GodotSharp.SourceGenerators

C# Source Generators for use with the Godot Game Engine (supports Godot 4 and .NET 8!)

• SceneTree class attribute:

  • Generates class property for uniquely named nodes
  • Provides strongly typed access to the scene hierarchy (via _ operator)

• GodotOverride method attribute:

  • Allows use of On, instead of virtual _ overrides
  • (Requires partial method declaration for use with Godot 4.0)

• Notify property attribute:

  • Generates boiler plate code, triggering only when values differ
  • (Automagically triggers nested changes for Resource and Resource[])

• InputMap class attribute:

  • Provides strongly typed access to input actions defined in godot.project

• LayerNames class attribute:

  • Provide strongly typed access to layer names defined in godot.project

• CodeComments class attribute:

  • Provides a nested static class to access property comments from code (useful for in-game tooltips, etc)

• OnInstantiate method attribute:

  • Generates a static Instantiate method with matching args that calls attributed method as part of the instantiation process
  • (Also generates a protected constructor to ensure proper initialisation - can be deactivated via attribute)

• OnImport method attribute (GD4 only):

  • Generates default plugin overrides and options to make plugin class cleaner (inherit from OnImportEditorPlugin)

• Includes base classes/helpers to create project specific source generators

• Version 2.x supports Godot 4

• Version 1.x supports Godot 3

(See GodotSharp.BuildingBlocks or local tests for example usage patterns)

Table of Contents

• GodotSharp.SourceGenerators
  • Table of Contents
  • Installation
  • Attributes
  • SceneTree
  • GodotOverride
  • Notify
  • InputMap
  • LayerNames
  • CodeComments
  • OnInstantiate
  • OnImport

Installation

Install via NuGet

Attributes

SceneTree

• Class attribute
• Generates class property for uniquely named nodes
• Provides strongly typed access to the scene hierarchy (via _ operator)
• Nodes are cached on first retrieval to avoid interop overhead

• Advanced options available as attribute arguments

  • tscnRelativeToClassPath: (default null) Specify path to tscn relative to current class

  • traverseInstancedScenes: (default false) Include instanced scenes in the generated hierarchy

    // Attach a C# script on the root node of the scene with the same name.
    // [SceneTree] will generate the members as the scene hierarchy.
    [SceneTree]
    public partial class MyScene : Node2D 
    {
    public override void _Ready() 
    {
    // You can access the node via '_' object.
    GD.Print(_.Node1.Node11.Node12.Node121);
    GD.Print(_.Node4.Node41.Node412);
    
    // You can also directly access nodes marked as having a unique name in the editor
    GD.Print(MyNodeWithUniqueName);
    GD.Print(_.Path.To.MyNodeWithUniqueName); // Long equivalent
    }
    }

    GodotOverride

• Method attribute
• Allows use of On, instead of virtual _ overrides
• (Requires partial method declaration for use with Godot 4.0)

• Advanced options available as attribute arguments

  • replace: (default false) Skip base call generation (ie, override will replace base)

    
    public partial class MyNode : Node2D 
    {
    [GodotOverride]
    protected virtual void OnReady()
    => GD.Print("Ready");

  [GodotOverride(replace: true)] private void OnProcess(double delta) => GD.Print("Processing");

  // Requires partial method declaration for use with Godot 4.0 public override partial void _Ready(); public override partial void _Process(double delta); }

