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feat(L.2g-S1): retail movement-event staleness gate (DEV-6)

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Port retail's three-stamp inbound gate for 0xF74C UpdateMotion:

- MotionSequenceGate (Core/Physics): CPhysicsObj::is_newer (0x00451ad0)
  wraparound u16 compare, verbatim per ACE PhysicsObj.is_newer (the BN
  pseudo-C setcc returns are garbled; ACE + branch structure are the
  oracle). Gates: INSTANCE_TS at dispatch (stale incarnation drops
  before any stamp is touched), MOVEMENT_TS strictly-newer (stamped
  BEFORE the server-control check, per CPhysics::SetObjectMovement
  0x00509690), SERVER_CONTROLLED_MOVE_TS drop-when-stored-newer.
- Seed from CreateObject's PhysicsDesc timestamp block (index 1 =
  ObjectMovement now parsed; ACE WorldObject_Networking.cs:411-420
  order) — without seeding, entities whose movement sequence is past
  0x8000 at spawn would drop every UM against a zero stamp.
  Adopt-on-first / advance-only-after, so the #138 rehydrate replay of
  retained spawns cannot regress live stamps.
- UpdateMotion + EntitySpawn now carry instance/movement/serverControl
  sequences + isAutonomous (was parsed-past; isAutonomous feeds the
  S2 funnel's last_move_was_autonomous). Gate wired at the top of
  OnLiveMotionUpdated before any state mutation; [UM_STALE] diag under
  ACDREAM_DUMP_MOTION / ACDREAM_REMOTE_VEL_DIAG; gate dropped with the
  entity on DeleteObject.

Register: AD-32 added (adopt-newer-incarnation instead of retail's
QueueBlobForObject); TS-26 updated (UM side closed, UP side open).
Deviation map: docs/research/2026-07-02-inbound-motion-deviation-map.md.

19 new gate tests + parser coverage; full suite 3276 green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
This commit is contained in:
Erik 2026-07-02 15:44:06 +02:00
parent fb3ee0544a
commit cb74e64343
9 changed files with 464 additions and 18 deletions
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10
src/AcDream.Core.Net/Messages/CreateObject.cs
View file

@ -119,6 +119,9 @@ public static class CreateObject
ushort TeleportSequence = 0,
ushort ServerControlSequence = 0,
ushort ForcePositionSequence = 0,
// L.2g S1 (DEV-6): ObjectMovement stamp (timestamp block index 1)
// seeds MotionSequenceGate's MOVEMENT_TS at spawn.
ushort MovementSequence = 0,
uint? PhysicsState = null,
uint? ObjectDescriptionFlags = null,
// L.3b (2026-04-30): per-object friction + elasticity from the
@ -531,11 +534,13 @@ public static class CreateObject
if ((physicsFlags & PhysicsDescriptionFlag.DefaultScriptIntensity) != 0) pos += 4;
// 9 sequence timestamps, always present at end of PhysicsData.
// Indices per holtburger: 0=position, 4=teleport, 5=serverControl,
// 6=forcePosition, 8=instance.
// PhysicsTimeStamp enum order (acclient.h:6084; ACE
// WorldObject_Networking.cs:411-420): 0=position, 1=movement,
// 4=teleport, 5=serverControl, 6=forcePosition, 8=instance.
if (body.Length - pos < 9 * 2) return PartialResult();
var seqSpan = body.Slice(pos, 9 * 2);
ushort instanceSeq = BinaryPrimitives.ReadUInt16LittleEndian(seqSpan.Slice(8 * 2));
ushort movementSeq = BinaryPrimitives.ReadUInt16LittleEndian(seqSpan.Slice(1 * 2));
ushort teleportSeq = BinaryPrimitives.ReadUInt16LittleEndian(seqSpan.Slice(4 * 2));
ushort serverControlSeq = BinaryPrimitives.ReadUInt16LittleEndian(seqSpan.Slice(5 * 2));
ushort forcePositionSeq = BinaryPrimitives.ReadUInt16LittleEndian(seqSpan.Slice(6 * 2));
@ -847,6 +852,7 @@ public static class CreateObject
return new Parsed(guid, position, setupTableId, animParts,
textureChanges, subPalettes, basePaletteId, objScale, name, itemType, motionState, motionTableId,
instanceSeq, teleportSeq, serverControlSeq, forcePositionSeq,
movementSeq,
physicsState, objectDescriptionFlags,
friction, elasticity,
IconId: iconId,

