Re: [ft-devel] [GSoC] CID font support, and others

[Werner LEMBERG]

>>> The only other solution that comes to mind is doing an extra pass
>>> just to build the initial hintmap, after which hint moves should
>>> presumably work right.
>>
>> I like your first suggestion better.
> 
> I would prefer changing the logic too, but that doesn't seem
> feasible.  Look at this output from another font (ztm-Reg): [...]
> 
> The initial hintmap is wrong, affecting the first set of hints.
> Because the (-10,48) pair is not in the first hint group, but is in
> a blue zone (hence locked and in the initial map).  For Type 1, the
> interpreter cannot know this until later in the charstring when that
> pair is actually inserted, and hence cannot possibly build the
> correct initial hintmap unless a preliminary pass is made to collate
> all the hints.

Hmm, hmm, hmm.  I'm not sure whether there is a tricky thinko
somewhere (actually, I hope that :-).  Let's see whether Dave Arnold
can give advice.

Until then, I suggest to do some more research.  Looking around in the
web for Type1->CFF converters I always read that hint conversion is
`trivial' [not sure whether those guys just report hearsay or whether
they have actually tried and tested it].  Your findings seem to
suggest that this is not the case – so I ask you to find out whether
the problem you encounter indeed affects other rendering engines also
– as far as I know, the Acroread engine for CFF is not the same as the
engine Adobe has contributed to FreeType.  It also comes with native
Type1 support, so there is a chance to directly compare results.

  . Test with Acroread whether Type1 fonts and its CFF conversions
    yield identical rendering results.

  . Try a program like `cfftot1' (from TeXLive or the LCDF bundle) to
    do the opposite conversion, again checking with Acroread for
    identical results.

  . Compare conversion results between different tools, for example,
    Adobe's `tx' tool, fontforge, and maybe others.  Maybe this gives
    further hints how Type1 fonts should be handled within a CFF
    environment.


     Werner