/// <reference path="../../../globals.d.ts" />
/// <reference path="./coordinate.d.ts" />

declare module goog.math {

    class Vec2 extends Vec2__Class { }
    /** Fake class which should be extended to avoid inheriting static properties */
    class Vec2__Class extends goog.math.Coordinate__Class  { 
    
            /**
             * Class for a two-dimensional vector object and assorted functions useful for
             * manipulating points.
             *
             * @param {number} x The x coordinate for the vector.
             * @param {number} y The y coordinate for the vector.
             * @constructor
             * @extends {goog.math.Coordinate}
             */
            constructor(x: number, y: number);
    
            /**
             * X-value
             * @type {number}
             */
            x: number;
    
            /**
             * Y-value
             * @type {number}
             */
            y: number;
    
            /**
             * Returns the magnitude of the vector measured from the origin.
             * @return {number} The length of the vector.
             */
            magnitude(): number;
    
            /**
             * Returns the squared magnitude of the vector measured from the origin.
             * NOTE(brenneman): Leaving out the square root is not a significant
             * optimization in JavaScript.
             * @return {number} The length of the vector, squared.
             */
            squaredMagnitude(): number;
    
            /**
             * Reverses the sign of the vector. Equivalent to scaling the vector by -1.
             * @return {!goog.math.Vec2} The inverted vector.
             */
            invert(): goog.math.Vec2;
    
            /**
             * Normalizes the current vector to have a magnitude of 1.
             * @return {!goog.math.Vec2} The normalized vector.
             */
            normalize(): goog.math.Vec2;
    
            /**
             * Adds another vector to this vector in-place.
             * @param {!goog.math.Coordinate} b The vector to add.
             * @return {!goog.math.Vec2}  This vector with {@code b} added.
             */
            add(b: goog.math.Coordinate): goog.math.Vec2;
    
            /**
             * Subtracts another vector from this vector in-place.
             * @param {!goog.math.Coordinate} b The vector to subtract.
             * @return {!goog.math.Vec2} This vector with {@code b} subtracted.
             */
            subtract(b: goog.math.Coordinate): goog.math.Vec2;
    
            /**
             * Rotates this vector in-place by a given angle, specified in radians.
             * @param {number} angle The angle, in radians.
             * @return {!goog.math.Vec2} This vector rotated {@code angle} radians.
             */
            rotate(angle: number): goog.math.Vec2;
    
            /**
             * Compares this vector with another for equality.
             * @param {!goog.math.Vec2} b The other vector.
             * @return {boolean} Whether this vector has the same x and y as the given
             *     vector.
             */
            equals(b: goog.math.Vec2): boolean;
    } 
    
}

declare module goog.math.Vec2 {

    /**
     * @return {!goog.math.Vec2} A random unit-length vector.
     */
    function randomUnit(): goog.math.Vec2;

    /**
     * @return {!goog.math.Vec2} A random vector inside the unit-disc.
     */
    function random(): goog.math.Vec2;

    /**
     * Returns a new Vec2 object from a given coordinate.
     * @param {!goog.math.Coordinate} a The coordinate.
     * @return {!goog.math.Vec2} A new vector object.
     */
    function fromCoordinate(a: goog.math.Coordinate): goog.math.Vec2;

    /**
     * Rotates a vector by a given angle, specified in radians, relative to a given
     * axis rotation point. The returned vector is a newly created instance - no
     * in-place changes are done.
     * @param {!goog.math.Vec2} v A vector.
     * @param {!goog.math.Vec2} axisPoint The rotation axis point.
     * @param {number} angle The angle, in radians.
     * @return {!goog.math.Vec2} The rotated vector in a newly created instance.
     */
    function rotateAroundPoint(v: goog.math.Vec2, axisPoint: goog.math.Vec2, angle: number): goog.math.Vec2;

    /**
     * Returns the distance between two vectors.
     * @param {!goog.math.Coordinate} a The first vector.
     * @param {!goog.math.Coordinate} b The second vector.
     * @return {number} The distance.
     */
    function distance(a: goog.math.Coordinate, b: goog.math.Coordinate): number;

    /**
     * Returns the squared distance between two vectors.
     * @param {!goog.math.Coordinate} a The first vector.
     * @param {!goog.math.Coordinate} b The second vector.
     * @return {number} The squared distance.
     */
    function squaredDistance(a: goog.math.Coordinate, b: goog.math.Coordinate): number;

    /**
     * Compares vectors for equality.
     * @param {!goog.math.Coordinate} a The first vector.
     * @param {!goog.math.Coordinate} b The second vector.
     * @return {boolean} Whether the vectors have the same x and y coordinates.
     */
    function equals(a: goog.math.Coordinate, b: goog.math.Coordinate): boolean;

    /**
     * Returns the sum of two vectors as a new Vec2.
     * @param {!goog.math.Coordinate} a The first vector.
     * @param {!goog.math.Coordinate} b The second vector.
     * @return {!goog.math.Vec2} The sum vector.
     */
    function sum(a: goog.math.Coordinate, b: goog.math.Coordinate): goog.math.Vec2;

    /**
     * Returns the difference between two vectors as a new Vec2.
     * @param {!goog.math.Coordinate} a The first vector.
     * @param {!goog.math.Coordinate} b The second vector.
     * @return {!goog.math.Vec2} The difference vector.
     */
    function difference(a: goog.math.Coordinate, b: goog.math.Coordinate): goog.math.Vec2;

    /**
     * Returns the dot-product of two vectors.
     * @param {!goog.math.Coordinate} a The first vector.
     * @param {!goog.math.Coordinate} b The second vector.
     * @return {number} The dot-product of the two vectors.
     */
    function dot(a: goog.math.Coordinate, b: goog.math.Coordinate): number;

    /**
     * Returns a new Vec2 that is the linear interpolant between vectors a and b at
     * scale-value x.
     * @param {!goog.math.Coordinate} a Vector a.
     * @param {!goog.math.Coordinate} b Vector b.
     * @param {number} x The proportion between a and b.
     * @return {!goog.math.Vec2} The interpolated vector.
     */
    function lerp(a: goog.math.Coordinate, b: goog.math.Coordinate, x: number): goog.math.Vec2;
}