Re: [ft] [ft-devel] Latin, Cyrillic, and Greek fonts questions

[Werner LEMBERG]

> The ideal thing would be for FreeType to suppress this difference in
> the EF at small heights and let it register at larger ones.

This is the normal behaviour.  Here are the blue zone character
strings, together with the stringset definition which uses them:

  AF_BLUE_STRING_CYRILLIC_CAPITAL_TOP
    "БВЕПЗОСЭ"
  AF_BLUE_STRING_CYRILLIC_CAPITAL_BOTTOM
    "БВЕШЗОСЭ"
  AF_BLUE_STRING_CYRILLIC_SMALL /* for both top and bottom */
    "хпншезос"
  AF_BLUE_STRING_CYRILLIC_SMALL_MINOR /* bottom only */
    "руф"

  AF_BLUE_STRINGSET_CYRL
    { AF_BLUE_STRING_CYRILLIC_CAPITAL_TOP,    AF_BLUE_PROPERTY_LATIN_TOP        
 }
    { AF_BLUE_STRING_CYRILLIC_CAPITAL_BOTTOM, 0                                 
 }
    { AF_BLUE_STRING_CYRILLIC_SMALL,          AF_BLUE_PROPERTY_LATIN_TOP       |
                                              AF_BLUE_PROPERTY_LATIN_SMALL_TOP  
 }
    { AF_BLUE_STRING_CYRILLIC_SMALL,          0                                 
 }
    { AF_BLUE_STRING_CYRILLIC_SMALL_MINOR,    0                                 
 }
    { AF_BLUE_STRING_MAX,                     0                                 
 }

Value `0' means that it is a bottom blue zone.  As you can see, there
is no string for lowercase letters with ascenders, which is
intentional.  In particular, there is no blue zone for the upper part
of lowercase EF.  On the other hand, lowercase letters with descenders
are aligned at the bottom.

Regarding the uppercase EF, it is intentionally not in any blue zone
charset; as a consequence, any special height or depth value of this
glyph doesn't influence the position of the blue zones (which is
computed as the mean value, based on the glyphs in the corresponding
string).  If the top or bottom position of a glyph is near the blue
zone, it gets snapped, otherwise it stays as-is.

> What do you expect will happen? I am about to find out because i am
> adding Cyrillic to Merriweather and will be hinting it with
> TTFA. :-)

I will soon add the recent changes to the auto-hinter to ttfautohint
also, so stay tuned :-) Meanwhile, if you have some time, I would be
glad if you could test your collection of Cyrillic fonts with the git
version of FreeType.  With the `ftgrid' demo program, for example, you
can easily observe the outline distortions at any ppem value.


    Werner