Transform/multiply the given 2D-vector, as if it was a 3D-vector with z=1, by
this matrix and store the result in that vector.
<p>
The given 2D-vector is treated as a 3D-vector with its z-component being 1.0, so it
will represent a position/location in 2D-space rather than a direction.
<p>
In order to store the result in another vector, use {@link #transformPosition(Vector2d, Vector2d)}.
Transform/multiply the given 2D-vector, as if it was a 3D-vector with z=1, by this matrix and store the result in that vector. <p> The given 2D-vector is treated as a 3D-vector with its z-component being 1.0, so it will represent a position/location in 2D-space rather than a direction. <p> In order to store the result in another vector, use {@link #transformPosition(Vector2d, Vector2d)}.
@see #transformPosition(Vector2d, Vector2d) @see #transform(Vector3d)
@param v the vector to transform and to hold the final result @return v