Files
firestorm/MW4COMPARE/tools/decompile/verify_roundtrip.py
T
83478b7666 Add MW4COMPARE: .mw4 decompiler toolchain and V4H comparison harness
Tooling built to recover editable source for six 'Mech chassis that exist
in the parallel FS_Build_V4H build but not in this repo. Reverse-engineers
every compiled record type in the .mw4 package format back to the .data /
.instance / .subsystems / .damage / .contents / .torso / .engine /
.armature sources the content pipeline consumes.

Nothing here is wired into the game build. It is a standalone analysis
harness run from Linux.

Package format
--------------
"#VBD" container. Directory records are [len][name][FILETIME][origSize]
[storedSize][offset], payload base at dword 0x0C. A record is stored raw
when storedSize == origSize, otherwise LZW (9->12-bit LSB-first codes,
256=clear, 257=EOF, dict from 258), per Database.cpp:451.

GameModel records are flat /Zp4 structs following the C++ inheritance
chain Entity(0) -> Mover(28) -> MWObject(80) -> Vehicle(664) -> Mech(756),
1636 bytes total. CreateMessage records follow Replicator -> Entity ->
Mover -> MWMover -> MWObject -> Vehicle -> Mech from start=16 (the
undeclared Connection__Message header), ending at 341 and padded to 344.

tools/decompile/
----------------
  datamap.py        header-driven layout engine; CHAIN + ANCHORS
                    {Vehicle:664, Mech:756} assert the struct offsets
  mw4msg.py         CreateMessage reader/walker
  data.py           .data      constants.py  define/table symbol resolution
  damage.py         .damage    contents.py   .contents
  smallmodel.py     .torso + .engine         instance.py  .instance
  armature.py / armature_parts.py  .armature + armaturedata/armaturevideo
  assembly.py       joint hierarchy renderer
  make_generic_doll.py  builds generic MFD/Radar damage dolls
  verify_*.py       per-type round-trip verifiers

Verified round-trip across all 64 shared chassis:
  .armature      2938/2976 pages     .subsystems  7579/7585 keys
  .data map      6071/6071 values    .data trip   8291/8306 keys
  .damage        6605/6605 keys      .contents    7480/7480 keys
  .torso+.engine 1280/1280 keys      .instance     896/896 keys, 64/64 pages
  armature_parts 1202/1202 .data, 1149/1202 .video

Layout-discovery lessons (documented in DECOMPILING.md)
-------------------------------------------------------
- Never let a field map be discovered by the values that verify it. A
  value-matching pass reported 4288/4288 while mis-assigning 34 keys. The
  map was rebuilt from header declaration order, anchored on uniquely
  resolved fields.
- Read the factory, not the data. 12 .data fields and 5 Torso fields are
  declared plain Stuff::Scalar but multiplied by Radians_Per_Degree in
  Mech_Tool.cpp:889 / Torso_Tool.cpp.
- Strip typedefs before walking a header. A stray `typedef int AttributeID;`
  masked a missing ClassID - two 4-byte errors cancelling out, caught only
  by the ANCHORS assertion.
- A verifier that silently narrows its own input reports success. Braced
  blocks must be hidden before splitting pages, replacing both CR and LF,
  because a `Shadow={...}` block contains a line reading `[shadow]` and
  splitlines() also splits on bare CR.
- NSWIZZLE is undefined, so the #else branch is live and orders members
  differently. bool is 1 byte; char x[MaxStringLength] is 256.
- V4H carries stale Mech IDs (their Atlas is 5, ours 6), so 64 of 65 shared
  chassis are off by one; --retarget-ids emits $(M_<Chassis>)/$(IDS_<Chassis>).

reports/ holds generated diffs. The two ~5 MB manifest-*.tsv intermediates
are gitignored; regenerate everything with run-comparison.sh.

