pilot: RB fires, Y is the main mount, and guided missiles produce the first kills

fire_probe.sh holds each pad input in flight and photographs the HUD ammo
counters. RB moves NOSE BM 06000 -> 05956 in 4 s (~11 rounds/s, HEAT rises);
Y moves MAIN MPM 00300 -> 00299; nothing else moves either counter. So the
control mapping is measured rather than assumed, and 'we never shoot' is dead:
we shoot and miss.

The disc data says to stop shooting: Shell_TCAF_DeltaSaber_Missile_P is Power
200, GuidanceType 5 (guided), MaximumRange 5000, versus the nose gun's Power 15
unguided — one missile is worth ~14 gun hits on a 500 HP fighter and it steers
itself. Launching them (press Y, release a tick later, >=2 s apart) produced
YOU KILLED: WARPLANES 0002 — the first non-zero kill counter of the series,
against 0000 in all five gun-only runs, with hostiles down 134 -> 104.

Still only 2 kills per 98 missiles (~2%). Likely cause: the game expects a lock
before launch and an unlocked missile is wasted. Reading the lock state out of
RAM is the next step.

docs/re/mission-escort-state.md

@@ -147,10 +147,35 @@ angular half-size **alone** (2.7° at 2584 units for a fighter) is far tighter t
 steering loop can hold the nose, and firing collapsed to 1 frame in 2639. Angular size
 belongs in the gate as a **floor** that opens it up close, never as a cap.
 
-**Open (next):** find out why nothing dies. The cheap decisive test is whether the
+### Why nothing died — settled by probe, then fixed
-`RB` command discharges the gun at all — the HUD carries a live ammo count
+
-(`MAIN MPM 00300`, which the weapon RE matched to `LoadingCount`), so holding fire and
+`fire_probe.sh` holds each pad input in turn in flight and photographs the HUD ammo
-watching that number settles "we never shoot" vs "we shoot and miss" in one run.
+counters. Result:
+
+| input | `NOSE BM` | `MAIN MPM` |
+|---|---|---|
+| idle | 06000 | 00300 |
+| **RB** | **05956** (−44 in 4 s, HEAT rises) | 00300 |
+| **Y** | 05951 | **00299** (−1) |
+| LB / X / B / A / RT / LT | no change | no change |
+
+So **`RB` is the nose gun (~11 rounds/s) and `Y` is the main mount** — measured, not
+assumed — and the "we never shoot" hypothesis is dead: **we shoot and miss.**
+
+Which is what the disc data says to stop doing. `Shell_TCAF_DeltaSaber_Missile_P` is
+**Power 200, `GuidanceType` 5 (guided), `MaximumRange` 5000**, against the nose gun's
+**Power 15, unguided**. One missile is worth ~14 gun hits on a 500 HP fighter *and it
+steers itself* — the accuracy problem solved rather than tuned. (`ASMissile_P` is
+Power **5000**, the anti-ship option.)
+
+Adding missile launches to the pilot (press `Y`, release a tick later, ≥2 s apart)
+produced **the first kills of the whole series: `YOU KILLED: WARPLANES 0002`**, versus
+`0000` in all five gun-only runs, with hostiles down 134 → 104 (the largest fall yet).
+
+**Still poor, and stated as such: 98 missiles for 2 kills (~2 %).** The likely cause is
+that the game expects a *lock* — holding the target in the reticle before launch — and
+an unlocked launch is wasted. Reading the lock state (or the lock timer) out of RAM is
+the next step, and it is the same anchoring trick as everything else here.
 
 ## Reimplementation notes
 

tools/re-capture/fire_probe.sh

@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+# Does the pad actually DISCHARGE a weapon? Hold each candidate input in turn
+# and photograph the HUD's ammo counters.
+#
+# Why this exists: the autopilot's HUD kill counters read WARSHIPS 0000 /
+# WARPLANES 0000 at the end of every run, in every targeting configuration, so
+# "fraction of frames with the guns commanded on" was never measuring anything.
+# Before tuning aim any further, settle the prior question — whether the fire
+# command reaches the gun at all. The HUD carries a live ammo count (`MAIN MPM
+# 00300`, matched to `LoadingCount` by the weapon RE), so the counter falling
+# during a hold is direct evidence of a discharge, and the counter sitting still
+# through every button is direct evidence that we have never fired a shot.
+#
+# `RB fires` came from an earlier session; this re-tests it rather than assuming
+# it, and sweeps the other buttons so a wrong mapping cannot hide.
+set -u
+export HOME=/sylph-home/re SDL_AUDIODRIVER=dummy DISPLAY=:98
+export PYTHONPATH=/sylph-home/.local/lib/python3.12/site-packages
+SD="$(cd "$(dirname "$0")" && pwd)"
+SHOTS=/sylph-home/re/shots
+HOLD="${1:-4}"
+
+shot(){ screenshot "$SHOTS/fire-$1.png" >/dev/null 2>&1; echo "  shot $1"; }
+
+"$SD/launch_mission.sh" fly || { echo "BOOT FAILED"; exit 1; }
+sleep 3
+echo "=== probing (hold ${HOLD}s each) ==="
+shot "00-idle"
+
+# RB first: it is the incumbent claim. Then the rest, so a wrong mapping cannot
+# hide behind it. A/B/X/Y may also switch weapon or open something — that is
+# fine for a probe, and the final frame records wherever it ended up.
+for b in RB LB Y X B A LS RS; do
+  vgamepad press "$b"; sleep "$HOLD"; shot "hold-$b"; vgamepad release "$b"; sleep 1.5
+done
+
+# triggers are analogue, not buttons
+vgamepad trig RT 1.0; sleep "$HOLD"; shot "hold-RT"; vgamepad trig RT 0.0; sleep 1.5
+vgamepad trig LT 1.0; sleep "$HOLD"; shot "hold-LT"; vgamepad trig LT 0.0; sleep 1.5
+vgamepad reset
+shot "99-final"
+echo "PROBE DONE"

