Phase 3: room features (modes, room size, doors, wall screens, obstacles, import/export)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

CLAUDE.md

@@ -2,7 +2,7 @@
 
 A web tool for venues (events, banquets, conferences) to lay out furniture in a room and, eventually, auto-optimize the layout.
 
-## Current scope: Phase 1 + Phase 2 (UI only)
+## Current scope: Phases 1-3 (UI only)
 
 Layout and editing UI. No optimizer yet.
 
@@ -22,7 +22,14 @@ Layout and editing UI. No optimizer yet.
 - Screens: while selected, unlocked and unrotated, left/right end handles change their length (`resizeLength`, min 0.5 m). Thickness is only changed by size wheels, never handles (top-down view).
 - Custom furniture: "Custom" tile opens a form (name, Seating/Table, width, length, seats, available). Saving adds a config + palette tile. Custom seating draws as a chair, custom tables as a table.
 
-Out of scope: room features (doors, room screen), room import, placement rules, optimization, scanning. Do not design in a way that blocks the roadmap below.
+**Room features (Phase 3)**
+- A Layout / Room toggle sits at the top of the sidebar. Switching closes menus and deselects. In Room mode furniture is visible but can't be moved or selected.
+- Room panel: width and length wheels (3-60 m, step 0.1; the room grows/shrinks from its top-left). It can't shrink past the bounding box of placed furniture, obstacles and wall items (`minRoomSize`; anything else that would clash is rejected via `tryResizeRoom` and the wheel glides back). Add door / Add screen (max 2) / Add obstacle, Export room, Import room.
+- Walls are drawn inside the canvas (`WALL_PX`); a door is a gap in the wall plus a quarter-circle swing arc. Doors and wall screens slide along their own wall only (no corner-hopping to adjacent walls). Door panel: width 0.7-4 m, "Loading door" toggle, delete (the last door can't be deleted). Wall-screen panel: width 1-12 m, delete. Obstacles (default 0.6 x 0.6 m, 0.2-10 m) drag anywhere; width/length wheels, delete. Delete/Backspace also deletes the selected room element.
+- Keep-clear zones: the door swing square and the 0.6 m strip inside the opening, the 0.3 m strip under a wall screen, and obstacles. `getBlockedRects(room)` returns them all and `isValidPlacement` reads it, so furniture can't overlap them (red outline, drop blocked). Doors/screens can't sit on furniture or obstacles or share wall length; obstacles can't overlap furniture, each other, or door/screen zones.
+- Export downloads `room.json` (width, height, doors, screens, obstacles; no furniture). Import validates with `parseRoom` (`roomSchema.ts`) and shows a clear error; if furniture is placed it asks for confirmation first, and if the placed furniture doesn't fit the imported room it clears all furniture and warns.
+
+Out of scope: non-rectangular rooms, floor plan image import, phone scanning, placement rules, scoring, optimization. Do not design in a way that blocks the roadmap below.
 
 ## Tech stack
 
@@ -48,7 +55,12 @@ interface FurnitureItem {
   seatsOverride?: number; // tables: overrides config.seatsPerUnit
 }
 
-interface Room { width: number; height: number; } // meters
+type Wall = "top" | "bottom" | "left" | "right";
+// offset = meters from the wall's start (top/bottom start at the left, left/right at the top) to the near edge
+interface Door { id: string; wall: Wall; offset: number; width: number; isLoading: boolean; }
+interface RoomScreen { id: string; wall: Wall; offset: number; width: number; } // spec calls it "Screen"; renamed to avoid clashing with the screen furniture type / DOM Screen
+interface Obstacle { id: string; x: number; y: number; width: number; height: number; }
+interface Room { width: number; height: number; doors: Door[]; screens: RoomScreen[]; obstacles: Obstacle[]; } // meters
 
 interface FurnitureTypeConfig {
   id: FurnitureType; name: string; shape: Shape;
@@ -62,7 +74,7 @@ interface FurnitureTypeConfig {
 // seats for an item = item.seatsOverride ?? config.seatsPerUnit        (effectiveSeats)
 ```
 
-Store (`store.ts`): `{ room, items, configs: Record<id, config>, typeOrder: id[] }`. Defaults live in the configs (chair 0.5x0.5, table 1.8x0.8 w/ 8 seats, screen 2x0.2). Chairs and table seats are independent.
+Store (`store.ts`; `setRoom` replaces the room, optionally clearing furniture): `{ room, items, configs: Record<id, config>, typeOrder: id[] }`. Defaults live in the configs (chair 0.5x0.5, table 1.8x0.8 w/ 8 seats, screen 2x0.2). Chairs and table seats are independent.
 
 ## Conventions
 
@@ -74,9 +86,9 @@ Store (`store.ts`): `{ room, items, configs: Record<id, config>, typeOrder: id[]
 
 ## File layout
 
-- `src/types.ts`; `src/geometry.ts` (pure: `boundsOf`, `clampToRoom`, `overlaps`, `isValidPlacement`, `tryUpdate`, `resizeLength`, `fitScale`); `src/inventory.ts` (pure: `placedCount`, `remaining`, `effectiveSeats`); `src/store.ts` (reducer + built-in configs).
+- `src/types.ts`; `src/geometry.ts` (pure: `boundsOf`, `clampToRoom`, `overlaps`, `isValidPlacement`, `tryUpdate`, `resizeLength`, `fitScale`, plus room rules: `getBlockedRects`, `isValidWallItem`, `isValidObstacle`, `isLayoutValid`, `minRoomSize`, `tryResizeRoom`, `findWallSpot`, `findObstacleSpot`); `src/roomSchema.ts` (pure: `parseRoom`, `exportRoom`); `src/inventory.ts` (pure: `placedCount`, `remaining`, `effectiveSeats`); `src/store.ts` (reducer + built-in configs).
 - `src/App.tsx`: owns the store, selection, sidebar mode, palette drag, room scale, Delete key.
-- `src/components/`: `Palette`, `TypeMenu`, `ItemPanel`, `CustomForm`, `Wheel`, `Room` (Konva), `FurnitureShape`, `Icons`, `ScaleBar`, `panelStyles`.
+- `src/components/`: `Palette`, `TypeMenu`, `ItemPanel`, `CustomForm`, `ModeToggle`, `RoomPanels`, `Wheel`, `Room` (Konva), `FurnitureShape`, `Icons`, `ScaleBar`, `panelStyles`.
 
 ## Roadmap (not built yet, don't block)
 
@@ -103,6 +115,6 @@ npx tsc --noEmit # type check
 
 ## Working agreement
 
-- Ask before expanding scope past Phase 2.
+- Ask before expanding scope past Phase 3.
 - After changes, make sure the app builds and type checks.
 - Hackathon pace: prefer simple and working over clever.

src/App.tsx

@@ -1,17 +1,34 @@
 import { useCallback, useEffect, useMemo, useReducer, useRef, useState } from "react";
-import { clampToRoom, fitScale, isValidPlacement, tryUpdate } from "./geometry";
+import {
+  DEFAULT_DOOR_WIDTH,
+  MAX_SCREENS,
+  clampToRoom,
+  findObstacleSpot,
+  findWallSpot,
+  fitScale,
+  isLayoutValid,
+  isValidObstacle,
+  isValidPlacement,
+  isValidWallItem,
+  minRoomSize,
+  tryResizeRoom,
+  tryUpdate,
+  wallLength,
+} from "./geometry";
+import { exportRoom, parseRoom } from "./roomSchema";
 import { initialState, reducer } from "./store";
-import type { FurnitureItem, FurnitureType, Rect } from "./types";
+import type { Door, FurnitureItem, FurnitureType, Obstacle, Rect, Room as RoomT, RoomScreen, Wall } from "./types";
 import { placedCount, remaining } from "./inventory";
 import { Palette } from "./components/Palette";
-import { Room, type Preview } from "./components/Room";
+import { Room, WALL_PX, type Mode, type Preview, type RoomSel } from "./components/Room";
+import { ModeToggle } from "./components/ModeToggle";
+import { DoorPanel, ObstaclePanel, RoomPanel, ScreenPanel } from "./components/RoomPanels";
 import { ScaleBar } from "./components/ScaleBar";
 import { TypeMenu } from "./components/TypeMenu";
 import { ItemPanel } from "./components/ItemPanel";
 import { CustomForm, type CustomDraft } from "./components/CustomForm";
 import { ShapeIcon } from "./components/Icons";
 
-const WALL_PX = 6; // room wall border, must match Room.tsx
 const SCALE_BAR_PX = 40;
 
 interface PaletteDrag {
@@ -30,7 +47,12 @@ export default function App() {
   const [selectedId, setSelectedId] = useState<string | null>(null);
   const floorRef = useRef<HTMLDivElement>(null);
   const mainRef = useRef<HTMLElement>(null);
+  const roomRef = useRef(state.room);
+  roomRef.current = state.room;
   const [pxPerM, setPxPerM] = useState(60);
+  const [mode, setMode] = useState<Mode>("layout");
+  const [roomSel, setRoomSel] = useState<RoomSel | null>(null);
+  const [roomNotice, setRoomNotice] = useState("");
   const nextItemId = useRef(1);
   const nextCustomId = useRef(1);
 
@@ -48,6 +70,19 @@ export default function App() {
   const closeSidebar = useCallback(() => setSidebar({ kind: "tiles" }), []);
   const deselect = useCallback(() => setSelectedId(null), []);
 
+  // Switching modes closes menus and clears every selection.
