feat(physics): R5-V4 behavioral slice — head stance dispatch (all mt) + #164 autonomy bit + mt-0 wire flags

Three unpack_movement parity items (facade deferred per the handoff's
own optional clause — see r5-wiring-handoff §V4 status):

1. HEAD style-on-change (0x00524440 @00524502-0052452c): both GameWindow
   routing heads (remote + player) now dispatch DoMotion(style, ctor
   defaults) when the UM's stance differs from the interp's current
   style, BEFORE the movement-type routing — for EVERY type. Previously
   style applied only through the mt-0 funnel copy, so a chase/turn UM
   (mt 6-9) carrying a stance change started the move in the OLD stance
   (a monster charged in NonCombat posture until the next mt-0). The
   RetailObserverTraceConformanceTests exclusion note updated — the
   trace filter stays (head calls can't appear in a
   MoveToInterpretedState replay) but the production gap it pointed at
   is closed.

2. #164 (closes): the action-replay loop threads each action's autonomy
   into the dispatch params (Autonomous = the 0x1000 splice, raw
   305982) — replayed actions enter the interpreted actions list with
   their real autonomy instead of ctor-default false.

3. mt-0 wire flags consumed (UpdateMotion parsed them since R4-V3):
   0x1 StickToObject → CPhysicsObj::stick_to_object port (0x005127e0:
   resolve target, PartArray radii — 0 when shapeless, guid-as-is for
   acdream's flat entity table — → PositionManager.StickTo; unresolvable
   target → no stick), at BOTH case-0 tails in retail order
   (@00524583-0052458e: funnel apply → stick → longjump flag);
   0x2 StandingLongJump → Motion.StandingLongJump, UNCONDITIONAL write
   (absent flag clears — retail @0052458e). ServerMotionState gains the
   StandingLongJump field.

Conformance: ChaseArm_WithStanceChange_AppliesStanceBeforeTheChase
(harness mirrors the routing-head dispatch) +
Actions_ReplayCarriesAutonomyIntoTheInterpretedList. Suite 4041 green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/ISSUES.md

@@ -398,7 +398,13 @@ retail; flat-ground landings unchanged; no micro-bounce death spiral
 
 ## #164 — UM action-replay dispatches drop the per-action Autonomous bit
 
-**Status:** OPEN (2026-07-03, filed during #161)
+**Status:** DONE (2026-07-04, R5-V4) — `DispatchInterpretedMotion` now threads
+the action's autonomy into the dispatch params (`Autonomous` = the 0x1000
+splice, raw 305982); the stored `InterpretedState.Actions` node carries the
+real autonomy. Conformance:
+`MotionInterpreterFunnelTests.Actions_ReplayCarriesAutonomyIntoTheInterpretedList`.
+(Move to Recently closed on next ISSUES tidy.) Original finding below.
+**Filed:** OPEN (2026-07-03, filed during #161)
 **Finding:** retail's `move_to_interpreted_state` action loop sets the
 dispatch params' Autonomous bit (0x1000) from each action's autonomy flag
 (raw 305982: `var_28 ^= ((autonomous << 0xc) ^ var_28) & 0x1000`), which

docs/research/2026-07-03-r5-managers/r5-wiring-handoff.md

@@ -111,6 +111,18 @@ commit.** **VISUAL GATE**: a sticky scenario (server /follow-style sticky moveto
 or a moving-platform stick) HOLDS the target instead of stopping-and-drifting.
 
 ### V4 (capstone) — MovementManager facade + #164 + head-stance dispatch + docs
+
+> **STATUS 2026-07-04: the three BEHAVIORAL items SHIPPED** (same session as
+> the V3 gates): head style-on-change at both GameWindow routing heads
+> (@00524502-0052452c, all movement types), #164 action-replay Autonomous
+> bit (raw 305982), mt-0 wire flags consumed (0x1 stick_to_object
+> 0x005127e0 → PositionManager.StickTo at both case-0 tails; 0x2 →
+> `Motion.StandingLongJump`, unconditional per @0052458e). Conformance:
+> stance-on-arm harness scenario + the autonomy funnel test; suite 4041
+> green. **The MovementManager facade DEFERRED to its own slice** (the
+> handoff's own "optional if the arc runs long" clause — this arc ran two
+> full gate cycles); it remains the structural capstone for a fresh
+> session, unblocked, spec below.
 - Collapse per-entity `Motion`+`MoveTo` into a `MovementManager` owner
   (structural; keep 183-case/funnel/moveto green UNMODIFIED). Optional if the
   arc runs long — the retirements above don't need it.

