Source: core/math/shapes/Ellipse.js

var Rectangle = require('./Rectangle'),
    CONST = require('../../const');

/**
 * The Ellipse object can be used to specify a hit area for displayObjects
 *
 * @class
 * @memberof PIXI
 * @param x {number} The X coordinate of the center of the ellipse
 * @param y {number} The Y coordinate of the center of the ellipse
 * @param width {number} The half width of this ellipse
 * @param height {number} The half height of this ellipse
 */
function Ellipse(x, y, width, height)
{
    /**
     * @member {number}
     * @default 0
     */
    this.x = x || 0;

    /**
     * @member {number}
     * @default 0
     */
    this.y = y || 0;

    /**
     * @member {number}
     * @default 0
     */
    this.width = width || 0;

    /**
     * @member {number}
     * @default 0
     */
    this.height = height || 0;

    /**
     * The type of the object, mainly used to avoid `instanceof` checks
     *
     * @member {number}
     */
    this.type = CONST.SHAPES.ELIP;
}

Ellipse.prototype.constructor = Ellipse;
module.exports = Ellipse;

/**
 * Creates a clone of this Ellipse instance
 *
 * @return {PIXI.Ellipse} a copy of the ellipse
 */
Ellipse.prototype.clone = function ()
{
    return new Ellipse(this.x, this.y, this.width, this.height);
};

/**
 * Checks whether the x and y coordinates given are contained within this ellipse
 *
 * @param x {number} The X coordinate of the point to test
 * @param y {number} The Y coordinate of the point to test
 * @return {boolean} Whether the x/y coords are within this ellipse
 */
Ellipse.prototype.contains = function (x, y)
{
    if (this.width <= 0 || this.height <= 0)
    {
        return false;
    }

    //normalize the coords to an ellipse with center 0,0
    var normx = ((x - this.x) / this.width),
        normy = ((y - this.y) / this.height);

    normx *= normx;
    normy *= normy;

    return (normx + normy <= 1);
};

/**
 * Returns the framing rectangle of the ellipse as a Rectangle object
 *
 * @return {PIXI.Rectangle} the framing rectangle
 */
Ellipse.prototype.getBounds = function ()
{
    return new Rectangle(this.x - this.width, this.y - this.height, this.width, this.height);
};