+  const switchMode = (m: Mode) => {
+    setMode(m);
+    setSelectedId(null);
+    setRoomSel(null);
+    setRoomNotice("");
+    setSidebar({ kind: "tiles" });
+  };
+  const deselectRoom = useCallback(() => {
+    setRoomSel(null);
+    setRoomNotice("");
+  }, []);
+
   const deleteSelected = useCallback(() => {
     if (!selectedId) return;
     dispatch({ kind: "remove", id: selectedId });
@@ -60,13 +95,19 @@ export default function App() {
       if (e.key !== "Delete" && e.key !== "Backspace") return;
       const t = e.target as HTMLElement | null;
       if (t && (t.tagName === "INPUT" || t.tagName === "TEXTAREA" || t.isContentEditable)) return;
+      if (roomSel) {
+        e.preventDefault();
+        deleteRoomSel();
+        return;
+      }
       if (!selectedId) return;
       e.preventDefault();
       deleteSelected();
     };
     window.addEventListener("keydown", key);
     return () => window.removeEventListener("keydown", key);
-  }, [selectedId, deleteSelected]);
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [selectedId, deleteSelected, roomSel, state.room]);
 
   // Maximise the room inside the center area (minus wall border and the scale bar).
   useEffect(() => {
@@ -74,11 +115,11 @@ export default function App() {
     if (!el) return;
     const ro = new ResizeObserver(([entry]) => {
       const { width, height } = entry.contentRect;
-      setPxPerM(fitScale(state.room, width - WALL_PX * 2, height - WALL_PX * 2 - SCALE_BAR_PX));
+      setPxPerM(fitScale(roomRef.current, width - WALL_PX * 2, height - WALL_PX * 2 - SCALE_BAR_PX));
     });
     ro.observe(el);
     return () => ro.disconnect();
-  }, [state.room]);
+  }, [state.room.width, state.room.height]);
 
   // Cursor position -> a new item's box (centered on cursor, clamped), or null if outside the floor.
   const toRoomRect = (d: PaletteDrag): Rect | null => {
@@ -151,6 +192,116 @@ export default function App() {
     return true;
   };
 
+  // ---- Room mode: every edit builds a new Room with pure rules, then replaces it in the store ----
+  const room = state.room;
+  const setRoom = (next: RoomT) => {
+    dispatch({ kind: "setRoom", room: next });
+    setRoomNotice("");
+  };
+  const reject = (msg: string) => setRoomNotice(msg);
+  const uid = (p: string) => `${p}-${Math.random().toString(36).slice(2, 8)}`;
+
+  const resizeRoom = (size: { width?: number; height?: number }) => {
+    const next = tryResizeRoom(room, state.items, size);
+    if (next) setRoom(next);
+    else reject("Can't shrink past what's placed in the room.");
+  };
+
+  const addDoor = () => {
+    for (const wall of ["bottom", "right", "left", "top"] as Wall[]) {
+      const offset = findWallSpot(room, state.items, "door", wall, DEFAULT_DOOR_WIDTH);
+      if (offset === null) continue;
+      const door: Door = { id: uid("door"), wall, offset, width: DEFAULT_DOOR_WIDTH, isLoading: false };
+      setRoom({ ...room, doors: [...room.doors, door] });
+      setRoomSel({ kind: "door", id: door.id });
+      return;
+    }
+    reject("No free space on any wall for a door.");
+  };
+
+  const addScreen = () => {
+    if (room.screens.length >= MAX_SCREENS) return;
+    for (const wall of ["top", "left", "right", "bottom"] as Wall[]) {
+      const width = Math.min(4, wallLength(room, wall));
+      const offset = findWallSpot(room, state.items, "screen", wall, width);
+      if (offset === null) continue;
+      const screen: RoomScreen = { id: uid("screen"), wall, offset, width };
+      setRoom({ ...room, screens: [...room.screens, screen] });
+      setRoomSel({ kind: "screen", id: screen.id });
+      return;
+    }
+    reject("No free space on any wall for a screen.");
+  };
+
+  const addObstacle = () => {
+    const spot = findObstacleSpot(room, state.items, 0.6, 0.6);
+    if (!spot) return reject("No free space for an obstacle.");
+    const o: Obstacle = { id: uid("obstacle"), ...spot, width: 0.6, height: 0.6 };
+    setRoom({ ...room, obstacles: [...room.obstacles, o] });
+    setRoomSel({ kind: "obstacle", id: o.id });
+  };
+
+  const patchDoor = (id: string, patch: Partial<Door>) => {
+    const d = room.doors.find((x) => x.id === id);
+    if (!d) return;
+    const next = { ...d, ...patch };
+    next.offset = Math.max(0, Math.min(next.offset, wallLength(room, next.wall) - next.width));
+    if (!isValidWallItem(room, state.items, { id, kind: "door", wall: next.wall, offset: next.offset, width: next.width }))
+      return reject("No room for that change.");
+    setRoom({ ...room, doors: room.doors.map((x) => (x.id === id ? next : x)) });
+  };
+
+  const patchScreen = (id: string, patch: Partial<RoomScreen>) => {
+    const sc = room.screens.find((x) => x.id === id);
+    if (!sc) return;
+    const next = { ...sc, ...patch };
+    next.offset = Math.max(0, Math.min(next.offset, wallLength(room, next.wall) - next.width));
+    if (!isValidWallItem(room, state.items, { id, kind: "screen", wall: next.wall, offset: next.offset, width: next.width }))
+      return reject("No room for that change.");
+    setRoom({ ...room, screens: room.screens.map((x) => (x.id === id ? next : x)) });
+  };
+
+  const patchObstacle = (id: string, patch: Partial<Obstacle>) => {
+    const o = room.obstacles.find((x) => x.id === id);
+    if (!o) return;
+    const next = clampToRoom({ ...o, ...patch }, room);
+    if (!isValidObstacle(room, state.items, next)) return reject("No room for that change.");
+    setRoom({ ...room, obstacles: room.obstacles.map((x) => (x.id === id ? next : x)) });
+  };
+
+  const deleteRoomSel = () => {
+    if (!roomSel) return;
+    if (roomSel.kind === "door") {
+      if (room.doors.length <= 1) return reject("A room needs at least one door.");
+      setRoom({ ...room, doors: room.doors.filter((d) => d.id !== roomSel.id) });
+    } else if (roomSel.kind === "screen") {
+      setRoom({ ...room, screens: room.screens.filter((s) => s.id !== roomSel.id) });
+    } else {
+      setRoom({ ...room, obstacles: room.obstacles.filter((o) => o.id !== roomSel.id) });
+    }
+    setRoomSel(null);
+  };
+
+  const exportRoomFile = () => {
+    const url = URL.createObjectURL(new Blob([exportRoom(room)], { type: "application/json" }));
+    const a = document.createElement("a");
+    a.href = url;
+    a.download = "room.json";
+    a.click();
+    URL.revokeObjectURL(url);
+  };
+
+  const importRoomFile = async (file: File) => {
+    const result = parseRoom(await file.text());
+    if (!result.ok) return reject(`Import failed: ${result.error}`);
+    if (state.items.length > 0 && !window.confirm("Importing replaces the current room. Continue?")) return;
+    const clear = state.items.length > 0 && !isLayoutValid(result.room, state.items);
+    dispatch({ kind: "setRoom", room: result.room, clearItems: clear });
+    setSelectedId(null);
+    setRoomSel(null);
+    setRoomNotice(clear ? "Furniture was cleared because it didn't fit the imported room." : "");
+  };
+
   const saveCustom = (d: CustomDraft) => {
     const id = `custom-${nextCustomId.current++}`;
     dispatch({
