[XeTeX] Adobe Kepler Std: Extraneous space always inserted between left paren and f

[David Perry]

Taylor,

This is really bizarre.  I copied your text from PDF X-change Viewer on 
Vista and pasted into Notepad, displaying the results in Charis SIL; see 
the attached screen shot.  The screen shot confirms what you say except 
that there is no extra space with the italic version, and the subhead 
and display versions seem to have extra space in the PDF but it is not 
selectable and does not produce a space when pasted.  Note also that the 
ligature fi is coming out as o-acute or, in one case, n-tilde, which I 
do not understand at all.  The little boxes instead of small capitals 
represent PUA characters that Adobe used to use for their small caps, so 
that is what I would expect to see.

My gut feeling is that it's a problem with the font.  If there were a 
real serious bug in XeTeX's handling of OpenType fonts, I think it would 
have surfaced before now.  Also, be aware that the letter f causes 
problems for font designers because it tends to run into other 
characters unless handled carefully.  One possibility is that some OT 
code in the font meant to (for instance) put extra space _after_ the f 
got messed up and put it before the f instead.

Do you have any other fonts that support OT features like ligatures? 
Other Adobe fonts would perhaps be the best test.  If they work, then 
it's probably not a XeTeX problem.

The best test would be to try Kepler Pro in another application that 
supports OT.  If you are on Linux, you may not have anything but XeTeX; 
on Mac you can try TextEdit or Pages, or most of the Adobe apps 
(InDesign, Illustrator, etc), which are cross-platform.  If Kepler Pro 
does work properly in other OT-aware apps that can generate PDF, then we 
do need to look at XeTeX again.  I don't have Kepler so I can't help much.

David



Taylor Venable wrote:
> On Thu, 2010-02-04 at 18:52 -0500, Taylor Venable wrote:
>> Hi, I am having an interesting problem when setting "(f" using XeTeX and
>> the Adobe Kepler Std fonts: in the resultant PDF, there is a space in
>> the middle, such that the output looks like "( f" instead.  I have
>> placed an example of the output on my website, showing several times
>> when the problem occurs:
>>
>> http://metasyntax.net/kepler.pdf
>>
>> In a PDF reader that allows character-wise selection (e.g. Evince) you
>> can select the space between the parenthesis and the f.  Here is the
>> source of that PDF above, which I compiled simply with "xetex <file>":
>>
>> \font\kepler="Kepler Std:+liga" \kepler Regular, Ligatures: (f) (fi)\par
>> \font\kepler="Kepler Std:-liga" \kepler Regular, No Ligatures: (f) (fi)\par
>> \font\kepler="Kepler Std Bold:+liga" \kepler Regular Bold, Ligatures: (f) (fi)\par
>> \font\kepler="Kepler Std Bold:-liga" \kepler Regular Bold, No Ligatures: (f) (fi)\par
>> \font\kepler="Kepler Std Italic:+liga" \kepler Regular Italic, Ligatures: (f) (fi)\par
>> \font\kepler="Kepler Std Italic:-liga" \kepler Regular Italic, No Ligatures: (f) (fi)\par
>> \font\kepler="Kepler Std:+smcp" \kepler Regular Small Caps: (f) (fi)\par
>> \font\kepler="Kepler Std Caption:+liga" \kepler Caption: (f) (fi)\par
>> \font\kepler="Kepler Std Subhead:+liga" \kepler Subhead: (f) (fi)\par
>> \font\kepler="Kepler Std Display:+liga" \kepler Display: (f) (fi)\par
>> \end
>>
>> All instances of "(f" show up in the output as "( f" with the exception
>> of the small capitals.  With the fi ligature, there is a visible space
>> equivalent in size to that before the standalone f, but the space isn't
>> selectable in Evince like it is before standalone f.
> 
> I don't mean to be too much of a pest by bumping this, but if anybody
> has any ideas on how to investigate this further, I'd really appreciate
> it.  It's unfortunate to lose the use of these fonts.
> 
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