editor/wiki/architecture/tools.md

# Tools

*Editor tools structure in `apps/editor`.*

Applies to: `apps/editor/components/tools/**`.

Tools are React components that capture user input (pointer, keyboard) and translate it into `useScene` mutations. They live exclusively in `apps/editor/components/tools/`.

## Lifecycle

`ToolManager` reads `useEditor` (phase + mode + tool) and mounts the active tool component. When the tool changes, the old component unmounts, cleaning up any transient state.

See `apps/editor/components/tools/tool-manager.tsx`.

## Tool Categories by Phase

**Site**
- `site-boundary-editor` — draw/edit property boundary polygon

**Structure**
- `wall-tool` — draw walls segment by segment
- `slab-tool` + `slab-boundary-editor` + `slab-hole-editor`
- `ceiling-tool` + `ceiling-boundary-editor` + `ceiling-hole-editor`
- `roof-tool`
- `door-tool` + `door-move-tool`
- `window-tool` + `window-move-tool`
- `item-tool` + `item-move-tool`
- `zone-tool` + `zone-boundary-editor`

**Furnish**
- `item-tool` — place furniture

**Shared utilities**
- `polygon-editor` — reusable boundary/hole editing logic
- `cursor-sphere` — 3D cursor visualisation

## Pattern

```tsx
// apps/editor/components/tools/my-tool/index.tsx
import { useScene } from '@pascal-app/core'
import { useEditor } from '../../store/use-editor'

export function MyTool() {
  const createNode = useScene(s => s.createNode)
  const setTool = useEditor(s => s.setTool)

  // Pointer handlers mutate the scene store directly.
  // No local geometry — use a renderer for any preview mesh.

  return (
    <mesh onPointerDown={handleDown} onPointerMove={handleMove}>
      {/* ghost / preview geometry only */}
    </mesh>
  )
}
```

## Rules

- **Tools mutate `useScene` for committed changes and `useLiveTransforms` for ephemeral drag state.** A tool's end-of-interaction write (click-to-commit, release-to-commit) goes to `useScene` and is captured in undo history. Per-mouse-move previews go to `useLiveTransforms` so history and subscribers aren't spammed.
- **Live-drag exception for direct mesh transforms.** During an active drag a tool may apply a transform offset directly to `sceneRegistry.nodes.get(id).position`/`rotation`/`scale` *when and only when* the same offset is mirrored into `useLiveTransforms` for that node. This exception exists because the 3D renderers don't reconcile `useLiveTransforms` onto `mesh.position` yet; once a `LiveTransformSystem` does that, this exception goes away. Conditions:
  - The mesh offset must mirror the `useLiveTransforms` entry (**same exact value**, not "same conceptual translation"), so anything reading `useLiveTransforms` sees the same preview as the 3D view. `ParametricNodeRenderer` (used for every kind that ships `def.geometry`) binds `<group position={liveTransform.position}>` via React — every Zustand notification re-renders and reconciles the group's position back to whatever value `useLiveTransforms` holds. If `mesh.position.set(delta)` and `useLiveTransforms.set({ position: someOtherValue })` disagree, the two writes fight every frame and the user sees jitter during the drag.
  - **For position-based kinds (spawn / item / column)**: the `position` field on the node IS the group's local-frame position, so `useLiveTransforms.position` should hold the live world position of the node (matches the eventual `scene.update`).
  - **For polygon-based kinds (slab / fence / ceiling / wall)**: the node has no `position` field — the canonical group position is `[0,0,0]` with geometry built in level-local coords. `useLiveTransforms.position` must hold the **delta** the tool wants to translate by (`[deltaX, 0, deltaZ]`), not the world location of the polygon's center. The cursor sphere position (which IS the translated polygon center) is tracked separately via React `useState`, not `useLiveTransforms`.
  - The offset must be cleared on tool unmount, cancel, *and* commit — both `mesh.position.set(0, 0, 0)` and `useLiveTransforms.clear(id)`.
  - The tool must not generate or mutate geometry in this path — only transform writes. Geometry generation still belongs in a core system.
- **No business logic in tools** — delegate geometry/constraint rules to core systems.
- **Preview geometry is local** — transient meshes shown while a tool is active live in the tool component, not in the scene store.
- **Clean up on unmount** — remove any pending/incomplete nodes *and* any live transforms/mesh offsets when the tool unmounts.
- **Tools must not import from `@pascal-app/viewer`** — use the scene store and core hooks only. `sceneRegistry` is exported from `@pascal-app/core` and is the allowed door into the Three.js graph for the narrow purposes above.
- Each tool should handle a single, well-scoped interaction. Split complex tools (e.g. "draw + move") into separate components selected by `useEditor`.

