Editor toolbar gains Play/Stop (Ctrl+P) with UE semantics:
- Play: serialize current scene to an in-memory YAML snapshot via new
SceneSerializer::SerializeToString, switch display to kDisplayDirect
(primary camera entity renders), unfreeze time (timeScale 0 -> 1)
- Stop: DeserializeFromString atomically rebuilds the pre-play scene,
back to kDisplayViewport (editor camera), refreeze time; selection
cleared and gizmo drag reset since all entity handles dangle
- SceneSerializer refactored: SerializeDoc/ParseRoot shared by file
and memory variants; file Save/Load behavior unchanged
- Running state disables gizmo + editor hotkeys in the viewport (input
goes to game scripts), draws yellow PLAYING hint and a no-camera
warning; File->Save/Load disabled while playing (UE behavior)
Physics bodies/constraints/characters and script instances are
reconciled automatically by the existing per-frame sync on restore.
EditorCamera (UE FEditorViewportClient semantics) owned by SceneRenderer:
own TransformComponent + reused Camera controller. BuildFrame dispatches
render source by display mode — editor form always renders from the
editor camera (usable in empty scenes), game form renders from the
scene's primary camera entity. AlignTo copies an entity pose into the
editor camera ("Align Viewport to Camera" button in Inspector). F focus
and viewport gizmo now follow the same dispatch. main.cpp stripped of
dangling sandbox camera/spinner state; onSceneLoaded hook removed.
Engine-layer SceneSerializer (yaml-cpp submodule): entities/components
to versioned YAML, atomic clear-and-rebuild on load with per-entity
fault tolerance, missing-field defaults, unknown-component skip and
UUID dedup. Asset references are {Guid, Path} pairs resolved through
the new AssetManager GUID registry (assets/asset_registry.yaml) with
path fallback; procedural:// pseudo-paths rebuild from parameters.
Editor File menu gets Save/Load Scene modals; app re-resolves stale
entity handles via onSceneLoaded callback.
atdunbg