2DCore

2DCore is a cross-platform 2D scene editor written in C# with Avalonia UI. The main editor targets Windows, Linux and macOS from one net9.0 project.

Requirements

• .NET 9 SDK or newer.
• Windows 10/11, a desktop Linux distribution, or macOS.
• On Debian/Ubuntu Linux, Avalonia may require: libx11-6 libice6 libsm6 libfontconfig1.

Run

git clone https://github.com/Teliar/2DCore.git
cd 2DCore
dotnet run

The root 2DCore.csproj is the Avalonia application and does not use a Windows-specific target framework.

Build the complete solution and run tests:

dotnet build 2DCore.slnx
dotnet test tests/TwoDCore.Tests/TwoDCore.Tests.csproj

Create a framework-dependent Linux build from any supported development OS:

dotnet publish 2DCore.csproj -c Release -r linux-x64 --self-contained false

Architecture

2DCore/
├── 2DCore.csproj                    # Cross-platform Avalonia entry point
├── 2DCore.slnx
├── EditorAssets/                    # Icons and editor resources
├── src/
│   ├── TwoDCore.Core/               # Scene model, hierarchy, audio math, history
│   ├── TwoDCore.Persistence/        # DTOs, legacy-compatible JSON mapping, project I/O
│   └── TwoDCore.Editor/             # Avalonia views, controls and editor state
├── tests/
│   └── TwoDCore.Tests/              # Scene graph and persistence compatibility tests
└── legacy/
    └── TwoDCore.Editor.WinForms/    # Temporary Windows-only reference implementation

Dependency direction:

Avalonia Editor → Persistence → Core
Avalonia Editor ─────────────→ Core

Core contains no WinForms, Avalonia, file-dialog or JSON dependencies. Persistence does not reference the UI.

Current editor features

• Scene hierarchy with folders and protected drag-to-reparent behavior.
• Shape, image, folder, global sound, sound trigger and spatial sound objects.
• Custom-drawn zoomable and pannable viewport.
• Type-aware Inspector with volume and transparency sliders.
• Spatial sound radius and attenuation visualization.
• New/Open/Save/Save As with .2dproj and .2dscene v1 compatibility.
• Undo, redo, copy, paste, duplicate and delete.
• Cross-platform file and asset pickers.

Project formats

• .2dproj stores project metadata and the start scene path.
• .2dscene stores object hierarchy and component data as readable JSON.

The persistence tests include a legacy v1 scene fixture to prevent accidental format breakage.

Keyboard shortcuts

Shortcut	Action
Ctrl+N	New project
Ctrl+O	Open project or scene
Ctrl+S	Save
Ctrl+Shift+S	Save As
Ctrl+Z	Undo
Ctrl+Shift+Z / Ctrl+Y	Redo
Ctrl+C / Ctrl+V	Copy / Paste
Ctrl+D	Duplicate
Delete	Delete selected object

Legacy WinForms editor

The previous implementation remains temporarily available as a migration reference:

dotnet run --project legacy/TwoDCore.Editor.WinForms/TwoDCore.Editor.WinForms.csproj

It is not part of the cross-platform solution and will be removed after the Avalonia editor reaches complete feature parity.