Re: [ft-devel] A review of ttfauthint by designer of Siri

[Werner LEMBERG]

> Does TTfautohint allways snap upwards, to the pixel edge above?
> rather than snapping to the pixel edge below, even if the pixel edge
> below is closest?

It depends.  For x-heights, the current code slightly favors rounding
up (using 0.375 instead of 0.5 as the threshold).  I will soon add an
option so that in the range 5 < ppem < 15 glyph x-heights are strongly
rounded up (using 0.125 as the threshold).  This should avoid filling
holes in bold letters like `e'.

> When hinting manually the direction of snapping can be controlled,
> so i'm wondering if it could be controlled by the autohinter
> too.

Not yet.  However, ...

> Does freetype do this already?

... Eric and I are working on this, see above (this intended change is
from his Infinality patches).  We have to develop a new API to control
the autohinter.

> If the snapping at smaller sizes could be controlled in TTFautohint
> to get rid off "i" becoming "l" in some fonts, then overall i'd say
> ttfautohint is worth all the time saved from manual hinting.

The unwanted conversion of `i' to `l' is a bug, I think (at least at
this size).  Alas, I don't know yet how to fix it.


    Werner