New mutator that overwrites cached PhysicsState bits on every shadow copy
of the named entity. The existing CollisionExemption.ShouldSkip(...) check
(acclient_2013_pseudo_c.txt:276782) reads the same cached field, so a
post-spawn ETHEREAL flip is now honored on the next resolver tick without
any resolver-path change.
Retail anchor: CPhysicsObj::set_state at acclient_2013_pseudo_c.txt:283044.
Slice 1 scopes to the bare state-write — retail's cosmetic side-effect
handlers (0x800 lighting, 0x20 nodraw, 0x4000 hidden) don't fire for the
ETHEREAL bit and stay deferred.
Three TDD tests cover: ETHEREAL flip from 0->0x4; unregistered-entity
no-op; entity spanning multiple cells gets all copies updated.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Plumbing-only foundation for the upcoming live-entity (NPC / monster
/ player) collision port. No behavior change — the new fields default
to zero/None so the 5 existing static-entity Register call sites in
GameWindow.cs are untouched.
Wire layer:
- CreateObject parser now surfaces PhysicsState (acclient.h:2815 —
ETHEREAL_PS=0x4, IGNORE_COLLISIONS_PS=0x10, HAS_PHYSICS_BSP_PS=0x10000,
...) which the parser previously dropped at line ~337 with a bare
`pos += 4`.
- CreateObject parser now surfaces ObjectDescriptionFlags (the retail
PWD._bitfield trailer per acclient.h:6431-6463), where
acclient_2013_pseudo_c.txt:406898-406918 ACCWeenieObject::IsPK /
IsPKLite / IsImpenetrable read bits 5 / 25 / 21 directly. Previously
read-and-discarded.
- WorldSession.EntitySpawn carries both new fields through to subscribers.
Physics layer:
- New `EntityCollisionFlags` enum (IsPlayer / IsCreature / IsPK /
IsPKLite / IsImpenetrable) + `FromPwdBitfield` helper. Bit
positions verified against retail's SetPlayerKillerStatus (
acclient_2013_pseudo_c.txt:441868-441890) which maps
PKStatusEnum→bitfield exactly: PK=0x4→bit5, PKLite=0x40→bit25,
Free=0x20→bit21.
- `ShadowEntry` extended with `State` (raw PhysicsState bits) +
`Flags` (decoded EntityCollisionFlags). Backward-compatible — all
five existing landblock-entity Register call sites omit them.
- `ShadowObjectRegistry.UpdatePosition(entityId, pos, rot, ...)` —
fast-path for the 5–10 Hz UpdatePosition (0xF748) stream the server
emits per visible entity. Reuses the entry's existing shape +
state + flags. Mirrors retail's CPhysicsObj::SetPosition
(acclient_2013_pseudo_c.txt:284276) which keeps the same shape and
re-registers cell membership.
- `ObjectInfoState` adds `IsPK = 0x800` and `IsPKLite = 0x1000`
matching retail's OBJECTINFO::state bits (acclient.h:6190-6194).
Used by Commit C's PvP exemption gate.
Tests:
- `EntityCollisionFlagsTests` — 7 tests covering empty / each bit
alone / PK+player combo / unrelated-bit ignore.
- `ShadowObjectRegistryTests` — 5 new tests: UpdatePosition moves
entry to new cell, preserves State/Flags, unregistered no-op,
Register stores State/Flags, defaults are zero/None.
- `CreateObjectTests` — 3 new tests verifying PhysicsState + PWD
bitfield (with PK / PKLite bit cases) parse and surface.
1454 → 1454 + 15 = covered by suite. dotnet build + dotnet test
green.
Foundation for Commit B (live-entity registration) and Commit C
(PvP exemption block in FindObjCollisions).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Replace simplified push-out with retail-faithful SlideSphere and
AdjustOffset from transition_pseudocode.md. Crease-projection between
collision normal and contact plane produces smooth wall-sliding.
Object collision uses proper rotation transform to object-local space.
SlideSphere (section 6): computes crease direction via cross product
of collision normal and contact plane normal, projects displacement
onto the crease, then applies the correction offset. Handles three
cases: crease exists, parallel same-direction, parallel opposing.
AdjustOffset (section 6): adds safety check to keep sphere above
contact plane by computing signed distance and pushing up along Z
when the sphere dips below.
FindObjCollisions: removes ad-hoc penetration push-out, now calls
SlideSphere after BSP hit detection for proper wall-slide behavior.
Also fixes: ShadowEntry gains Rotation field, tests updated to match
Register signature, unused variables removed from GameWindow.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Register static entities into terrain cells during streaming.
Transition system queries nearby objects and runs BSP collision.
Player can no longer walk through trees and buildings.
- ShadowObjectRegistry: 24m×24m cell index, Register/Deregister/
RemoveLandblock/GetNearbyObjects matching retail AC's approach
- PhysicsEngine: ShadowObjects property + DataCache wiring point;
RemoveLandblock now also clears shadow objects; TryGetLandblockContext
helper lets Transition resolve landblock id+offset for a world pos
- Transition.FindObjCollisions: queries registry, broad-phase sphere test,
narrow-phase BSPQuery.SphereIntersectsPoly in object-local space,
returns Slid on hit to redirect movement along the surface
- GameWindow.ApplyLoadedTerrainLocked: registers each static entity after
physics BSP data is cached; selects radius from BSP bounding sphere or
Setup.Radius; wires PhysicsDataCache into engine on OnLoad
- 16 new ShadowObjectRegistry unit tests, all 361 tests green
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
