Re: Abort glyph rendering if everything is clipped

> That looks better yes; it's still a bit complex IMO, but I'm not sure
> it's possible to do much better with that glyph index thing. Still I'm
> wondering if you shouldn't do the IsRectEmpty check after the LPtoDP
> and coordinates swap.

It looks to me like LPtoDP is just doing a linear transform, so the area should
be preserved - the rectangle should be empty after the transform if and only if
it is empty before the transform.

Or am I missing something?  Is there another reason to move the IsRectEmpty
check after the transform?

Warren

Abort glyph rendering if everything is clipped

[Alexandre Julliard]

Warren_Baird(a)cimmetry.com writes:
> It looks to me like LPtoDP is just doing a linear transform, so the area should
> be preserved - the rectangle should be empty after the transform if and only if
> it is empty before the transform.
>
> Or am I missing something?  Is there another reason to move the IsRectEmpty
> check after the transform?

There can be rounding issues, if multiple logical pixels correspond to
a single physical pixel. Also there are sign issues, IsRectEmpty will
return TRUE for left >= right which is why it's better to check after
the coordinate swap.

-- 
Alexandre Julliard
julliard(a)winehq.com