javafx.util.Math.atan2 has its arguments reversed when calling java.lang.Math.atan2().

The javafx.util.Math.atan2() function calls java.lang.Math.atan2() with the arguments reversed
resulting in wrong return values.

public function atan2(x : Double, y : Double) : Double { return java.lang.Math.atan2(x, y); }

The JavaDOC for java.lang.Math shows the "y" coming before the "x".

public static double atan2(double y, double x)