MP: authentic update-record deadbands streamed from the model record (task #3)

Binary ctor @0x4a26a7-0x4a26ef: mech+0x768/76c/770 <- raw record words
0x26/0x27/0x28 (UpdatePositionDiffrence / UpdateTurnVelocityDiffrence /
UpdateTurnDegreeDiffrence x pi/180 [const @0x4a2d44]).  Read at RAW record
offsets -- the Mech__ModelResource struct is layout-skewed (field98 gave
-1.5 where the record holds 0.3; audit filed as task #4, also explains the
old forwardCycleRate "floor 25" hack).  Sender triggers now use the
authored constants: pos-deadband type 0, quat-Y delta + yaw-rate delta +
stopped-turn edge type 4 (binary @0x4aad35/@0x4aac2b/@0x4aac6c).
Verified 2-node: madcat streams 0.3/0.045/3deg, type-4 spam gone, walking
replicant clean.

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

game/reconstructed/mech.cpp

@@ -1267,9 +1267,19 @@ Mech::Mech(
 	Wword(0x15a) = (int)(model->lookRightAngle * DegreesToRadians);	// +0x54
 	Wword(0x15b) = (int)(model->lookFrontAngle * DegreesToRadians);	// +0x58
 	Wword(0x15c) = (int)(model->lookBackAngle  * DegreesToRadians);	// +0x5c
-	Wword(0x1dc) = (int)(model->fieldA0        * DegreesToRadians);
+	// The update-record deadbands, read at the RAW record offsets the binary
-	Wword(0x1db) = model->field9c;
+	// itself uses ([esi+0x98/0x9c/0xa0], disasm @0x4a26a7-0x4a26ef) -- the
-	Wword(0x1da) = model->field98;
+	// Mech__ModelResource struct fieldXX members are LAYOUT-SKEWED (audit
+	// task: struct field98 read -1.5 where raw word 0x26 holds 0.3).  A
+	// resource record is a byte blob, so word-indexed reads are the correct
+	// idiom (not the object databinding trap).
+	updateTurnAngleDeadband    = ((Scalar *)model)[0x28] * DegreesToRadians;	// @0x770 <- UpdateTurnDegreeDiffrence
+	updateTurnVelocityDeadband = ((Scalar *)model)[0x27];	// @0x76c <- UpdateTurnVelocityDiffrence
+	updatePositionDeadband     = ((Scalar *)model)[0x26];	// @0x768 <- UpdatePositionDiffrence
+	if (getenv("BT_REPL_LOG"))
+		DEBUG_STREAM << "[deadband] pos=" << updatePositionDeadband
+			<< " turnVel=" << updateTurnVelocityDeadband
+			<< " turnAngle=" << updateTurnAngleDeadband << " (rad)" << std::endl;
 	Wword(0x10c) = model->fieldA4;
 	// NOTE: the decomp writes word slots this[0x15d]/this[0x15e].  Routed to the
 	// scratch bank (unnamed pose-angle fields) -- writing through (float*)(this +

game/reconstructed/mech.hpp

@@ -581,6 +581,14 @@ public:
 	Scalar		fallScalar;					// binary @0x4b4 -- same record family; ctor 0  [T4 name]
 	int			heatLevelSnapshot;			// binary @0x780 -- heatAlarm level at frame
 											//   entry; the type-7 impact-record deadband
+	// The AUTHENTIC update-record deadbands (task #3): streamed by the ctor
+	// from the model record (disasm @0x4a26d7-0x4a26ef: 0x770 <- rec+0xa0 x
+	// pi/180 [const @0x4a2d44 = 0.01745329], 0x76c <- rec+0x9c raw, 0x768 <-
+	// rec+0x98 raw = UpdateTurnDegreeDiffrence / UpdateTurnVelocityDiffrence /
+	// UpdatePositionDiffrence).  Consumed by the perf-loop senders.  [T1]
+	Scalar		updatePositionDeadband;		// binary @0x768 -- type-0 pose trigger
+	Scalar		updateTurnVelocityDeadband;	// binary @0x76c -- type-4 yaw-rate trigger
+	Scalar		updateTurnAngleDeadband;	// binary @0x770 -- type-4 orientation trigger (rad)
 	// AUTHENTIC GROUND MODEL ctor products (task #15, ground-model-decode;
 	// binary part_012.c:9938-9940 + 9974-9975).  By-name access only; declared
 	// after the layout-locked fields so nothing shifts.