  Generates:
  ```cs
  public override void _Ready()
  {
      base._Ready();
      OnReady();
  }
  
  public override _Process(double delta)
      => OnProcess(delta);

  Notify

• Property attribute
• Generates public events Value1Changed & Value1Changing and a private class to manage field and event delivery
• (Automagically triggers nested changes for Resource and Resource[])
• Events are triggered only if value is different

• [NEW] Initial value can be set without triggering update (useful when using a non-nullable reference type)

  public partial class NotifyTest : Node
  {
  [Notify]
  public float Value1
  {
      get => _value1.Get();
      set => _value1.Set(value); // You can also pass onchanged event handler here
  }
  
  public override void _Ready()
  {
      Value1Changing += () => GD.Print("Value1Changing raised before value is changed");
      Value1Changed += () => GD.Print("Value1Changed raised after value is changed");
  
      // You can also subscribe to private events if needed 
      //   _value1.Changing += OnValue1Changing;
      //   _value1.Changed += OnValue1Changed;
      // This might be useful... erm... if you need to clear the public listeners for some reason...?
  
      Value1 = 1; // Raise Value1Changing and Value1Changed
      Value1 = 2; // Raise Value1Changing and Value1Changed
      Value1 = 2; // No event is raised since value is the same
  }
  
  public NotifyTest()
      => InitValue1(7); // [NEW] Set initial value without triggering events (optional)
  }

  InputMap

• Class attribute
• Provides strongly typed access to input actions defined in godot.project (set via editor)
• If you want access to built-in actions, see BuiltinInputActions.cs

  [InputMap]
  public static partial class MyInput { }

  Equivalent (for defined input actions) to:

  // (static optional)
  // (string rather than StringName for Godot 3)
  // (does not provide access to built-in actions)
  partial static class MyInput
  {
  public static readonly StringName MoveLeft = "move_left";
  public static readonly StringName MoveRight = "move_right";
  public static readonly StringName MoveUp = "move_up";
  public static readonly StringName MoveDown = "move_down";
  }

  LayerNames

• Class attribute

• Provides strongly typed access to layer names defined in godot.project (set via editor)

  [LayerNames]
  public static partial class MyLayers { }

  Equivalent (for defined layers) to:

  // (static optional)
  partial static partial class MyLayers
  {
  public static class Render2D
  {
      public const int MyLayer1 = 0; // Yes, layers start at 1 in editor, but 0 in code
      public const int MyLayer2 = 1;
      public const int MyLayer7 = 6;
      public const int _11reyaLyM = 10; // Yes, we will append an underscore if required...
  
      public static class Mask
      {
          public const uint MyLayer1 = 1 << 0;
          public const uint MyLayer2 = 1 << 1;
          public const uint MyLayer7 = 1 << 6;
          public const uint _11reyaLyM = 1 << 10;
      }
  }
  public static class Render3D
  {
      public const int MyLayer1 = 0;
  
      public static class Mask
      {
          public const uint MyLayer1 = 1 << 0;
      }
  }
  // Also for Physics2D, Physics3D, Navigation2D, Navigation3D, Avoidance, etc...
  }

  CodeComments

• Class attribute
• Provides a nested static class to access property comments from code

• Advanced options available as attribute arguments

  • strip: (default "// ") The characters to remove from the start of each line

    
    [CodeComments]
    public partial class CodeCommentsTest : Node 
    {
    // This a comment for Value1
    // [CodeComments] only works with Property
    [Export] public float Value1 { get; set; }

  // Value 2 is a field so no comment [Export] public float value2;

  public override void _Ready() { GD.Print(GetComment(nameof(Value1))); // output: "This a comment for Value1\n[CodeComments] only works with Property" GD.Print(GetComment(nameof(value2))); // output: "" (No output for fields, but could be added if needed) } }

  
  ### `OnInstantiate`

• Method attribute
• Generates a static Instantiate method with matching args that calls attributed method as part of the instantiation process
• (Also generates a protected constructor to ensure proper initialisation - can be deactivated via attribute)

• Advanced options available as attribute arguments

  • ctor: (default "protected") Scope of generated constructor (null, "" or "none" to skip)

    // Initialise can be public or protected if required; args also optional
    // Currently assumes tscn is in same folder with same name
    // Obviously only valid for root nodes
    public partial class MyScene : Node
    {
    [OnInstantiate]
    private void Initialise(string myArg1, int myArg2)
    => GD.PrintS("Init", myArg1, myArg2);
    }

    Generates (simplified):

    
    private static PackedScene __scene__;
    private static PackedScene __Scene__ => __scene__ ??= GD.Load<PackedScene>("res://Path/To/MyScene.tscn");

  public static MyScene Instantiate(string myArg1, int myArg2) { var scene = Scene.Instantiate(); scene.Initialise(myArg1, myArg2); return scene; }

  private Test3Arg() {}

  Usage:
  ```cs
  // ... in some class
  private void AddSceneToWorld()
  {
      var myScene = MyScene.Instantiate("str", 3);
      MyWorld.AddChild(myScene);
  }

  OnImport

• Method attribute (GD4 only)
• Generates default plugin overrides and options to make plugin class cleaner (inherit from OnImportEditorPlugin)
• Includes base classes/helpers to create project specific source generators
• (Not that useful unless writing lots of plugins - might remove in v3)