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BT411/scratchpad/flushsnd2.py
T
arcattackandClaude Opus 5 d39227ef39 Gitea #51 ROOT CAUSE: LoopAtWill was mapped to "loop forever", arming 224 of 603 samples as endless OpenAL sources
SAURON's "coolant flush sound glitched and perma" is one instance of a systemic
defect.  SetupPatch (L4AUDLVL.cpp) decided looping from the SAMPLE flag alone:

    AL_LOOPING = (info.loop != ForceStatic)

That armed every non-ForceStatic sample -- 224 of the 603 authored zones,
including unmistakable one-shots -- as an OpenAL source that never ends on its
own.  Any such sound whose note-off never arrives plays forever.  Measured 1946
LoopAtWill x Transient arming events in one short session.

The sample flag expresses PERMISSION; the SOURCE decides.  Three facts [T1]:

  * the enum's own comments (L4AUDLVL.h:14-19) -- LoopAtWill = "will play once
    OR LOOP AS DESIRED", ForceStatic = "plays only once EVEN IF LOOPED" (a
    veto), LoopAlways = "ramp up and then down";
  * LoopAtWill is enum value 0, i.e. the DEFAULT an unauthored sample receives
    (WTPresets.cpp:37) -- it cannot mean "loop forever";
  * LoopAlways, the real always-loop, is used by ZERO shipped samples.

"As desired" is the source's authored AudioRenderType (Transient=one-shot vs
Sustained=held), streamed from AUDIO*.RES (AUDLVL.cpp:28) and already consulted
by the renderer (L4AUDRND.cpp:567, AUDREND.cpp:184).  SetupPatch now takes it,
threaded from all three L4AudioSource call sites (Direct/Dynamic3D/Static3D).
New rule: LoopAlways->1, ForceStatic->0, LoopAtWill->the source's render type.

MEASURED before changing behaviour (BT_LOOP_AUDIT=1, scratchpad/loopaudit.py):

    LoopAtWill  x Transient -> loop=0  (was 1)   1946 events
    LoopAtWill  x Sustained -> loop=1  unchanged    65 events
    ForceStatic x Transient -> loop=0  unchanged   292 events

The engine loops (EngineAccel07_z0..z2, EngineMotor01, EnginePower01) are all
LoopAtWill/Sustained and PRESERVED -- no regression there.  All 24 reclassified
samples are genuine one-shots: laser charge/fire/explosion/loaded, missile
loading, engine shift, coolant pressure inc/dec.

A/B PROOF (scratchpad/loopab.py, same session both arms, only BT_LOOP_LEGACY
differs), asking the engine's own BT_AUDIO_DUMP what is still playing with
loop=1 long after every release:

    [legacy] EnginePower01, CoolantPresInc03_z2, CoolantPresDcr03_z2
    [fixed]  EnginePower01

The two stuck coolant sources are the reported symptom.  They were eventually
reclaimed when a later trigger reused the source, which is why the bug was
intermittent -- the "perma" case is when nothing else retriggers it.  The fix
removes the mechanism.

BT_LOOP_LEGACY=1 restores the old rule for a field A/B without a rebuild.  The
layers to listen to are the beam sustains: LaserA/CSustain* are authored
LoopAtWill on a TRANSIENT source, so they now end with the sample instead of
looping until note-off.  The render type is T1 authored data; the interpretation
that LoopAtWill defers to it is a strong reading of the enum + defaults rather
than a disassembled statement, and is flagged as such in the KB.

Plausibly bears on #32 (audio cutting in/out late in a match): a stuck looping
source holds its pool slot for the rest of the round.

Rigs: scratchpad/flushsnd.py (flush start/stop pairing), flushsnd2.py (stuck-
source hunt), loopaudit.py (the classification matrix), loopab.py (the A/B).
KB: context/wintesla-port.md audio section, context/decomp-reference.md env
table (BT_LOOP_AUDIT / BT_LOOP_LEGACY / BT_AUDIO_DUMP / BT_AUD_TAIL),
docs/AUDIO_FIDELITY.md F38.  checkctx.py CLEAN.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-07-25 13:20:19 -05:00

