testing building some core systems

- serialization
- chunks
- parralelfor test

Nerfed.Runtime/Scene/SceneData.cs

@@ -0,0 +1,65 @@
+namespace Nerfed.Runtime.Scene;
+
+/// <summary>
+/// Root data model for a scene. A scene and a prefab are the same thing —
+/// there is no distinction between the two, mirroring Godot's design.
+/// </summary>
+public sealed class SceneData
+{
+    /// <summary>Incremented when the file format changes in a breaking way.</summary>
+    public int Version { get; set; } = SceneData.CurrentVersion;
+    public string Name { get; set; } = string.Empty;
+    public List<SceneEntityData> Entities { get; set; } = new();
+    /// <summary>All user-defined relations between entities in this scene.</summary>
+    public List<SceneRelationData> Relations { get; set; } = new();
+
+    public const int CurrentVersion = 1;
+}
+
+/// <summary>
+/// Serialized representation of a single entity.
+/// The <see cref="Id"/> is a scene-local identifier that only exists in the
+/// serialized data and is used to reconstruct parent–child and relation references.
+/// It is never stored as a component on a live entity.
+/// An entity is included if it owns at least one <see cref="SceneComponentAttribute"/> component
+/// OR participates in at least one <see cref="SceneRelationAttribute"/> relation.
+/// </summary>
+public sealed class SceneEntityData
+{
+    public Guid Id { get; set; } = Guid.NewGuid();
+    public string Tag { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Scene-local <see cref="Id"/> of this entity's <see cref="Components.ChildParentRelation"/>
+    /// parent, or <c>null</c> if this is a root entity.
+    /// </summary>
+    public Guid? ParentId { get; set; }
+
+    public List<SceneComponentData> Components { get; set; } = new();
+}
+
+/// <summary>
+/// Serialized representation of a single component value on an entity.
+/// <see cref="Type"/> is the fully-qualified CLR type name used to resolve the component on load.
+/// <see cref="Value"/> is the boxed runtime value; each <see cref="ISceneSerializer"/> is
+/// responsible for converting it to/from its wire format.
+/// </summary>
+public sealed class SceneComponentData
+{
+    public string Type { get; set; } = string.Empty;
+    public ValueType Value { get; set; } = default!;
+}
+
+/// <summary>
+/// Serialized representation of a relation between two entities.
+/// <see cref="EntityA"/> and <see cref="EntityB"/> reference scene-local <see cref="SceneEntityData.Id"/> values.
+/// <see cref="Type"/> identifies the relation kind (must be marked with <see cref="SceneRelationAttribute"/>).
+/// <see cref="Value"/> holds the relation data payload (may be an empty struct).
+/// </summary>
+public sealed class SceneRelationData
+{
+    public string Type { get; set; } = string.Empty;
+    public Guid EntityA { get; set; }
+    public Guid EntityB { get; set; }
+    public ValueType Value { get; set; } = default!;
+}