Ports retail's missile Position handling into the canonical Runtime
placement owner instead of the deleted ApplyAuthoritativePosition
short-circuit. The Create/residence-window halves of the projectile
pipeline (RuntimeProjectile binding, TryBind's adopted-body branch,
the collision/shadow registration) were already canonical from prior
slices; this closes the remaining gap — how an ACCEPTED Position for
an in-flight missile is classified, placed, and presented.
Byte-decode (Step 1 hard gate, before any code was written):
CPhysicsObj::MoveOrTeleport @0x00516330-0x00516438 disassembled from
the PDB-paired binary (Capstone, x86 32-bit thiscall). `ret 0x10`
establishes four stack args; [esp+0x7c] (arg5, the velocity pointer)
is never referenced in any of the three branches (teleport/near/far).
The retail reviewer independently reproduced this by searching the
whole function body for the `24 7c` mod/rm+disp8 encoding a
`[esp+0x7c]` read would require and found zero occurrences. This
retired a fabricated `?? Vector3.Zero` fallback in the deleted method
— retail's PositionPack::UnPack initializes an absent velocity to
zero and MoveOrTeleport never installs it; the projectile's Vector
channel (RuntimeProjectilePhysicsUpdater.ApplyAuthoritativeVector)
remains the sole velocity authority for a missile. D-P5 in the
contract; the Runtime seam commits no velocity from the Position
packet at all.
The unbound-missile fix: RuntimeEntityObjectLifetime's
ClassifyRemoteAcceptedPosition now derives ProjectileAuthoritative
from a CONJUNCTIVE predicate — the Missile bit AND a bound
RuntimeProjectile whose Body is the canonical PhysicsBody — never the
bit alone. Retail places every non-player CPhysicsObj unconditionally
(there is no missile-specific placement gate in MoveOrTeleport or its
callers), so an unbindable or not-yet-bound missile taking the
ordinary remote tail is retail-faithful, not a fallback: the earlier
bit-only discriminator would have silently frozen it instead.
AP-141 records this as a deliberate, recorded divergence, not
fidelity. Retail mechanically WOULD arm a missile's ConstrainTo leash
on any nonzero MoveOrTeleport return: HandleReceivedPosition
@0x00453FD0's only kind test is player-vs-not, ConstrainTo
@0x00454272 has no kind test of its own, and CPhysicsObj::ConstrainTo
@0x00510520 creates a PositionManager on demand via
MakePositionManager @0x00510523 if one doesn't exist. acdream
deliberately does not construct that EntityPhysicsHost/
PositionManager/InterpolationManager chain for a ballistic body — the
route-5b split the C4 route 5 contract rejected — so a live missile
never shows an armed leash and never catches up via the near/
UnroutedCatchUp policy. This divergence is safe specifically because
ACE never sends UpdatePosition for a missile
(references/ACE/Source/ACE.Server/WorldObjects/WorldObject_Tick.cs:
333-334, SendUpdatePosition() commented out inside the
PhysicsState.Missile branch at :265) — every half of this row is
deterministic-test-gated only, never exercised against a real server.
AP-141 also records the surviving ConstrainTo re-anchor divergence
under clause (b): for the adopted-body case (TryBind's shared-body
branch — an ordinary remote whose Missile bit is set by a later
State packet, so it still carries a live RemoteMotion), acdream now
ports retail's teleport-branch and far-branch StopInterpolating
action (Interp.Clear()), but never re-arms or re-anchors the
inherited ConstrainTo leash the way retail's HandleReceivedPosition
@0x00454254/@0x00454272 does on every nonzero return. The risk
column's earlier wording — that a stale leash "would drag the body
toward a stale anchor" — was wrong and is retracted in this same
commit: ConstraintManager.ConstraintPos is write-only in both retail
and the port (never read by AdjustOffset), and
ConstraintManager::adjust_offset @0x00556180 only tapers or zeroes an
already-composed per-tick offset while InContact — a leash brakes
motion the interp/sticky chain already produced, it cannot pull
anything toward the anchor. The real residual is one tick of un-reset
brake accumulator, contact-gated, and it cannot move an airborne
far-snapped missile at all (the clamp branch does not run while
airborne).
NO CONNECTED GATE EXISTS for this route, by design: ACE never sends a
missile UpdatePosition (see above), so retail's own server never
exercises this code path in play. Every proof obligation here is
test-gated only — Runtime and App-level fixtures constructing the
packet directly — never a live client/server capture.
Three review rounds closed 8 MAJOR findings before this landed:
round 1 (A1 App discarded the seam's status; A2/R1 silent swallow on
an unbound missile; A3/R2 the adopted-body teleport_hook never
wired; A4/A5 zero Runtime/App test coverage); round 2 (a
ParentCellId regression introduced by round 1's own R6 finding,
which the retail reviewer retracted the following round as factually
wrong — the fix here is the REVERT to record.FullCellId, not the
relocation round 1 shipped; B2 the far-branch StopInterpolating skip
never extended to the adopted-body case; residual App/Runtime store-
path coverage; a per-packet closure contradicting the file's own
#315 cached-delegate pattern). Round 3 closed on coverage alone (no
defect): the Advance() retry arm's projectile branch — added at
round 2, semantically reordered at round 2's B5 fix (skip prediction
invalidation on a re-parked Contention, since it writes nothing) —
had never been executed by any test; two new tests drive it directly
and are sabotage-verified against both the reordering and the
retry-arm's own SyncProjectilePresentation call site. The one
recorded defect this campaign produced (the ParentCellId regression)
was caused by complying with a review finding that its own author
later retracted — the standing lesson recorded for future rounds is
that review findings are evidence to re-verify against the code, not
commands to obey unconditionally.
Complete Release suite: 11,063 passed / 4 skipped / 0 failed
(baseline 11,036 at 30d3d114, +27 new tests across this campaign).
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Erik