Module transitions 

Terrain transitions (docs/spec/FORMAT.md section 13): the profile’s rules that choose the edge, corner and variant tiles around painted terrain, and the deterministic resolver that applies them.

A world’s source stores only the terrain a brush paints. Transitions::resolve_chunk derives a chunk’s ground tiles from its terrain and its neighbours’, across chunk edges, so the compiler, the editor and every other tool draw the same tiles.

Structs

Pattern

The variants of one pattern, at least one, with the running sum of their weights.

ResolvedChunk

A chunk’s ground tiles with transitions applied: for each ground layer, each tile’s prototype, or None for an empty tile. Values borrow from the source grids and the transitions.

Terrain

One terrain: the prototypes that are it when painted.

Transition

One transition of a terrain.

Transitions

A profile’s terrain transitions, as read and checked by the loader.

Variant

One variant of a pattern’s tile.

Enums

Draw

Where a transition draws.

Model

The neighbourhood a transition reads, and the patterns it maps to tiles.

Constants

MAXIMUM_TERRAINS

Most terrains a transitions document declares.

MAXIMUM_TERRAIN_PROTOS

Most prototypes one terrain lists.

MAXIMUM_TERRAIN_TRANSITIONS

Most transitions one terrain has.

MAXIMUM_TILE_TRANSITIONS

Most transitions resolving one tile evaluates, however large the document: the transitions of the tile’s own terrain and of the terrains of its eight neighbours, since an outside transition draws only next to its terrain.

MAXIMUM_TRANSITIONS

Most transitions a transitions document has in all.

MAXIMUM_VARIANTS

Most variants one pattern lists.

MAXIMUM_WEIGHT

Largest weight of a variant.

TRANSITIONS_FORMAT

The format of a transitions document.

Traits

TerrainSource

Where the resolver reads painted terrain: the ground grids of chunks by address. A Plane is one; an editor can implement it over its own chunks, such as ones with unsaved edits.

Functions

variant_hash

The hash that picks a tile’s variant (docs/spec/FORMAT.md section 13): the transition’s seed and the tile’s layer and plane coordinates, mixed in that order, so the same world always picks the same variants.