Smooth = function (polygon)
{
    var i;
    var points = [];
    var data = polygon.points;

    for (i = 0; i < data.length; i++)
    {
        points.push([ data[i].x, data[i].y ]);
    }

    var output = [];

    if (points.length > 0)
    {
        output.push(copy([ 0, 0 ], points[0]));
    }

    for (i = 0; i < points.length - 1; i++)
    {
        var p0 = points[i];
        var p1 = points[i + 1];
        var p0x = p0[0];
        var p0y = p0[1];
        var p1x = p1[0];
        var p1y = p1[1];

        output.push([ 0.85 * p0x + 0.15 * p1x, 0.85 * p0y + 0.15 * p1y ]);
        output.push([ 0.15 * p0x + 0.85 * p1x, 0.15 * p0y + 0.85 * p1y ]);
    }

    if (points.length > 1)
    {
        output.push(copy([ 0, 0 ], points[points.length - 1]));
    }

    return polygon.setTo(output);
}
Takes a Polygon object and applies Chaikin's smoothing algorithm on its points.

@function Phaser.Geom.Polygon.Smooth
@since 3.13.0

@generic {Phaser.Geom.Polygon} O - [polygon,$return]

@param {Phaser.Geom.Polygon} polygon - The polygon to be smoothed. The polygon will be modified in-place and returned.

@return {Phaser.Geom.Polygon} The input polygon.