Retail-faithful 8-light cap selection (r13 §12) — the fixed-function
D3D pipeline's "hardware lights" constraint carried over to modern GL
via UBO-per-draw.
Core layer (AcDream.Core/Lighting):
- LightSource: Kind (Directional/Point/Spot), WorldPosition,
WorldForward, ColorLinear, Intensity, Range (hard cutoff),
ConeAngle (spot), OwnerId (entity attachment), IsLit latch.
- CellAmbientState: (AmbientColor, SunColor, SunDirection) sourced from
R12 sky state for outdoor cells or EnvCell dat for indoor cells.
- LightManager: Register/Unregister/UnregisterByOwner/Clear + Tick
per frame. Selection matches r13 §12.2 exactly:
1) Skip unlit + directional.
2) Compute DistSq for every registered point/spot.
3) Drop lights outside Range² * 1.1 (10% slack prevents pop).
4) Sort by DistSq ascending; take up to 7 (slot 0 reserved for Sun).
5) Slot 0 = Sun (Directional); slots 1..7 = nearest in-range.
Tests (9 new):
- Register/Unregister/Idempotent register.
- Tick picks top 8 by distance when 12 registered.
- Range filter drops far lights (5.0 range, 20m away).
- Range slack includes lights at exactly the boundary.
- Sun reserved at slot 0 across ticks.
- Unlit lights excluded; toggling IsLit brings them back.
- UnregisterByOwner removes all owner's lights.
- DistSq updated each tick for viewer movement.
Build green, 596 tests pass (up from 587).
Next: wire LightManager into the shader UBO pass (G.2 second commit)
and feed Sun from WorldTimeService.CurrentSunDirection per frame.
Ref: r13 §10.2 (D3D attenuation = none inside Range + hard cutoff),
§12 (full port plan).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
