export type AnchoredSide = 'top' | 'right' | 'bottom' | 'left';
export type AnchoredAlign = 'start' | 'center' | 'end';
export interface AnchoredPositionInput {
    anchorRect: Pick<DOMRectReadOnly, 'top' | 'left' | 'right' | 'bottom' | 'width' | 'height'>;
    popupWidth: number;
    popupHeight: number;
    side: AnchoredSide;
    align: AnchoredAlign;
    sideOffsetPx: number;
    alignOffsetPx: number;
    viewportPadPx: number;
    viewportWidth: number;
    viewportHeight: number;
}
export interface AnchoredPosition {
    x: number;
    y: number;
    /** Side actually used, which differs from the request when placement flipped. */
    resolvedSide: AnchoredSide;
}
/**
 * Pure viewport-fixed anchored-popup layout math shared by every element-anchored
 * overlay: menus, selects, tooltips, and anchored toasts.
 *
 * `side` is preferred. When the popup spills past the padded viewport there and
 * the opposite side spills less, placement flips on the main axis; the result is
 * then clamped into the viewport on both axes. Cross-axis `align` is applied
 * before clamping so `alignOffsetPx` stays an additive nudge.
 *
 * Callers own their own anchor semantics — inner-cell alignment offsets and
 * minimum widths belong to the calling component, not here.
 * @see choice-popup-alignment.ts for the choice-cell alignment transform.
 */
export declare function computeAnchoredPosition(input: AnchoredPositionInput): AnchoredPosition;