Gate-2 fallout chain: session 1's bare-id wedge poisoned ACE's save (the
client reported garbage cells while walking through walls), so session 2
logged in with (cell=0xA9B4013F inn interior, pos=(91.4,32.7)) — a
position that cell does not contain. Probe evidence: exactly one
[cell-transit] line all session; the player free-fell into an empty
world. Two holes, both fixed at the root:
1. CellTransit pick escape hatch — restores the #83/A1.7 + #90
verification that lived in PhysicsEngine.ResolveCellId before the
collide-then-pick rewrite moved membership into
BuildCellSetAndPickContaining: an indoor current cell that IS
hydrated but whose CellBSP no longer overlaps ANY part of the foot
sphere is a bogus claim (corrupt save, or walked out through an
unblocked gap). The portal BFS can never reach an exit portal from a
cell the sphere isn't in, so no candidates exist and the claim held
forever — wedging collision (ShadowObjectRegistry's #98 gate reads
"indoor primary" -> outdoor object sweep skipped), wall BSP, terrain,
and the render root. The pick now demotes to the outdoor column under
the sphere centre (the LandDefs.AdjustToOutside result already
computed for the pick — cross-block safe). Sphere-overlap
(BSPQuery.SphereIntersectsCellBsp, pseudo_c:317666 -> :323267), NOT
point-in: doorway push-back leaves the centre a few cm outside while
the sphere still overlaps — no demotion, #90's ping-pong stays dead.
An unhydrated cell cannot be verified — stale beats null while
streaming hydrates (retail-equivalent: stale curr_cell kept when the
pick finds nothing).
2. PlayerModeAutoEntry spawn-ground hold — player-mode entry now waits
for the terrain under the spawn position to stream in
(isSpawnGroundReady predicate, K.2 pattern). Entering earlier
integrates gravity against an empty world: indoor-claimed spawns got
no floor from any source and free-fell into the void; outdoor spawns
raced hydration by ~1s every login. Retail never has this state (it
loads cells synchronously) — the hold is the async-streaming
equivalent of that invariant. With the hold, the entry snap
(Resolve, stepUp=100) runs against hydrated cell floors + terrain
and re-seats a corrupt save's claim immediately.
Tests: IndoorSeed_SphereFullyOutsideHydratedCell_DemotesToOutdoorColumn
(the gate-2 wedge shape, red pre-fix), straddle + no-BSP guards (the #90
hysteresis and stale-beats-null), TryEnter_Armed_SpawnGroundNotReady_
DoesNotFire. Full suite: 294+218+420 green; Core 1375 green + the same
4 pre-existing door/#99-era failures + 1 skip.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The player's outdoor cell froze at the last in-block cell the moment they
walked over a landblock boundary (10,449-frame playerCell freeze in the
2026-06-09 capture; whole neighbouring-block interiors unenterable, plus
the running-distortion from the stale render anchor). Root cause: the
add_all_outside_cells port clamped BOTH the candidate proposal and the
find_cell_list containing-cell pick to the current landblock's 8x8 grid,
in a frame that silently assumed the current block sits at world origin.
One step over the line -> zero candidates -> FindCellSet returns
currentCellId forever.
Retail has no such clamp. Its cell math runs in a GLOBAL landcell grid
(lcoord 0..2039 spanning the map): get_outside_lcoord = blockid_to_lcoord
+ floor(blockLocalPos/24) with no bounds besides the map edge, and
lcoord_to_gid re-derives the landblock id from the lcoord's upper bits —
crossings are inherent, never special-cased.
The fix, decomp-cited throughout:
- New AcDream.Core.Physics.LandDefs: in_bounds (pc:68509),
blockid_to_lcoord (pc:68520), inbound_valid_cellid (pc:163438),
gid_to_lcoord (pc:163500), lcoord_to_gid (pc:171859),
get_outside_lcoord (pc:438690), adjust_to_outside (pc:438719).
Cross-checked against ACE LandDefs.cs; three artifacts documented and
avoided: BN's int8_t mis-render of block_y, BN's dropped 192f
BlockLength constant, and ACE add_cell_block's "FIXME!" same-block
guard (an ACE divergence, not retail).
