// p = Point or any object with public x/y properties var RotateAround = function (point, x, y, angle) { var c = Math.cos(angle); var s = Math.sin(angle); var tx = point.x - x; var ty = point.y - y; point.x = tx * c - ty * s + x; point.y = tx * s + ty * c + y; return point; }; module.exports = RotateAround;