Re: [ft-devel] New `slight' auto-hinting mode

[Alexei Podtelezhnikov]

On Tue, May 2, 2017 at 12:35 PM, Werner LEMBERG <address@hidden> wrote:
>> - Autohinter warping option will migrate from LIGHT to NORMAL
>
> There are some issues.
>
> . NORMAL currently means full auto-hinting, i.e., hinting along both
>   the horizontal and vertical axes.  I believe we can't change that.

I see warping is a kind of hinting where shifting/scaling is tweaked
for all segments at once rather than for each segment individually.
Therefore, warping option would replace normal hinting, of course.

>
>> - Autohinter LIGHT and LCD modes will switch to fractional advances
>
> For LIGHT, I'm not sure that we can do that for backward
> compatibility...

Yes, but such incompatibility should go either unnoticed or result in
improvement as if we are fixing a bug:
- If someone was using lsb_delta and rsb_delta correctly, then the
fractional part just shifts from rsb_delta to fractional advance
width, while lsb_delta is always 0 in LIGHT. There should not be no
changes in layout whatsoever.
- Even if someone was not using the deltas, he now has a chance to do
his own rounding, whichever way. Nikolas is right, we have fractional
advance with disabled hinting, so this is not a big surprise.