Re: [ft-devel] [GSoC] Extending the CF2 interpreter

[Dave Arnold]

Adobe has produced several Open Source CFF fonts that should be useful for testing. Consider:

Western sans, serif and monospaced CFF:

• https://github.com/adobe-fonts/source-sans-pro
  
• https://github.com/adobe-fonts/source-serif-pro
• https://github.com/adobe-fonts/source-code-pro

Pan CJK gothic and mincho (CID-based CFF):

• https://github.com/adobe-fonts/source-han-sans
• https://github.com/adobe-fonts/source-han-serif

Prototype CFF2 variable:

• https://github.com/adobe-fonts/adobe-variable-font-prototype

When Adobe first developed CFF, they did convert their Type 1 library to CFF and did extensive round-trip testing for compatibility. In the end, Adobe decided not to risk releasing the converted fonts with the same names, but instead produced new CFF fonts with names including "Std" and "Pro" designations. The conversion code is available in the tool "tx", which is part of the Adobe Font Development Kit for OpenType. While I am not aware of any open source Type 1 fonts from Adobe, I'd suggest looking into converting some CFF fonts to Type 1 for testing.

• http://www.adobe.com/devnet/opentype/afdko.html

-Dave

On 7/10/2017 6:09 AM, Werner LEMBERG wrote:

Finally fixed and pushed Type 1 seac.

Great, thanks!

One thing does bother me - the base characters of accented glyphs
(using seac), i.e. the stuff appearing around the fifth row, seem to
shift horizontally.  This is especially obvious with the accented
'i's which appear off center in Adobe mode.  Not sure if this is a
problem with the handling of left sidebearing, or some other metric,
I'm looking into it.

I suggest that you add calls to `FT_TRACE7' to trace seac stuff.  This
might be beneficial in general.

Once I've got that fixed up, I'll reorganize all the commits, add
changelogs, and update the clean branch.

Excellent.

Do tell me if you spot any other discrepancies in the new output.

I suggest that you compare output from, say, Adobe Acroread with your
new code; you won't get identical results but it should be similar
enough to catch gross errors.

Dave, what font or fonts do you recommend for testing?  AFAIK, Adobe
has converted virtually all of its Type1 fonts to CFF, and I think
that great care has been taken to reduce rendering differences to an
absolute minimum (if at all).


    Werner
.