@@ -175,7 +326,33 @@ export default function App() {
   );
 
   let panel = null;
-  if (selectedItem) {
+  if (mode === "room") {
+    const door = roomSel?.kind === "door" ? room.doors.find((d) => d.id === roomSel.id) : undefined;
+    const screen = roomSel?.kind === "screen" ? room.screens.find((s) => s.id === roomSel.id) : undefined;
+    const obstacle = roomSel?.kind === "obstacle" ? room.obstacles.find((o) => o.id === roomSel.id) : undefined;
+    if (door) {
+      panel = (
+        <DoorPanel key={door.id} door={door} isLast={room.doors.length <= 1} notice={roomNotice}
+          onPatch={(p) => patchDoor(door.id, p)} onDelete={deleteRoomSel} onClose={deselectRoom} />
+      );
+    } else if (screen) {
+      panel = (
+        <ScreenPanel key={screen.id} screen={screen} notice={roomNotice}
+          onPatch={(p) => patchScreen(screen.id, p)} onDelete={deleteRoomSel} onClose={deselectRoom} />
+      );
+    } else if (obstacle) {
+      panel = (
+        <ObstaclePanel key={obstacle.id} obstacle={obstacle} notice={roomNotice}
+          onPatch={(p) => patchObstacle(obstacle.id, p)} onDelete={deleteRoomSel} onClose={deselectRoom} />
+      );
+    } else {
+      panel = (
+        <RoomPanel room={room} minSize={minRoomSize(room, state.items)} notice={roomNotice}
+          onResize={resizeRoom} onAddDoor={addDoor} onAddScreen={addScreen} onAddObstacle={addObstacle}
+          onExport={exportRoomFile} onImport={importRoomFile} />
+      );
+    }
+  } else if (selectedItem) {
     panel = (
       <ItemPanel
         key={selectedItem.id}
@@ -209,6 +386,7 @@ export default function App() {
         onStartDrag={startDrag}
         onOpenMenu={(id) => openSidebar({ kind: "type", id })}
         onNewCustom={() => openSidebar({ kind: "custom" })}
+        header={<ModeToggle mode={mode} onChange={switchMode} />}
         panel={panel}
       />
       <main
@@ -216,6 +394,14 @@ export default function App() {
         style={{ flex: 1, minWidth: 0, display: "flex", flexDirection: "column", alignItems: "center", justifyContent: "center", overflow: "hidden", padding: 24 }}
       >
         <Room
+          mode={mode}
+          roomSel={roomSel}
+          onSelectRoom={(sel) => {
+            setRoomSel(sel);
+            setRoomNotice("");
+          }}
+          onMoveWallItem={(kind, id, offset) => (kind === "door" ? patchDoor(id, { offset }) : patchScreen(id, { offset }))}
+          onMoveObstacle={(id, x, y) => patchObstacle(id, { x, y })}
           pxPerM={pxPerM}
           room={state.room}
           items={state.items}

src/components/ModeToggle.tsx

@@ -0,0 +1,25 @@
+import type { Mode } from "./Room";
+
+export function ModeToggle({ mode, onChange }: { mode: Mode; onChange: (m: Mode) => void }) {
+  const seg = (m: Mode): React.CSSProperties => ({
+    flex: 1,
+    height: 30,
+    border: "none",
+    borderRadius: 6,
+    cursor: "pointer",
+    font: "600 13px system-ui, sans-serif",
+    background: mode === m ? "#fff" : "transparent",
+    color: mode === m ? "#222" : "#666",
+    boxShadow: mode === m ? "0 1px 3px rgba(0,0,0,0.15)" : "none",
+  });
+  return (
+    <div style={{ gridColumn: "1 / -1", display: "flex", gap: 2, padding: 3, background: "#d9d9d9", borderRadius: 9 }}>
+      <button style={seg("layout")} onClick={() => onChange("layout")}>
+        Layout
+      </button>
+      <button style={seg("room")} onClick={() => onChange("room")}>
+        Room
+      </button>
+    </div>
+  );
+}

src/components/Palette.tsx

@@ -10,6 +10,7 @@ interface Props {
   onStartDrag: (type: FurnitureType, clientX: number, clientY: number) => void;
   onOpenMenu: (type: FurnitureType) => void;
   onNewCustom: () => void;
+  header?: ReactNode; // always shown first (mode toggle)
   panel: ReactNode; // when set, replaces the tiles (type menu, item panel, custom form)
 }
 
@@ -119,7 +120,7 @@ function NewCustomTile({ onClick }: { onClick: () => void }) {
   );
 }
 
-export function Palette({ types, remaining, onStartDrag, onOpenMenu, onNewCustom, panel }: Props) {
+export function Palette({ types, remaining, onStartDrag, onOpenMenu, onNewCustom, header, panel }: Props) {
   const [width, setWidth] = useState(264);
 
   const startResize = (e: PointerEvent) => {
@@ -158,6 +159,7 @@ export function Palette({ types, remaining, onStartDrag, onOpenMenu, onNewCustom
           gap: 12,
         }}
       >
+        {header}
         {panel ?? (
           <>
             {types.map((cfg) => (

src/components/Room.tsx

@@ -1,8 +1,19 @@
 import { useRef, useState, type RefObject } from "react";
-import { Stage, Layer, Group, Rect, Path } from "react-konva";
+import { Stage, Layer, Group, Rect, Path, Arc, Line, RegularPolygon } from "react-konva";
 import type Konva from "konva";
-import { boundsOf, isValidPlacement, clampToRoom, resizeLength } from "../geometry";
-import type { FurnitureItem, FurnitureTypeConfig, Rect as RectM, Room as RoomT, Shape } from "../types";
+import {
+  SCREEN_DEPTH_M,
+  boundsOf,
+  clampToRoom,
+  doorSwingRect,
+  isValidObstacle,
+  isValidPlacement,
+  isValidWallItem,
+  resizeLength,
+  wallLength,
+  wallRect,
+} from "../geometry";
+import type { Door, FurnitureItem, FurnitureTypeConfig, Obstacle, Rect as RectM, Room as RoomT, RoomScreen, Shape, Wall } from "../types";
 import { FurnitureShape, type Outline } from "./FurnitureShape";
 
 export interface Preview {
@@ -14,7 +25,16 @@ export interface Preview {
   valid: boolean;
 }
 
+export const WALL_PX = 6; // drawn wall thickness around the floor
+export type Mode = "layout" | "room";
+export type RoomSel = { kind: "door" | "screen" | "obstacle"; id: string };
+
 interface Props {
+  mode: Mode;
+  roomSel: RoomSel | null;
+  onSelectRoom: (sel: RoomSel | null) => void;
+  onMoveWallItem: (kind: "door" | "screen", id: string, offset: number) => void;
+  onMoveObstacle: (id: string, x: number, y: number) => void;
   room: RoomT;
   items: FurnitureItem[];
   configs: Record<string, FurnitureTypeConfig>;
@@ -38,7 +58,99 @@ interface ResizeInfo {
   valid: boolean;
 }
 
+interface WallDrag {
+  kind: "door" | "screen";
+  id: string;
+  offset: number;
+  valid: boolean;
+}
+
 const HANDLE_PX = 10;
+const O = WALL_PX;
+const WALL_COLOR = "#2b2b2b";
+const SEL = "#1c7ed6";
+const BAD = "#e03131";
+const GOOD = "#2f9e44";
+
+/** Wall pieces between door openings, in meters along each wall. */
+function wallSegments(room: RoomT): { wall: Wall; a: number; b: number }[] {
+  const out: { wall: Wall; a: number; b: number }[] = [];
+  for (const wall of ["top", "bottom", "left", "right"] as Wall[]) {
+    const len = wallLength(room, wall);
+    const gaps = room.doors.filter((d) => d.wall === wall).sort((p, q) => p.offset - q.offset);
+    let at = 0;
+    for (const g of gaps) {
+      if (g.offset > at + 1e-6) out.push({ wall, a: at, b: g.offset });
+      at = Math.max(at, g.offset + g.width);
+    }
+    if (at < len - 1e-6) out.push({ wall, a: at, b: len });
+  }
+  return out;
+}
+
+// Quarter-circle swing: hinge at the door's near end, leaf swings into the room.