- CellTransit.AddAllOutsideCells rewritten as the faithful sphere
variant (pc:317499 @0x00533630): adjust_to_outside re-seats the
(cell, position) pair cross-block, check_add_cell_boundary (pc:317229)
adds up to 3 neighbours by global lcoord, add_outside_cell (pc:317056)
has no same-block filter. adjust_to_outside failure breaks the sphere
loop (pc:533699 verbatim).
- BuildCellSetAndPickContaining: the outdoor containing-cell pick is now
the global XY-column under the sphere centre (AdjustToOutside), not
the [0,8)-clamped current-prefix reconstruction. Interior-wins order
and current-cell-first hysteresis unchanged.
- World->block-local frame conversion via the landblock origin already
registered in CellGraph (new TryGetTerrainOrigin); Zero fallback
preserves the legacy anchor-block assumption for unregistered terrain.
- Cross-landblock building entry comes free: the candidate snapshot now
contains neighbour-block landcells, so GetBuilding/CheckBuildingTransit
fire for cottages across the line (the capture's one failing entry).
Investigated FIRST per the pickup brief: the b3ce505#98 stopgap gate is
definitively exonerated — it is a collision-object query gate that fires
only for indoor primary cells; no membership path touches
ShadowObjectRegistry.
Tests: 31 new (25 LandDefs conformance incl. capture-geometry goldens
0xA9B40031 -> 0xA9B30038/0xA9B30034 and the northbound return; 4
AddAllOutsideCells cross-block; 3 FindCellSet membership goldens incl.
the non-anchor-frame origin conversion). Full suite: 294+218+420 green;
Core 1369 green + the 4 pre-existing door/#99-era failures + 1 skip
(unchanged from baseline).
Pseudocode + artifact notes:
docs/research/2026-06-09-landdefs-outside-cells-pseudocode.md.
Remaining acceptance: live boundary walk with ACDREAM_PROBE_CELL=1
(ISSUES.md #106).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Port CObjCell::find_cell_list (acclient_2013_pseudo_c.txt:308742) faithfully:
- build candidates into an ordered CellArray with the CURRENT cell at index 0
(add_cell @308766);
- EXPAND via a single forward walk over the growing array, mirroring retail's
for(i=0;i<num_cells;i++) cells[i].find_transit_cells loop (308775-308785),
replacing the order-losing Queue/visited BFS;
- PICK in array order with interior-wins-break (308788-308825): current cell at
index 0 wins a boundary straddle, so membership no longer ping-pongs.
Deletes the 5ca2f44 current-first pre-check (the ordered array subsumes it for every
seed). Keeps its guard test (TwoOverlappingCells_CurrentCellWinsTheStraddle) + adds
two conformance tests (current-cell-first ordering; interior-wins over outdoor
fallback). Membership net: 45 pass. Decomp finding: retail stability is emergent from
the ordered pick + carried seed, not a separate portal-crossing detector — see
docs/research/2026-06-03-cell-membership-ordered-cellarray-pseudocode.md.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The flap R1 exposed is a cell-membership ping-pong: the find_cell_list containing-
cell pick (CellTransit.BuildCellSetAndPickContaining) iterated an UNORDERED HashSet
and returned the first interior cell whose BSP contains the sphere center, with no
preference for the current cell. Retail CObjCell::find_cell_list adds the current
cell at index 0 (add_cell, pc:308766) and iterates current-first with interior-wins-
break (pc:308791-308819) — you STAY in your current cell until the center genuinely
leaves it. acdream's HashSet dropped that ordering; once the candidate set churns at
a boundary the enumeration can surface a neighbour before the current cell → the
ping-pong. Restore the explicit, deterministic current-cell-first test (retail's
index-0 hysteresis). + a two-direction regression guard (current cell wins the
straddle).
Diagnosed from the existing [cell-transit] walk log (no new probing): room flips are
the pick non-determinism; stairs flips additionally show the foot Z oscillating
~0.2m/tick (a separate stairs-physics residual, #98 family, to verify after this).
The 2 DoorBugTrajectoryReplay failures are PRE-EXISTING (verified: they fail without
this change too) — 2 of the handoff's '3 door-collision apparatus / A6.P5'.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
CellTransit.AddAllOutsideCells assumed sphere coords were absolute world
coords (subtracting lbXf = 0xA9 * 192 = 32448 from the sphere position).
