> Only FT_PIXEL_MODE_MONO is necessary to add. I do not understand how
> LCD or BGRA can be used for SDF; GRAY2 and GRAY4 are defunct.
It might be possible to convert LCD and BGRA to SDF, either using a single
channel or by converting them to grayscale, but yeah I don't think that will be
useful. And I will skip GRAY2 and GRAY4.
> If I understand correctly, overlaps cause unexpected discontinuity in
> SDF, which otherwise should not have any. I doubt that detecting and
> removing contour overlaps is productive. I would rather deal with the
> discontinuity directly. Perhaps there is a clever way to ignore
> smaller distances that unexpectedly have an opposite sign. The
> distance cannot change by more than the grid size. If it does, ignore
> the offending value.
Yes, overlaps cause discontinuity in both sign and distances. Detecting
unexpected opposite sign is possible, but the sign may not be opposite.
In many cases the sign is not flipped (there is no unexpected change
in sign) and the distances interpolate smoothly, in those cases it becomes
hard to find the true distances of the point.
There is a way to do it, which is done in the 'msdfgen' library, but it is
not perfect and I don't know whether it will work with subdivision optimization
or not.
I will try to think of some other way of handling overlaps without actually
removing overlaps, but I think the most robust way to do it would be to
remove the overlaps.
Thanks,
Anuj