AttributeValues.java 文件源码

private static AffineTransform extractRotation(Point2D.Double pt,
    AffineTransform tx, boolean andTranslation) {

    tx.deltaTransform(pt, pt);
    AffineTransform rtx = AffineTransform.getRotateInstance(pt.x, pt.y);

    try {
        AffineTransform rtxi = rtx.createInverse();
        double dx = tx.getTranslateX();
        double dy = tx.getTranslateY();
        tx.preConcatenate(rtxi);
        if (andTranslation) {
            if (dx != 0 || dy != 0) {
                tx.setTransform(tx.getScaleX(), tx.getShearY(),
                                tx.getShearX(), tx.getScaleY(), 0, 0);
                rtx.setTransform(rtx.getScaleX(), rtx.getShearY(),
                                 rtx.getShearX(), rtx.getScaleY(), dx, dy);
            }
        }
    }
    catch (NoninvertibleTransformException e) {
        return null;
    }
    return rtx;
}