+const SWING = {
+  top: { rot: 0, dir: [0, 1] },
+  bottom: { rot: 270, dir: [0, -1] },
+  left: { rot: 0, dir: [1, 0] },
+  right: { rot: 90, dir: [-1, 0] },
+} as const;
+
+function hinge(room: RoomT, d: Pick<Door, "wall" | "offset">): [number, number] {
+  switch (d.wall) {
+    case "top":
+      return [d.offset, 0];
+    case "bottom":
+      return [d.offset, room.height];
+    case "left":
+      return [0, d.offset];
+    case "right":
+      return [room.width, d.offset];
+  }
+}
+
+function DoorShape({ room, door, px, color }: { room: RoomT; door: Door; px: number; color: string }) {
+  const [hx, hy] = hinge(room, door);
+  const sw = SWING[door.wall];
+  const r = door.width * px;
+  return (
+    <Group listening={false}>
+      <Arc
+        x={hx * px}
+        y={hy * px}
+        innerRadius={0}
+        outerRadius={r}
+        angle={90}
+        rotation={sw.rot}
+        fill={door.isLoading ? "rgba(237,137,54,0.2)" : "rgba(66,153,225,0.14)"}
+        stroke={color}
+        strokeWidth={1}
+        dash={[4, 4]}
+      />
+      <Line points={[hx * px, hy * px, hx * px + sw.dir[0] * r, hy * px + sw.dir[1] * r]} stroke={color} strokeWidth={3} lineCap="round" />
+    </Group>
+  );
+}
+
+const ARROW_ROT: Record<Wall, number> = { top: 180, bottom: 0, left: 90, right: -90 };
+
+function ScreenShape({ room, screen, px, outline }: { room: RoomT; screen: RoomScreen; px: number; outline: string }) {
+  const r = wallRect(room, screen.wall, screen.offset, screen.width, SCREEN_DEPTH_M);
+  const rad = Math.max(4, SCREEN_DEPTH_M * px * 0.5);
+  return (
+    <Group listening={false}>
+      <Rect x={r.x * px} y={r.y * px} width={r.width * px} height={r.height * px} fill="#2d3748" stroke={outline} strokeWidth={outline === WALL_COLOR ? 1 : 2.5} cornerRadius={2} />
+      <RegularPolygon
+        x={(r.x + r.width / 2) * px}
+        y={(r.y + r.height / 2) * px}
+        sides={3}
+        radius={rad}
+        rotation={ARROW_ROT[screen.wall]}
+        fill="#63b3ed"
+      />
+    </Group>
+  );
+}
 const ENDS: ("left" | "right")[] = ["left", "right"];
 
 function LockIcon({ w, h, rotation }: { w: number; h: number; rotation: number }) {
@@ -52,10 +164,14 @@ function LockIcon({ w, h, rotation }: { w: number; h: number; rotation: number }
   );
 }
 
-export function Room({ room, items, configs, preview, pxPerM, floorRef, selectedId, onSelect, onMove, onResize }: Props) {
+export function Room({ mode, roomSel, onSelectRoom, onMoveWallItem, onMoveObstacle, room, items, configs, preview, pxPerM, floorRef, selectedId, onSelect, onMove, onResize }: Props) {
+  const interactive = mode === "layout";
   const [drag, setDrag] = useState<DragInfo | null>(null);
   const [resize, setResize] = useState<ResizeInfo | null>(null);
   const resizeStart = useRef<RectM | null>(null);
+  const [wallDrag, setWallDrag] = useState<WallDrag | null>(null);
+  const wallStart = useRef<{ along: number; offset: number } | null>(null);
+  const [obDrag, setObDrag] = useState<{ id: string; valid: boolean } | null>(null);
   const w = room.width * pxPerM;
   const h = room.height * pxPerM;
 
@@ -70,26 +186,167 @@ export function Room({ room, items, configs, preview, pxPerM, floorRef, selected
       room,
     );
 
+  const fw = w + O * 2;
+  const fh = h + O * 2;
+
+  // ---- wall items (doors / screens): slide along their wall only ----
+  const alongOf = (wall: Wall, p: { x: number; y: number }) => ((wall === "top" || wall === "bottom" ? p.x : p.y) - O) / pxPerM;
+
+  const wallHit = (kind: "door" | "screen", id: string, wall: Wall, offset: number, width: number, rect: RectM) => {
+    return (
+      <Rect
+        key={`hit-${id}`}
+        x={rect.x * pxPerM}
+        y={rect.y * pxPerM}
+        width={rect.width * pxPerM}
+        height={rect.height * pxPerM}
+        fill="transparent"
+        draggable
+        dragBoundFunc={function (this: Konva.Node) {
+          return this.absolutePosition();
+        }}
+        onMouseDown={() => onSelectRoom({ kind, id })}
+        onTouchStart={() => onSelectRoom({ kind, id })}
+        onDragStart={(e) => {
+          e.cancelBubble = true;
+          const p = e.target.getStage()?.getPointerPosition();
+          if (p) wallStart.current = { along: alongOf(wall, p), offset };
+        }}
+        onDragMove={(e) => {
+          const p = e.target.getStage()?.getPointerPosition();
+          const st = wallStart.current;
+          if (!p || !st) return;
+          const next = Math.min(Math.max(st.offset + alongOf(wall, p) - st.along, 0), wallLength(room, wall) - width);
+          setWallDrag({ kind, id, offset: next, valid: isValidWallItem(room, items, { id, kind, wall, offset: next, width }) });
+        }}
+        onDragEnd={() => {
+          if (wallDrag?.valid) onMoveWallItem(kind, id, wallDrag.offset); // else snap back
+          setWallDrag(null);
+          wallStart.current = null;
+        }}
+        onMouseEnter={(e) => {
+          const c = e.target.getStage()?.container();
+          if (c) c.style.cursor = wall === "top" || wall === "bottom" ? "ew-resize" : "ns-resize";
+        }}
+        onMouseLeave={(e) => {
+          const c = e.target.getStage()?.container();
+          if (c) c.style.cursor = "";
+        }}
+      />
+    );
+  };
+
+  const colorFor = (kind: "door" | "screen", id: string, normal: string) => {
+    if (wallDrag?.kind === kind && wallDrag.id === id) return wallDrag.valid ? GOOD : BAD;
+    return roomSel?.kind === kind && roomSel.id === id ? SEL : normal;
+  };
+
   return (
     <div
-      ref={floorRef}
       style={{
-        width: w,
-        height: h,
-        border: "6px solid #2b2b2b",
-        boxSizing: "content-box",
+        width: fw,
+        height: fh,
         background: "#fff",
         boxShadow: "0 4px 18px rgba(0,0,0,0.12)",
         touchAction: "none",
       }}
+      ref={floorRef}
     >
       <Stage
-        width={w}
-        height={h}
-        onMouseDown={(e) => e.target === e.target.getStage() && onSelect(null)}
-        onTouchStart={(e) => e.target === e.target.getStage() && onSelect(null)}
+        width={fw}
+        height={fh}
+        onMouseDown={(e) => {
+          if (e.target !== e.target.getStage()) return;
+          if (interactive) onSelect(null);
+          else onSelectRoom(null);
+        }}
+        onTouchStart={(e) => {
+          if (e.target !== e.target.getStage()) return;
+          if (interactive) onSelect(null);
+          else onSelectRoom(null);
+        }}
       >
-        <Layer>
+        <Layer x={O} y={O}>
+          <Rect width={w} height={h} fill="#fff" listening={false} />
+
+          {/* walls with a gap at every door */}
+          {wallSegments(room).map((sg, n) => {
+            const a = sg.a * pxPerM;
+            const len = (sg.b - sg.a) * pxPerM;
+            const r =
+              sg.wall === "top"
+                ? { x: a, y: -O, width: len, height: O }
+                : sg.wall === "bottom"
+                  ? { x: a, y: h, width: len, height: O }
+                  : sg.wall === "left"
+                    ? { x: -O, y: a, width: O, height: len }
+                    : { x: w, y: a, width: O, height: len };
+            return <Rect key={n} {...r} fill={WALL_COLOR} listening={false} />;
+          })}
+          {[[-O, -O], [w, -O], [-O, h], [w, h]].map(([x, y]) => (
+            <Rect key={`${x},${y}`} x={x} y={y} width={O} height={O} fill={WALL_COLOR} listening={false} />
+          ))}
+
+          {/* doors: swing arc inside the room */}
+          {room.doors.map((d) => {
+            const live = wallDrag?.kind === "door" && wallDrag.id === d.id ? { ...d, offset: wallDrag.offset } : d;
+            return <DoorShape key={d.id} room={room} door={live} px={pxPerM} color={colorFor("door", d.id, d.isLoading ? "#c05621" : "#4a5568")} />;
+          })}
+
+          {/* wall screens */}
+          {room.screens.map((sc) => {
+            const live = wallDrag?.kind === "screen" && wallDrag.id === sc.id ? { ...sc, offset: wallDrag.offset } : sc;
+            return <ScreenShape key={sc.id} room={room} screen={live} px={pxPerM} outline={colorFor("screen", sc.id, WALL_COLOR)} />;
