From-scratch reimplementation of the Sword of the Stars (2006) engine. Clean-room; engine code only — bring your own game copy. Planning/RE evidence live in sots-re.
98257b9e82
The milestone needs a second input. The AI is a client, not part of the sim: it decides once,
on one machine, and its decisions reach the server as commands. A save carries the board and
half the input, which is why our turn wrote ModCount 14 where the original writes 24 -- the
missing ten ARE the turn's command stream.
* `game/ai/apply_order` -- the thirty-step schedule the original drains a batch in: twenty-
seven per-LIST steps (every player's elements of one list before the next list starts) with
three per-PLAYER gate loops spliced in at step 10, 29 and 30. Neither list order nor member
order, and both facts are asserted so a port that sorted cannot pass.
* `game/ai/command_capture` -- a `.tcb` recorded turn: gates, list lengths, elements in wire
order, per-client seeds, and `?` for a field the instrument could not read. An element count
that disagrees with its declaration is REJECTED, because a counter quietly one short is
indistinguishable from a turn that issued one fewer command.
* `app/command_replay` -- applies it before the drivers, where the End-Turn dispatcher does.
Every command is CHARGED; only the ones whose subsystem we hold are APPLIED; the rest are
declined with the named gap, or marked incomplete when the capture itself lacks the payload.
* `--turn-commands`, `--replay-count-only`, `--replay-recorded-names`, `--ai-seed`.
Measured on a fresh build directory, canonical pair turn2-state -> turn3-state:
108 -> 62, closed 46, regressed 0 (was 108 -> 63, closed 45) -- /Sim/ModCount now reads the
original's 24, decomposed as 2 drivers + 4 research-rate gates + build + rates + list 10 +
two list-14 + fleet move, with the list-23 population element free.
turn1-state replayed against the SAME run's autosave closes 7 (ModCount and all six research
leaves); against the historical turn2-state it closes 6 and leaves player 512's research pick
diverging -- which is correct, because that recording is from a process that picked differently.
One prediction was falsified and it paid for itself: the first run regressed two leaves because
the rates element's MEMORY field order is not its wire order. The converter no longer claims a
mapping it cannot support.
Two new addresses (the second and third gate-loop heads) via ghidra/addresses.d/lane-rb.json;
header regenerated, never hand-resolved.
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| cmake | ||
| docs | ||
| include/generated | ||
| src | ||
| tests | ||
| third_party | ||
| tools | ||
| .gitignore | ||
| CMakeLists.txt | ||
| CMakePresets.json | ||
| CONTRIBUTING.md | ||
| LICENSE | ||
| README.md | ||
sots-engine
A from-scratch, functional reimplementation of the engine behind Sword of the Stars (2006). Not a byte-for-byte decompilation: behavior-equivalent code, built up one verified piece at a time (OpenRCT2-style) until the tree can build the whole application on its own.
Bring your own game. This repository contains engine code only. Game data, assets, saves, and
the original binaries are never included; tests and tools read an owner-supplied copy via
$SOTS_DATA_DIR. See CONTRIBUTING.md for the clean-room rules.
Status
Phase 2. M0 done — the shim frontend (src/shim/, a proxy binkw32.dll the original game
loads) builds, deploys, hooks, and logs from a real game launch. Engine code accrues under
src/mars/ and src/game/; each module is oracle-verified against the owner's game data before merge:
mars/parse— brace-block +.effectreaders (1,531/1,531 files agree with the reference)mars/text— flat key/value tables, id manifests, CSV (64/64 files agree)game/sim— strategic formulas (economy, research, colonies, movement) as pure functions; 356 hand-computed checksmars/vfs—.gob(ZIP) archive reader + loose-file override; entry counts and bytes verified againstunzipmars/stream— the game's self-describing save/serialization format (reader, writer, typed shapes) + gzip; three real saves round-trip byte-identicalmars/rng— MT19937 with save-state load/store; layout confirmed against real saves, draw mappings read off the binary (docs/mars-rng.md)game/data— typed catalogs (weapons, ship sections, turrets, id registries, tech tree, strings) with cross-reference checks; 229k values agree with the referencegame/design— ship-design assembly/fit/tech-gating rules and derived stats; validates all 127 stock designs from real savesapp— the standalone:sots_turnloads a save, runs one strategic turn over the published phase order of all three turn drivers, and writes a save. 14 of the 44 turn-driver phases are modelled; every phase that is not appears in the run log as a named no-op. How far it is from the byte-match, and what stands in the way, is indocs/S-standalone.md
Build: cmake --preset host && cmake --build --preset host && ctest --preset host (Linux);
tools/sync-build.sh cross-builds the shim on the lab box and stages it for deployment.
Layout (grows with the work)
src/shim/— binkw32 proxy + hooks + old-vs-new compare harness (frontend #1)src/mars/,src/game/— the engine and game reimplementation (accruing)src/app/— the standalone turn driver (frontend #2): load a save, run a turn, write a saveinclude/generated/sots_addresses.h— binary facts (RVAs/prototypes), generated from the RE repotests/— host tests; real-data tests skip unless$SOTS_DATA_DIRis settools/— build (MinGW i686 cross) and deploy scripts
Planning, findings, and verification evidence are tracked in the private RE repo (sots-re).