public Matrix4f mul( Matrix4f r )
	{
		Matrix4f res = new Matrix4f();

		for ( int i = 0; i < 4; i++ )
		{
			for ( int j = 0; j < 4; j++ )
			{
				res.set( i, j, m[i][0] * r.get( 0, j ) +
						m[i][1] * r.get( 1, j ) +
						m[i][2] * r.get( 2, j ) +
						m[i][3] * r.get( 3, j ) );
			}
		}

		return res;
	}