+          })}
+
+          {/* obstacles */}
+          {room.obstacles.map((o: Obstacle) => {
+            const state = obDrag?.id === o.id ? (obDrag.valid ? GOOD : BAD) : roomSel?.kind === "obstacle" && roomSel.id === o.id ? SEL : "#4a4a4a";
+            return (
+              <Rect
+                key={o.id}
+                x={o.x * pxPerM}
+                y={o.y * pxPerM}
+                width={o.width * pxPerM}
+                height={o.height * pxPerM}
+                fill="#9aa0a6"
+                stroke={state}
+                strokeWidth={state === "#4a4a4a" ? 1.5 : 3}
+                cornerRadius={2}
+                listening={!interactive}
+                draggable={!interactive}
+                onMouseDown={() => onSelectRoom({ kind: "obstacle", id: o.id })}
+                onTouchStart={() => onSelectRoom({ kind: "obstacle", id: o.id })}
+                dragBoundFunc={(pos) => ({
+                  x: Math.min(Math.max(pos.x, O), O + w - o.width * pxPerM),
+                  y: Math.min(Math.max(pos.y, O), O + h - o.height * pxPerM),
+                })}
+                onDragMove={(e) =>
+                  setObDrag({
+                    id: o.id,
+                    valid: isValidObstacle(room, items, { ...o, x: e.target.x() / pxPerM, y: e.target.y() / pxPerM }),
+                  })
+                }
+                onDragEnd={(e) => {
+                  const nx = e.target.x() / pxPerM;
+                  const ny = e.target.y() / pxPerM;
+                  const ok = isValidObstacle(room, items, { ...o, x: nx, y: ny });
+                  e.target.position({ x: (ok ? nx : o.x) * pxPerM, y: (ok ? ny : o.y) * pxPerM });
+                  if (ok) onMoveObstacle(o.id, nx, ny);
+                  setObDrag(null);
+                }}
+                onMouseEnter={(e) => {
+                  const c = e.target.getStage()?.container();
+                  if (c && !interactive) c.style.cursor = "grab";
+                }}
+                onMouseLeave={(e) => {
+                  const c = e.target.getStage()?.container();
+                  if (c) c.style.cursor = "";
+                }}
+              />
+            );
+          })}
+
           {items.map((item) => {
             const shape = configs[item.type]?.shape ?? "chair";
             const isResizing = resize?.id === item.id;
@@ -110,7 +367,8 @@ export function Room({ room, items, configs, preview, pxPerM, floorRef, selected
                 offsetX={wpx / 2}
                 offsetY={hpx / 2}
                 rotation={item.rotation}
-                draggable={!item.locked}
+                listening={interactive}
+                draggable={interactive && !item.locked}
                 onMouseDown={() => onSelect(item.id)}
                 onTouchStart={() => onSelect(item.id)}
                 // Keep the rotated bounds inside the walls (stage is unscaled, so absolute = local).
@@ -118,8 +376,8 @@ export function Room({ room, items, configs, preview, pxPerM, floorRef, selected
                   const hx = (half.width / 2) * pxPerM;
                   const hy = (half.height / 2) * pxPerM;
                   return {
-                    x: Math.min(Math.max(pos.x, hx), w - hx),
-                    y: Math.min(Math.max(pos.y, hy), h - hy),
+                    x: Math.min(Math.max(pos.x, O + hx), O + w - hx),
+                    y: Math.min(Math.max(pos.y, O + hy), O + h - hy),
                   };
                 }}
                 onDragStart={(e) => {
@@ -155,7 +413,7 @@ export function Room({ room, items, configs, preview, pxPerM, floorRef, selected
           {items.map((item) => {
             // Screens get length handles on their ends while selected, unlocked and unrotated.
             const isScreen = configs[item.type]?.shape === "screen";
-            if (item.id !== selectedId || !isScreen || item.locked || item.rotation !== 0 || drag?.id === item.id) return null;
+            if (!interactive || item.id !== selectedId || !isScreen || item.locked || item.rotation !== 0 || drag?.id === item.id) return null;
             const r: RectM = resize?.id === item.id ? resize.rect : item;
             const mid = {
               left: [r.x, r.y + r.height / 2],
@@ -188,7 +446,7 @@ export function Room({ room, items, configs, preview, pxPerM, floorRef, selected
                   const p = e.target.getStage()?.getPointerPosition();
                   const start = resizeStart.current;
                   if (!p || !start) return;
-                  const next = resizeLength(start, edge, p.x / pxPerM, room);
+                  const next = resizeLength(start, edge, (p.x - O) / pxPerM, room);
                   setResize({ id: item.id, rect: next, valid: isValidPlacement({ ...item, ...next }, items, room, item.id) });
                 }}
                 onDragEnd={() => {
@@ -207,6 +465,16 @@ export function Room({ room, items, configs, preview, pxPerM, floorRef, selected
               />
             ));
           })}
+          {!interactive &&
+            room.doors.map((d) => {
+              const live = wallDrag?.kind === "door" && wallDrag.id === d.id ? wallDrag.offset : d.offset;
+              return wallHit("door", d.id, d.wall, live, d.width, doorSwingRect(room, { ...d, offset: live }));
+            })}
+          {!interactive &&
+            room.screens.map((sc) => {
+              const live = wallDrag?.kind === "screen" && wallDrag.id === sc.id ? wallDrag.offset : sc.offset;
+              return wallHit("screen", sc.id, sc.wall, live, sc.width, wallRect(room, sc.wall, live, sc.width, SCREEN_DEPTH_M));
+            })}
           {preview && (
             <Group x={preview.x * pxPerM} y={preview.y * pxPerM} listening={false}>
               <FurnitureShape

src/components/RoomPanels.tsx

@@ -0,0 +1,209 @@
+import { useEffect, useRef } from "react";
+import type { Door, Obstacle, Room, RoomScreen } from "../types";
+import { DOOR_WIDTH, MAX_SCREENS, OBSTACLE_SIZE, ROOM_SIZE, SCREEN_WIDTH } from "../geometry";
+import { Wheel } from "./Wheel";
+import { backBtn, btn, hint, label, panelRoot, title, twoCol } from "./panelStyles";
+
+const fmt = (v: number) => v.toFixed(1);
+
+function useEscape(onClose: () => void) {
+  useEffect(() => {
+    const key = (e: KeyboardEvent) => e.key === "Escape" && onClose();
+    window.addEventListener("keydown", key);
+    return () => window.removeEventListener("keydown", key);
+  }, [onClose]);
+}
+
+const dangerBtn: React.CSSProperties = { ...btn, color: "#e03131", borderColor: "#e8a8a8" };
+
+// ---------------- Room settings (Room mode, nothing selected) ----------------
+
+interface RoomPanelProps {
+  room: Room;
+  minSize: { width: number; height: number };
+  notice: string;
+  onResize: (size: { width?: number; height?: number }) => void;
+  onAddDoor: () => void;
+  onAddScreen: () => void;
+  onAddObstacle: () => void;
+  onExport: () => void;
+  onImport: (file: File) => void;
+}
+
+export function RoomPanel({ room, minSize, notice, onResize, onAddDoor, onAddScreen, onAddObstacle, onExport, onImport }: RoomPanelProps) {
+  const fileRef = useRef<HTMLInputElement>(null);
+  const limited = minSize.width > ROOM_SIZE.min || minSize.height > ROOM_SIZE.min;
+  return (
+    <div style={panelRoot}>
+      <div style={title}>Room</div>
+      <div>
+        <div style={label}>Size (m)</div>
+        <div style={twoCol}>
+          <div>
+            <div style={hint}>Width</div>
+            <Wheel value={room.width} min={minSize.width} max={ROOM_SIZE.max} step={0.1} rows={3} format={fmt} onChange={(v) => onResize({ width: v })} />
+          </div>
+          <div>
+            <div style={hint}>Length</div>
+            <Wheel value={room.height} min={minSize.height} max={ROOM_SIZE.max} step={0.1} rows={3} format={fmt} onChange={(v) => onResize({ height: v })} />
+          </div>
+        </div>
+        {limited && (
+          <div style={hint}>
+            The room can't shrink past what's placed in it (min {fmt(minSize.width)} × {fmt(minSize.height)} m).
