Files
BT411/context/glass-cockpit.md
T
arcattackandClaude Fable 5 5ba5697a08 Fix glass panel dead-button crash: null-init MessageHandlerSet gap slots (Gitea #18)
Clicking a per-display glass Engineering panel button (0x21 on an Eng page)
hard-crashed via a wild call through an uninitialised pointer (eip=cdcdcdcd
debug / 0x01048748 release), zero btl4 frames above Receiver::Receive.

Root cause is the dense message-handler-table gap hazard (reconstruction-
gotchas #11), the message-side twin of the attribute-table one -- NOT a /FORCE
unresolved external (the glass link log carried only the known-benign mech3.obj
CreateStreamedSubsystem set). Receiver::MessageHandlerSet::Find(id) returns
messageHandlers[id-1].entryHandler for any id <= entryCount with no populated-
check, and Receive() calls it when != NullHandler. The streamed Eng-page .CTL
dispatches subsystem msg id 3/0xb to whatever subsystem is shown; a weapon
(Emitter) registers only PoweredSubsystem 4-8 + MechWeapon 9-10, so id 3 is a
gap below entryCount 10. Build did new HandlerEntry[entryCount] and left gaps
uninitialised -> (this->*garbage)(msg). The 1995 binary has the identical non-
zeroing new[] (part_002.c Build) and survived only on fresh-heap-zero luck: a
weapon receiving id 3 was always meant to IGNORE it (id 3 = a Condenser/
Reservoir action in a different subsystem branch; the uniform Eng-page button
template makes buttons for unimplemented actions authentically inert). The new
per-display windows just made the id reachable live.

Fix (engine, class-wide, faithful): Build now null-inits every slot
(entryID=0/entryName=""/entryHandler=NullHandler) before copying inherited /
placing supplied, so a gap is deterministically NullHandler -> Receive drops it
(the authentic "Receiver ignores unhandled messages"), with an empty never-NULL
name so the name-based Find() strcmp can't deref a gap. Correct dispatch
contract, not a glass-path guard -> protects the whole dead-button class (#14).

Also lands the [glasswin] CLICK crash-forensics log (names the button before
dispatch).

Verified under cdb: click-soaked every MFD bank (Engineering/L+R Weapons/Heat/
Comm, ~130 clicks through Quad<->Eng page cycles) -> zero AVs, reconstructed
mapper preset selects still fire ([mode] preset (1,1)/(2,1)...); pod build +
solo mission un-regressed.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-20 15:59:37 -05:00

163 lines
12 KiB
Markdown

---
id: glass-cockpit
title: "Glass Cockpit — the desktop developer layer (BT_GLASS / BT_STEAM)"
status: living
source_sections: "plan 2026-07-17; CMakeLists.txt gates; BT412 prior art (reference only)"
related_topics: [pod-hardware, build-and-run, multiplayer, gauges-hud]
key_terms: [PadRIO, miniconsole, glass-cockpit]
open_questions: []
---
# Glass Cockpit — the desktop developer layer
**Purpose:** developer tooling so game developers can test their work WITHOUT booting a Tesla II
pod — and stay far enough out of the game that nothing a real pod requires can break. NOT a
consumer product (GDI-grade UI is the ceiling). Pod fidelity outranks desktop convenience in
every trade-off.
## The compile gates (the ONLY compile-time feature gates in the tree)
| Gate | Default | Adds |
|---|---|---|
| `BT_GLASS` | OFF | PadRIO input (XInput+keyboard), per-display cockpit windows (or the legacy single button panel), desktop plasma window, `glass` platform preset, miniconsole mission launcher |
| `BT_STEAM` | OFF (requires `BT_GLASS`) | Steam transport (`ISteamNetworkingSockets`) + `ISteamMatchmaking` lobby |
- A **no-flags configure is the pure pod game** — the build of record. `cmake` options are
cached, so a developer configures a `build/` with `-DBT_GLASS=ON` once.
- Build dirs: `build-pod/` (defaults, purity), `build/` (dev, glass ON), `build-steam/` (ON/ON).
- **Convention:** `BT_GLASS`/`BT_STEAM` are compile gates; every other `BT_*` name is a RUNTIME
env gate (`BTEnvOn`) — do not add compile gates without updating this file.
