/**
 * useOrientationDrift — detects mid-capture device rotation.
 *
 * Pairs with `useDeviceOrientation()` to surface the case where the
 * user rotates the device *during* an active capture.  The
 * incremental stitching engine supports both portrait (Mode B,
 * horizontal pan) and landscape (Mode A, vertical pan) capture
 * modes as first-class — but mixing them mid-capture produces
 * malformed output ("cross-mode capture is best-effort," per
 * `incremental.ts:373-403`).  Hosts that want to protect against
 * this use this hook + `OrientationDriftModal` together: the
 * `<Camera>` flagship component auto-abandons capture the instant
 * `drifted === true` (PR-2 wiring); the modal surfaces an
 * explanatory popup to the user.
 *
 * ## API contract
 *
 * Pass `active` true while a capture is in flight, false otherwise.
 * Returns:
 *
 *   - `captureOrientation` — the orientation snapshotted at the
 *     moment `active` transitioned false → true.  `undefined` when
 *     `active` is false.
 *   - `currentOrientation` — live orientation from
 *     `useDeviceOrientation()`.  Always defined (defaults to
 *     `'portrait'` until the accelerometer's first sample).
 *   - `drifted` — `true` IFF `active` is currently true AND
 *     `currentOrientation !== captureOrientation` at some point
 *     since the snapshot.  **Latching** — once true, stays true
 *     until `active` flips back to false.  This is intentional:
 *     after detection, callers should auto-abandon the capture
 *     (engine `stop()`); allowing the flag to clear before then
 *     would mask the drift if the user rotated back to the
 *     original orientation between the detection tick and the
 *     callers' abandonment effect.
 *
 * ## Semantics by transition
 *
 *   - `active` false → true:  snapshot `currentOrientation`;
 *     reset `drifted` to false.
 *   - `active` true (steady):  if `currentOrientation !==
 *     captureOrientation` at any point, latch `drifted = true`.
 *   - `active` true → false:  clear snapshot; reset `drifted`.
 *
 * ## Why a separate hook (rather than inlining in `<Camera>`)
 *
 * Hosts using the Layer-2 building blocks (`CameraView` directly,
 * custom capture UX) can reuse this hook without mounting the
 * full `<Camera>` flagship.  Same composition pattern as
 * `useIMUTranslationGate` and `useKeyframeStream`.
 *
 * ## Testing
 *
 * The pure state-transition function `_computeDriftStateForTests`
 * is exported separately so jest can exercise all 5 transition
 * cases without booting a React render.  The hook itself is a
 * thin wrapper around it (verified via on-device manual flow in
 * the v0.12 verification checklist).
 */
import { type DeviceOrientation } from './useDeviceOrientation';
export interface UseOrientationDriftReturn {
    /**
     * `true` IFF a capture is active and the device has rotated since
     * the snapshot taken at capture start.  Latching: once true, stays
     * true until `active` flips false.
     */
    drifted: boolean;
    /**
     * Snapshot of `currentOrientation` at the moment `active`
     * transitioned false → true.  `undefined` when `active` is false.
     */
    captureOrientation: DeviceOrientation | undefined;
    /**
     * Live device orientation from `useDeviceOrientation()`.  Always
     * defined.  Exposed so callers (e.g. the drift modal) can show
     * "captured in PORTRAIT, now LANDSCAPE-LEFT" copy without
     * mounting `useDeviceOrientation()` themselves.
     */
    currentOrientation: DeviceOrientation;
}
/**
 * Internal state of the drift detector.  Two scalar pieces: the
 * snapshotted capture orientation (undefined when inactive) + the
 * latched drift flag.
 */
interface DriftState {
    captureOrientation: DeviceOrientation | undefined;
    drifted: boolean;
}
/**
 * Pure state-transition function for the drift detector.  Exported
 * with a `_` prefix to signal "internal — not part of the public
 * API."  Jest uses this directly so tests don't need a React
 * renderer (the lib's jest config is pure-data / no RN preset).
 *
 * Given the previous state + the current `active` flag + the
 * current device orientation, returns the new state.  Idempotent
 * when nothing changed (returns the same object reference) so
 * downstream `useState(setState)` calls become no-ops.
 */
export declare function _computeDriftStateForTests(prev: DriftState, active: boolean, currentOrientation: DeviceOrientation, settled: boolean): DriftState;
export declare function useOrientationDrift(active: boolean): UseOrientationDriftReturn;
export {};
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