Negative = function (point, out)
{
    if (out === undefined) { out = new Point(); }

    return out.setTo(-point.x, -point.y);
}
Inverts a Point's coordinates.

@function Phaser.Geom.Point.Negative
@since 3.0.0

@generic {Phaser.Geom.Point} O - [out,$return]

@param {Phaser.Geom.Point} point - The Point to invert.
@param {Phaser.Geom.Point} [out] - The Point to return the inverted coordinates in.

@return {Phaser.Geom.Point} The modified `out` Point, or a new Point if none was provided.