autokerning (was [ft-devel] New FreeType proofing tool: ftdiff)

[apodtele]

David Turner finally admitted:
> I previously thought that implementing sub-pixel hinting and positioning
> would be the next step required to improve text rendering with FreeType,
> but obviously simply using the LSB/RSB deltas to adjust inter-character
> space has much more obvious benefits.
[skip]
> This means changing the caching mechanism used by libraries/applications,
> which can be more or less complex, depending on their implementation.

I have been lobbying for years on this mailing list, that feetype is actually
the best place to deal with autokerning, because it is just too interdependent
with autohinting.

My question again. Why is it better to pass lsb/rsb knowledge to higher level
than to teach freetype to render a single word and provide an
interface for that?
Do we really need to replicate the same code in every application?