Targeting: lock mirrors the pick per frame (sticky designation removed)

The sticky lock made aim irrelevant after the first acquisition (the
crosshair starts on the face-to-face enemy, so it locked at spawn and
never let go -- played as auto-targeting). The binary treats no-target
as a frequent live state (fire path re-checks 0x388!=0 at every step,
part_013.c:7689/7727; HUD range feed has a permanent no-target default,
:5636), so the target slots now mirror the reticle pick each frame:
locked while the crosshair is ON the mech, no lock otherwise. Keeping
the crosshair on the enemy is the gunnery.

Verified headless: BT_AIM="0 0" -> HOT + aimed zone hits; BT_AIM="0.6
0.4" -> no lock, zero damage.

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

context/combat-damage.md

@@ -53,10 +53,14 @@ the MOUSE (dev-box stand-in for the pod stick free-aim; `BT_AIM="x y"` pins it h
 `BTGetAimRay` (L4VIDEO; the ACTIVE eye publishes pos+LookAtRH basis via `BTSetAimCamera`, the
 render loop publishes proj._22) → `Mech::PickRayHit` (world ray → local frame →
 `BoundingBox::HitBy` slab test vs the collision template's ExtentBox → world hit point) → the
-entity target slots. Designation is STICKY (persists off-crosshair; re-hover refreshes; cleared
-when the target leaves the roster at burial). While HOT (crosshair on the hull) the impact point
-= the PICKED point → STEP-6 resolves the zone under the crosshair (verified: center-aim at the
-head band → zone 13 dominant); off-crosshair the converge point is center-mass chest. The HUD
+entity target slots. The slots MIRROR the pick EACH FRAME: locked while the crosshair is ON the
+mech, no target otherwise — keeping the crosshair on the enemy IS the gunnery. (⚠ A first cut
+made the designation STICKY — once hovered, locked forever — which made aim irrelevant after the
+first acquisition; play-tested wrong, and the binary treats no-target as a FREQUENT live state:
+the fire path re-checks 0x388!=0 at every step, part_013.c:7689/7727, and the HUD range feed has
+a permanent no-target default, :5636. Corrected 2026-07-08.) While locked the impact point = the
+PICKED hull point → STEP-6 resolves the zone under the crosshair (verified: center-aim at the
+head band → zone 13 dominant). The HUD
 draws the aim group at the slewed position ([0x9a] translate list, contained by push/pop), the
 designator ring at the target's projected point (subB9 hot / subB8 designated,
 `BTProjectToReticle`), and the edge arrows when off-screen/behind. `BT_FIRE_ARC` is now an

context/open-questions.md

@@ -53,8 +53,8 @@ authentic path scoped.
   the basic-mission behavior. The MessageBoard feed is separate (StatusMessagePool, below).
 - **✅ Authentic target acquisition RECONSTRUCTED (task #36, 2026-07-08)** — the `Reticle`
   pick-ray chain is LIVE (see [[combat-damage]] Targeting for the full port map): mouse slew →
-  pick ray → sticky designation → aimed zone damage + designator ring/arrows; `BT_FIRE_ARC` is
-  opt-in-only now. Residue: (a) the binary's own per-frame reticle→mech copy is still in an
+  pick ray → per-frame lock (crosshair ON the mech = locked; off = none) → aimed zone damage +
+  designator ring; `BT_FIRE_ARC` is opt-in-only now. Residue: (a) the binary's own per-frame reticle→mech copy is still in an
   un-exported gap (our writer follows RETICLE.h semantics [T3 dynamics]); (b) the pod's REAL slew
   device channel (stick free-aim via the controls mapper / `freeAimSlew` @HUD+0x28C) is bridged
   by the mouse — wire the real channel when pod hardware lands; (c) pre-burial, the pick still

game/reconstructed/mech4.cpp

@@ -2332,30 +2332,25 @@ void
 			if (hotTarget != 0)
 				targetReticle.rayIntersection = hotPoint;
 
+			// The target slots MIRROR the pick each frame: you are locked while
+			// the crosshair is ON the mech, and not otherwise.  (A first cut
+			// made the designation STICKY -- once hovered, locked forever -- but
+			// that made aim irrelevant after the first acquisition, and the
+			// binary's own code treats no-target as a FREQUENT live state: the
+			// fire path re-checks 0x388!=0 at every step (part_013.c:7689/7727)
+			// and the HUD range feed has a permanent no-target default of 1200
+			// (part_013.c:5636).  Keeping the crosshair on the enemy IS the
+			// gunnery.)
 			if (hotTarget != 0)
 			{
-				MECH_TARGET_ENTITY(this) = hotTarget;	// designate (sticky)
+				MECH_TARGET_ENTITY(this) = hotTarget;
 				MECH_TARGET_SUBIDX(this) = -1;
 				MECH_TARGET_POS(this)    = hotPoint;	// the aimed hull point
 			}
-			else if (MECH_TARGET_ENTITY(this) != 0)
+			else
 			{
-				if (MECH_TARGET_ENTITY(this) != gEnemyMech)
-				{
-					// the designated mech left the target roster (wreck buried /
-					// entity gone): drop the designation.
-					MECH_TARGET_ENTITY(this) = 0;
-					MECH_TARGET_SUBIDX(this) = -1;
-				}
-				else
-				{
-					// crosshair off the mech: the designation persists; the
-					// converge point tracks the target's center mass (chest).
-					Mech *des = (Mech *)MECH_TARGET_ENTITY(this);
-					Point3D cm = des->localOrigin.linearPosition;
-					cm.y += kMuzzleHeight;
-					MECH_TARGET_POS(this) = cm;
-				}
+				MECH_TARGET_ENTITY(this) = 0;			// crosshair off -> no lock
+				MECH_TARGET_SUBIDX(this) = -1;
 			}
 		}
 
@@ -2369,7 +2364,7 @@ void
 				float hddx = dp.x - localOrigin.linearPosition.x;
 				float hddz = dp.z - localOrigin.linearPosition.z;
 				BTSetHudTargetRange((Scalar)sqrtf(hddx*hddx + hddz*hddz));
-				gBTHudLockState    = (hotTarget != 0) ? 2 : 1;
+				gBTHudLockState    = 2;				// locked == crosshair on it
 				gBTHudLockWorld[0] = dp.x;
 				gBTHudLockWorld[1] = dp.y + kMuzzleHeight;
 				gBTHudLockWorld[2] = dp.z;