- No weak-linkage/optional symbols — `/FORCE` turns unresolved externals into runtime AVs
([[reconstruction-gotchas]]); gated calls must be structurally present-or-absent at compile time.
## Plan of record (2026-07-17)
Working branch `glass-cockpit` (from master `e2c21c4`). Steps: (1) gates+scaffolding [THIS],
(2) PadRIO glass cockpit, (3) miniconsole self-launch, (4) Steam transport+lobby. Full plan:
the approved plan file; running detail: `docs/GLASS_COCKPIT.md`. The retired BT412 trees
(`C:\VWE\BT412`; local branch `local-abandoned-20260717`) are read-only reference — no code is
copied from them.
## Status
- **Step 1 (gates + scaffolding): DONE 2026-07-17.** CMake options + defines; 3-config
configure matrix + negative test + defaults build verified.
- **Step 2a (.CTL id audit): DONE 2026-07-17 [T2].** The streamed `.CTL` positional ids landed
every `MechControlsMapper` record ONE MEMBER LATE (our chain starts at 2, the binary's at 3)
— a latent REAL-POD bug (RIO throttle would drive pedalsPosition), masked on dev boxes by the
keyboard bridge. Fixed ungated: ids pinned to binary numbering + id-2 pad + static_assert
locks (`mechmppr.hpp/.cpp`); torso/weapon chains were already aligned. Permanent env-gated
diagnostic: `BT_CTRLMAP_LOG=1` dumps every streamed record's resolved member offset
(`L4CTRL.cpp CreateStreamedMappings`). Full evidence: `docs/GLASS_COCKPIT.md` §2a.
- **Step 2 (PadRIO glass cockpit): DONE 2026-07-17 [T2].** `RIOBase` seam (`L4RIO.h`,
unconditional) + gated `L4CONTROLS=PAD``PadRIO` (`L4PADRIO.*` XInput+keyboard,
`L4PADBINDINGS.*` `content\bindings.txt`); bridge stand-downs auto-yield to a live device
(`BTRIODevicePresent`, `BT_KEY_BRIDGE` unset=auto/0=off/1=on); on-screen panel `L4PADPANEL.*`
follows **vRIO** (`C:\VWE\vrio` CockpitLayout/PanelCanvas — 104 controls incl. the two hex
keypads → real KeyEvents; right-click latch); desktop plasma `L4PLASMAWIN.*`
(`L4PLASMA=SCREEN`, buffer is top-down); `-platform glass` preset + run.cmd token. Secondary
displays reuse the EXISTING dev-gauge modes (dock / `BT_DEV_GAUGES_WINDOW=1` window /
`_DOCK=1` overlay — [[gauges-hud]]); no new MFD code, no `L4VB16.cpp` exposure.
**Button-trap guard:** base `ConfigureMappableMessageHandler` no longer `abort()`s by default
(`BT_BUTTON_TRAP=1` restores) — each `[FAIL]` log = a missing L4 override to reconstruct.
Verified: authentic-path input (engine push → streamed `.CTL` → mapper), panel-click
survival, 2-node loopback MP un-regressed on the pod build. Detail: `docs/GLASS_COCKPIT.md`.
- **Step 3 (miniconsole): DONE 2026-07-17 [T2].** `game/glass/btl4fe.*` (menu + console-shape
egg writer, golden-tested vs MP.EGG) + `btl4console.*` (the marshal: a worker-thread console
CLIENT speaking the btconsole.py wire verbatim; `content\marshal.log`). ZERO engine hooks —
the engine runs the stock console ladder. Per-mission process relaunch; `BT_FE_*` env arms the
marshal (menu relaunches clear it). Verified: solo cycle (menu→mission→60s clock→stop→menu)
and menu-hosted 2-node LAN.
- **Step 4 (Steam): CODE COMPLETE 2026-07-18 [T2 single-machine].** See [[steam-networking]] —
the wire seam + `L4STEAMNET` identity-token transport + `btl4lobby`. Live 2-account
cross-machine session pending (`docs/STEAM_TEST.md`).