## Adding a New Tool

1. Create `apps/editor/components/tools/<name>/index.tsx`.
2. Register the tool in `ToolManager` under the correct phase and mode.
3. Add the tool identifier to the `useEditor` tool union type.
4. If the tool requires new node types, add schema + renderer + system first.

## Move coexistence: 2D `FloorplanRegistryMoveOverlay` + legacy 3D mover

While a kind is mid-migration its move can run through two paths at once: the registry-driven 2D `FloorplanRegistryMoveOverlay` (`def.floorplanMoveTarget`) and the legacy 3D mover (e.g. `MoveItemContent`). Both react to `setMovingNode(node)`, both mount, both want to commit. Two pitfalls surfaced and have stable fixes; replicate the patterns when porting another kind to coexist.

### Pitfall: the 2D cleanup clobbering the 3D commit

`FloorplanRegistryMoveOverlay` pauses scene history at mount and snapshots the moving node. If the user actually commits in 3D, the 3D path writes new state and clears `movingNode`. The 2D overlay then unmounts — and its cleanup `useEffect` would call `updateNodes(snapshot)`, overwriting the just-committed 3D state with the original.

Fix in `floorplan-registry-move-overlay.tsx`: gate the cleanup revert on a `hasMovedSinceStart` flag that is only set inside `onMove` **after** the `target.closest('[data-floorplan-scene]')` guard. If no 2D apply ever ran, the divergence in scene state must be an external committer's — skip the revert, just resume history. Symptom when missing: items snap back to their pre-drag position / rotation on 3D commit.

### Pitfall: `useDraftNode.destroy()` clobbering the 2D commit

Mirror problem in the other direction. The legacy 3D mover's `usePlacementCoordinator` cleanup unconditionally calls `draftNode.destroy()`, which for adopted moves writes the original position back to scene. If the 2D path committed first, the destroy reverts it.

Fix in `use-draft-node.ts`: in move-mode `destroy()`, compare the live scene position to the `adopt()`-time snapshot. If they diverge, an external committer has already written the new value — skip the restore (and the mesh reset). Cancellation paths (Escape) still revert, because they revert before unmount so live == snapshot at destroy time.

### Pitfall: pointermove fires globally; treat 3D-canvas events as out of scope

`FloorplanRegistryMoveOverlay` listens to `window` pointermove. When the user drags in 3D the listener still fires — without a target check it converts 3D-canvas client coords through the floor-plan SVG's CTM, producing garbage plan coordinates that fight the 3D mover's mesh updates.

Always gate `onMove` (and `onPointerUp`) with `target.closest('[data-floorplan-scene]')` so the 2D path only acts when the pointer is actually over the floor plan scene.

## `useLiveTransforms` contract is per-kind, not generic

The store name suggests a uniform contract; the writes in practice are not. Document the frame on the writer side; consumers must either know the kind or be narrowed.

| Writer | `position` frame | `rotation` frame |
|---|---|---|
| `usePlacementCoordinator` (item floor / wall / ceiling) | world plan (level-local) | world Y |
| `door` / `window` move tools | wall-local | wall-local (0 or π) |
| `slab` / `ceiling` / `fence` / polygon-based movers | position **delta** (`[Δx, 0, Δz]`) | unused / 0 |
| `column` / `roof` / `elevator` / `spawn` / single-position kinds | world plan | world Y |

Anything that subscribes to `useLiveTransforms` to inform 2D rendering needs to handle these frames explicitly. The `FloorplanRegistryLayer` override currently branches by kind: `item` / `shelf` / `column` are treated as world-plan (it copies `live.position` onto the effective node and forces `parentId: null` so the resolver skips the parent-chain transform), while `slab` / `ceiling` / `zone` are treated as a polygon **delta** (it translates the polygon vertices by `live.position`). Each kind added to the live-drag path grows this consumer-side switch; the preferred long-term fix is to standardise the frame at the writer so the consumer stops branching by `node.type`.

## Wall-attached node rotations must be wall-local

`door` / `window` / wall-attached `item` are children of the wall mesh in 3D. The wall's `mesh.rotation.y = -atan2(dy, dx)`. The child node's `rotation.y` therefore lives in the wall's local frame and composes with the wall's rotation at render time.

