public void ScaleAt ()
{
var m = new Matrix (1, 0, 0, 1, 2, 2);
m.ScaleAt (2, 2, 0, 0);
CheckMatrix (new Matrix (2, 0, 0, 2, 2, 2), m);
m = new Matrix (1, 0, 0, 1, 2, 2);
m.ScaleAt (2, 2, 4, 4);
CheckMatrix (new Matrix (2, 0, 0, 2, -2, -2), m);
m = new Matrix (1, 0, 0, 1, 2, 2);
m.ScaleAt (2, 2, 2, 2);
CheckMatrix (new Matrix (2, 0, 0, 2, 0, 0), m);
}