tools/re-capture/pilot.py

@@ -77,6 +77,22 @@ SHELL_VELOCITY = 8000.0
 SHELL_MAX_RANGE = 4000.0
 SHELL_RADIUS = 20.0
 
+# The MAIN weapon, fired with Y — measured, not assumed: a hold-each-input probe
+# (fire_probe.sh) moved NOSE BM 06000 -> 05956 under RB and MAIN MPM 00300 ->
+# 00299 under Y, so RB is the nose gun (~11 rounds/s) and Y is the main mount.
+# That probe also settled the lethality question the other way round: we DO
+# shoot, so the kill counters reading 0000 mean we shoot and MISS.
+#
+# Which is exactly what the disc data says to stop doing. Shell_TCAF_DeltaSaber_
+# Missile_P is Power 200 with GuidanceType 5 (guided) and MaximumRange 5000,
+# against the nose gun's Power 15 unguided — one missile is worth ~14 gun hits
+# on a 500 HP fighter, and it steers itself, which is the accuracy problem
+# solved rather than tuned. Range is held under the confirmed 5000 because which
+# main weapon is actually loaded is not read from RAM yet.
+MISSILE_RANGE = 4000.0
+MISSILE_CONE = math.radians(20.0)
+MISSILE_PERIOD = 2.0      # s between launches; 300 rounds is not unlimited
+
 # Stage 02's protected asset. Named rather than derived: "the biggest friendly"
 # picks the f105 cruiser (30000 HP > the Acropolis's 25000), and "the friendly
 # with the most HP" picks it too, so neither rule finds the right ship. The
@@ -126,6 +142,9 @@ class Pilot:
         self.asset_hist = deque(maxlen=64)
         self.asset_hp0 = None
         self.asset_last_hit = -1e9
+        self.missile_down = False
+        self.missile_t = -1e9
+        self.missiles = 0
 
     def f32(self, off):
         b = os.pread(self.W.fd, 4, off)
@@ -431,17 +450,33 @@ class Pilot:
         aim_ok = abs(aim[0]) < cone and abs(aim[1]) < cone
         fire = bool(fire and tgt and aim_ok and tgt[4] < self.FIRE_RANGE and pn < 1.2)
 
+        # The main mount is a discrete launch, not a continuous stream: press Y
+        # and let go a tick later, then wait out MISSILE_PERIOD. Holding it
+        # would empty 300 rounds in half a minute.
+        msl = bool(tgt and self.mode in ("ENGAGE", "DEFEND")
+                   and tgt[4] < MISSILE_RANGE
+                   and abs(aim[0]) < MISSILE_CONE and abs(aim[1]) < MISSILE_CONE
+                   and pn < 1.2)
         if not self.dry:
             self.pad.axis("LX", sx)
             self.pad.axis("LY", sy)
             if fire != self.firing:
                 (self.pad.press if fire else self.pad.release)("RB")
                 self.firing = fire
+            if self.missile_down and t - self.missile_t > 0.15:
+                self.pad.release("Y")
+                self.missile_down = False
+            elif (not self.missile_down and msl
+                  and t - self.missile_t > MISSILE_PERIOD):
+                self.pad.press("Y")
+                self.missile_down = True
+                self.missile_t = t
+                self.missiles += 1
 
         msg = (f"{self.mode:<7} hull={hull:6.0f} shd={shield:6.0f} spd={speed:6.0f} "
                f"thr={self.throttle:+d} yaw={math.degrees(yaw):+6.1f} "
                f"pit={math.degrees(pitch):+6.1f} aim={math.degrees(aim[0]):+6.1f}"
-               f"/{math.degrees(aim[1]):+6.1f} fire={int(fire)}")
+               f"/{math.degrees(aim[1]):+6.1f} fire={int(fire)} msl={self.missiles}")
         if ast is not None:
             msg += f" ast={a_frac*100:5.1f}%"
             if a_dmg > self.ASSET_ALERT: