Optional Spatializer Architecture (Option A)

Intent

Keep all 2D levels and logic unchanged while enabling 3D/4D presentation via an optional spatializer. This matches the current Sphere behavior (projected 2D gameplay) and avoids forcing extra layers on 2D content.

Core idea

• Rules remain in existing BaseLevel subclasses (Standard/Clock/DarkMode/etc).
• Spatializer exists only when Dimension > 2.
• The spatializer owns all spatial presentation logic:
  • projection/unprojection
  • visibility/backface logic
  • line projection
  • overlays (equator)
  • rotation/axis input
  • menu preview reset behavior
  • optional feature modules (see "Core + Modifiers inside the Spatializer")

Data model (minimal)

LevelDataSO
  LevelType = Standard | Clock | DarkMode | ...
  Dimension = 2 | 3 | 4
  BoundaryType = Rect | Circle | Custom | ...

The spatializer can validate boundary compatibility (e.g., Sphere expects Circle).

Responsibilities

LevelMgr

• Spawns dots/lines/obstacles as it does today.
• Creates rule instance from LevelType.
• Creates spatializer only if Dimension > 2.
• Ticks and disposes the spatializer alongside rule logic.

Rules (BaseLevel subclasses)

• Own progression, win conditions, UI/audio effects.
• No projection or dimension logic.

Spatializer (new)

• Caches dot/line local positions.
• Updates projected Line.Pts each tick.
• Adjusts dot visibility/colliders based on depth.
• Manages overlays (equator) and axis hints.
• Handles spatial rotation input.

Core + Modifiers inside the Spatializer (optional)

You can treat each spatializer as a preset that includes:

• Core behaviors that are intrinsic to the space (always on):
  • projection/unprojection
  • rotation state and input
  • line projection + local caches
• Modifiers that are optional and can be toggled per spatializer:
  • equator overlay
  • backface visibility tweaks
  • axis hint / reveal messaging
  • menu preview reset tween

This keeps the "optional spatializer" model while letting each spatializer compose small feature modules internally without exposing modifiers to 2D levels.

Mapping SphereLevel -> Spatializer

Move these from SphereLevel.cs into SphereSpatializer:

• Projection: ProjectWorldToLocal, ProjectLocalToWorld
• Dot visibility/backface: UpdateDots, GetBackfaceHidePos
• Line projection: UpdateLines, ApplyProjectedLinePts
• Rotation input: UpdateRotation, HandleAxisInput, ShowAxisMessage
• Equator overlay: EnsureEquatorLine, RefreshEquatorStyle, UpdateEquatorLine, ShowEquator/HideEquator
• Menu preview reset: ResetMenuPreview, tween handling
• Init/cache: PrimeSphere, CacheDots, SyncLns

Effects and collisions

• Collisions remain 2D using projected points.
• Arrow effects continue to use Line.Pts after connection (no change needed).
• Obstacles remain 2D overlays in projected space.

Flow diagram

LoadLevelVisuals
  -> spawn boundary/dots/obstacles (unchanged)
  -> rules = LevelFactory.Create(LevelType)
  -> if Dimension > 2: spatializer = SpatializerFactory.Create(Dimension)
       -> spatializer.Init(LevelMgr, LevelDataSO)
  -> rules.Init(LevelMgr, LevelDataSO)
  -> GameEvents.TriggerLevelLoaded

Update
  -> rules.Tick(dt)
  -> spatializer?.Tick(dt)

Connection
  -> LevelMgr.CreateLine(...) adds Line with 2D pts
  -> spatializer keeps Line.Pts updated (projected 2D)
  -> EffectsFactory shows arrow using Line.Pts (unchanged)

Exit
  -> spatializer?.Dispose()
  -> rules.Dispose()
  -> LevelMgr clears visuals (unchanged)

Why this is minimal and clean

• 2D levels never see the spatializer.
• All existing gameplay and editor flows remain valid.
• Spatial complexity is isolated to Dimension > 2 only.