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

[Alexei Podtelezhnikov]

On Wed, May 3, 2017 at 7:16 PM, Alexei Podtelezhnikov
<address@hidden> wrote:
>>> Maybe.  I am talking about width as in bounding box that may and
>>> will change if you shift and hint.
>>
>> I don't understand this your paragraph.  Please reformulate.
>
> Yes. This is really important. In subpixel positioning you have to
> shift glyph to take into account previous fractional advance. If you
> follow that by hinting, the result is not deterministic. The bounding
> box may differ by 1 pixel. Warping is more stable basically because
> its shift will undo some of the original shift.

Here is an example two stems shifted but with the same spacing
[0   64]  [260 324]
[30 94]  [290 354]

after hinting
[0 64]   [256 320]
[0 64]   [320 384]

This is ugly! Forget hinting in the context of subpixel positioning.
Nothing better than lsb_ and rsb_delta exists,