Module grid 

Grid geometry: positions, the four directions, a rectangular grid and sets of its tiles, and the terrain a tile is.

Structs

Grid

A width × height rectangle of cells, stored row-major. The cell count always equals width * height; deserialising checks it.

GridSizeError

A saved grid whose cell count is not width * height.

Pos

A tile position. Signed so neighbour maths can go negative before bounds checks; (0, 0) is the top-left tile, x grows right, y grows down.

TerrainId

A terrain: its index in the game’s table of terrains. The engine knows no terrain of its own; a game’s map is a Grid of these, and its skins look each one up in the game’s table.

TileSet

A set of tiles of a width × height map, stored as a bitset. Iterates in row-major order. Positions outside the map are never members.

Enums

Dir

One of the four grid directions.