Application: gvSIG desktop

    /* (non-Javadoc)

     * @see org.gvsig.fmap.geom.Geometry#offset(double)

     */

    public Geometry offset(double distance) throws GeometryOperationNotSupportedException, GeometryOperationException {

        // TODO Auto-generated method stub

        Point center = getCenterPoint();

        double radius = center.distance(init);

        double scale = (radius+distance)/radius;

        AffineTransform at = getScaleAffineTransform(center, scale);

        Geometry cloned = this.cloneGeometry();

        cloned.transform(at);

        return cloned;

    }

    protected AffineTransform getScaleAffineTransform(Point center, Double scale)

        throws GeometryOperationNotSupportedException,

        GeometryOperationException {

        AffineTransform translate =

            AffineTransform

                .getTranslateInstance(-center.getX(), -center.getY());

        AffineTransform scaleTransform = AffineTransform.getScaleInstance(scale,scale);

        AffineTransform inverseTranslate =

            AffineTransform.getTranslateInstance(center.getX(), center.getY());

        AffineTransform at = new AffineTransform(translate);

        at.preConcatenate(scaleTransform);

        at.preConcatenate(inverseTranslate);

        return at;

    }