The retail-faithful exemption block at the top of
CPhysicsObj::FindObjCollisions
(acclient_2013_pseudo_c.txt:276782-276839,276971), ported line-for-
line as a small static helper.
Behaviour now matches retail:
- Two non-PK players walk through each other.
- Two PK players collide.
- Two PKLite players collide.
- Mismatched PK status (PK vs non-PK, PK vs PKLite) — exempt.
- Impenetrable target ("Free" PK status) — always collides.
- Player vs creature/NPC — always collides (this is what closes the
user-facing complaint that walking into a Holtburg vendor was
walking through them).
- Mover with IGNORE_CREATURES — walks through creature targets.
- Viewer (camera ray) — walks through creatures.
- Target with ETHEREAL+IGNORE_COLLISIONS — universally exempt.
CollisionExemption.ShouldSkip(targetState, targetFlags, moverState)
- new file src/AcDream.Core/Physics/CollisionExemption.cs.
- 13-test matrix covering every documented case
(CollisionExemptionTests.cs).
- Static + pure → cheap to call from the hot path.
Wiring:
- TransitionTypes.FindObjCollisions: after broadphase distance
reject, call ShouldSkip on the obj and ObjectInfo.State; on true,
`continue`. Static landblock entries (State=0, Flags=None) fall
through cheaply — no behavior change for static collision.
- PhysicsEngine.ResolveWithTransition: new optional moverFlags
parameter (default None for back-compat). PlayerMovementController
passes ObjectInfoState.IsPlayer; remote dead-reckoning leaves it
None (matches non-player movers, no PvP exemption applies).
- PK/PKLite/Impenetrable bits for the LOCAL player are not yet
sourced from PlayerDescription's PlayerKillerStatus property —
that's a follow-up. Default "non-PK player" matches ACE's
character-creation default and the user's +Acdream test
character.
Cross-checked against ACE PhysicsObj.cs:381-405 (line-for-line C# port
of the same retail block). Only intentional divergence: ACE adds
state.HasFlag(IsImpenetrable) (mover-impenetrable) to the collide list;
retail's pseudo-C only checks the target — acdream follows retail.
dotnet build green, dotnet test 1467 passing (+13 new). Live test:
+Acdream walking into Holtburg vendors now stops at their cylinder;
walking through small plants still passes (Commit B's phantom skip).
Closes the live-entity collision arc: A (plumbing) + B (registration)
+ C (exemption).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>