WorldSerializer

Remarks

The item [14](../../../docs/plan/14-roadmap.md) parks behind the scene format, and the dependency was real rather than administrative. A world is entities and the bytes in their chunks; what it is not is anything that knows what those bytes mean. Naming a component and finding its serializer is SceneComponentRegistry's job, and until that existed a world serialiser could only have written raw chunk memory — which is WorldSnapshot, is the right answer for play mode, and is not a format.

It lives here and not in Vixen.Ecs because the pieces do. The ECS references no serializer by design; the binders and the transforms are the engine's. A seam in the ECS filled from here would be a second way to say the same thing, and the layer boundary is what would have to hold it up.

⚠ Three components are never written, and are rebuilt instead: Parent, Child and Sibling. All three hold Entity handles, which are slots in a running process. Storing them would mean either remapping bytes nothing can identify as handles, or promising to hand back the same slot numbers — and the second is a promise a fresh world cannot keep. The hierarchy travels as a table of indices and the links are made by SetParent, which is the same bargain SceneContent struck and for the same reason.

⚠ A game component holding an Entity is not solved by that, and cannot be from here: nothing generic knows which of a component's fields are handles. World.CopyComponentsFrom says the same and leaves the fix-up to its caller. What this does is give a caller what it needs to do the fix-up — Capture fills an optional list with the entity at each index and Restore returns the same thing, so zipping the two is the translation table.

Fields and properties (1)

• public const string BuiltInPrefix

  The prefix a built-in column's name carries, and a contract alias may not.

Methods (2)

• public static WorldContent Capture(World world, IList<Entity>? order = null)

  Writes every live entity in a world.

• public static IReadOnlyList<Entity> Restore(WorldContent content, World world)

  Makes the captured world again, in place of whatever the target holds.

Used by (2)

• LocalTransformColumnVixen.Engine
• WorldSerializerTestsVixen.Engine.Tests