118 lines
4.0 KiB
Python

"""Gitea #51 part 2 -- catch the STUCK looping coolant source red-handed.
Part 1 (flushsnd.py) showed the flush picks one of five CoolantDump variants and
that the note-off does arrive. But three of the five variants contain a zone
authored **LoopAtWill**, and SetupPatch (L4AUDLVL.cpp:290-296) maps anything that
is not ForceStatic to **AL_LOOPING = 1** -- an OpenAL source that never ends on
its own. The enum's own comment says LoopAtWill means "will play once OR loop as
desired" (L4AUDLVL.h:16), i.e. permission to loop, not a command.
So: drive several flushes (variant selection differs per trigger), then sit idle
and use the engine's own BT_AUDIO_DUMP once-a-second playing-source dump to see
whether anything is STILL playing with loop=1 long after the last release.
PASS (bug absent) = no [playing] lines with loop=1 after the idle period.
FAIL (bug present) = a coolant source still playing with loop=1 forever.
Kills only the PID it spawns.
"""
import ctypes
import os
import re
import subprocess
import sys
import time
KEYUP = 0x0002
VK_H = 0x48
user32 = ctypes.windll.user32
REPO = r"C:\git\bt411"
LOG = os.path.join(REPO, "scratchpad_flushsnd2.log")
if os.path.exists(LOG):
os.remove(LOG)
env = dict(os.environ)
env.update({
"BT_START_INSIDE": "1",
"BT_KEY_NOFOCUS": "1",
"BT_DEV_GAUGES": "1",
"BT_FLUSH_LOG": "1",
"BT_AUD_TAIL": "1",
"BT_AUDIO_DUMP": "1", # once-a-second dump of every PLAYING source + its loop flag
"BT_LOG": LOG,
})
proc = subprocess.Popen(
[os.path.join(REPO, "build", "Release", "btl4.exe"), "-egg", "LAST.EGG"],
cwd=os.path.join(REPO, "content"), env=env,
stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
print("pid", proc.pid)
def tap(hold=0.35):
user32.keybd_event(VK_H, 0, 0, 0)
time.sleep(hold)
user32.keybd_event(VK_H, 0, KEYUP, 0)
try:
deadline = time.time() + 240
while time.time() < deadline:
if os.path.exists(LOG) and "first frame" in open(LOG, errors="replace").read():
break
time.sleep(2)
else:
print("FAIL: never reached the mission")
proc.terminate()
sys.exit(2)
time.sleep(6)
# six flushes, spaced -- the variant selection differs per trigger
for i in range(6):
tap()
print(" flush %d dispatched" % (i + 1))
time.sleep(3.0)
print(" idling 25s -- anything still playing now is STUCK")
idle_mark = len(open(LOG, errors="replace").read())
time.sleep(25)
finally:
proc.terminate()
time.sleep(1)
t = open(LOG, errors="replace").read() if os.path.exists(LOG) else ""
tail_t = t[idle_mark:] if "idle_mark" in dir() else t
tx = re.findall(r"^\[flush-tx\].*$", t, re.M)
variants = sorted(set(re.findall(r"file=(CoolantDump\d+_z\d+\.wav)", t)))
# playing-source dumps recorded DURING the idle window (post-release)
idle_play = re.findall(r"^\[playing\].*$", tail_t, re.M)
stuck = [l for l in idle_play if "loop=1" in l]
stuck_coolant = [l for l in stuck if "oolant" in l]
print("\n=============== RESULT ===============")
print("[flush-tx] edges:", len(tx), "(expect 12 = 6 press + 6 release)")
print("coolant zones that actually played:", len(variants))
for v in variants:
print(" ", v)
print("\n[playing] lines during the 25s IDLE window:", len(idle_play))
seen = {}
for l in idle_play:
m = re.search(r"src=(\d+) (\S+).*loop=(\d+)", l)
if m:
seen[(m.group(1), m.group(2), m.group(3))] = seen.get((m.group(1), m.group(2), m.group(3)), 0) + 1
for (src, nm, lp), n in sorted(seen.items(), key=lambda kv: -kv[1]):
print(" src=%-4s %-28s loop=%s seen %dx" % (src, nm, lp, n))
print("\nSTILL PLAYING with loop=1 after all releases:", len(stuck))
print(" ...of which coolant:", len(stuck_coolant))
for l in stuck_coolant[:5]:
print(" ", l[:120])
print("\nVERDICT:", "REPRODUCED -- a looping coolant source outlives its release (#51)"
if stuck_coolant else
("looping sources stuck, but not coolant -- same class, different sample"
if stuck else "no stuck looping source in this run"))
sys.exit(0)