Re: Pango OS X pango_coverage_from_cf_charset issue

[Behdad Esfahbod <behdad behdad org>]

On 07/22/11 17:10, Bill Kelly wrote:
> 
> John Ralls wrote:
>>
>> You thought wrong. Open it in FontBook and select
>> Preview>Repertoire from the menu. No non-european glyphs.
> 
> Ah, thanks.
> 
> Would one normally expect Pango to fall back to alternate
> fonts if the glyphs aren't available in the primary font?
> 
> We're passing a string like "Helvetica, Sans 24" to
> pango_font_description_from_string() (via libclutter.)
> 
> Currently there seems to be a difference in Pango's font
> "fall back" handling on Windows vs. OS X:
> 
> Looking briefly at Arial on Windows using charmap.exe,
> and also on the Mac using FontBook, the font appears to
> contain the same set of glyphs on both platforms (neither
> has Japanese glyphs that I can see.)
> 
> However, on Win32, Pango is able to render the Japanese
> glyphs given "Arial, Sans 18"; whereas on OS X boxes are
> rendered instead.
> 
> I'm very new to Pango, so I'm in the dark as to where
> the "fall back" handling would normally take place, which
> appears to exist on Win32 but not OS X.

Pango normally does font fallback automatically.  If it's not working on OS X,
it's probably a but with the OS X backend.

behdad


> The rendering back-end in my case would be libcogl-pango
> (part of the Clutter library.)
> 
> If the back-end is supposed to handle the "fall back" in
> PANGO_COVERAGE_NONE cases, then this would seem to be a
> Clutter/COGL issue.
> 
> But I don't know yet where the "fall back" handling is
> supposed to occur.  (Is "fall back" even the correct
> term?)
> 
> 
> Thanks,
> 
> Bill