# Rebuilding RPL4.RES

`RPL4.RES` is Red Planet's resource file — every vehicle, map, model, damage
zone, control mapping and audio stream the game loads. It is *compiled* from
authored sources by `RPL4TOOL -b`, the original 1996 resource tool, which
still builds in this tree as `Release\RPL4TOOL.exe` (see `BUILD.md`).

Until now that pipeline did not work. `RPL4TOOL -b` aborted on the very first
model, so `assets/RP411/RPL4.RES` could only be consumed, never regenerated.
This folder makes it build again.

```powershell
# rebuild exactly what RP411 ships (minus the maps, see below)
powershell -ExecutionPolicy Bypass -File tools\resbuild\build-res.ps1

# ...plus the three vehicles that were cut after 4.10
powershell -ExecutionPolicy Bypass -File tools\resbuild\build-res.ps1 -RestoreCutVehicles
```

Output lands in `%TEMP%\rp412-resbuild\rpl4.res`. Inspect any resource file
with `Release\RPL4TOOL.exe -l <file>`; that listing is the acceptance test for
anything built here. **The result is not yet a drop-in replacement for
`assets/RP411/RPL4.RES`** — see *What is still missing*.

## Why it was broken

`RPL4TOOL -b` died in `PlugStream_FindEntryAndWriteObjectID` while building
`player.mod`'s audio stream, resolving `resource=Translocation01` from
`AUDIO/PLYINT.SCP`. That name is defined in no file in `CONTENT/RP`.

The first guess — that it needed the AWE32 soundbanks through
`AudioCard::LoadSBK`, which the Win32 port stubbed to `return 1` — was wrong.
Supplying the banks changes nothing, because nothing reads them at build time.

The real answer is `L4AudioResourceManager::CreateStaticAudioStreamResource`
(`MUNGA_L4/L4AUDRES.cpp`), which opens **`audio\static.scp`**. That file
declares all 154 of RP's patch resources as plain text:

```
[PatchLevelOfDetail]
bank_ID=2
patch_ID=29
name=Translocation01LOD1
...
[PatchResource]
audio_level_of_detail=0.0, Translocation01LOD1
name=Translocation01
```

Every model's audio script resolves its `resource=` names against those, so
without `static.scp` the first model aborts and no `.res` is ever written.
`CONTENT/RP/AUDIO` does not have it — but the sda4 developer drive does.

No engine change was needed. The pipeline was missing content, not code.

## What the build tree is made of

`build-res.ps1` assembles three sources, and never overwrites an authored file
with a shipped one — archival content stays authoritative where it exists.

| source | provides |
|---|---|
| `TeslaRel410\CONTENT\RP` | models, solids, gauge art, audio scripts, `RPL4.BLD` |
| `recovered\` (this folder) | `STATIC.SCP`, `VTVINT.SCP`, `VTVEXT.SCP` |
| `assets\RP411\` | `AUDIO1/2.RES` soundbanks, ~547 `VIDEO` files |

The three recovered scripts came from `TeslaRel410\sda4\RPDAVE\AUDIO` (identical
to `RPLIVE`) and are kept here because they are the keystone and are small.
`VTVINT.SCP` and `VTVEXT.SCP` are `[include]`d by 27 vehicle audio scripts and
are absent from `CONTENT/RP` as well.

The `VIDEO` gap is mostly `.SKL` skeletons — `MAN.SKL`, `BAN.SKL`, `BUN.SKL`,
`DUN.SKL` and their `S` variants. A model missing one logs
`video\<x>.skl is empty or missing!`, then `<model> has no Segments!`, and is
**silently dropped from the build** — the tool does not fail, it just produces
a resource file with fewer models. Always check the model count.

## What is still missing

**Eleven maps have no source in any tree.** The build reports each one and
carries on:

| map | source |
|---|---|
| `wise`, `yip`, `pain`, `blade`, `lyzlane` | only in `sda4\RPDAVE\MAPS` (1996 dev state, older than retail) |
| `otto`, `frstrm`, `burnt`, `brewers`, `headoff`, `headmf` | **nowhere** |

`CONTENT/RP/MAPS` has the `.CAM` camera files and `SOLIDS` has the `.XST`
existence boxes, but the `.MAP` files themselves are gone. So a build from
here produces 45 GameModels and **zero maps**, against RP411's 9. Until those
are recovered, this pipeline can rebuild vehicles but cannot replace the
shipped resource file.

## The three cut vehicles

`-RestoreCutVehicles` uncomments three lines in `RPL4.BLD` that were commented
out after 4.10 shipped, with their model IDs left in place:

```
//Armadillo Class
model=puck.mod       /id:19
//model=dark.mod       /id:56          <- dark puck
//Experimental Vehicles
//model=blktrn.mod     /id:47          <- black tornado
//model=blkspk.mod     /id:48          <- black speck
```

All three build clean, taking the model count from 42 to 45 — exactly retail's
count. Each gets its full resource set: GameModel, Model List, VideoModel,
Subsystems, Segments, DamageZones, ControlsMappings and GaugeImage.

Two caveats. `blktrn` has no audio script anywhere (`BLKTRN.SCP` is absent from
every tree) and no gauge block in `L4GAUGE.CFG`, so its cockpit panel has no
layout to select — `dark` and `blkspk` still have theirs. And nothing has been
verified in-game; building is not the same as playable.

See `docs/CONTROL-PRESETS.md` for what these vehicles carry and the preset
tables they shipped with.