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

[Alexei Podtelezhnikov]

On Wed, May 3, 2017 at 3:12 AM, Werner LEMBERG <address@hidden> wrote:
> However, it would fail miserably if lsb_delta and rsb_delta are used
> to adjust integer advance widths by ±1 pixel, as documented in the
> FreeType reference.  *This* is what we can't neglect IMHO.

With warping out of the way, the light mode becomes a clean case. The
left phantom point stays at zero, i.e. lsb_delta is always zero. The
right phantom point is simply rounded, i.e. rsb_delta is a rounding
residual always between -31 and 32. Therefore, (prev_rsb_delta -
lsb_delta) is always between -31 and 32 and advance is NEVER adjusted
in light mode. ∎