39
src/AcDream.Core.Net/Messages/UpdateMotion.cs
View file

@ -57,10 +57,21 @@ public static class UpdateMotion
/// command is nullable because the <c>ForwardCommand</c> flag may be
/// unset in the InterpretedMotionState; the stance is always present
/// (even if 0, meaning "no specific stance").
///
/// <para>L.2g S1 (DEV-6): the three staleness stamps + autonomy flag are
/// exposed for the retail gate (<see cref="AcDream.Core.Physics"/>
/// <c>MotionSequenceGate</c>) — retail compares them against
/// <c>update_times[INSTANCE_TS/MOVEMENT_TS/SERVER_CONTROLLED_MOVE_TS]</c>
/// and stores <c>last_move_was_autonomous</c>
/// (<c>CPhysics::SetObjectMovement</c> 0x00509690).</para>
/// </summary>
public readonly record struct Parsed(
uint Guid,
CreateObject.ServerMotionState MotionState);
CreateObject.ServerMotionState MotionState,
ushort InstanceSequence,
ushort MovementSequence,
ushort ServerControlSequence,
bool IsAutonomous);
/// <summary>
/// Parse a reassembled UpdateMotion body. <paramref name="body"/> must
@ -82,8 +93,11 @@ public static class UpdateMotion
uint guid = BinaryPrimitives.ReadUInt32LittleEndian(body.Slice(pos));
pos += 4;
// ObjectInstance sequence (u16) — tracked but not used for pose.
// ObjectInstance sequence (u16) — retail's dispatch-level
// INSTANCE_TS staleness gate compares this against the object's
// known incarnation (DispatchSmartBoxEvent case 0xF74C).
if (body.Length - pos < 2) return null;
ushort instanceSequence = BinaryPrimitives.ReadUInt16LittleEndian(body.Slice(pos));
pos += 2;
// MovementData header: u16 movementSequence, u16 serverControlSequence,
@ -102,8 +116,18 @@ public static class UpdateMotion
// Previous version mistakenly reserved 8 bytes here, which shifted
// every subsequent field by 2 and made every remote-char UpdateMotion
// decode as garbage (stance read from the packed-flags dword).
//
// L.2g S1 (DEV-6): the header fields feed retail's
// CPhysics::SetObjectMovement staleness gates + the
// last_move_was_autonomous store, so parse them instead of
// skipping.
if (body.Length - pos < 6) return null;
pos += 6;
ushort movementSequence = BinaryPrimitives.ReadUInt16LittleEndian(body.Slice(pos));
pos += 2;
ushort serverControlSequence = BinaryPrimitives.ReadUInt16LittleEndian(body.Slice(pos));
pos += 2;
bool isAutonomous = body[pos] != 0;
pos += 2; // u8 isAutonomous + Align(4) pad byte
// movementType u8, motionFlags u8, currentStyle u16
if (body.Length - pos < 4) return null;
@ -139,7 +163,7 @@ public static class UpdateMotion
// MovementInvalid branch, just reached via the header'd path.
// Includes the Commands list (MotionItem[]) that carries
// Actions, emotes, and other one-shots not in ForwardCommand.
if (body.Length - pos < 4) return new Parsed(guid, new CreateObject.ServerMotionState(currentStyle, null, MovementType: movementType));
if (body.Length - pos < 4) return new Parsed(guid, new CreateObject.ServerMotionState(currentStyle, null, MovementType: movementType), instanceSequence, movementSequence, serverControlSequence, isAutonomous);
uint packed = BinaryPrimitives.ReadUInt32LittleEndian(body.Slice(pos));
pos += 4;
uint flags = packed & 0x7Fu;
@ -162,13 +186,13 @@ public static class UpdateMotion
if ((flags & 0x1u) != 0)
{
if (body.Length - pos < 2) return new Parsed(guid, new CreateObject.ServerMotionState(currentStyle, null, MovementType: movementType));
if (body.Length - pos < 2) return new Parsed(guid, new CreateObject.ServerMotionState(currentStyle, null, MovementType: movementType), instanceSequence, movementSequence, serverControlSequence, isAutonomous);
currentStyle = BinaryPrimitives.ReadUInt16LittleEndian(body.Slice(pos));
pos += 2;
}
if ((flags & 0x2u) != 0)
{
if (body.Length - pos < 2) return new Parsed(guid, new CreateObject.ServerMotionState(currentStyle, null, MovementType: movementType));
if (body.Length - pos < 2) return new Parsed(guid, new CreateObject.ServerMotionState(currentStyle, null, MovementType: movementType), instanceSequence, movementSequence, serverControlSequence, isAutonomous);
forwardCommand = BinaryPrimitives.ReadUInt16LittleEndian(body.Slice(pos));
pos += 2;
}
@ -244,7 +268,8 @@ public static class UpdateMotion
moveToParameters,
moveToSpeed,
moveToRunRate,
moveToPath));
moveToPath),
instanceSequence, movementSequence, serverControlSequence, isAutonomous);
}
catch
{