+          </div>
+        )}
+      </div>
+
+      <div style={{ display: "grid", gap: 8 }}>
+        <button style={btn} onClick={onAddDoor}>
+          Add door
+        </button>
+        <button style={{ ...btn, opacity: room.screens.length >= MAX_SCREENS ? 0.45 : 1 }} disabled={room.screens.length >= MAX_SCREENS} onClick={onAddScreen}>
+          Add screen
+        </button>
+        {room.screens.length >= MAX_SCREENS && <div style={{ ...hint, marginTop: -4 }}>Maximum of {MAX_SCREENS} screens.</div>}
+        <button style={btn} onClick={onAddObstacle}>
+          Add obstacle
+        </button>
+      </div>
+
+      {notice && <div style={{ ...hint, color: "#e03131", marginTop: 0 }}>{notice}</div>}
+
+      <div style={{ display: "flex", gap: 8 }}>
+        <button style={{ ...btn, flex: 1 }} onClick={onExport}>
+          Export room
+        </button>
+        <button style={{ ...btn, flex: 1 }} onClick={() => fileRef.current?.click()}>
+          Import room
+        </button>
+        <input
+          ref={fileRef}
+          type="file"
+          accept="application/json,.json"
+          style={{ display: "none" }}
+          onChange={(e) => {
+            const f = e.target.files?.[0];
+            e.target.value = ""; // allow re-importing the same file
+            if (f) onImport(f);
+          }}
+        />
+      </div>
+      <div style={hint}>Furniture isn't included in room.json.</div>
+    </div>
+  );
+}
+
+// ---------------- Door ----------------
+
+interface DoorPanelProps {
+  door: Door;
+  isLast: boolean;
+  notice: string;
+  onPatch: (p: Partial<Door>) => void;
+  onDelete: () => void;
+  onClose: () => void;
+}
+
+export function DoorPanel({ door, isLast, notice, onPatch, onDelete, onClose }: DoorPanelProps) {
+  useEscape(onClose);
+  return (
+    <div style={panelRoot}>
+      <button onClick={onClose} style={backBtn}>
+        ← Done
+      </button>
+      <div style={title}>Door</div>
+      <div>
+        <div style={label}>Width (m)</div>
+        <Wheel value={door.width} min={DOOR_WIDTH.min} max={DOOR_WIDTH.max} step={0.1} rows={3} format={fmt} onChange={(v) => onPatch({ width: v })} />
+      </div>
+      <div>
+        <button
+          style={{ ...btn, width: "100%", background: door.isLoading ? "#2b2b2b" : "#fff", color: door.isLoading ? "#fff" : "#222" }}
+          onClick={() => onPatch({ isLoading: !door.isLoading })}
+        >
+          Loading door: {door.isLoading ? "on" : "off"}
+        </button>
+        <div style={hint}>Furniture is carried through a loading door.</div>
+      </div>
+      <div style={hint}>The swing area and 0.6 m inside the opening stay clear of furniture.</div>
+      {notice && <div style={{ ...hint, color: "#e03131", marginTop: 0 }}>{notice}</div>}
+      <div>
+        <button style={{ ...dangerBtn, width: "100%", opacity: isLast ? 0.45 : 1, cursor: isLast ? "not-allowed" : "pointer" }} disabled={isLast} onClick={onDelete}>
+          Delete door
+        </button>
+        {isLast && <div style={hint}>A room needs at least one door.</div>}
+      </div>
+    </div>
+  );
+}
+
+// ---------------- Wall screen ----------------
+
+interface ScreenPanelProps {
+  screen: RoomScreen;
+  notice: string;
+  onPatch: (p: Partial<RoomScreen>) => void;
+  onDelete: () => void;
+  onClose: () => void;
+}
+
+export function ScreenPanel({ screen, notice, onPatch, onDelete, onClose }: ScreenPanelProps) {
+  useEscape(onClose);
+  return (
+    <div style={panelRoot}>
+      <button onClick={onClose} style={backBtn}>
+        ← Done
+      </button>
+      <div style={title}>Screen</div>
+      <div>
+        <div style={label}>Width (m)</div>
+        <Wheel value={screen.width} min={SCREEN_WIDTH.min} max={SCREEN_WIDTH.max} step={0.1} rows={3} format={fmt} onChange={(v) => onPatch({ width: v })} />
+      </div>
+      <div style={hint}>Drag it along its wall. A 0.3 m strip in front of the wall stays clear.</div>
+      {notice && <div style={{ ...hint, color: "#e03131", marginTop: 0 }}>{notice}</div>}
+      <button style={dangerBtn} onClick={onDelete}>
+        Delete screen
+      </button>
+    </div>
+  );
+}
+
+// ---------------- Obstacle ----------------
+
+interface ObstaclePanelProps {
+  obstacle: Obstacle;
+  notice: string;
+  onPatch: (p: Partial<Obstacle>) => void;
+  onDelete: () => void;
+  onClose: () => void;
+}
+
+export function ObstaclePanel({ obstacle, notice, onPatch, onDelete, onClose }: ObstaclePanelProps) {
+  useEscape(onClose);
+  return (
+    <div style={panelRoot}>
+      <button onClick={onClose} style={backBtn}>
+        ← Done
+      </button>
+      <div style={title}>Obstacle</div>
+      <div>
+        <div style={label}>Size (m)</div>
+        <div style={twoCol}>
+          <div>
+            <div style={hint}>Width</div>
+            <Wheel value={obstacle.width} min={OBSTACLE_SIZE.min} max={OBSTACLE_SIZE.max} step={0.1} rows={3} format={fmt} onChange={(v) => onPatch({ width: v })} />
+          </div>
+          <div>
+            <div style={hint}>Length</div>
+            <Wheel value={obstacle.height} min={OBSTACLE_SIZE.min} max={OBSTACLE_SIZE.max} step={0.1} rows={3} format={fmt} onChange={(v) => onPatch({ height: v })} />
+          </div>
+        </div>
+      </div>
+      {notice && <div style={{ ...hint, color: "#e03131", marginTop: 0 }}>{notice}</div>}
+      <button style={dangerBtn} onClick={onDelete}>
+        Delete obstacle
+      </button>
+    </div>
+  );
+}

src/geometry.ts

@@ -1,11 +1,69 @@
 // Pure geometry/rules. No React or Konva imports so an optimizer can reuse this.
