/**
 * 平面图视口缓存：localStorage 读写、锁定态；供 useFloorMapTransformMetrics 使用。
 */
/** 平面图包围盒单侧默认外扩（像素）；过大会导致首屏大量空白 */
export declare const DEFAULT_BOUNDING_PADDING = 56;
/** 视口内与首屏对齐时，图元束左上与容器边缘的留白 */
export declare const VIEWPORT_TOP_LEFT_MARGIN = 16;
/** 平面图视口（缩放 + 平移）持久化到 localStorage 的 key 前缀 */
export declare const VIEWPORT_STORAGE_PREFIX = "pisell-floor-map-layout.viewport:";
/** 视口锁定态持久化前缀（与视口位置分开存储） */
export declare const VIEWPORT_LOCK_STORAGE_PREFIX = "pisell-floor-map-layout.viewport-lock:";
/** 视口持久化写入节流（避免拖动 / 缩放过程中高频写 localStorage） */
export declare const VIEWPORT_PERSIST_DEBOUNCE_MS = 300;
/** 判定当前 transform 是否处于「适配视口」结果时的容差 */
export declare const FIT_BOUNDS_MATCH_POS_EPSILON = 0.5;
export declare const FIT_BOUNDS_MATCH_SCALE_EPSILON = 0.005;
export interface ViewportSnapshot {
    x: number;
    y: number;
    scale: number;
}
export declare function readPersistedViewport(key: string): ViewportSnapshot | null;
export declare function writePersistedViewport(key: string, snapshot: ViewportSnapshot): void;
export declare function readPersistedViewportLock(key: string): boolean;
export declare function writePersistedViewportLock(key: string, locked: boolean): void;