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.
ed6602e9ed
Reference pair turn1->turn2: 81 leaves closed, 0 regressed (was 78/0). Pair turn2->turn3: 39 closed, 0 regressed (was 36/0). With --commit-blocked=T31 --ai-player 1: 83/0 and 41/0. game/sim/colony: GrowCivilianPopulations models ServerSystem's civilian growth sub-pass. The whole system's delta is clamped to 20,000,000 -- an int64 column of the population-type table, built in the executable from its own literals -- and on both reference pairs that clamp, not the growth curve and not any carrying capacity, is what decides the value: the uncapped delta is 7.5x it and the capacity headroom 25x it. So the pass commits with no tuning table loaded, and says by how much each unmodelled input would have to be wrong before it mattered. The one input genuinely off the wire is the per-species civilian capacity factor. It is handled by running the pass twice, once with the modelled capacity and once with the system's own wire-known dcs limit, and committing only when the two agree. Imperial growth is deliberately NOT committed: it is a no-op on this corpus and would need a capacity the corpus can bound from below but not from above. game/sim/economy: both interest rates in ComputeBudget are WIDENED FLOAT literals, (double)0.01f and (double)0.15f, and are then truncated -- so a treasury of exactly 50,000 earns 499, not 500. This module used the exact decimals, which left the human's savings one money high on the first reference pair and exact on the second. Sixteen hand-computed test expectations moved by one; they were derived from the model, not measured. The live ComputeBudget compare (4,437 calls, 0 divergences) did not catch this because it presented only 20 distinct states and none sat on a rounding boundary. game/sim/colony: ShipRepairCost, the last unmodelled input of the output turn path. The demand is still 0 -- its two design fields are cached stats the save does not carry -- but the zero is now evidenced rather than silent: S13 reports the candidate set, and the independent colony keeps a ten-ship fleet over a colony whose savings close exactly at zero demand. Gates run as separate commands: clean-room OK, host ctest 49/49, and the CT111 shim cross-build exit 0 (required: game/sim is compiled into the shim). The host build and report were also re-run on CT111 and produced identical numbers. docs/G3-civilian-growth.md; notes repo findings/subsystems/population-growth.md. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01ARBgSooAfokKUy6wKUKEyZ |
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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).