Re: [ft-devel] Experimental: v38 interpreter with minimal backwards compatibility mode and linear advance widths

[Werner LEMBERG]

> Classical in the sense that it was originally (super)hinted for
> black-and-white display, e.g. Arial, Times New Roman, Verdana,
> Georgia.  The spacing they do looks off when stopping movement on
> the x-axis.  Fonts developed with ClearType in mind do this a lot
> less and sometimes even react to the subpixel positioning GETINFO
> flag.  The trouble is that I know of no way to tell the two groups
> apart beforehand.

AFAIK, Microsoft maintains a whitelist of common fonts that must be
handled specially, that is, where the default settings for backwards
compatibility don't work correctly.  Essentially, the Infinality stuff
does something similar.  If a font is not contained in the whitelist
we simply have to trust that it does the right thing.

And yes, if you enable sub-pixel hinting and positioning, advance
width changes should be ignored in backwards-compatibility mode, but
*not* in native ClearType mode.


    Werner