[cairo] rotated characters does not keep baseline

[Behdad Esfahbod]

On Wed, 2007-04-04 at 12:47 -0400, Jan Slupski wrote:
> Hi list,
> 
> Since 1.4 rush seems to slow down, I would like to bring back
> a few issues reported before 1.4.0.
> 
> Problem:
> (http://lists.freedesktop.org/archives/cairo/2007-February/009686.html)
> 
> 2. I'm trying to force metrics hinting to be OFF for rotated text
>      (correct me, but I think that should be default?), but it seems
>      that some kind of hinting is still applied (or maybe that's some
>      cache effect?)

This bug was fixed in 1.4.2


>      On attached picture you can see that letters are not layed out
>      on the same baseline.
> 
>      Also, looking closely (zoom x8) I noticed that shapes of all
>      same letters looks identically (although they are not necessairly
>      on the same basline - compare 'l' in "display" and 'l' in "angle").
> 
>      The same string with the same font at the same angle look way better
>      at bare FreeType.
> 
>      ftstring  -m "Hello this is long text to be display at some angle" 10 times.ttf
> 
>      and rotate with right cursor until 45 degrees.
> 
> My configuration:
>     Cairo version: 1.3.14
>     freetype-2.2.1-16
>     fontconfig-2.4.1-3
> 
> 
> ***UPDATE***:
>    Tested with cairo 1.4.2
>    Use test string "iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii" to easily see the problem.
> 
>    During some (unrelated directly) discussions on the list I have learned that
>    the effect can be due to glyph cache, that stores only single image of a letter
>    that is later reused.  This seems to be wrong in any (metrics-)unhinted mode
>    (rotated or not).

True.  We don't have a plan to fix it right now.  Any ideas?

behdad


> Thanks,
> Jan
> 
> 
>     _  _  _  _  _____________________________________________
>     | |_| |\ |  S L U P S K I             jslupski at juljas.net
>   |_| | | | \|                             http://juljas.net/
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behdad
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