Previous cellId-mask fix was necessary but insufficient: the engine
correctly identified the player as outdoor, but then immediately
transitioned to an indoor cell because a CellSurface floor polygon
covered the player's XY at a Z within stepUpHeight. The floor
polygon was a roof or upper floor of a nearby building that happens
to sit at terrain level — not a walkable indoor floor the player
should snap to.
Fix: outdoor→indoor transition now requires bestCellZ < terrainZ - 1.
A genuine indoor transition is into a cell whose floor is BELOW the
terrain surface (basement, ground floor of elevated building). Cells
at or above terrain Z are roofs/upper floors viewed from outside and
must not capture the player.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
ROOT CAUSE of the fall-through-ground bug. The currentlyIndoor check
compared the FULL 32-bit cell ID (0xA9B40001, includes landblock
prefix) against 0x0100. Every outdoor cell ID with a landblock
prefix is >= 0x0100, so the engine ALWAYS took the "stay indoors"
path, snapping the player to the nearest EnvCell floor at Z=66
instead of the outdoor terrain at Z=94.
ACE confirmed the bug: "AddWorldObjectInternal: couldn't spawn
+Acdream at 0xA9B40121 [84.2 37.7 66.0]" — we were sending the
server an indoor cell ID with a below-terrain Z position.
Fix: mask cellId with 0xFFFF before the indoor check (outdoor
cells are 0x0001–0x0040; indoor are 0x0100+; the high 16 bits
are the landblock prefix and must be stripped). Also mask the
returned targetCellId from CellSurface (which carries the full
EnvCell dat id) to just the cell index.
265 tests still green.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Three more fixes from the diagnostic dump:
1. Initial position: PhysicsEngine.Resolve was mapping the player
into an indoor EnvCell (foundry at Z=66) when they're standing
on outdoor terrain at Z=93+. The cell-containment check was too
aggressive for initial placement. Now uses the server-sent
position directly — the server already gave us a valid position.
2. Yaw unbounded: mouse delta accumulated without wrapping, growing
to 24+ radians. Now wraps to [-PI, PI] after every turn.
3. Turn command spam: MouseDeltaX > 0.5 threshold was too low for
raw pixel deltas. Any mouse jitter triggered turnCmd flips every
frame → stateChanged=True → MoveToState flood to the server.
Mouse turning now only affects yaw directly; turn COMMANDS only
come from A/D keyboard (matching retail client behavior where
mouse-look doesn't generate a TurnRight/TurnLeft command).
265 tests still green.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Combines TerrainSurface + CellSurface into a single Resolve() API
that handles outdoor terrain walking, indoor floor walking,
outdoor<->indoor cell transitions, step-height enforcement, and
ground detection.
Step-height blocks upward Z deltas exceeding the limit (walls,
cliffs); downhill movement is always accepted. Indoor transitions
pick the cell whose floor Z is closest to the entity's current Z
(handles multi-story buildings). Reports IsOnGround=false when
no landblock or surface covers the entity's position (gravity
applied by the caller).
One API mismatch fixed vs plan: plan encoded the upper 16 landblock
bits into the returned cell ID, but the tests assert the raw cell ID
(0x0100, <0x0100) — so Resolve returns targetCellId directly.
6 new tests covering flat terrain, slopes, step-height rejection,
indoor entry/exit, and void detection. 243 total, all green.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