src/AcDream.App/Rendering/GameWindow.cs

@@ -4474,6 +4474,27 @@ public sealed class GameWindow : IDisposable
                     + delta.GetHeading());
     }
 
+    /// <summary>
+    /// R5-V4: retail <c>CPhysicsObj::stick_to_object</c> (0x005127e0) — the
+    /// mt-0 WIRE sticky (unpack_movement case 0 @00524589, gated on the
+    /// motionFlags 0x1 trailer guid): resolve the target, read its PartArray
+    /// radius/height (0 when shapeless — retail's null-PartArray arm), then
+    /// <c>PositionManager::StickTo</c>. Unresolvable target → no stick at
+    /// all (retail's GetObjectA-null path). Retail resolves the target's
+    /// top-level PARENT first (<c>parent ?? self</c>); acdream's entity
+    /// table is flat (no client-side parenting), so the guid is used as-is —
+    /// the same convention as RouteServerMoveTo's TopLevelId.
+    /// </summary>
+    private void StickToObjectFromWire(EntityPhysicsHost? host, uint targetGuid)
+    {
+        if (host is null)
+            return;
+        if (!_entitiesByServerGuid.TryGetValue(targetGuid, out var tgtEnt))
+            return;
+        var (radius, height) = GetSetupCylinder(targetGuid, tgtEnt);
+        host.PositionManager.StickTo(targetGuid, radius, height);
+    }
+
     private bool RemoveLiveEntityByServerGuid(uint serverGuid)
     {
         if (!_entitiesByServerGuid.TryGetValue(serverGuid, out var existingEntity))
@@ -4936,6 +4957,24 @@ public sealed class GameWindow : IDisposable
                     _playerController.Motion.InterruptCurrentMovement?.Invoke();
                     _playerController.Motion.UnstickFromObject?.Invoke();
 
+                    // R5-V4a: unpack_movement HEAD style-on-change
+                    // (0x00524440 @00524502-0052452c): wire style index →
+                    // command word (command_ids[]; style-class indices map to
+                    // 0x80000000|index — the funnel's S0-verified conversion)
+                    // and `if (current style != wire style) DoMotion(style,
+                    // ctor defaults)` BEFORE the movement-type switch — for
+                    // EVERY type. acdream previously applied style only via
+                    // the mt-0 funnel copy, so a chase/turn UM (mt 6-9)
+                    // carrying a stance change started the move in the OLD
+                    // stance (the RetailObserverTraceConformanceTests "S3
+                    // wires the unpack-level style-on-change" exclusion —
+                    // this is that wiring).
+                    uint wireStylePlayer = stance != 0
+                        ? (0x80000000u | (uint)stance) : 0x8000003Du;
+                    if (_playerController.Motion.InterpretedState.CurrentStyle != wireStylePlayer)
+                        _playerController.Motion.DoMotion(wireStylePlayer,
+                            new AcDream.Core.Physics.Motion.MovementParameters());
+
                     if (_playerController.MoveTo is { } playerMoveTo
                         && RouteServerMoveTo(playerMoveTo, _playerController.Motion,
                                              _playerController.CellId, update))
@@ -4947,6 +4986,23 @@ public sealed class GameWindow : IDisposable
                         }
                         return;
                     }
+
+                    // R5-V4: retail unpack_movement case-0 TAIL for the local
+                    // player (@00524583-0052458e) — stick_to_object when the
+                    // motionFlags 0x1 trailer carried a guid, then
+                    // standing_longjump ← motionFlags 0x2 (UNCONDITIONAL —
+                    // an absent flag clears it). The interpreted-state COPY
+                    // stays skipped for the local player (the
+                    // sequencer-authority posture above); these two writes
+                    // are the only case-0 effects that apply here.
+                    if (update.MotionState.MovementType == 0)
+                    {
+                        if (update.MotionState.StickyObjectGuid is { } playerSticky
+                            && playerSticky != 0)
+                            StickToObjectFromWire(_playerHost, playerSticky);
+                        _playerController.Motion.StandingLongJump =
+                            update.MotionState.StandingLongJump;
+                    }
                 }
             }
             else
@@ -4996,6 +5052,18 @@ public sealed class GameWindow : IDisposable
                     remoteMot.Motion.InterruptCurrentMovement?.Invoke();
                     remoteMot.Motion.UnstickFromObject?.Invoke();
 
