AnacreonReconstructed4021

A from-scratch C# port of the DOS 4X game Anacreon (targeting the 1.31 release), reconstructed directly from its original Turbo Pascal source (reference/DOSAnacreonSource131/).

The goal is a fun, playable game that's true to the original 1.31 release, not a byte-for-byte simulation exercise for its own sake. Once the faithful baseline is solid, the plan is to layer in optional, opt-in features on top of it, and the game itself should feel modern to actually sit down and play, not just correct on paper.

Getting the original right still matters a lot, and it's the more interesting part of this project from a port-design angle: reference/verify/ builds and runs the actual original source under FreePascal and compares its output against the C# port's, so game-logic decisions trace back to what the original game actually did instead of a plausible-sounding guess.

Status

Core simulation (economy, galaxy/scenario setup, probes, news, combat), Kingdom NPE AI, and save/load (DOS .SAV import plus a native JSON format) are done. The interactive UI (src/Reconstructed4021.Tui, built on src/Reconstructed4021.Panemonde, a from-scratch renderer — see docs/PORT_DESIGN.md) covers every menu command, F-key report window, save/load path, combat flow, and the pregame sequence; a handful of menu items remain stubs, tracked as GitHub issues. See docs/ROADMAP.md for how this was built.

Building and testing

Requires the .NET 10 SDK. There's no solution file — build or test a specific project directly from the repo root:

dotnet build src/Reconstructed4021.Tui
dotnet test src/Reconstructed4021.Tests

Most tests run against the C# port alone. A subset compares against real compiled Pascal output through committed golden files under reference/verify/golden/. With FreePascal (fpc) and git on PATH, a test run regenerates those files from the real Pascal first. Without them, the regeneration test skips (naming the missing tool), the comparisons run against the committed files, and the few tests that call Pascal directly skip too. See reference/verify/README.md for how that comparison works and what it takes to add to it.

Investigation scripts

Two scripts help check the simulation against real play (both read the JSON saves the Tui writes under saves/ and saves/auto/):

• scripts/saves.ps1 -Empire <name> prints one CSV row per planet the empire owns per save year: population, industry, cargo, defenses, shortfalls, and so on. Narrow it with -Location x,y, -Year, and -Columns (wildcards, such as industry.*). See Get-Help ./scripts/saves.ps1 -Examples.
• dotnet run scripts/WorldDiff.cs -- <save.json> <x,y> [years] [--all] runs one planet through both the real Pascal UpdateWorld and the port for several years, and reports the first year and fields that differ. It needs fpc and git, and builds the Pascal harness when it's out of date. It models the world alone and fully researched, so it checks the per-world economy tick, not the whole game.

Repository layout

• src/ — the C# port. Reconstructed4021.Core is the simulation itself; Reconstructed4021.Panemonde is a from-scratch console rendering engine (see its own README); Reconstructed4021.Tui is the interactive UI built on it; Reconstructed4021.TuiDriver is a headless driver for exercising Tui screens without a real terminal; *.Tests is everything else, including the Pascal ground-truth harness.
• reference/DOSAnacreonSource131/ — the pristine, unmodified 1.31 Turbo Pascal source. Never edited directly — see reference/verify/README.md for how changes to it are made (as patches, not in place).
• reference/DOSAnacreonSource20/ — the 2.0 Pascal source tree, consulted only to distinguish real bugfixes from opt-in gameplay/feature changes (see docs/PASCAL_V1_VS_V2_DIFF.md) — 1.31 is canonical for this port.
• reference/verify/ — the ground-truth harness: a patched, compilable copy of the pristine source plus the driver/tooling that runs it and compares its output to the C# port's.
• reference/scenarios/, reference/saves/ — real .SCN scenario files and a real .SAV save file, both used as ground-truth fixtures.
• docs/ — design and reference documentation, see the map below.

Documentation map

• docs/ROADMAP.md — a development log: how this port was built, bottom-up, simulation core first.
• docs/PORT_DESIGN.md — this port's own cross-cutting design decisions: how Pascal's data/behavior gets modeled in C# and why (RNG strategy, entity/interface shapes, the empire-elimination model, ground-truth harness methodology).
• docs/PASCAL_ARCHITECTURE_NOTES.md — a map of the original Pascal source (file-by-file, subsystem-by-subsystem), plus findings turned up while porting: dead code, quirks, real bugs, and the scenario golden-file investigation.
• reference/verify/README.md — how ground-truth (real, compiled Pascal output) is used to verify the port: what gets patched and why, the ground-truth domain catalog, known landmines. Read this before touching the harness itself.
• docs/QUESTIONS_FOR_GEORGE.md — a working list of real ambiguities in the source for the original author to weigh in on.
• docs/PASCAL_V1_VS_V2_DIFF.md — what changed between the 1.31 and 2.0 Pascal source trees (bugfixes vs. opt-in gameplay/feature changes).
• docs/TUI_LIBRARY_RECOMMENDATION.md — why Terminal.Gui v2 was the initial choice for the interactive UI, and why it was later replaced (see docs/PORT_DESIGN.md's "Presentation layer" section for the short version).
• docs/AnacreonManual.md — the original player-facing manual.
• src/Reconstructed4021.Panemonde/README.md — how the rendering engine underneath Tui works.