[XeTeX] Windows views XeTeX PDF with bad font size

[Jonathan Kew]

On 18 Feb 2012, at 15:37, mskala at ansuz.sooke.bc.ca wrote:

> I'm sorry I don't have many details because it wasn't my own system on
> which the problem appeared, but:  I have a PDF file generated with XeTeX
> (xdvipdfm), and a Japanese font embedded in the PDF.  It looks fine on my
> screen (under Linux, with a couple of different viewers) and it prints
> correctly when I send it to my laser printer.  But when my friend tries to
> view it on a Windows machine, he complains that "there's not enough space
> between the characters" and from the screen shot it's apparent that the
> viewer has scaled the font to a too-large size while still positioning
> each glyph at its correct reference point.  As a result the glyphs touch
> and overlap.
> 
> Most likely this is some problem with the Windows PDF viewer.  I've seen
> similar things before though not as extreme as the current case - it may
> have some standard sizes, and round things to the nearest standard size
> even if that's a bad idea, as a result of trying to make pixel hinting
> look nice.  But if there's anything I can change in the way I generate the
> PDF file (or by editing the font) to make this issue less likely to occur
> on Windows systems, it'd be valuable to know about.

This sounds like an issue I've seen previously, where certain OpenType/CFF fonts where the font matrix is not the usual 1000 units per em display incorrectly when embedded in PDF by xetex and viewed with more recent versions of Adobe Reader. (I forget exactly which version changed the interpretation of these fonts...)

Your Windows-using friend may be able to view the document by using a non-Adobe reader such as SumatraPDF; equally, you may be able to verify the problem yourself by using an Adobe viewer rather than one based on xpdf/poppler/ghostscript/etc.

If you're in a position to edit the font such that it has a 1000-unit em square, this may resolve the incompatibility.

What really needs to happen is a change in how (x)dvipdfmx embeds such fonts, but I don't have the time and expertise to work on this at the moment... :(

JK