25
src/AcDream.Core.Net/WorldSession.cs
View file

@ -109,7 +109,13 @@ public sealed class WorldSession : IDisposable
uint? Priority = null,
int? Structure = null,
int? MaxStructure = null,
float? Workmanship = null);
float? Workmanship = null,
// L.2g S1 (DEV-6): PhysicsDesc timestamp-block stamps that seed the
// per-entity MotionSequenceGate (retail update_times INSTANCE_TS /
// MOVEMENT_TS / SERVER_CONTROLLED_MOVE_TS).
ushort InstanceSequence = 0,
ushort MovementSequence = 0,
ushort ServerControlSequence = 0);
/// <summary>Fires when the session finishes parsing a CreateObject.</summary>
public event Action<EntitySpawn>? EntitySpawned;
@ -131,7 +137,11 @@ public sealed class WorldSession : IDisposable
/// </summary>
public readonly record struct EntityMotionUpdate(
uint Guid,
CreateObject.ServerMotionState MotionState);
CreateObject.ServerMotionState MotionState,
ushort InstanceSequence,
ushort MovementSequence,
ushort ServerControlSequence,
bool IsAutonomous);
/// <summary>
/// Fires when the session parses a 0xF74C UpdateMotion game message.
@ -825,7 +835,10 @@ public sealed class WorldSession : IDisposable
parsed.Value.Priority,
parsed.Value.Structure,
parsed.Value.MaxStructure,
parsed.Value.Workmanship));
parsed.Value.Workmanship,
InstanceSequence: parsed.Value.InstanceSequence,
MovementSequence: parsed.Value.MovementSequence,
ServerControlSequence: parsed.Value.ServerControlSequence));
}
}
else if (op == DeleteObject.Opcode)
@ -862,7 +875,11 @@ public sealed class WorldSession : IDisposable
{
MotionUpdated?.Invoke(new EntityMotionUpdate(
motion.Value.Guid,
motion.Value.MotionState));
motion.Value.MotionState,
motion.Value.InstanceSequence,
motion.Value.MovementSequence,
motion.Value.ServerControlSequence,
motion.Value.IsAutonomous));
}
}
else if (op == UpdatePosition.Opcode)