Spaceport Architect

Technical deep-dive

Engine & Tech Stack

• Engine / language: Godot 4.7 with C# on .NET 10. The game logic sits in plain C# libraries with no Godot code: Shared, Domain, Contracts and Application. Only the game project touches Godot. Code generators and architecture tests keep those layers apart.
• Map representation: eight stacked 2D tile layers: Ground → Foundation → Floor → Zone → Wall → Object → Road → Roof. All of them use 16px tiles except Road, which uses 64px tiles. Each layer is a domain object inside one world-map object, drawn by a Godot TileMapLayer. Zones are flood-filled areas, re-flooded on every edit, so their IDs don't last.
• Content & config: tuning comes from JSON files such as world_config.json, where every section falls back to a default. There is no modding layer yet.
• Rendering: the tiles use Godot TileMapLayers with shaders. Passengers skip nodes entirely: they're drawn as quad meshes straight through RenderingServer, bucketed by screen row and culled to what's on screen.

• Architecture: two models side by side:

• Dispatch: there's no central brain. Work goes out through job boards (repairs, baggage, cargo audits) and dispatchers (buses, trucks, deliveries). Workers claim jobs, and slots, seats and amenities are claimed, not flagged. A crowd-wide "something is free" flag would send everyone to one slot.
• No behavior trees, utility AI or GOAP.

• Model: clean architecture.

• Persistence:

Tick Scheduling & Performance Tricks

• Clock: game time runs 60× real time. One knob sets it, and a command scheduler fires timed events on game time.
• ECS frame: one ordered pass each _Process: admit → signals → state systems → path upkeep → move → transitions → tag cleanup. Only chunk queries run in parallel.
• Budgets: every per-tick budget scales with game speed, so fast-forward doesn't starve anyone. Path upkeep runs in separate rotating lanes (missing target, idle drift, waiting, queue refresh, beauty) instead of everyone each frame.
• Batching:

• Determinism: one seeded random source and minted IDs. Wall-clock random and GUIDs are banned by tests.

• People: custom A* on the 16px grid, split into 32×32 chunks, with flat arrays and pooled scratch memory. The grid is an immutable snapshot, so searches can run off the main thread. Edits update only the cells that changed.
• Reachability: each cell carries a connected-region label, so impossible walks are refused before any search. A cache also remembers routes that failed.
• Flow fields: precomputed per desk for queues, instead of an A* search per passenger.
• Vehicles: A* on a one-way, right-hand road graph with four lane points per road tile. Road tiles are reserved piece by piece, covering crossings too, to keep vehicles apart. A deadlock breaker clears gridlock.
• Access zones: three floods from the road entrances sort ground into Before Security, Past Security and Staff-only. One-way doors and checkpoints shape the result.
• Cost matrix: roads and vehicle bays add a small step cost for walkers. Restrooms and the checkpoint floor are closed in the grid and reopened only for the search that needs them, which is what keeps restrooms single-sex.