps1 in PowerShell. The extracted files will be placed inside a folder named content.
3. Edit Game.json so that dev.contentRoot points to the content directory. Avoid unescaped backslashes in the path.
4. Run Game.exe.

License

NitroSharp is licensed under the MIT license. This project uses a number of third-party components. See THIRDPARTY.md for more details.

Legal disclaimers

• This project is non-commercial and is not affiliated with Nitroplus or MAGES. in any way.
• This is a black-box reimplementation: the code in this project was written based on observing the runtime behavior of the original closed-source implementation.
• No assets from any Nitroplus games are included in this repo.