Co-authored-by: Claude Opus 5 (Anthropic) <noreply@anthropic.com>
Co-authored-by: GitHub Copilot <copilot@github.com>
2026-08-08 16:47:57 -05:00

129 lines
4.9 KiB
Python

#!/usr/bin/env python3
"""Round-trip verifier for the mech .data decompiler.
Regenerates a whole `.data` from the compiled records for every chassis we hold
both forms of, and compares it key by key against the authored source. This is
the standard `.armature` and `.subsystems` were held to; nothing should be
emitted for the new chassis until this passes.
Comparison is semantic, not byte-exact: NotationFile is order-independent, and
Windows path lookup is case-insensitive (our own tree writes both
`mechs\\atlas_destroyed\\...` and `Mechs\\Atlas_Destroyed\\...` for the same
key), so keys are matched case-insensitively and numbers within tolerance.
python3 verify_roundtrip.py [--show CHASSIS]
"""
import argparse, collections, os, re, sys
sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
import datamap, data, subsystems
REC = "/home/rich/Repositories/FS_Ours_extracted/core/mechs"
NUM = re.compile(r'^-?\d+\.?\d*(?:[eE][-+]?\d+)?$')
def canon(v):
"""Normalise one value for comparison."""
v = str(v).strip()
v = re.sub(r'^content[\\/]', '', v.replace("/", "\\"), flags=re.I)
v = re.sub(r'\s+', " ", v).lower()
# normalise every number in place so "20.0 20.0 20.0" == "20 20 20"
return re.sub(r'-?\d+\.\d+(?:[eE][-+]?\d+)?|-?\d+',
lambda m: f"{float(m.group(0)):.4g}", v)
def canon_set(val):
"""Sorted, de-duplicated: some sources repeat a key with the same value."""
return sorted({canon(v) for v in (val if isinstance(val, list) else [val])})
def source_kv(path):
"""Authored [GameData] page, keeping repeated keys as lists."""
txt = open(path, "rb").read().decode("latin-1")
# protect braced blocks first: Shadow={...} contains a line reading
# "[shadow]", which otherwise looks like the start of the next page.
# Both CR and LF must go -- splitlines() splits on a bare CR too.
txt = re.sub(r'\{.*?\}',
lambda x: x.group(0).replace("\r", "").replace("\n", "\x01"),
txt, flags=re.S)
m = re.search(r'^\[GameData\]\r?\n(.*?)(?=^\[[A-Za-z]|\Z)', txt, re.M | re.S)
body = m.group(1) if m else ""
kv = collections.OrderedDict()
for line in body.splitlines():
if "=" not in line or line.lstrip().startswith("//"):
continue
k, v = line.split("=", 1)
kv.setdefault(k.strip(), []).append(v.replace("\x01", "\n").strip())
return kv
def main():
ap = argparse.ArgumentParser()
ap.add_argument("--show")
args = ap.parse_args()
manifest = subsystems.load_manifest(data.MANIFEST)
totals = collections.Counter()
wrong = collections.Counter()
missing = collections.Counter()
extra = collections.Counter()
examples = []
chassis = 0
for ch, kv_ignored, _blob in datamap.corpus():
src_path = [p for p in
__import__("glob").glob(datamap.SRC + "/*/*.data")
if os.path.basename(p).lower() == ch.lower() + ".data"]
if not src_path:
continue
chassis += 1
want = source_kv(src_path[0])
got = data.decompile(os.path.join(REC, ch), manifest)
got_l = {k.lower(): v for k, v in got.items()}
for key, wvals in want.items():
if key in data.UNRECOVERABLE:
totals["omitted"] += 1
continue
totals["keys"] += 1
if key.lower() not in got_l:
missing[key] += 1
continue
if canon_set(got_l[key.lower()]) == canon_set(wvals):
totals["ok"] += 1
else:
wrong[key] += 1
if len(examples) < 12:
examples.append((ch, key, wvals, got_l[key.lower()]))
for key in got:
if key.lower() not in {k.lower() for k in want}:
extra[key] += 1
if args.show and args.show.lower() == ch.lower():
sys.stdout.write(data.emit(got))
return
print(f"chassis : {chassis}")
print(f"keys compared : {totals['keys']} exact: {totals['ok']} "
f"wrong: {sum(wrong.values())} missing: {sum(missing.values())}")
print(f"deliberately omitted: {totals['omitted']} (unreadable by the engine)")
if missing:
print("\nmissing from output:")
for k, n in missing.most_common(15):
print(f" {k:30s} x{n}")
if wrong:
print("\nvalue mismatches:")
for k, n in wrong.most_common(15):
print(f" {k:30s} x{n}")
print("\nexamples:")
for ch, k, w, g in examples:
print(f" {ch:12s} {k:26s} want={w!r:44s} got={g!r}")
if extra:
print("\nemitted but not in source:")
for k, n in extra.most_common(10):
print(f" {k:30s} x{n}")
if __name__ == "__main__":
main()