-import type { FurnitureItem, Rect, Room } from "./types";
+import type { Door, FurnitureItem, Obstacle, Rect, Room, RoomScreen, Wall } from "./types";
 
 /** Largest px-per-meter that fits the room inside the given pixel box. */
 export const fitScale = (room: Room, availW: number, availH: number): number =>
   Math.max(1, Math.min(availW / room.width, availH / room.height));
 
-export const DEFAULT_ROOM: Room = { width: 10, height: 8 };
+export const DEFAULT_DOOR_WIDTH = 1.2;
+
+export const DEFAULT_ROOM: Room = {
+  width: 10,
+  height: 8,
+  doors: [{ id: "door-1", wall: "bottom", offset: (10 - DEFAULT_DOOR_WIDTH) / 2, width: DEFAULT_DOOR_WIDTH, isLoading: false }],
+  screens: [],
+  obstacles: [],
+};
+
+// ---- Room features: sizes, keep-clear zones ----
+export const ROOM_SIZE = { min: 3, max: 60 };
+export const DOOR_WIDTH = { min: 0.7, max: 4 };
+export const SCREEN_WIDTH = { min: 1, max: 12 };
+export const OBSTACLE_SIZE = { min: 0.2, max: 10 };
+export const MAX_SCREENS = 2;
+export const DOOR_STRIP_M = 0.6; // keep-clear strip just inside a door opening
+export const SCREEN_DEPTH_M = 0.3; // strip a wall screen occupies
+
+const EPS = 1e-6;
+export const WALLS: Wall[] = ["top", "bottom", "left", "right"];
+
+export const wallLength = (room: Room, wall: Wall): number =>
+  wall === "top" || wall === "bottom" ? room.width : room.height;
+
+/** Rect hugging `wall` on the inside: `length` along the wall from `offset`, `depth` into the room. */
+export function wallRect(room: Room, wall: Wall, offset: number, length: number, depth: number): Rect {
+  switch (wall) {
+    case "top":
+      return { x: offset, y: 0, width: length, height: depth };
+    case "bottom":
+      return { x: offset, y: room.height - depth, width: length, height: depth };
+    case "left":
+      return { x: 0, y: offset, width: depth, height: length };
+    case "right":
+      return { x: room.width - depth, y: offset, width: depth, height: length };
+  }
+}
+
+/** Swing area of a door: the bounding square of its quarter-circle, width x width. */
+export const doorSwingRect = (room: Room, d: Door): Rect => wallRect(room, d.wall, d.offset, d.width, d.width);
+
+/** Keep-clear zones of a door: the 0.6 m strip inside the opening and the swing area. */
+export const doorZones = (room: Room, d: Door): Rect[] => [
+  wallRect(room, d.wall, d.offset, d.width, DOOR_STRIP_M),
+  doorSwingRect(room, d),
+];
+
+export const screenStrip = (room: Room, s: RoomScreen): Rect =>
+  wallRect(room, s.wall, s.offset, s.width, SCREEN_DEPTH_M);
+
+/** Every rectangle furniture can't overlap: door zones, screen strips, obstacles. */
+export function getBlockedRects(room: Room): Rect[] {
+  return [
+    ...room.doors.flatMap((d) => doorZones(room, d)),
+    ...room.screens.map((s) => screenStrip(room, s)),
+    ...room.obstacles,
+  ];
+}
 
 /** A rect with an optional rotation (degrees) around its center. */
 export type Box = Rect & { rotation?: number };
@@ -63,7 +121,11 @@ export function isValidPlacement(
   ignoreId?: string,
 ): boolean {
   const cb = boundsOf(c);
-  return isInsideRoom(cb, room) && !items.some((o) => o.id !== ignoreId && overlaps(cb, boundsOf(o)));
+  return (
+    isInsideRoom(cb, room) &&
+    !items.some((o) => o.id !== ignoreId && overlaps(cb, boundsOf(o))) &&
+    !getBlockedRects(room).some((b) => overlaps(cb, b))
+  );
 }
 
 /**
@@ -85,7 +147,134 @@ export function tryUpdate(
   return isValidPlacement(next, items, room, item.id) ? next : null;
 }
 
-// ---- Screens: drag an end handle to change length (only while unrotated) ----
+// ---- Room feature rules (pure; the optimizer reuses these) ----
+
+export interface WallSpec {
+  id: string;
+  kind: "door" | "screen";
+  wall: Wall;
+  offset: number;
+  width: number;
+}
+
+const zonesOf = (room: Room, s: WallSpec): Rect[] =>
+  s.kind === "door"
+    ? doorZones(room, { id: s.id, wall: s.wall, offset: s.offset, width: s.width, isLoading: false })
+    : [wallRect(room, s.wall, s.offset, s.width, SCREEN_DEPTH_M)];
+
+/**
+ * A door/screen is valid if it fits on its wall, doesn't share wall length with another door/screen,
+ * and its keep-clear zones stay in the room and off furniture and obstacles.
+ */
+export function isValidWallItem(room: Room, items: FurnitureItem[], s: WallSpec): boolean {
+  if (s.offset < -EPS || s.offset + s.width > wallLength(room, s.wall) + EPS) return false;
+  const others = [
+    ...room.doors.filter((d) => d.id !== s.id),
+    ...room.screens.filter((o) => o.id !== s.id),
+  ];
+  const clash = others.some(
+    (o) => o.wall === s.wall && s.offset < o.offset + o.width - EPS && s.offset + s.width > o.offset + EPS,
+  );
+  if (clash) return false;
+  const bounds = items.map(boundsOf);
+  return zonesOf(room, s).every(
+    (z) =>
+      isInsideRoom(z, room) &&
+      !bounds.some((b) => overlaps(z, b)) &&
+      !room.obstacles.some((o) => overlaps(z, o)),
+  );
+}
+
+/** Obstacles stay inside the room and off furniture, other obstacles, and door/screen zones. */
+export function isValidObstacle(room: Room, items: FurnitureItem[], o: Obstacle): boolean {
+  if (!isInsideRoom(o, room)) return false;
+  if (items.some((i) => overlaps(o, boundsOf(i)))) return false;
+  if (room.obstacles.some((p) => p.id !== o.id && overlaps(o, p))) return false;
+  const zones = [
+    ...room.doors.flatMap((d) => doorZones(room, d)),
+    ...room.screens.map((s) => screenStrip(room, s)),
+  ];
+  return !zones.some((z) => overlaps(o, z));
+}
+
+/** Whole-layout check: used when the room size changes or a room is imported. */
+export function isLayoutValid(room: Room, items: FurnitureItem[]): boolean {
+  if (room.doors.length < 1 || room.screens.length > MAX_SCREENS) return false;
+  const wall = [
+    ...room.doors.map((d): WallSpec => ({ ...d, kind: "door" })),
+    ...room.screens.map((s): WallSpec => ({ ...s, kind: "screen" })),
+  ];
+  return (
+    wall.every((s) => isValidWallItem(room, items, s)) &&
+    room.obstacles.every((o) => isValidObstacle(room, items, o)) &&
+    items.every((i) => isValidPlacement(i, items, room, i.id))
+  );
+}
+
+const ceil1 = (v: number): number => Math.ceil(v * 10 - 1e-6) / 10;
+
+/** Smallest room that still holds the placed furniture, obstacles and wall items (bounding box). */
+export function minRoomSize(room: Room, items: FurnitureItem[]): { width: number; height: number } {
+  let w: number = ROOM_SIZE.min;
+  let h: number = ROOM_SIZE.min;
+  const grow = (r: Rect) => {
+    w = Math.max(w, r.x + r.width);
+    h = Math.max(h, r.y + r.height);
+  };
+  items.map(boundsOf).forEach(grow);
+  room.obstacles.forEach(grow);
+  const along = (s: { wall: Wall; offset: number; width: number }) => {
+    if (s.wall === "top" || s.wall === "bottom") w = Math.max(w, s.offset + s.width);
+    else h = Math.max(h, s.offset + s.width);
+  };
+  room.screens.forEach(along);
+  for (const d of room.doors) {
+    along(d);
+    if (d.wall === "top" || d.wall === "bottom") h = Math.max(h, d.width); // swing depth
+    else w = Math.max(w, d.width);
+  }
+  return { width: ceil1(w), height: ceil1(h) };
+}
+
+/** Resize the room (top-left stays put). Returns null if anything placed wouldn't fit. */
+export function tryResizeRoom(room: Room, items: FurnitureItem[], size: { width?: number; height?: number }): Room | null {
+  const next = { ...room, ...size };
+  if (next.width < ROOM_SIZE.min - EPS || next.height < ROOM_SIZE.min - EPS) return null;
+  return isLayoutValid(next, items) ? next : null;
+}
+
+/** Closest free offset on `wall` to the wall's center, or null if the wall has no room. */
+export function findWallSpot(room: Room, items: FurnitureItem[], kind: "door" | "screen", wall: Wall, width: number): number | null {
+  const len = wallLength(room, wall);
+  const center = (len - width) / 2;
+  for (let k = 0; k * 0.1 <= len; k++) {
+    for (const sign of k === 0 ? [1] : [1, -1]) {
+      const offset = Math.round((center + sign * k * 0.1) * 100) / 100;
+      if (isValidWallItem(room, items, { id: "__new", kind, wall, offset, width })) return offset;
+    }
+  }
+  return null;
+}
+
+/** Free top-left for a new obstacle, nearest the room center, or null if the room is full. */
+export function findObstacleSpot(room: Room, items: FurnitureItem[], width: number, height: number): { x: number; y: number } | null {
+  const cx = (room.width - width) / 2;
+  const cy = (room.height - height) / 2;
+  const step = 0.25;
+  const cands: { x: number; y: number; d: number }[] = [];
+  for (let x = 0; x <= room.width - width + EPS; x += step) {
+    for (let y = 0; y <= room.height - height + EPS; y += step) cands.push({ x, y, d: Math.hypot(x - cx, y - cy) });
+  }
+  cands.sort((a, b) => a.d - b.d);
+  const first = { x: cx, y: cy, width, height, id: "__new" };
+  if (isValidObstacle(room, items, first)) return { x: cx, y: cy };
+  for (const c of cands) {
+    if (isValidObstacle(room, items, { id: "__new", x: c.x, y: c.y, width, height })) return { x: c.x, y: c.y };
+  }
+  return null;
+}
+
+// ---- Screens (furniture type): drag an end handle to change length (only while unrotated) ----
 
 export const MIN_SCREEN_LENGTH = 0.5;
 

src/roomSchema.ts

@@ -0,0 +1,84 @@
+// Validation for room.json import/export. No dependencies; pure.