game/reconstructed/mech4.cpp

@@ -2540,23 +2540,54 @@ void
 			angular_deviation.Subtract(
 				projectedOrigin.angularPosition,
 				localOrigin.angularPosition);
-			if (
+			// Position deadband (binary @0x4aad35: |pos - lastSent|^2 vs the
-				error.LengthSquared() > 0.04f
+			// model's UpdatePositionDiffrence @0x768) + the 2s heartbeat.
-				|| lastPerformance - lastUpdate > 2.0f
+			// Guard against an unstreamed/zero deadband with the old stand-in.
-			)
 			{
-				ForceUpdate();						// type 0: position deadband + heartbeat
+				Scalar posDb = (updatePositionDeadband > 0.0f)
+					? updatePositionDeadband : 0.04f;
+				if (
+					error.LengthSquared() > posDb
+					|| lastPerformance - lastUpdate > 2.0f
+				)
+				{
+					ForceUpdate();					// type 0: pose record
+				}
 			}
-			// ORIENTATION rides ONLY the type-4 resync record now (the
+			// ORIENTATION rides ONLY the type-4 resync record (the authentic
-			// authentic case-0 writer/reader save-restore strips it from the
+			// case-0 writer/reader save-restore strips it from the pose
-			// pose record) -- request it on angular deviation or the turn
+			// record).  Binary triggers (@0x4aac2b / @0x4aac6c):
-			// never reaches the replicant.  Binary deadbands @0x4aac2b/
+			//   |localOrigin.angular.y - projectedOrigin.angular.y| > @0x770
-			// @0x4aac6c diff the live vs last-replicated angular channels
+			//   |localVelocity.angular.y - projectedVelocity.angular.y| > @0x76c
-			// against model constants (+0x76c/+0x770, not yet streamed);
+			//   or (live yaw-rate == 0 && replicated yaw-rate != 0)
-			// the quat-deviation test stands in.  [T3 threshold only]
+			// -- the quaternion Y component and the yaw rate, against the
-			if (Abs(angular_deviation.w) < 0.997f)
+			// model's UpdateTurnDegreeDiffrence (deg->rad) and
+			// UpdateTurnVelocityDiffrence.  [T1 expressions; zero-deadband
+			// guard falls back to the old quat-w stand-in]
 			{
-				ForceUpdate(1 << MechResyncUpdateModelBit);		// type 4
+				Scalar angDb = (updateTurnAngleDeadband    > 0.0f) ? updateTurnAngleDeadband    : -1.0f;
+				Scalar velDb = (updateTurnVelocityDeadband > 0.0f) ? updateTurnVelocityDeadband : -1.0f;
+				Logical resync = False;
+				if (angDb > 0.0f)
+				{
+					if (Abs(localOrigin.angularPosition.y
+							- projectedOrigin.angularPosition.y) > angDb)
+						resync = True;
+					if (Abs((Scalar)localVelocity.angularMotion.y
+							- (Scalar)projectedVelocity.angularMotion.y) > velDb)
+						resync = True;
+					if ((Scalar)localVelocity.angularMotion.y == 0.0f
+						&& (Scalar)updateVelocity.angularMotion.y != 0.0f)
+						resync = True;
+				}
+				else if (Abs(angular_deviation.w) < 0.997f)
+				{
+					resync = True;					// stand-in when unstreamed
+				}
+				if (resync)
+				{
+					ForceUpdate(1 << MechResyncUpdateModelBit);	// type 4
+				}
 			}
 			// Commanded-speed deadband (binary @0x4aac88): the mapper's live
 			// speedDemand vs the last-replicated bodyTargetSpeed -> the tiny

scratchpad/scan_deadband.py

@@ -0,0 +1,39 @@
+import capstone, struct, sys
+sys.stdout.reconfigure(encoding="utf-8", errors="replace")
+data = open("../content/BTL4OPT.EXE","rb").read()
+# established mapping (from dis_4b2980.py usage): file offset = VA - 0x400000 - 0xc00 adjustments;
+# use the section table: .text typically RVA 0x1000, raw 0x400/0x600.  Recover from PE header.
+pe = struct.unpack_from("<I", data, 0x3c)[0]
+nsec = struct.unpack_from("<H", data, pe+6)[0]
+opt = pe+24; szopt = struct.unpack_from("<H", data, pe+20)[0]
+sec0 = opt+szopt
+imgbase = struct.unpack_from("<I", data, opt+28)[0]
+secs=[]
+for i in range(nsec):
+    off=sec0+i*40
+    name=data[off:off+8].rstrip(b"\0").decode()
+    vsz,va,rsz,ra=struct.unpack_from("<IIII",data,off+8)
+    secs.append((name,va,rsz,ra))
+text=[s for s in secs if s[0]=="CODE"][0]
+va0=imgbase+text[1]; ra0=text[3]; n=text[2]
+md=capstone.Cs(capstone.CS_ARCH_X86, capstone.CS_MODE_32)
+md.detail=True
+code=data[ra0:ra0+n]
+hits=[]
+# quick byte-pattern prescan for disp32 0x768/0x76c/0x770 little-endian
+import re
+for target,label in [(0x768,"0x768"),(0x76c,"0x76c"),(0x770,"0x770")]:
+    pat=struct.pack("<I",target)
+    for m in re.finditer(re.escape(pat),code):
+        start=max(0,m.start()-8)
+        for ins in md.disasm(code[start:m.start()+12], va0+start):
+            if ins.op_str and label in ins.op_str and ("ptr [" in ins.op_str):
+                # writes: mov [reg+disp], src  OR fstp
+                if ins.mnemonic in ("mov","fstp","fst") and ins.op_str.index("[")<ins.op_str.index(","):
+                    hits.append((ins.address,f"{ins.mnemonic} {ins.op_str}"))
+                elif ins.mnemonic in ("fld","fcomp","fcom","mov") :
+                    pass
+seen=set()
+for a,t in sorted(hits):
+    if (a,t) not in seen:
+        seen.add((a,t)); print(f"0x{a:x}: {t}")