phaser/src/geom/ellipse/Contains.js

A fast, free and fun HTML5 Game Framework for Desktop and Mobile web browsers from the team at Phaser Studio Inc.

/**
 * @author       Richard Davey <rich@phaser.io>
 * @copyright    2013-2025 Phaser Studio Inc.
 * @license      {@link https://opensource.org/licenses/MIT|MIT License}
 */

/**
 * Check to see if the Ellipse contains the given x / y coordinates.
 *
 * @function Phaser.Geom.Ellipse.Contains
 * @since 3.0.0
 *
 * @param {Phaser.Geom.Ellipse} ellipse - The Ellipse to check.
 * @param {number} x - The x coordinate to check within the ellipse.
 * @param {number} y - The y coordinate to check within the ellipse.
 *
 * @return {boolean} True if the coordinates are within the ellipse, otherwise false.
 */
var Contains = function (ellipse, x, y)
{
    if (ellipse.width <= 0 || ellipse.height <= 0)
    {
        return false;
    }

    //  Normalize the coords to an ellipse with center 0,0 and a radius of 0.5
    var normx = ((x - ellipse.x) / ellipse.width);
    var normy = ((y - ellipse.y) / ellipse.height);

    normx *= normx;
    normy *= normy;

    return (normx + normy < 0.25);
};

module.exports = Contains;