- **Input-coverage audit + keyboard reconciliation: DONE 2026-07-20 [T2].** Root cause of the
dead panel: `MechRIOMapper`'s message ids were chained one enum too high (0x19-0x2a) — the
binary RIO table @0051dd30 re-registers the BASE aux/zoom ids 3..0x13 (Hotbox 0x1a); fixed
ungated + static_assert-locked (`btl4mppr.hpp`) → all 24 MFD-bank + 2 zoom buttons live
(52/72 panel buttons now work; 8 dead await handler reconstruction — Gitea backlog issue;
12 have no streamed mapping authored, authentically inert). **Keyboard = the ~20 core
gameplay actions on the CONTROLS.MAP keys; the PANEL covers every pod address by click**
(right-click = hold latch) — the merged default profile lives in `L4PADBINDINGS.cpp`
(auto-writes `content\bindings.txt`; W/S/A/D/Q/E/R/F/X drive, 1-4/Space/Ctrl fire, M/N/H/C =
pod buttons 0x18/0x15/0x2C/0x2F, `/V view toggle + J/K/L preset cycles hardcoded in PadRIO).
Bound keys are SUPPRESSED from the typed 1995 channel (`PadRIO::SuppressKey`, the btinput
pattern — ended the glass double-dispatch: 'w'=pilot-select, numpad/F-key key-up aliases);
unbound keys keep their authentic meanings (5/z presets, t-o pilot select, +/- zoom).
In BAS control mode the pod turns with the STICK (Q/E) and pedals are inactive — authentic;
A/D turn in MID/ADV. Arrow keys mirror the drive cluster (UP/DOWN = the W/S throttle lever,
LEFT/RIGHT = the A/D pedals). Full audit + census: `docs/GLASS_COCKPIT.md` §2026-07-20.
- **2026-07-20 live "keymap regression" report: STALE EXE [T2].** The human-reported glass
regressions (arrows/lever/detent dead, V/J/K/L/N inert, ground-fire) were a
`build-glass/Release/btl4.exe` built BEFORE 5dd3536 landed — relaunched without rebuilding.
No input-code change was needed; a clean rebuild + full SendInput re-verification (lever
holds + zero stop, MID turns, V toggle shot-pair, level boresight, pod smoke) closed every
symptom, and V's edge is now [T2]. `BT_MPPR_TRACE` now prints mode/pedals/stick/turn/elev.
Procedural rule: rebuild every live build dir after landing an input/engine commit.
Detail: `docs/GLASS_COCKPIT.md` §2026-07-20 (later).
- **2026-07-20 human re-test: GAIT DETENT ported to the PadRIO lever [T2].** The remaining
"our detent is missing" (mixed walk/run mode + repeated accel sample) was the gait DEAD BAND
([[locomotion]]): the pod-build keyboard lever snaps out of the walk/run hysteresis band at
key-rest (mech4.cpp GAIT DETENT), and the PadRIO throttle slew lacked it. Ported faithfully:
mech4.cpp publishes the band in lever units (`gBTGaitDetentLo/Hi` seam, +0.002 engage
margin), `L4PADRIO.cpp` applies the identical nearer-edge snap when no throttle slew key/pad
axis is active. Verified: parks at 0.414/0.465 snap to 0.358/0.504 (band = demand
22.02-30.87), no at-rest sample in-band, exactly ONE up-shift + ONE down-shift clip across a
full graduated sweep, zero-stop + pod build unaffected. Detail: `docs/GLASS_COCKPIT.md`
§2026-07-20 (later still).
A/D turn in MID/ADV. Full audit + census: `docs/GLASS_COCKPIT.md` §2026-07-20.
