/** * From the point of view of an observer located outside the polygon, only a continuous subset of * the polygon's edges can be seen defining a line-of-sight. This method finds the last vertex * that is in the line-of-sight. * * @param observer the coordinates of the observer. Not modified. * @return the coordinates of the last vertex in the line-of-sight or {@code null} if this method * failed. Modified. * @throws ReferenceFrameMismatchException if {@code observer} and {@code this} are not expressed * in the same reference frame. * @see #lineOfSightEndVertexCopy(Point2DReadOnly) */ default FramePoint2DBasics lineOfSightEndVertexCopy(FramePoint2DReadOnly observer) { checkReferenceFrameMatch(observer); return lineOfSightEndVertexCopy((Point2DReadOnly) observer); }