import { Degrees, TurnDirection } from "./common";
/**
 * Returns the delta of inbound and outbound course.
 * If the turn direction is given, 359 degree turns
 * are possible at max. If no turn direction is omitted,
 * less than 180 degree turns are possible.
 *
 * @example
 * let delta = getCourseDelta(
 *     180, // inbound course
 *     90   // outbound course
 * );
 * // delta = -90 // left turn, no initial turn direction given
 *
 * @param inboundCourse Initial course inbound
 * @param outboundCourse Eventual course outbound
 * @param turnDirection Optional direction of turn (left or right)
 * @returns The delta between inbound and outbound course. Negative results
 * indicate a left turn, positive results indicate a right turn.
 */
export declare function getCourseDelta(inboundCourse: Degrees, outboundCourse: Degrees, turnDirection?: TurnDirection): Degrees;