Verbatim port of CObjCell::find_cell_list (Ghidra 0x0052b4e0, pc:308742)
as invoked by calc_cross_cells / calc_cross_cells_static (0x00515230 /
0x00515160) - the flood retail runs at SHADOW REGISTRATION time, minus
the containing-cell pick (registration passes a null out-cell):
- Seed: indoor -> exactly that one cell (added even when unloaded, like
retail's null-pointer add_cell; the walk is then skipped per the
0052b576 seed-pointer gate); outdoor -> block-crossing
AddAllOutsideCells.
- Growing-array walk: indoor cells via FindTransitCellsSphere
(sphere-vs-neighbor-BSP admission; exterior straddle -> outside cells
once per walk, retail CELLARRAY.added_outside); outdoor cells via the
CLandCell leg (0x00533800) = add_all_outside_cells (same once-guard)
+ the building bridge CSortCell -> CBuildingObj ->
check_building_transit (0x00534060/0x006b5230/0x0052c5d0) - how an
outdoor-positioned door reaches the vestibule's shadow list at
registration. No XY grid, no visibility lists (the spec's
VisibleCellIds rule was REFUTED by the WF1 verification).
- Static prune (do_not_load_cells, 0052b66e): indoor-seeded statics keep
only {seed} + seed.stab_list (VisibleCellIds) - also strips outdoor
cells, matching retail (interior statics never shadow into landcells;
outdoor spheres reach them through their own array's building bridge).
11 unit tests: seeds (indoor/outdoor/unloaded), neighbor-BSP admission,
building bridge incl. the C1 negative-portal-id gate, exterior straddle
on/off, static prune drop/keep, zero-sphere no-op.
Consumed by C3 (ShadowObjectRegistry rewrite).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
