import Vector2 from './index';
import { VectorLike } from '@equinor/videx-linear-algebra';
/**
 * Rotate vector by a given amount of radians.
 * @private
 * @param v Vector to rotate
 * @param rad Angle in radians
 * @param target Target for storing the results
 * @return Rotated vector
 */
export declare function rotate(v: Vector2, rad: number, target: Vector2): Vector2;
/**
 * Rotate vector by 90 degrees. (Counter-clockwise)
 * @private
 * @param v Vector to rotate
 * @param target Target for storing the results
 * @return Rotated vector
 */
export declare function rotate90(v: Vector2, target: Vector2): Vector2;
/**
 * Flip/Rotate vector by 180 degrees.
 * @private
 * @param v Vector to rotate
 * @param target Target for storing the results
 * @return Flipped/rotated vector
 */
export declare function rotate180(v: Vector2, target: Vector2): Vector2;
/**
 * Rotate vector by 270 degrees. (Counter-clockwise)
 * @private
 * @param v Vector to rotate
 * @param target Target for storing the results
 * @return Rotated vector
 */
export declare function rotate270(v: Vector2, target: Vector2): Vector2;
/**
 * Find the cross product between two 2d vectors.
 * @private
 * @param a Left operand
 * @param b Right operand
 * @return Signed area of the parallellogram defined by v1 and v2
 */
export declare function cross(a: VectorLike, b: VectorLike): number;
/**
 * Find angle (in radians) between vector and right vector, [1, 0].
 * @private
 * @param v Target vector
 * @return Angle in radians
 */
export declare function angleRight(v: VectorLike): number;
/**
 * Calculates the signed angle between two vectors.
 * @private
 * @param a First vector
 * @param b Second vector
 * @returns Signed angle between vectors
 */
export declare function signedAngle(a: VectorLike, b: VectorLike): number;
/**
 * Rotates a vector, v1, towards a second vector, v2, based on a factor, n.
 * An n-value of 0.5, will return a vector with rotation in between
 * v1 and v2.
 * @private
 * @param a Vector to interpolate from
 * @param b Vector to interpolate to
 * @param n Value between 0 - 1 used for interpolation
 * @param target Target for storing the results (Default: a)
 * @returns Interpolated vector
 */
export declare function lerpRot(a: any, b: any, n: number, target?: any): Vector2;