tools+docs: the flight pad was writing into a dead file - every autopilot input went nowhere

flight_probe.Pad opened /tmp/sylph-vgamepad.fifo, "the vgamepad server's FIFO".
That server was removed when the uinput pad was replaced by Canary's --hid=file
driver, because a uinput device is not namespaced and scripted presses leaked to
the host's desktop. The FIFO is now an ordinary 91-byte file nothing reads, and
/tmp/xenia_pad.txt - the file the emulator polls - was 0 bytes while the
"autopilot" was flying. So every axis, trigger and button from pilot.py,
autopilot3.py, aim_probe.py and flight_probe.py went nowhere, silently.

The corpus already carried this trap for the SHELL scripts
(canary-scripted-input-traps.md, "every call here failed silently"). This class
was missed, and every flight tool imports it.

Verified against the oracle rather than by inspection, on runs confirmed
animating at both ends of every phase: before, full stick produced 0.00 degrees
of heading change over 4 s while the ship travelled 350-735 units, and the
attitude matrix at pos-0x70 was byte-identical; after, LX=-1 turns 12.72 degrees
and LX=+1 swings the flight direction from [1,0,0] to [0.13,-0.14,-0.98], with
the matrix moving 0.44/0.31 under stick and 0.0000 at neutral.

That also REFUTES the "stale attitude matrix" suspicion from the earlier pass -
pos-0x70 is live and tracks the ship; it only looked dead because nothing was
turning the ship.

Still open and said plainly: with the pad fixed a 150 s pilot run still fires 0
times, with |aim yaw| still exactly 90.0 and the target 36-43 km away. Steering
works now, so what is left is the stick SIGN against the pilot's error convention
or a target selection that commits to something too far to close. Both are
finally testable.

findrot_global/findself/findspeed/selfstate still write to the dead FIFO and now
say so in place; they are not repaired because none has been re-run since.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PMRJjbxLqZtsb5Vb7KunPE

tools/re-capture/flight_probe.py

@@ -19,44 +19,91 @@ import time
 sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
 import gworld  # noqa: E402
 
-FIFO = "/tmp/sylph-vgamepad.fifo"
+# (the old vgamepad FIFO constant is gone with the server it named)
 
 
 class Pad:
-    """Talk to the vgamepad server directly over its FIFO.
+    """Drive Canary's `--hid=file` pad by rewriting its state file.
 
-    The `vgamepad` CLI spawns a process per command (~20 ms); a control loop
-    cannot afford that, and `tap`/`hold` additionally sleep *inside* the server.
-    Writing lines to the FIFO ourselves keeps a tick under a millisecond.
+    🔴 REWRITTEN 2026-08-23, and this is the whole reason `pilot.py` never fired.
+    This class used to write lines to `/tmp/sylph-vgamepad.fifo`, "the vgamepad
+    server's FIFO". That server does not exist any more — the uinput pad was
+    replaced by the `--hid=file` driver, because a uinput device is not
+    namespaced and every scripted press leaked to the HOST's desktop. The FIFO is
+    now an ordinary 91-byte file that **nothing reads**, so every axis, trigger
+    and button this class emitted went nowhere, silently, and the craft flew on
+    its own for the whole of every "autopilot" run.
+
+    The corpus already carries this exact trap for the MENU path
+    (`canary-scripted-input-traps.md`: "pad.py, NOT vgamepad … every call here
+    failed silently"). The shell scripts were fixed then; this class was not, and
+    every flight tool imports it — `pilot.py`, `autopilot3.py`, `aim_probe.py`,
+    `flight_probe.py` itself.
+
+    Measured symptom, on a run confirmed to be animating throughout: full left
+    and full right stick for four seconds each, and the ship's **velocity
+    direction did not move by 0.01°** — heading change 0.00° in every phase while
+    it travelled 350–735 units. With this rewrite the same probe is what checks
+    the fix.
+
+    Format is the driver's own (`file_input_driver.h`): `key=value` pairs, with
+    `press=A,START`, `lt`/`rt` 0..255 and `lx`/`ly`/`rx`/`ry` -32768..32767.
+    Written through a temp file and renamed, so a poll can never see a partial
+    state; the driver re-parses on any nanosecond-mtime or size change.
     """
 
+    PATH = os.environ.get("XENIA_PAD_FILE", "/tmp/xenia_pad.txt")
+
     def __init__(self):
-        self.f = open(FIFO, "w", buffering=1)
-        self.state = {"LX": 0.0, "LY": 0.0, "RX": 0.0, "RY": 0.0, "LT": 0.0, "RT": 0.0}
+        self.state = {"LX": 0.0, "LY": 0.0, "RX": 0.0, "RY": 0.0,
+                      "LT": 0.0, "RT": 0.0}
+        self.buttons = set()
+        self._write()
+
+    def _write(self):
+        parts = []
+        if self.buttons:
+            parts.append("press=" + ",".join(sorted(self.buttons)))
+        for k, key in (("LT", "lt"), ("RT", "rt")):
+            v = int(round(max(0.0, min(1.0, self.state[k])) * 255))
+            if v:
+                parts.append(f"{key}={v}")
+        for k, key in (("LX", "lx"), ("LY", "ly"), ("RX", "rx"), ("RY", "ry")):
+            v = int(round(max(-1.0, min(1.0, self.state[k])) * 32767))
+            if v:
+                parts.append(f"{key}={v}")
+        tmp = self.PATH + ".tmp"
+        with open(tmp, "w") as f:
+            f.write(" ".join(parts))
+        os.replace(tmp, self.PATH)
 
     def axis(self, name, v):
         self.state[name] = v
-        self.f.write(f"axis {name} {v:.3f}\n")
+        self._write()
 
     def trig(self, name, v):
         self.state[name] = v
-        self.f.write(f"trig {name} {v:.3f}\n")
+        self._write()
 
     def press(self, b):
-        self.f.write(f"press {b}\n")
+        self.buttons.add(b.upper())
+        self._write()
 
     def release(self, b):
-        self.f.write(f"release {b}\n")
+        self.buttons.discard(b.upper())
+        self._write()
 
     def reset(self):
-        self.f.write("reset\n")
         for k in self.state:
             self.state[k] = 0.0
+        self.buttons.clear()
+        self._write()
 
     def vector(self):
         return [self.state[k] for k in ("LX", "LY", "RX", "RY", "LT", "RT")]
 
 
+
 # (duration_s, description, action)
 SCRIPT = [
     (3.0, "idle", lambda p: p.reset()),