Standing inside (or looking into) a windowed building like the Agent of
Arcanum, interior objects (furniture, NPCs, the player) were lit by the
directional sun because acdream's sun gate was per-FRAME (keyed on the
player being in a sealed cell), not per-DRAW as retail does it.
Retail's PView::DrawCells (0x005a4840) runs two stages per frame:
outdoor stage → useSunlightSet(1) (0x005a485a): sun ON
interior stage → useSunlightSet(0) (0x005a49f3): sun OFF
DrawMeshInternal (0x0059f398) then calls minimize_object_lighting only
when useSunlight==0, so indoor objects ALWAYS skip the sun regardless of
whether the player's cell is windowed or sealed.
Fix: add a per-instance uint SSBO (binding=6 instanceIndoor[]) whose value
is IndoorObjectReceivesTorches(ParentCellId) — the same predicate AP-43
already uses for the torch gate. In mesh_modern.vert, nest the sun loop
inside an additional `if (instanceIndoor[instanceIndex] == 0u)` check
inside the existing `if (uLightingMode == 0)` block. Indoor objects get
torches (unchanged) but now skip the sun; outdoor objects keep the sun and
still get no torches. The ambient regime (UpdateSunFromSky: 0.2 sealed /
sky otherwise) is untouched — it was already correct.
Mechanically: _currentEntityIndoor set once per entity in
ComputeEntityLightSet; appended to InstanceGroup.IndoorFlags in
AppendCurrentLightSet; grown/packed/uploaded in the same cursor loop as
_clipSlotData and _lightSetData; deleted in Dispose. Mode-1 draws
(EnvCellRenderer) never read binding=6 — the sun loop is inside the
uLightingMode==0 uniform-control-flow branch.
AP-43 divergence register updated: the sun half is now per-draw (no
longer a residual). Residual narrowed to the unaudited ebp_2 test in
CellManager::ChangePosition (no observed impact).
Tests: WbDrawDispatcherIndoorFlagTests pins IndoorObjectReceivesTorches
for the spec §5 representative ids: 0xA9B40172 (Agent of Arcanum EnvCell)
→ 1; 0xA9B40031 (land sub-cell) → 0; 0xA9B4FFFF (landblock) → 0; null
(outdoor shell) → 0; plus the boundary cases 0x0100/0x00FF.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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