From 567ffacaae319e158bac8b66a78c498f323f08da Mon Sep 17 00:00:00 2001
From: Joe DiPrima <epilectrik@gmail.com>
Date: Thu, 13 Aug 2026 19:54:24 -0500
Subject: [PATCH] cadence census item 5: ring registry productionized -- the
 16-slot bench-era fixed registry becomes the heat.cpp #119 static-map pattern
 (unbounded, per-instance, no layout growth). The old registry's silent
 overflow would have reverted a 17th mech to render-cadence |a| sampling with
 zero receipts -- exactly the failure class gotcha 32 exists to kill. Smoke
 bench (identical rig to the sway run): instab median 0.130 vs 0.109, |a| p90
 13.8 vs 14.5 -- the same 28Hz signature within run-to-run noise, nowhere near
 the render-cadence control (16.8/48).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bw71WVsccjwW7uKRg4aWD
---
 game/reconstructed/mech4.cpp | 39 +++++++++++++-----------------------
 1 file changed, 14 insertions(+), 25 deletions(-)

diff --git a/game/reconstructed/mech4.cpp b/game/reconstructed/mech4.cpp
index f890a58..c484fe2 100644
--- a/game/reconstructed/mech4.cpp
+++ b/game/reconstructed/mech4.cpp
@@ -159,6 +159,7 @@
 #include <matchlog.hpp>		// MP match forensics (DEATH/PROJ/SPLASH/RAM event lines)
 #include "btinput.hpp"		// the CONTROLS.MAP + XInput binding engine
 #include <string.h>			// [aud-tail] strchr -- BT_FIRE_PULSE "on,off" parse (Gitea #5, instrumentation only)
+#include <map>				// the ring 28Hz dt-accumulator registry (heat.cpp #119 pattern, census item 5)
 #if !defined(PLAYER_HPP)
 #	include <player.hpp>	// Player::VehicleDeadMessage -- the death->respawn notification (task #52)
 #endif
@@ -8813,32 +8814,20 @@ void
 			}
 			if (s_ringHz > 0.0f)
 			{
-				// per-instance dt accumulator (tiny fixed registry -- bench
-				// scaffolding; a solo bench has one mech, MP a handful)
-				static const void *s_raKey[16];
-				static Scalar      s_raAcc[16];
-				int slot = -1, freeSlot = -1;
-				for (int k = 0; k < 16; ++k)
+				// per-instance dt accumulator -- the heat.cpp #119 static-map
+				// pattern (unbounded, keyed per instance, no layout growth).
+				// Replaces the bench-era 16-slot fixed registry, whose silent
+				// overflow would have reverted a 17th mech to render-cadence
+				// sampling (cadence census item 5, night17).
+				static std::map<const void *, Scalar> s_ringClock;
+				Scalar &acc = s_ringClock[this];
+				acc += dt;
+				if (acc < 1.0f / s_ringHz)
+					ringPush = 0;
+				else
 				{
-					if (s_raKey[k] == (const void *)this) { slot = k; break; }
-					if (s_raKey[k] == 0 && freeSlot < 0) freeSlot = k;
-				}
-				if (slot < 0 && freeSlot >= 0)
-				{
-					slot = freeSlot;
-					s_raKey[slot] = (const void *)this;
-					s_raAcc[slot] = 0.0f;
-				}
-				if (slot >= 0)
-				{
-					s_raAcc[slot] += dt;
-					if (s_raAcc[slot] < 1.0f / s_ringHz)
-						ringPush = 0;
-					else
-					{
-						ringDt = s_raAcc[slot];
-						s_raAcc[slot] = 0.0f;
-					}
+					ringDt = acc;
+					acc = 0.0f;
 				}
 			}
 		}