import type { Types } from '@cornerstonejs/core';
export type Interval = Types.Point2;
export type FanPair = [Types.Point2, Types.Point2];
export type FanPairs = FanPair[];
export declare function angleFromCenter(center: Types.Point2, point: Types.Point2): number;
export declare function intervalFromPoints(center: Types.Point2, pair: FanPair): Types.Point2;
export declare function mergeIntervals(intervals: Interval[]): Interval[];
export declare function subtractIntervals(blocked: Interval[], target: Interval): Interval[];
export declare function clipInterval(inner: Types.Point2, outerMerged: Interval[]): Interval[];
export declare function calculateInnerFanPercentage(center: Types.Point2, outerFanPairs: FanPairs, innerFanPairs: FanPairs): number;