export type Point = [number, number];
/**
 * Calculates the length of a chord given the radius of a circle and the central angle.
 * @param radius - The radius of the circle.
 * @param angle - The central angle in radians.
 * @returns The length of the chord.
 */
export declare const calcChordLength: (radius: number, angle: number) => number;
/**
 * Calculates the coordinates of a point on a circle given the radius and angle.
 * @param radius - The radius of the circle.
 * @param angle - The angle in radians.
 * @returns A tuple representing the [x, y] coordinates of the point.
 */
export declare const getCoordOnCircle: (radius: number, angle: number) => Point;
/**
 * Calculates the intersection points of a circle and a horizontal line.
 * @param radius - The radius of the circle.
 * @param horizontalY - The y-coordinate of the horizontal line.
 * @returns An array of intersection points (empty if no intersection, one point if tangent, two points if intersecting).
 */
export declare const calcCircleIntersectionByHorizontalLine: (radius: number, horizontalY: number) => [] | [Point] | [Point, Point];
/**
 * Calculates the available length for a donut slice label.
 * @param innerRadius - The inner radius of the donut.
 * @param outerRadius - The outer radius of the donut.
 * @param startAngle - The start angle of the slice, in radians.
 * @param endAngle - The end angle of the slice, in radians.
 * @param fontSize - The font size of the label.
 * @param labelPosition - The position of the label, either "horizontal" or "radial".
 * @returns The available length for the label.
 */
export declare const calcAvailableDonutSliceLabelLength: (innerRadius: number, outerRadius: number, startAngle: number, endAngle: number, fontSize: number, labelPosition: "horizontal" | "radial") => number;
/**
 * Calculates the inner and outer radiuses for a specific ring in a multi-ring donut chart.
 * @param innerRadius - The inner radius of the entire donut.
 * @param outerRadius - The outer radius of the entire donut.
 * @param numRings - The total number of rings in the donut.
 * @param ring - The index of the current ring (1-based).
 * @returns An object containing the inner and outer radiuses for the specified ring.
 */
export declare const calcInnerOuterRadiusesForRing: (innerRadius: number, outerRadius: number, numRings: number, ring: number) => {
    inner: number;
    outer: number;
};
