Re: [ft-devel] Stem darkening toggling API

[Werner LEMBERG]

>> Just to sum up what we currently have to control stem darkening
>> (for CFF).  The same essentially holds for all other parameters
>> that control FreeType modules.
>>
>> 1. A configure-time option (more or less).
>> 2. A run-time option to globally control stem darkening for all
>>    faces.
>> 3. An environment option to globally control stem darkening for all
>>    faces.
>> 4. Your proposed interface to control stem darkening for a specific
>>    face.
> 
> Does it make sense to be able to adjust 1 per face?

I don't think so, at least not for CFF.  The stem darkening parameters
are *really* a global option, aren't they?

> I originally thought about removing 2 and 3 (the global toggles) and
> stick with per-face-options only, but I guess that will just break
> compatibility and expectations.

Have a global option to set, say, v35 as the default for *all* TTFs is
not bad, I think.  At least this is already actively used, and using
your new option 4 can't be controlled at all by the user.

> I'm somewhat unhappy that this would be another property setter
> besides FT_Property_Set, though.

Why?  I can imagine different situations where different levels are
necessary to control rendering.

> What about the LCD stuff?  [...]  They would be font-specific
> overrides for the library defaults.

Yes.


    Werner