@react-arch/core

The canonical semantic building model and the immutable commands that operate on it. The single source of truth for building data.

Depends only on @react-arch/shared and @react-arch/geometry — never on React, Three.js, PixiJS, or browser APIs (ADR 0001).

Model

BuildingDocument → Building → Floor → { walls, rooms, openings, objects }, plus materials, assets, units, version, and metadata. Walls are stored by centerline + thickness; the visible polygon is derived by @react-arch/geometry. Openings attach to walls semantically (by offset along the centerline), so they follow when a wall moves.

Commands

Pure functions returning { document, changes, warnings } — they never mutate the input:

import { createWall, createOpening, deleteWall } from "@react-arch/core";

const a = createWall(doc, { floorId: "ground", start: [0, 0], end: [5, 0] });
const b = createOpening(a.document, { wallId, type: "door", offset: 2, width: 0.9, height: 2.1 });
// deleteWall cascades: attached openings are removed too.

Floor commands: createFloor, duplicateFloor, reorderFloor, updateFloor, deleteFloor. Room/opening commands mirror the wall ones.

History

History provides snapshot-based undo/redo (push, undo, redo, canUndo/canRedo). Designed to migrate to patches/op-logs later without changing the surface.

Serialization

serialize / deserialize (JSON is the lossless canonical format) with a forward-only migrate registry and isCompatibleVersion.