public void ResetWillRePositionTheDeltaOrigin()
{
var d = new Delta();
d.Update(new Point(23, 45));
d.Reset(new Point(24,64));
Assert.Equal(0, d.DX);
Assert.Equal(0, d.DY);
d.Update(new Point(36, 98));
Assert.Equal(12, d.DX);
Assert.Equal(34, d.DY);
}
public void DeltaUpdatesChangeDxAndDy()
{
var d = new Delta();
d.Update(new Point(23, 45));
Assert.Equal(23, d.DX);
Assert.Equal(45, d.DY);
}
public void NegativeValuesAreValidToo()
{
var d = new Delta(new Point(23, 45));
d.Update(new Point(22, 44));
Assert.Equal(-1, d.DX);
Assert.Equal(-1, d.DY);
}
public void ADeltaHasZeroForItsInitialValues()
{
var d = new Delta();
Assert.Equal(0, d.DX);
Assert.Equal(0, d.DY);
d.Update(new Point(0,0));
Assert.Equal(0, d.DX);
Assert.Equal(0, d.DY);
}