The 3D source of truth is `calculateItemRotation(normal)` in `editor/src/components/tools/item/placement-math.ts`, which returns 0 (front face) or π (back face). Any 2D move helper that writes `node.rotation[1]` for wall-attached nodes must produce the same wall-local value. Writing a world-space rotation gets you orientation bugs that vary with wall direction — typically 90° on horizontal walls and 180° on vertical walls (which sometimes "looks OK" by symmetry, which is worse — silent corruption).

See `nodes/src/shared/wall-attach-target.ts`'s `WallHit.itemRotation`. Side determination there is calibrated to the same convention: in wall-local space the wall extends along +X, the front-face normal is +Z, and `perpRaw >= 0` is the front side.

## Move / placement: disable raycast on the moved mesh

A 3D move tool that follows the cursor by writing `mesh.position.set(x, 0, z)` runs into a feedback loop: as the mesh tracks the cursor it sits between the camera and the grid plane, so R3F's raycaster hits the moved mesh first → only `${kind}:move` fires → `grid:move` stops firing → the cursor snapshot (used as the commit position) freezes at its initial value. The user clicks at a new spot and the node commits at the starting one.

Fix in `MoveRegistryNodeTool`: at drag-start, traverse the moved mesh and overwrite `child.raycast = () => {}` on every descendant; restore the originals in the effect's cleanup. The ray now passes through the moved mesh, hits the grid plane, and `grid:move` keeps firing.

The same applies to placement previews — see `nodes/src/shelf/preview.tsx` for the `(obj as { raycast: () => void }).raycast = () => {}` pattern. A preview that captures rays starves the placement tool's own `grid:move` snapshot.

## Move / placement: commit handlers listen to every `${kind}:click`

R3F's pointer raycaster dispatches the click event to whichever mesh is closest, even when the user thinks they're clicking the ground. A tool that only listens to `grid:click` misses commits whenever the click ray lands on a wall face, a shelf side, an item, or the still-being-placed cursor mesh itself. Symptom: clicks visibly hit "near" the cursor but the tool does nothing.

The fix is the pattern used by `ShelfTool` and `MoveRegistryNodeTool`: keep the latest `grid:move` snapshot in a ref, then register one shared commit handler against `grid:click` **and** every common kind-click event:

```ts
const CLICK_TRIGGER_KINDS = [
  'shelf', 'item', 'slab', 'ceiling', 'wall',
  'fence', 'column', 'roof', 'roof-segment',
  'stair', 'stair-segment',
] as const

emitter.on('grid:click', commitAtCursor)
for (const kind of CLICK_TRIGGER_KINDS) {
  emitter.on(`${kind}:click` as `${typeof kind}:${EventSuffix}`, commitAtCursor as never)
}
```

The commit reads `lastCursorRef.current` (set by `grid:move`), not the click event's position — clicks on vertical surfaces carry the hit point on that surface, which can be metres away from the cursor the user was visually targeting.

## Move tools must preserve the node's actual rotation in `useLiveTransforms`

A tool that writes `useLiveTransforms.set(id, { position: [x, 0, z], rotation: 0 })` during drag wipes the node's true Y-rotation for the duration of the drag. `ParametricNodeRenderer` reads `liveTransform.rotation` and applies `<group rotation={[0, liveTransform.rotation, 0]}>`, so the moved node visually un-rotates to 0 the moment the tool mounts, then snaps back to its real rotation on commit when the live transform clears. Users perceive that snap as "the node went to a weird position."

Capture the original `node.rotation[1]` at mount time and forward it on every `set`:

```ts
const originalRotationY = useMemo(() => {
  const r = (node as { rotation?: unknown }).rotation
  return typeof r === 'number' ? r : Array.isArray(r) ? (r[1] ?? 0) : 0
}, [node])

// in onMove:
useLiveTransforms.getState().set(node.id, {
  position: [x, 0, z],
  rotation: originalRotationY,
})
```

If the tool *also* rotates the node during the drag, it should drive `rotation` from the current tool state — not from 0, not from the stale node value.

## SVG `fill="none"` is click-through

When emitting a `FloorplanGeometry` polygon that should remain interactive but visually invisible (e.g. an item with a thumbnail image carrying the visual weight), use `fill="transparent"`, not `fill="none"`. The default `pointer-events: visiblePainted` only hit-tests the interior when there's a paint server — `none` is not paint, `transparent` is. Without this the floor-plan layer's wrapping `<g>` never sees the `onPointerDown` and clicks don't select the node.