Re: NSLayoutManager background and glyphs do not line up

FROM : Dave Dribin
DATE : Thu Jan 02 19:13:17 2003

On Thursday, January 2, 2003, at 05:37  PM, Hubert Figuiere wrote:

> According to Dave Dribin <<email_removed>>:

>> Hmm... all I get are rectangles as if it does not know the correct
>> character.  I even tried CGContextSelectFont(), but that didn't help
>> either.

>
> I'd use the NSAttributedString extension to NSString to draw text. It
> uses ATSUI and CG to draw text, but perform remapping to draw glyphs
> that are not in the selected font by using another. Since NSString are
> inherently Unicode oriented, this allow drawing Cyrillic, Chinese and
> Japanese all along mixed with Western chars.
>
> <http://www.abisource.com/~hub/new_cocoa.jpg> show the result. Here
> text is stored as Unicode UCS-2 and I simply use [-NSString
> drawAtPoint:withAttributes:] to draw my text. All the layout in
> handled by the cross platform engine and I simply needed to draw
> Unicode a specified location.


Wow, interesting!  I downloaded the AbiWord source just to take a look
at what was going on.  I've got a couple questions for ya.  How do you
layout characters with this method?  Do you draw characters one at a
time to make sure they go where you laid them out?  How do you track
the mouse over characters, for example, when you select some text?

> And I have been told that performance was pretty much the best you
> could get. :-) (I haven't checked yet)


Well, drawAtPoint: is certainly the easiest method.  I think I'll try
this again, and see what the performance is like before I try and
optimize taking one of the more complicated methods.

-Dave