Apply scaling to this matrix by scaling the base axes by the given <code>xy.x</code> and
<code>xy.y</code> factors, respectively.
<p>
If <code>M</code> is <code>this</code> matrix and <code>S</code> the scaling matrix,
then the new matrix will be <code>M * S</code>. So when transforming a
vector <code>v</code> with the new matrix by using <code>M * S * v</code>, the
scaling will be applied first!
@param xy
the factors of the x and y component, respectively
@return this
Apply scaling to this matrix by scaling the base axes by the given <code>xy.x</code> and <code>xy.y</code> factors, respectively. <p> If <code>M</code> is <code>this</code> matrix and <code>S</code> the scaling matrix, then the new matrix will be <code>M * S</code>. So when transforming a vector <code>v</code> with the new matrix by using <code>M * S * v</code>, the scaling will be applied first!
@param xy the factors of the x and y component, respectively @return this