Re: [Pnet-developers] Rectangle.Union

[Gopal V]

> > Rectangle r = Rectangle.Union (Rectangle.Empty,
> new Rectangle (1,1,1,1));
> > r is now
> > {0, 0, 2, 2}

top = Min([all tops])
bottom = Max([all bottoms])
left = Min([all lefts])
right = Max([all rights])

> > I would expect
> > {1, 1, 1, 1}
> > because union with nothing an identity transform

Rectangle.Empty is not NOTHING :) .. There is no
identity transform for Union operation, as we're
not talking about sets here (where |aUb| <= |a| + |b|
as well).

> "Rectangle.Empty" differently than we humans do ;-)

Because humans think in areas when they hear Empty,
and not in co-ordinates. Empty in this case means a
zero-area rectangle *at* origin, to get an identity
transformation the other rectangle should share at 
least a corner with the Zero-area rectangle.

Gopal

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