Production has used landblock-local coords since Phase A.1
(streaming-center landblock at world origin), so the subtraction
produced localX = -32316, gridX = -1346 → out-of-range → early return
→ ZERO outdoor cells added.
For outdoor primary cells the bug was masked by GetNearbyObjects's
radial sweep. For indoor primary cells (where #98 gates the outdoor
sweep), the door's outdoor cell 0xA9B40029 never reached
portalReachableCells, the door's BSP was never queried, and the player
walked through Holtburg cottage doors unimpeded.
Fix: AddAllOutsideCells treats worldSphereCenter as landblock-local
directly. Matches retail CLandCell::add_all_outside_cells which uses
the per-cell 6-byte landblock-relative position struct.
Existing CellTransitAddAllOutsideCellsTests + CellTransitFindCellSetTests
updated to use landblock-local sphere coords (they were the only callers
using the world-coord convention; production never did).
Apparatus shipped:
- DoorBugTrajectoryReplayTests — live-capture-driven replay harness
that pinpointed the bug per-field at unit-test speed (<500ms iteration)
- AddAllOutsideCells_LandblockLocalSphere_AddsDoorOutdoorCell — direct
unit test that demonstrates the fix
- FindTransitCellsSphere_IndoorExitPortal_AddsOutsideForCapturedSpherePos
— verifies cell-portal traversal at the captured sphere position
- DoorSetupGfxObjInspectionTests.HoltburgCottage_CellPortals_DatInspection
— dat-direct EnvCell + Environment.Cells + portal-poly inspector
- Fixture: tests/AcDream.Core.Tests/Fixtures/door-bug/live-capture.jsonl
(tick 13558 walkthrough + tick 22760 outdoor block)
Visual verification (user-driven at Holtburg cottage door, ~50cm off-center):
- outside→inside RUN: now BLOCKS (was: walks through)
- outside→inside WALK: presumed blocks (not retested)
- inside→outside RUN: PARTIAL — body intersects door, sphere slides through
- inside→outside WALK: same partial behavior
The remaining inside→outside asymmetry is a SEPARATE bug in BSP
collision response for two-sided polygons. The [bsp-test] probe now
fires 245 times for the door entity from indoor (was 0 pre-fix) —
door IS being queried; the BSP polygon-level collision response is
the new bug. Handoff at
docs/research/2026-05-25-door-bug-partial-fix-shipped.md.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Triage step from the plan at C:\Users\erikn\.claude\plans\
i-did-some-work-sharded-acorn.md. Four sessions on issue #98 left the
worktree dirty with ~1352 LOC of mixed work. This commit splits the
work into "keep" (defensible + diagnostic) and "drop" (failed
experiments), then commits the keep set with the drops removed.
Plan asked for three commits (diag / fix / revert); consolidated to one
because the diagnostic emits in TransitionTypes.cs are tightly
interleaved with the multi-sphere CellTransit calls and the CellId
switch. Hunk-level splitting in those files for marginal bisect
granularity didn't justify the misclick risk.
Reverted entirely (failed experiments per slice 7 handoff):
- src/AcDream.Core/Physics/PhysicsDataCache.cs — neg-poly storage
fields (Stippling, PosSurface, NegSurface, HasNegativeSide,
IsNegativeSide, NegativeSide).
- src/AcDream.Core/Physics/ShadowObjectRegistry.cs — isBuilding flag
propagation through Register / ShadowEntry.
- tests/AcDream.Core.Tests/Physics/BSPQueryTests.cs — 165 lines of
PolygonWithNegativeSide_* tests.
- tests/AcDream.Core.Tests/Physics/ShadowObjectRegistryTests.cs —
isBuilding propagation tests.
- src/AcDream.Core/World/WorldEntity.cs — IsLandblockBuilding field
(no consumer once ShadowObjectRegistry.isBuilding is gone).
- src/AcDream.Core/World/LandblockLoader.cs — IsLandblockBuilding=true
setter on building entities (kept BuildBuildingTerrainCells).
- src/AcDream.App/Rendering/GameWindow.cs — isBuilding: arg passed to
ShadowObjects.Register.
- src/AcDream.Core/Physics/BSPQuery.cs — TryAdjustWalkableSide /
IsWalkableAt helpers, their callers, the Path 5 / Path 6 neg-poly
branch split, the BldgCheck-tied clearCell conditional, and the
neg-poly ResolveCellPolygons writes.
