Re: font sizes

[Ben Pfaff]

John Darrington <address@hidden> writes:

> When I load your patch, and change pango_font_description_set_size
> to pango_font_description_set_absolute_size, then everything seems
> fine.
>
> This is the opposite of what I previously concluded.  So  I'd need to
> understand exactly the meaning of "absolute" to find out what's going on.

My experience is:

        * For on-screen display, pango_font_description_set_size
          is correct, because it scales fonts by the same factor
          as other programs on my computer (106 dpi for my
          machine), so fonts look the same size as with other
          programs.

        * For PDF, pango_font_description_set_size does the wrong
          thing.  I think that this is because it *still* scales
          fonts by the fontconfig dpi.  10pt * (106/72) is
          14.7pt, so that would explain the huge fonts in my
          printouts.

        * For PDF, pango_font_description_set_absolute_size does
          the right thing, because the PSPP cairo driver is
          designed so that cairo device units match Pango font
          units 1:1 so that I can be less confused while working
          on the code.

The Pango library is confusing.  It manages to have a lot of
documentation without actually explaining anything very well.
-- 
Ben Pfaff 
http://benpfaff.org