+import { DOOR_WIDTH, MAX_SCREENS, OBSTACLE_SIZE, ROOM_SIZE, SCREEN_WIDTH, WALLS, isLayoutValid } from "./geometry";
+import type { Door, Obstacle, Room, RoomScreen, Wall } from "./types";
+
+export type ParseResult = { ok: true; room: Room } | { ok: false; error: string };
+
+const isObj = (v: unknown): v is Record<string, unknown> => typeof v === "object" && v !== null && !Array.isArray(v);
+const isNum = (v: unknown): v is number => typeof v === "number" && Number.isFinite(v);
+const inRange = (v: number, r: { min: number; max: number }) => v >= r.min - 1e-6 && v <= r.max + 1e-6;
+const round1 = (v: number) => Math.round(v * 10) / 10;
+
+export function exportRoom(room: Room): string {
+  const { width, height, doors, screens, obstacles } = room;
+  return JSON.stringify({ width, height, doors, screens, obstacles }, null, 2);
+}
+
+export function parseRoom(text: string): ParseResult {
+  let raw: unknown;
+  try {
+    raw = JSON.parse(text);
+  } catch {
+    return { ok: false, error: "Not valid JSON." };
+  }
+  if (!isObj(raw)) return { ok: false, error: "Expected a JSON object with width, height, doors, screens and obstacles." };
+
+  const fail = (error: string): ParseResult => ({ ok: false, error });
+  if (!isNum(raw.width) || !isNum(raw.height)) return fail("width and height must be numbers.");
+  if (!inRange(raw.width, ROOM_SIZE) || !inRange(raw.height, ROOM_SIZE))
+    return fail(`Room width and height must be between ${ROOM_SIZE.min} and ${ROOM_SIZE.max} m.`);
+  if (!Array.isArray(raw.doors) || !Array.isArray(raw.screens) || !Array.isArray(raw.obstacles))
+    return fail("doors, screens and obstacles must all be arrays.");
+
+  const ids = new Set<string>();
+  const uniqueId = (v: unknown, what: string): string | null => {
+    if (typeof v !== "string" || !v) return `${what}: id must be a non-empty string.`;
+    if (ids.has(v)) return `${what}: duplicate id "${v}".`;
+    ids.add(v);
+    return null;
+  };
+  const isWall = (v: unknown): v is Wall => typeof v === "string" && (WALLS as string[]).includes(v);
+
+  const doors: Door[] = [];
+  for (const [n, d] of raw.doors.entries()) {
+    const what = `Door ${n + 1}`;
+    if (!isObj(d)) return fail(`${what} must be an object.`);
+    const e = uniqueId(d.id, what);
+    if (e) return fail(e);
+    if (!isWall(d.wall)) return fail(`${what}: wall must be top, bottom, left or right.`);
+    if (!isNum(d.offset) || !isNum(d.width)) return fail(`${what}: offset and width must be numbers.`);
+    if (!inRange(d.width, DOOR_WIDTH)) return fail(`${what}: width must be ${DOOR_WIDTH.min}-${DOOR_WIDTH.max} m.`);
+    if (typeof d.isLoading !== "boolean") return fail(`${what}: isLoading must be true or false.`);
+    doors.push({ id: d.id as string, wall: d.wall, offset: d.offset, width: d.width, isLoading: d.isLoading });
+  }
+  if (doors.length < 1) return fail("A room needs at least one door.");
+
+  if (raw.screens.length > MAX_SCREENS) return fail(`At most ${MAX_SCREENS} screens are allowed.`);
+  const screens: RoomScreen[] = [];
+  for (const [n, s] of raw.screens.entries()) {
+    const what = `Screen ${n + 1}`;
+    if (!isObj(s)) return fail(`${what} must be an object.`);
+    const e = uniqueId(s.id, what);
+    if (e) return fail(e);
+    if (!isWall(s.wall)) return fail(`${what}: wall must be top, bottom, left or right.`);
+    if (!isNum(s.offset) || !isNum(s.width)) return fail(`${what}: offset and width must be numbers.`);
+    if (!inRange(s.width, SCREEN_WIDTH)) return fail(`${what}: width must be ${SCREEN_WIDTH.min}-${SCREEN_WIDTH.max} m.`);
+    screens.push({ id: s.id as string, wall: s.wall, offset: s.offset, width: s.width });
+  }
+
+  const obstacles: Obstacle[] = [];
+  for (const [n, o] of raw.obstacles.entries()) {
+    const what = `Obstacle ${n + 1}`;
+    if (!isObj(o)) return fail(`${what} must be an object.`);
+    const e = uniqueId(o.id, what);
+    if (e) return fail(e);
+    if (!isNum(o.x) || !isNum(o.y) || !isNum(o.width) || !isNum(o.height)) return fail(`${what}: x, y, width and height must be numbers.`);
+    if (!inRange(o.width, OBSTACLE_SIZE) || !inRange(o.height, OBSTACLE_SIZE))
+      return fail(`${what}: size must be ${OBSTACLE_SIZE.min}-${OBSTACLE_SIZE.max} m.`);
+    obstacles.push({ id: o.id as string, x: o.x, y: o.y, width: o.width, height: o.height });
+  }
+
+  const room: Room = { width: round1(raw.width), height: round1(raw.height), doors, screens, obstacles };
+  if (!isLayoutValid(room, [])) return fail("The doors, screens and obstacles don't fit together (overlap or outside the room).");
+  return { ok: true, room };
+}

src/store.ts

@@ -14,6 +14,7 @@ export type Action =
   | { kind: "move"; id: string; x: number; y: number }
   | { kind: "update"; id: string; patch: Partial<FurnitureItem> }
   | { kind: "remove"; id: string }
+  | { kind: "setRoom"; room: Room; clearItems?: boolean }
   | { kind: "setAvailable"; type: FurnitureType; value: number }
   | { kind: "setSeats"; type: FurnitureType; value: number }
   | { kind: "addConfig"; config: FurnitureTypeConfig };
@@ -57,6 +58,8 @@ export function reducer(state: LayoutState, action: Action): LayoutState {
         ...state,
         items: state.items.map((i) => (i.id === action.id ? { ...i, ...action.patch } : i)),
       };
+    case "setRoom":
+      return { ...state, room: action.room, items: action.clearItems ? [] : state.items };
     case "remove":
       return { ...state, items: state.items.filter((i) => i.id !== action.id) };
     case "setAvailable":

src/types.ts

@@ -16,9 +16,42 @@ export interface FurnitureItem {
   seatsOverride?: number; // tables only: overrides the type-level seatsPerUnit
 }
 
+export type Wall = "top" | "bottom" | "left" | "right";
+
+/**
+ * offset = meters from the wall's start to the near edge. Top/bottom walls start at the left,
+ * left/right walls start at the top.
+ */
+export interface Door {
+  id: string;
+  wall: Wall;
+  offset: number;
+  width: number;
+  isLoading: boolean; // the door furniture is carried through (used by the optimizer later)
+}
+
+/** A screen / stage on a wall (not the "screen" furniture type). */
+export interface RoomScreen {
+  id: string;
+  wall: Wall;
+  offset: number;
+  width: number;
+}
+
+export interface Obstacle {
+  id: string;
+  x: number; // meters, top-left, room coordinates
+  y: number;
+  width: number;
+  height: number;
+}
+
 export interface Room {
   width: number; // meters
   height: number;
+  doors: Door[];
+  screens: RoomScreen[];
+  obstacles: Obstacle[];
 }
 
 export interface Rect {