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Centroid.js
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Centroid.js
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/**
* @author Richard Davey <rich@photonstorm.com>
* @copyright 2020 Photon Storm Ltd.
* @license {@link https://opensource.org/licenses/MIT|MIT License}
*/
var Point = require('../point/Point');
// The three medians (the lines drawn from the vertices to the bisectors of the opposite sides)
// meet in the centroid or center of mass (center of gravity).
// The centroid divides each median in a ratio of 2:1
/**
* Calculates the position of a Triangle's centroid, which is also its center of mass (center of gravity).
*
* The centroid is the point in a Triangle at which its three medians (the lines drawn from the vertices to the bisectors of the opposite sides) meet. It divides each one in a 2:1 ratio.
*
* @function Phaser.Geom.Triangle.Centroid
* @since 3.0.0
*
* @generic {Phaser.Geom.Point} O - [out,$return]
*
* @param {Phaser.Geom.Triangle} triangle - The Triangle to use.
* @param {(Phaser.Geom.Point|object)} [out] - An object to store the coordinates in.
*
* @return {(Phaser.Geom.Point|object)} The `out` object with modified `x` and `y` properties, or a new Point if none was provided.
*/
var Centroid = function (triangle, out)
{
if (out === undefined) { out = new Point(); }
out.x = (triangle.x1 + triangle.x2 + triangle.x3) / 3;
out.y = (triangle.y1 + triangle.y2 + triangle.y3) / 3;
return out;
};
module.exports = Centroid;