- src/AcDream.Core/Physics/PhysicsDiagnostics.cs — neg-poly fields
in the poly-dump format.
- src/AcDream.Core/Physics/TransitionTypes.cs — SpherePath.BldgCheck +
SpherePath.HitsInteriorCell fields and every consumer, the
savedBldgCheck try/finally around FindCollisions, and the neg-poly
format additions to the dump-on-error helper.
- src/AcDream.Core/Physics/CellTransit.cs — FindCellSet overloads
with hitsInteriorCell out-param and the BuildCellSetAndPickContaining
out-param threading.
Kept (defensible correctness fixes + diagnostic infrastructure):
- src/AcDream.App/Rendering/GameWindow.cs — render-vs-physics cell
origin split: the 0.02m render lift no longer leaks into physics
BSP caching. lb.BuildingTerrainCells threaded into LandblockMesh.Build.
- src/AcDream.Core/World/LoadedLandblock.cs — BuildingTerrainCells
record field.
- src/AcDream.Core/World/LandblockLoader.cs — BuildBuildingTerrainCells
(cy*8+cx from LandBlockInfo.Buildings).
- src/AcDream.Core/Terrain/LandblockMesh.cs — hiddenTerrainCells
param that collapses owned-cell triangles to a zero-area degenerate.
- src/AcDream.App/Streaming/{GpuWorldState,LandblockStreamer}.cs —
mechanical BuildingTerrainCells threading through LoadedLandblock
reconstructions.
- src/AcDream.Core/Physics/CellTransit.cs — multi-sphere
FindTransitCellsSphere variant + multi-sphere AddAllOutsideCells +
FindCellSet(IReadOnlyList<Sphere>, …) overload + the
BSPQuery.SphereIntersectsCellBsp call for loaded neighbours. Matches
retail CObjCell::find_cell_list / CEnvCell::find_transit_cells.
- src/AcDream.Core/Physics/TransitionTypes.cs — multi-sphere FindCellSet
call site, retail-faithful CellId switch after CheckOtherCells, the
outdoor-landcell terrain-walkable fallback in CheckOtherCells, and
the full diagnostic suite ([step-walk], [walkable-nearest],
[issue98-walkable-detail], [cell-set-summary], LastBspHitPoly
emits).
- src/AcDream.Core/Physics/PhysicsDiagnostics.cs — ProbeStepWalkEnabled
gate (ACDREAM_PROBE_STEP_WALK=1) + LogStepWalk helper + FormatVector
/ FormatPlane utilities. All emit-gated.
- src/AcDream.Core/Physics/BSPQuery.cs — diagnostic emits to
LastBspHitPoly at four sites in SphereIntersectsPolyInternal /
the placement adjustment path.
- Test files for the kept work: CellTransitFindCellSetTests,
CellTransitFindTransitCellsSphereTests, PhysicsDiagnosticsTests,
TransitionCheckOtherCellsTests, LandblockMeshTests,
LandblockLoaderTests.
Verification:
- dotnet build: green, 0 errors, 3 pre-existing warnings.
- dotnet test: 1156 passed + 8 failed (baseline was 1148 + 8 pre-
existing; the +8 passing are the new tests for the kept defensible
work). Same 8 pre-existing failures, no new regressions.
Backup of pre-triage worktree state in stash@{0}.
A6.P3 #98 is still open; this is the apparatus-prep step, not a fix.
Next: cell-dump probe (Step 2 of the plan).
Refactors FindCellList to delegate to a private helper
(BuildCellSetAndPickContaining) that returns BOTH the containing cell
id AND the full candidate HashSet. Public surface gains a new
FindCellSet overload; existing FindCellList behavior is unchanged.
Used by the upcoming Transition.CheckOtherCells (Phase A4) to iterate
every cell the sphere overlaps for per-cell BSP collision. Mirrors
retail's CObjCell::find_cell_list filling both cell_array AND var_4c
at acclient_2013_pseudo_c.txt:272725.
Three new unit tests cover sphere-fully-inside-primary,
sphere-straddling-portal, and outdoor-seed-neighbour-landcells cases.
Spec: docs/superpowers/specs/2026-05-20-phase-a4-multi-cell-bsp-design.md
Plan: docs/superpowers/plans/2026-05-20-phase-a4-multi-cell-bsp.md
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Erik