- **Per-display cockpit windows (`BT_GLASS_PANELS`): DONE 2026-07-20 [T2 startup-verified].**
The `-platform glass` preset now breaks the secondary displays out of the single combined
panel/strip into ONE desktop window PER pod display, each carrying that display's surface
WITH its RIO button bank placed around it, arranged pod-faithfully around the main view
(`engine/MUNGA_L4/L4GLASSWIN.*`, new TU). Windows: **Heat (UL) / Mfd2 (UC) / Comm (UR) /
Mfd1 (LL) / Mfd3 (LR)** each with 8 RED MFD buttons split 4 above / 4 below the surface;
**Secondary/Radar** (portrait `sec`) with the 12 YELLOW Secondary buttons split left/right;
a **Flight Controls** window for the no-display banks (throttle 0x38-3F, joystick/fire
0x40-47, panic). Each window is a GDI window (like [[gauges-hud]]'s pad panel + the plasma
window) — the surface is CPU-expanded from the shared gauge buffer
(`SVGA16::ExpandPlaneToBGRA`, no D3D) and `StretchDIBits`'d in, so the **whole D3D
dev-composite path (dock / separate window / overlay) stands down** while these are up
(`BTDrawGaugeInset`/`BTGaugeWindowRenderAndPresent` early-return; no `gBTGaugeDockBottom`
strip). Runtime gate **`BT_GLASS_PANELS`** (default ON under `-platform glass`, `=0` falls
back to the single pad panel + docked gauges) — read by `L4PADRIO` (which panel to create),
`L4VB16` (suppress compositing), and `btl4main` (skip the world-window dock strip). The
display↔bank map (spine of the feature): Heat 0x28-2F, Mfd2 0x20-27, Comm 0x30-37,
Mfd1 0x08-0F, Mfd3 0x00-07, sec 0x10-1B ([[pod-hardware]] §Bank→MFD). Verified: build +
bounded glass launch — `[glasswin] per-display cockpit up (7 windows…)`, no crash, full
mission loop un-regressed; surfaces carry LIVE gauge content (`BT_GLASS_LOG` = per-surface
resolve/pixel diagnostic). Layout constants (surface sizes, exact button sub-positions,
yellow left/right split) are marked tunable in `L4GLASSWIN.cpp`. Detail: `docs/GLASS_COCKPIT.md`.
⚠ **Bug found + fixed during bring-up:** surfaces were blank because `application`/`ghWnd` are
duplicate-defined globals that bind non-deterministically under `/FORCE` — the fresh
`L4GLASSWIN` TU read `application == NULL` → gauge renderer NULL. Fix: reach the
renderer/window via `BTResolveGaugeRenderer()`/`BTResolveMainWindow()`, DEFINED in
`game/btl4main.cpp` off its real `btl4App`/`hWnd` pointers (never the globals directly). See
[[reconstruction-gotchas]] §6 duplicate-GLOBAL corollary.
- **Glass per-display panel button click-crash (Gitea #18): FIXED 2026-07-20 [T2].** Clicking a
per-display Engineering panel button (0x21 reported) on an **Eng page** hard-crashed — cdb: a
wild call through an uninitialised pointer (`eip=cdcdcdcd` debug / `0x01048748` release) with
**zero btl4 frames above `Receiver::Receive`**. Root cause was NOT a `/FORCE` unresolved
external (the glass link log carried only the known-benign `mech3.obj` `CreateStreamedSubsystem`
set) but a **dense message-handler-table GAP slot** ([[reconstruction-gotchas]] §11): the
streamed Eng-page `.CTL` dispatches subsystem msg **id 3 / 0xb** to whatever subsystem is shown,
and a **weapon (Emitter)** registers only PoweredSubsystem 4-8 + MechWeapon 9-10 — so id 3 is a
gap below `entryCount`, and `Receiver::MessageHandlerSet::Build`'s `new HandlerEntry[]` left it
as heap garbage → `(this->*garbage)(msg)`. The 1995 binary has the identical non-zeroing
`new[]` and survived only on fresh-heap-zero luck (id 3 on a weapon was always meant to be
IGNORED — it's a Condenser/Reservoir action in a different subsystem branch; the uniform
Eng-page button template makes buttons for unimplemented actions authentically inert). The new
per-display windows just made the id reachable live. **Fix (engine, class-wide, faithful):**
`Build` null-inits every slot (`entryID=0/entryName=""/entryHandler=NullHandler`) before
copying inherited / placing supplied, so a gap is deterministically NullHandler → `Receive`
drops it — the authentic "Receiver ignores unhandled messages", not a glass-path guard. Fixes
the entire dead-button class (#14) at once. Verified: click-soaked every MFD bank
(Engineering/L+R Weapons/Heat/Comm, ~130 clicks through Quad↔Eng page cycles) under cdb — ZERO
AVs, and the reconstructed mapper preset selects still fire (`[mode] preset (1,1)/(2,1)…`); pod
build + solo un-regressed. The `[glasswin] CLICK` forensics log (names the button before
dispatch) landed with this. Detail: `engine/MUNGA/RECEIVER.cpp` Build.
## Key Relationships
- Extends: [[pod-hardware]] (RIO input path) · Uses: [[gauges-hud]] dev-gauge modes ·
Feeds: [[multiplayer]] (miniconsole hosting, Steam transport) · Build: [[build-and-run]]