+                    // R5-V4a: unpack_movement head style-on-change — see the
+                    // player-side comment (@00524502-0052452c). Runs BEFORE
+                    // the type routing for every movement type; the mt-0
+                    // funnel below still performs its own full style
+                    // adoption (retail has BOTH — the head fires on CHANGE
+                    // only, so an unchanged stance is a no-op here).
+                    uint wireStyleRemote = stance != 0
+                        ? (0x80000000u | (uint)stance) : 0x8000003Du;
+                    if (remoteMot.Motion.InterpretedState.CurrentStyle != wireStyleRemote)
+                        remoteMot.Motion.DoMotion(wireStyleRemote,
+                            new AcDream.Core.Physics.Motion.MovementParameters());
+
                     // R4-V5: the type-6..9 routing body is shared with the
                     // local player (RouteServerMoveTo) — behavior identical
                     // to the R4-V4 inline blocks it was extracted from.
@@ -5086,6 +5154,18 @@ public sealed class GameWindow : IDisposable
                     // motion-table stack (GetObjectSequence + is_allowed
                     // decide) — mt-0 only post-V4 (types 6-9 returned above).
                     remoteMot.Motion.MoveToInterpretedState(ims, sink);
+
+                    // R5-V4: retail unpack_movement case-0 TAIL order
+                    // (@00524583-0052458e): move_to_interpreted_state FIRST
+                    // (above), THEN stick_to_object when the motionFlags 0x1
+                    // trailer carried a guid, THEN standing_longjump ←
+                    // motionFlags 0x2 (UNCONDITIONAL — an absent flag
+                    // CLEARS it).
+                    if (update.MotionState.StickyObjectGuid is { } stickyGuid
+                        && stickyGuid != 0)
+                        StickToObjectFromWire(remoteMot.Host, stickyGuid);
+                    remoteMot.Motion.StandingLongJump =
+                        update.MotionState.StandingLongJump;
                 }
             }
 

src/AcDream.Core.Net/Messages/CreateObject.cs

@@ -259,10 +259,16 @@ public static class CreateObject
         // InterpretedMotionState::UnPack (r4-moveto-decomp.md §2f
         // @0052455d: `if (header & 0x100) sticky_object_guid = read_dword()`
         // — bit 0x100 of the combined header word is motionFlags byte1&0x1).
-        // Carried unconsumed until R5's PositionManager::StickTo body binds
+        // R5-V4 consumes it: the GameWindow mt-0 tail routes it into
-        // it; parsing it here just keeps the buffer cursor honest past this
+        // CPhysicsObj::stick_to_object's port (target PartArray radii →
-        // field (deliverable C — no behavior).
+        // PositionManager.StickTo — decomp 0x005127e0, call @00524589).
-        uint? StickyObjectGuid = null)
+        uint? StickyObjectGuid = null,
+        // R5-V4 (closes the "documented but NOT consumed" note in
+        // UpdateMotion.cs): motionFlags & 0x2 — retail `unpack_movement`
+        // case 0 writes it onto `motion_interpreter->standing_longjump`
+        // UNCONDITIONALLY (@0052458e: absent flag CLEARS it). Consumed at
+        // the GameWindow mt-0 tails (remote + player).
+        bool StandingLongJump = false)
     {
         /// <summary>
         /// ACE/retail movement types 6 and 7 are server-controlled

src/AcDream.Core.Net/Messages/UpdateMotion.cs

@@ -151,13 +151,11 @@ public static class UpdateMotion
             // `_motionFlags`. StickToObject now drives the sticky-guid
             // trailer parse below (mt=0 only, per ACE MovementInvalid.Write
             // + decomp §2f case 0 @0052455d). StandingLongJump (0x2) is
-            // DOCUMENTED here but NOT consumed — retail's
+            // carried on ServerMotionState.StandingLongJump (R5-V4) and
+            // consumed at the GameWindow mt-0 tails — retail's
             // `unpack_movement` case 0 writes it onto
-            // `motion_interpreter->standing_longjump` (§2f @0052458e), an
+            // `motion_interpreter->standing_longjump` (§2f @0052458e,
-            // R5 unpack_movement item (this parser has no MotionInterpreter
+            // UNCONDITIONAL — an absent flag clears it).
-            // reference to write it onto; the bit is simply not read past
-            // this comment, matching "not consumed" rather than
-            // mis-consumed).
             byte motionFlags = body[pos]; pos += 1;
             ushort currentStyle = BinaryPrimitives.ReadUInt16LittleEndian(body.Slice(pos));
             pos += 2;
@@ -323,7 +321,11 @@ public static class UpdateMotion
                 moveToRunRate,
                 moveToPath,
                 turnToPath,
-                stickyObjectGuid),
+                stickyObjectGuid,
+                // R5-V4: MotionFlags 0x2 — consumed at the GameWindow mt-0
+                // tails (retail unpack_movement @0052458e writes it onto
+                // minterp->standing_longjump unconditionally).
+                (motionFlags & 0x2) != 0),
                 instanceSequence, movementSequence, serverControlSequence, isAutonomous);
         }
         catch

