question: public Point2D translateToTrueArenaCoords ( Point2D point ) { final double dpiScaleFactor = ShootOFFController . getDpiScaleFactorForScreen ( ) ; final Point2D origin = arenaPane . getArenaScreenOrigin ( ) ; return new Point2D ( origin . getX ( ) + ( point . getX ( ) * dpiScaleFactor ) , origin . getY ( ) + ( point . getY ( ) * dpiScaleFactor ) ) ; }
target:  This function corrects coordinates in the arena area for the DPI of the arena screen and relative to the origin.  This is for creating mouse events and other javafx functions that need true coordinates rather  than scaled ones.