import { Tuple2 } from './tuple2';
/**
 * A vector with 2 components: x and y.
 */
export declare class Vector2 extends Tuple2 {
    /**
     * Constructs a new vector with two components.
     * @param x the x-component.
     * @param y the y-component.
     */
    constructor(x: number, y: number);
    /**
     * The length of this vector.
     * @returns the length of this vector.
     */
    get length(): number;
    /**
     * The length of this vector, squared.
     * @returns the length of this vector, squared.
     */
    get lengthSquared(): number;
    /**
     * Computes the negation -u of this vector u.
     * @returns the negation.
     */
    negate(): Vector2;
    /**
     * Sets this vector to its negation.
     * @returns a reference to this vector.
     */
    negateEquals(): this;
    /**
     * Computes the unit vector with the same direction as this vector.
     * @returns the unit vector.
     */
    normalize(): Vector2;
    /**
     * Sets this vector to its unit vector.
     * @returns a reference to this vector.
     */
    normalizeEquals(): this;
    /**
     * Returns the vector sum u + v for this vector u
     * @param v the other vector.
     * @returns the vector sum u + v.
     */
    plus(v: Vector2): Vector2;
    /**
     * Adds a vector v to this vector u.
     * @param v the other vector.
     * @returns a reference to this vector, after adding vector v.
     */
    plusEquals(v: Vector2): this;
    /**
     * Returns the vector difference u - v for this vector u.
     * @param v the other vector.
     * @returns the vector difference u - v.
     */
    minus(v: Vector2): Vector2;
    /**
     * Subtracts a vector v from this vector u.
     * @param v the other vector.
     * @returns a reference to this vector, after subtracting vector v.
     */
    minusEquals(v: Vector2): this;
    /**
     * Returns the scaled vector s * u for this vector u.
     * @param s the scale factor.
     * @returns the scaled vector.
     */
    times(s: number): Vector2;
    /**
     * Scales this vector.
     * @param s the scale factor.
     * @returns a reference to this vector, after scaling.
     */
    timesEquals(s: number): this;
    /**
     * Computes the dot product of this vector and the specified vector v.
     * @param v the vector v.
     * @returns the dot product.
     */
    dot(v: Vector2): number;
}