# /Tools/Scripts — generation logic

C# backend for the offline developer tools. Decoupled from the live server and client.

## `MapGenerator.cs`

Generates the entire 2D blueprint. Roughly in order:

1. **Config** — reads `ServerConfig.json`, which sets `MapSize` (8192 by default) and the crater
   radius. The `MapSize = 4096` field initialiser is a fallback that is immediately overwritten.
2. **Topography** — FastNoiseLite base height plus a mountain spine, minus a squircle distance
   falloff, giving a guaranteed island. Noise frequency is divided by `scaleFactor`
   (`MapSize / 1024f`) so terrain features stay the same real-world size at any map profile.
3. **Sea level and water** — temperature-driven sea level; flood fill separates true ocean from
   inland lakes; a mainland fill guarantees one contiguous landmass.
4. **The crater** — placed along the northern coast and carved to below sea level, but only out to
   **80 % of its radius**, which guarantees a landbridge rather than severing the island.
5. **Biomes and towns** — biome zoning by height and temperature; tiered town placement (Capitol,
   Hubs, Villages, Outposts, POIs) filtered by slope, water proximity and spacing.
6. **Roads** — see below.
7. **Export** — writes the `.dat` blueprint, then renders the PNG snapshot.

### The road network

`AStarGrid2D` over the whole map at one node per pixel. Mountains are made expensive rather than
impassable (`1 + elevation³ × 400`), water and the crater are marked solid.

- **Continental loop** — highway nodes sorted by radial angle and connected in a ring.
- **Mountain branch** — a spur from the loop to the snow hub.
- **County roads** — Prim's algorithm daisy-chains remaining towns onto the network. Villages become
  Rugged roads, everything else Trails.
- **Abandon protocol** — a town further than 8 % of the map from the network is skipped rather than
  pathed to, so one unreachable outpost cannot hang generation.
- **Smoothing** — every path is decimated with Ramer–Douglas–Peucker (tolerance 4.0) then smoothed
  with 4 Chaikin passes.

⚠ **This is the project's dominant performance problem.** At 8K the grid is 67 million nodes, and the
weight-setup pass touches every one before the first path is requested. The `await` yields between
stages cannot interrupt a single engine-side `GetPointPath` call, so a long path still blocks. Full
regenerations frequently get abandoned.

### The PNG snapshot

`SaveMapSnapshot()` builds an offscreen `SubViewport` in code rather than relying on the scene's
layout, because Godot's UI layout engine will otherwise crush a 4096+ render down to the editor
window size. A `MapDrawProxy` control re-issues the `_Draw()` calls into that viewport — `GetImage()`
captures only the base texture and would otherwise miss the roads and towns entirely — and the code
awaits two `RenderingServer.FramePostDraw` signals so the GPU has actually painted before the image
is read back.

Road colours on the snapshot, useful for identifying a road: **red** = Highway, **black** = Branch,
**dark brown** = Rugged, **light brown** = Trail.

### Outputs
`MapData_Seed_<seed>.dat` and `Map_Seed_<seed>.png`, both to `user://`.

## Rules
1. **No magic numbers.** Distances, radii and thresholds derive from `MapSize` or `scaleFactor`, so
   the generator behaves identically at 4K and 10K.
2. **Respect the GPU.** Anything exporting visual data must `await` the appropriate frame signals
   before reading pixels back.