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.
Find a file
alex 5e409cfa05 lane A2: S04, the alliance mask -- 80 player-records, 560 fields, 0 mismatches
The spine's fourth phase, read byte-for-byte and implemented:

    almem[i] = (1 << i) | (ALid != -1 ? AL : 0)

with i the player's POSITION IN THE PLAYER VECTOR, not its index field. Both
inputs are on the wire and so is the output, through the turn-record archive,
so the phase is checkable against bytes the original wrote:

    app_turn_record: 11 saves, 80 player-records, 560 fields, 0 mismatches
                     (was 480 fields over six fields; almem is the seventh)

The eight zero masks of the corpus's earliest archived turn are PREDICTED, not
excluded: the archiving phase also runs on load, and the load path does not run
the spine. BuildTurnRecord takes spineRan and models it, so all 80 records are
compared.

Three parts of the rule the corpus cannot separate -- the bit index, the OR,
and the ALid guard -- are pinned in app_alliance with the separating inputs no
save provides, and app_turn_record prints that it could not separate them.

Divergence, closed and regressed reported separately:

    turn1->turn2  default          209 -> 204   closed 5, regressed 0
    turn1->turn2  --commit-blocked 209 -> 189   closed 29, regressed 9  (was 17)
    turn2->turn3  default          108 -> 103   closed 5, regressed 0
    turn2->turn3  --commit-blocked 108 -> 106   closed 13, regressed 11 (was 19)

T36 stays blocked: nine leaves would still be wrong (inc x3, sav x3 behind the
budget; three census leaves behind the design catalogue). It now closes all 24
turnstats leaves on the reference pair, so it becomes a clean +24 once those
two land.

Prediction and falsification committed first in 49ae628.
Gates run separately: clean-room OK; host ctest 43/43. No src/shim touched.
2026-09-08 12:44:00 -04:00
cmake m0: binkw32 proxy shim, minhook, trace hook on Application::Initialize; build/deploy tooling 2026-09-07 17:22:15 -04:00
docs lane A2: S04, the alliance mask -- 80 player-records, 560 fields, 0 mismatches 2026-09-08 12:44:00 -04:00
include/generated lane N: the population -> base-output term, live-verified 2026-09-08 12:11:36 -04:00
src lane A2: S04, the alliance mask -- 80 player-records, 560 fields, 0 mismatches 2026-09-08 12:44:00 -04:00
tests lane A2: S04, the alliance mask -- 80 player-records, 560 fields, 0 mismatches 2026-09-08 12:44:00 -04:00
third_party mars/vfs: gob ZIP reader + native override, miniz 3.1.2; oracle-verified 8352+2035 entries 2026-09-07 17:40:51 -04:00
tools b4: colony + movement hooks; 22 formula corrections (growth curve has no capacity term, range margin +0.05f, ties-to-even rounding); 3 verified signatures 2026-09-08 00:57:55 -04:00
.gitignore init commit 2026-09-07 17:07:54 -04:00
CMakeLists.txt lane N: the population -> base-output term, live-verified 2026-09-08 12:11:36 -04:00
CMakePresets.json m0: binkw32 proxy shim, minhook, trace hook on Application::Initialize; build/deploy tooling 2026-09-07 17:22:15 -04:00
CONTRIBUTING.md CONTRIBUTING: note uv tool install cmake as the local workaround 2026-09-08 09:07:47 -04:00
LICENSE init commit 2026-09-07 17:07:54 -04:00
README.md src/app: the standalone -- load a save, run a turn, write a save 2026-09-08 10:35:45 -04:00

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 + .effect readers (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 checks
  • mars/vfs — .gob (ZIP) archive reader + loose-file override; entry counts and bytes verified against unzip
  • mars/stream — the game's self-describing save/serialization format (reader, writer, typed shapes) + gzip; three real saves round-trip byte-identical
  • mars/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 reference
  • game/design — ship-design assembly/fit/tech-gating rules and derived stats; validates all 127 stock designs from real saves
  • app — the standalone: sots_turn loads 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 in docs/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 save
  • include/generated/sots_addresses.h — binary facts (RVAs/prototypes), generated from the RE repo
  • tests/ — host tests; real-data tests skip unless $SOTS_DATA_DIR is set
  • tools/ — build (MinGW i686 cross) and deploy scripts

Planning, findings, and verification evidence are tracked in the private RE repo (sots-re).