From b3558448478758e5e8d0b40996ba546bb9ba748b Mon Sep 17 00:00:00 2001
From: Joe DiPrima <epilectrik@gmail.com>
Date: Thu, 13 Aug 2026 19:54:34 -0500
Subject: [PATCH] cadence census item 3: footstep smoother intake clocked at
 28Hz (gotcha 32) -- the authored olympic windows breathe at their authored
 width again. The N=30/15 fill-0 windows (AUDWTHR.h:457) are sized for one
 sample per POD frame; the port's watcher poll fed one per poll, and the bench
 measured the poll path at ~141-147/s (MORE than render -- the wall window was
 0.2s, not even 0.5s). Fix: only the Add is clocked (per-instance 28Hz wall
 clock, catch-up repeats the current sample capped at the largest authored
 window 30); the downstream forward still runs every poll with the held
 average, so watcher semantics are untouched; N untouched. BT_AUD_SMOOTH_HZ
 override (=0 restores per-poll). Measured: avgUpdates 70.6 -> 19-20/s,
 envelope wobble -26-45%, ramp90 0.55s -> 1.23s (the authored 30-sample/28Hz ~
 1.07s window restored in wall time), steady levels unchanged (0.852 vs 0.863
 -- smoothing only, no level shift).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bw71WVsccjwW7uKRg4aWD
---
 engine/MUNGA/AUDCMP.cpp | 50 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 49 insertions(+), 1 deletion(-)

diff --git a/engine/MUNGA/AUDCMP.cpp b/engine/MUNGA/AUDCMP.cpp
index 9c2c3b9..6f2db9c 100644
--- a/engine/MUNGA/AUDCMP.cpp
+++ b/engine/MUNGA/AUDCMP.cpp
@@ -1,4 +1,5 @@
 #include <cstdlib>
+#include <map>				// (BT411) the 28Hz smoother-intake clock (cadence census item 3)
 #include "munga.h"
 #pragma hdrstop
 
@@ -958,7 +959,54 @@ void
 
    if (control_ID == controlID)
 	{
-      audioControlAverage.Add(control_value);
+      // (BT411 cadence census item 3, gotcha 32) SAMPLE INTAKE AT 28 Hz:
+      // the authored olympic windows (N=30/15, fill 0) are SIZED for one
+      // sample per POD frame (28 Hz -- AUDWTHR.h:457); the port's watcher
+      // poll feeds one per RENDER frame (~59), which halves the smoothing
+      // window in wall time and feeds a noisier operand.  Clock ONLY the
+      // Add (the smoother's own intake) on a per-instance 28 Hz wall
+      // clock; the forward below still runs EVERY poll with the held
+      // average, so downstream watcher semantics are untouched.  During a
+      // hitch the pod would have taken ~28 samples/s of the stalled
+      // value -- catch-up repeats the current sample, capped at the
+      // largest authored window (30), heat.cpp #119 pattern.
+      // BT_AUD_SMOOTH_HZ=<hz> overrides (=0 restores per-poll intake).
+      {
+         static Scalar s_hz = -2.0f;
+         if (s_hz < -1.0f)
+         {
+            const char *hz = getenv("BT_AUD_SMOOTH_HZ");
+            s_hz = (hz != 0 && *hz != '\0') ? (Scalar)atof(hz) : 28.0f;
+         }
+         if (s_hz > 0.0f)
+         {
+            static std::map<const void *, DWORD> s_nextMs;
+            const DWORD now  = GetTickCount();
+            const DWORD tick = (DWORD)(1000.0f / s_hz);      // 35 ms at 28
+            DWORD &next = s_nextMs[this];
+            if (next == 0)
+            {
+               audioControlAverage.Add(control_value);
+               next = now + tick;
+            }
+            else if ((long)(now - next) >= 0)
+            {
+               int added = 0;
+               while ((long)(now - next) >= 0 && ++added <= 30)
+               {
+                  audioControlAverage.Add(control_value);
+                  next += tick;
+               }
+               if ((long)(now - next) >= 0)
+                  next = now + tick;                         // hitch: resync
+            }
+            // else: off-tick poll -- hold; the average is forwarded below
+         }
+         else
+         {
+            audioControlAverage.Add(control_value);          // legacy per-poll
+         }
+      }
 
       if (getenv("BT_AUDIO_SPATIAL")) { static int s_sa=0;
          if ((controlID == 100 || controlID == 101) && s_sa++ < 3000)