rrt/docs/README.md

# RT3 Reverse-Engineering Handbook

This handbook is the project bootstrap for reverse-engineering and rewriting Railroad Tycoon 3.
It is written for future us first: enough structure to resume work quickly, without pretending the
project is already mature.

## Canonical Target

- Canonical executable: `rt3_wineprefix/drive_c/rt3/RT3.exe` (patch 1.06)
- Reference executable: `rt3_wineprefix/drive_c/rt3_105/RT3.exe` (patch 1.05)
- Canonical SHA-256: `01b0d2496cddefd80e7e8678930e00b13eb8607dd4960096f527564f02af36d4`
- Reference SHA-256: `9e96b0695cb722a700f99c8dce498d34da7235e562b1e275bcc1764f8c9b7eb1`

## Documents

- `setup-workstation.md`: toolchain baseline and local environment setup.
- `re-workflow.md`: how to analyze the binary, record findings, and export reusable artifacts.
- `function-map.md`: canonical schema and conventions for function-by-function mapping.
- `control-loop-atlas.md`: curated atlas of top-level loops, gateways, and subsystem handoffs.

## Repo Conventions

- `docs/`: stable project guidance and durable design notes.
- `tools/py/`: committed Python helpers for analysis and validation.
- `artifacts/exports/`: committed derived outputs that can be regenerated.
- Local-only state stays untracked: `.venv/`, Ghidra projects, Rizin databases, crash dumps, and other
  bulky/generated working files.

## Current Baseline

The current technical milestone is a repeatable loop-mapping workflow for the 1.06 executable.
Before injection work or deep file-format work, we capture:

- executable hashes and PE metadata
- section layout, imports, and notable strings
- a starter subsystem inventory plus a control-loop atlas
- focused address and string context exports for branch-deepening passes
- a reusable CLI RE kit for branch dossiers where the atlas needs deeper grounding
- a stable curated function ledger in `artifacts/exports/rt3-1.06/function-map.csv`

Current coverage is broad enough to support future sessions without rediscovery, especially in:

- CRT startup and bootstrap handoff
- shell frame, layout, presentation, deferred-message, and frontend overlay flow
- Multiplayer.win UI, chat, session-event, and transport ownership
- map/scenario load and text-export paths
- shared support layers such as intrusive queues, vectors, hashed stores, and tracked heaps

README maintenance rule:

- Keep this section at subsystem level only.
- Do not mirror per-pass function additions here.
- Detailed mapping progress belongs in `artifacts/exports/rt3-1.06/function-map.csv` and the derived branch artifacts under `artifacts/exports/rt3-1.06/`.

Current local tool status:

- Ghidra is installed at `~/software/ghidra`
- `~/software/ghidra/ghidraRun` launches successfully in an interactive shell
- Rizin is installed and available on `PATH`
- `winedbg` works with `rt3_wineprefix`
- RT3 launches under `/opt/wine-stable/bin/wine` when started from `rt3_wineprefix/drive_c/rt3`

## Next Focus

The next milestone is breadth first. The highest-value passes are:

- promote `docs/control-loop-atlas.md` into the primary human-readable artifact for high-level flow
- name and connect the major loop roots and gateways for startup, shell/UI, frame or presentation,
  simulation, map/scenario load, input, save/load, and multiplayer/network
- use `export_startup_map.py` and `export_analysis_context.py` to widen breadth around candidate loop
  dispatchers before doing deep leaf naming
- keep the pending-template and multiplayer transport dossiers available, but treat them as targeted
  deep-dive tools once a missing atlas edge needs branch-specific grounding
- stand up the Rust workspace so artifacts can be validated in code and a minimal hook DLL can be
  built as soon as the 32-bit linker is present

Regenerate the initial exports with:

```bash
python3 tools/py/collect_pe_artifacts.py \
  rt3_wineprefix/drive_c/rt3/RT3.exe \
  artifacts/exports/rt3-1.06
```

Regenerate the startup-focused Ghidra exports with:

```bash
python3 tools/py/export_startup_map.py \
  rt3_wineprefix/drive_c/rt3/RT3.exe \
  artifacts/exports/rt3-1.06
```

That default export now walks two roots:

- `entry:0x005a313b`
- `bootstrap:0x00484440`

For a focused branch-deepening pass, regenerate the analysis context exports with:

```bash
python3 tools/py/export_analysis_context.py \
  rt3_wineprefix/drive_c/rt3/RT3.exe \
  artifacts/exports/rt3-1.06 \
  --addr 0x00444dd0 \
  --addr 0x00508730 \
  --addr 0x00508880 \
  --string gpdLabelDB \
  --string gpdCityDB \
  --string 2DLabel.imb \
  --string 2DCity.imb \
  --string "Geographic Labels"
```

For the pending-template dispatch-store branch, regenerate the new branch dossier with:

```bash
python3 tools/py/rt3_rekit.py \
  pending-template-store \
  rt3_wineprefix/drive_c/rt3/RT3.exe \
  artifacts/exports/rt3-1.06
```

That dossier is now a targeted follow-up tool, not the default first pass.