@elite-dangerous-almanac/core / astro/codex-region-lookup

Resolve a coordinate or system address to its Elite Dangerous galactic codex region.

The region a system belongs to is fixed by its position on a flat ≈49.35 ly (4096 / 83 ly) grid over the galactic plane. Each region's cells are stored as run-length geometry in data/astro/galactic-region-cells.jsonc (kept separate from the lightweight metadata so metadata-only consumers never bundle it); this module rebuilds a per-row lookup index from them. The per-region metadata objects live in ./codex-region.

Two lookups are provided, matching the two things the game calls "the region":

• findCodexRegionAt — the region at a set of coordinates (what the codex records a discovery against, and what is shown when jumping into a system).
• findCodexRegionForBoxel — the region of a system's boxel 0/0/0 corner (what the journal and the codex main page display for the system).

These can differ near a region border; see the upstream discussion linked in the data file's attribution.

Algorithm ported from klightspeed's EliteDangerousRegionMap (RegionMap.js). See ATTRIBUTIONS.md for credit and licence terms.

• BoxelCodexRegionLookup
• CodexRegionPoint

• CODEX_REGION_MAP_LY_PER_CELL
• CODEX_REGION_MAP_X0
• CODEX_REGION_MAP_Y0
• CODEX_REGION_MAP_Z0

• findCodexRegionAt
• findCodexRegionForBoxel

Re-exports SystemAddressInput