Cockpit: the authentic punch STENCIL-CUT -- all 8 cockpits real (task #55)

The user caught the inversion (blocked viewports, see-through frames); the
answer came from the rasterizer board itself: an i860 disassembly of the
VREND.MNG firmware decoded the damageize handler (@0xf040f6f8) -- cmd 0x20
(vr_damage_action) writes the dpl_Punchize token triple onto the punch
geogroup's first three geometry chunks IN FILE ORDER:

  chunk1 = the detailed window-aperture shapes -> an invisible per-pixel MASK
  chunk2 = the coarse hull -> the ONLY colour-drawn geometry (where not masked)
  chunk3 = byte-identical hull twin -> the damage-reset record, never visible

Visible canopy = hull-minus-apertures.  Both earlier readings were wrong ways
around the same three chunks: dropping all punch left floating fragments (no
hull); hiding the duplicate pair hid the HULL and drew the MASK -- the exact
inversion observed.

Port: bgfload tags per punch patch {non-paired pmesh = mask (role 1),
first twin = hull (role 2), second twin = skip}; L4D3D DrawMesh runs
mask->stencil-1 (no colour/z-write, z-tested), hull->stencil-NOTEQUAL,
mask->stencil-0; device D24X8 -> D24S8 + stencil clear.  The cut never
touches z, so later-drawn entities show through the apertures.
BT_COP_PLATES=1 disables (diag).

In-game, all 8 mechs on pure defaults: connected dark frames with clear
viewports -- thor (the footage mech) shows the central viewport + surrounding
frame exactly as filmed.  Combat regression clean (kill + no NaN).

Arena textured punch uses the same firmware kit; the black-texel alpha path
there is a working approximation, flagged in the KB.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

context/decomp-reference.md

@@ -56,7 +56,7 @@ reconciled via `CLASSMAP.md`, not the case label. [T1]
 | 0xBC1 | **Generator** | @4b… | power bus |
 | 0xBC2 | **PoweredSubsystem** | @004b0f74 | sizeof 0x31C |
 | 0xBC3 | **Sensor** | — | `case`=MyomersClassID |
-| 0xBC4 | **Gyroscope** | @004b3778 | DEFERRED (NaN integrator; reverted to stub) |
+| 0xBC4 | **Gyroscope** | @004b3778 | LIVE (task #56: byte-exact ctor/integrators/writers; hit-bounce fan-out wired) |
 | 0xBC5 | **Torso** | @004b6b0c | sizeof 0x280; `case`=SinkSource |
 | 0xBC6 | **Myomers** | @4b8fec | `case`=Actuator; INERT un-stub |
 | 0xBC8 | **Emitter** | @004b1d18 | sizeof 0x478; energy weapon |
@@ -188,6 +188,14 @@ recoil @4bc136-4bc19c (damage>3 → (0,0.6,−1.5) × damage/16; `gyroRumbleTime
 ex-"clipLoadGuard").  Byte tooling: `scratchpad/dis_4b2980.py` / `dis_range.py` over
 `reference/decomp/section_dump.txt`.
 
+**PUNCH firmware decode** [T1] (the definitive mechanism, 2026-07-11): cmd 0x20 =
+vr_damage_action (VR_PROT.H enum); the i860 firmware content/VREND.MNG (code @0xf0400000)
+handler 'damageize' @0xf040f6f8 writes the token triple onto the geogroup's first THREE
+geometry-list nodes' geometry_type@+8 IN FILE ORDER (superlist appends at tail @0xf040c620);
+DPL_PRIV.H names the roles: f_t_dam(0x92)/sca(0x05)/undamage(0x04)/f_t_undam(0x17)/
+damage_set(0x03).  Punchize triple = mask, hull, reset-twin -- the visible surface is the HULL
+with the MASK shapes stencil-cut through it.  Disassembler: scratchpad/i860dis.py.
+
 **Cockpit-eye / punch addresses** [T1] (full story: [[cockpit-view]]): eye ctor
 **`FUN_004579a8`** (part_007.c:9274 = DPLEyeRenderable; offset = segment `GetBaseOffset`
 segment+0x74, parent = parent-segment DCS; caller part_014.c:5525-66 gates on `"siteeyepoint"`);