src/AcDream.Core/Physics/MotionInterpreter.cs

@@ -2860,7 +2860,7 @@ public sealed class MotionInterpreter : IMotionDoneSink
                 if (IsLocalPlayer && a.Autonomous) continue;
 
                 ServerActionStamp = incoming;
-                DispatchInterpretedMotion(a.Command, a.Speed, sink);
+                DispatchInterpretedMotion(a.Command, a.Speed, a.Autonomous, sink);
             }
         }
 
@@ -3291,10 +3291,16 @@ public sealed class MotionInterpreter : IMotionDoneSink
     /// <c>ModifyInterpretedState = true</c>, so replayed actions DO enter the
     /// interpreted actions list via <c>InterpretedMotionState::AddAction</c>),
     /// unlike the apply pass's rewritten params (see
-    /// <see cref="ApplyInterpretedMovement"/>). Known residual gap: retail
+    /// <see cref="ApplyInterpretedMovement"/>). R5-V4 (#164): the params'
-    /// also sets the params' <c>Autonomous</c> bit (0x1000) per action (raw
+    /// <c>Autonomous</c> bit (0x1000) is spliced from the ACTION's autonomy
-    /// 305982) — not yet threaded (tracked in ISSUES, #161 follow-up note).
+    /// flag — retail raw 305982:
+    /// <c>var_28 ^= ((action.autonomous &lt;&lt; 0xc) ^ var_28) &amp; 0x1000</c>
+    /// — so a replayed action enters the state lists
+    /// (<c>AddAction(motion, speed, stamp, autonomous)</c>) with its real
+    /// autonomy instead of the ctor-default false.
     /// </summary>
-    private WeenieError DispatchInterpretedMotion(uint motion, float speed, IInterpretedMotionSink? sink)
+    private WeenieError DispatchInterpretedMotion(
-        => DoInterpretedMotion(motion, new MovementParameters { Speed = speed }, sink);
+        uint motion, float speed, bool autonomous, IInterpretedMotionSink? sink)
+        => DoInterpretedMotion(
+            motion, new MovementParameters { Speed = speed, Autonomous = autonomous }, sink);
 }

tests/AcDream.Core.Tests/Physics/Motion/RemoteChaseEndToEndHarnessTests.cs

@@ -251,11 +251,22 @@ internal sealed class RemoteChaseHarness
         bool sticky = false,
         bool useSpheres = false,
         float targetRadius = 0f,
-        float targetHeight = 0f)
+        float targetHeight = 0f,
+        uint wireStance = 0u)
     {
         Interp.InterruptCurrentMovement?.Invoke();
         Interp.UnstickFromObject?.Invoke();
 
+        // R5-V4a: the unpack_movement HEAD style-on-change (GameWindow's
+        // routing-head mirror — 0x00524440 @00524502-0052452c): fires for
+        // EVERY movement type, BEFORE the type routing, on CHANGE only.
+        if (wireStance != 0u)
+        {
+            uint wireStyle = 0x80000000u | wireStance;
+            if (Interp.InterpretedState.CurrentStyle != wireStyle)
+                Interp.DoMotion(wireStyle, new MovementParameters());
+        }
+
         var mp = new MovementParameters
         {
             CanWalk = true,
@@ -871,4 +882,47 @@ public sealed class RemoteChaseEndToEndHarnessTests
             $"chase did not re-stick after the re-arm; mt={h.Mgr.MovementTypeState} " +
             $"dist={h.DistToPlayer:F2}");
     }
+
+    /// <summary>
+    /// R5-V4a: the unpack-head style-on-change — a chase arm (mt-6) whose UM
+    /// carries a CHANGED stance applies the stance FIRST (retail
+    /// unpack_movement @00524502-0052452c dispatches DoMotion(style) before
+    /// the movement-type switch), so the creature draws into Combat and THEN
+    /// runs — instead of chasing in the old NonCombat stance until the next
+    /// mt-0 UM. Closes the RetailObserverTraceConformanceTests "S3 wires the
+    /// unpack-level style-on-change" exclusion's production gap.
+    /// </summary>
+    [Fact]
+    public void ChaseArm_WithStanceChange_AppliesStanceBeforeTheChase()
+    {
+        var h = new RemoteChaseHarness(_out);
+        h.PlayerPos = new Vector3(0f, 12f, 0f);
+        h.PlayerVelocity = Vector3.Zero;
+
+        // settle in NonCombat — NO prior stance UM (the pre-V4 gap: nothing
+        // but an mt-0 could change the stance).
+        for (int i = 0; i < Seconds(0.5f); i++) h.Tick();
+        Assert.Equal(RemoteChaseHarness.NonCombat, h.Seq.Manager.State.Style);
+
+        // the arm carries the Combat stance in its UM header (mt-6).
+        h.UmMoveToObject(wireStance: RemoteChaseHarness.Combat & 0xFFFFu);
+
+        // the stance adopts at the head — before any chase motion completes.
+        Assert.Equal(RemoteChaseHarness.Combat, h.Interp.InterpretedState.CurrentStyle);
+
+        // ...and the chase still installs its forward cycle normally, now in
+        // the Combat style family.
+        int installTick = -1;
+        for (int i = 0; i < Seconds(6f) && installTick < 0; i++)
+        {
+            h.Tick();
+            if (h.Seq.Manager.State.Substate == RemoteChaseHarness.Run
+                || h.Seq.Manager.State.Substate == RemoteChaseHarness.Walk)
+                installTick = i;
+        }
+        Assert.True(installTick >= 0,
+            $"forward cycle never installed after the stance-carrying arm; " +
+            $"mt={h.Mgr.MovementTypeState} substate=0x{h.Seq.Manager.State.Substate:X8}");
+        Assert.Equal(RemoteChaseHarness.Combat, h.Seq.Manager.State.Style);
+    }
 }

tests/AcDream.Core.Tests/Physics/MotionInterpreterFunnelTests.cs

@@ -340,6 +340,26 @@ public class MotionInterpreterFunnelTests
         Assert.DoesNotContain(sink.Calls, c => c.StartsWith("DIM 10000062"));
     }
 
+    [Fact]
+    public void Actions_ReplayCarriesAutonomyIntoTheInterpretedList()
+    {
+        // R5-V4 (#164): retail splices the ACTION's autonomy into the
+        // dispatch params (bit 0x1000 — raw 305982:
+        // `var_28 ^= ((action.autonomous << 0xc) ^ var_28) & 0x1000`), so a
+        // replayed action enters the interpreted actions list
+        // (InterpretedMotionState::AddAction consumes p.Autonomous) with its
+        // REAL autonomy. Pre-V4 the replay params were ctor-default →
+        // Autonomous always false.
+        var mi = GroundedInterp(); // remote posture: IsLocalPlayer = false
+        var sink = new RecordingSink();
+
+        mi.MoveToInterpretedState(
+            Ims(actions: new[] { new InboundMotionAction(0x10000062u, 5, Autonomous: true, 1f) }), sink);
+
+        var entry = Assert.Single(mi.InterpretedState.Actions, a => a.Command == 0x0062);
+        Assert.True(entry.Autonomous);
+    }
+
     [Fact]
     public void InboundState_Defaults_MatchRetailUnPack()
     {

tests/AcDream.Core.Tests/Physics/RetailObserverTraceConformanceTests.cs

@@ -30,7 +30,14 @@ namespace AcDream.Core.Tests.Physics;
 ///    tests in MotionInterpreterFunnelTests instead.
 ///  - motion==0x80000000 entries (the unpack-level DoMotion(command_ids[0])
 ///    style call for wire style index 0) — outside
-///    move_to_interpreted_state; S3 wires the unpack-level style-on-change.
+///    move_to_interpreted_state, so it can never appear in a
+///    MoveToInterpretedState replay; the filter stays for that trace-
+///    mechanics reason. The PRODUCTION gap the old note pointed at ("S3
+///    wires the unpack-level style-on-change") CLOSED in R5-V4: the
+///    GameWindow routing heads dispatch DoMotion(style) on change for every
+///    movement type (unpack_movement @00524502-0052452c; conformance:
+///    RemoteChaseEndToEndHarnessTests.ChaseArm_WithStanceChange_
+///    AppliesStanceBeforeTheChase).
 /// </summary>
 public class RetailObserverTraceConformanceTests
 {