[CREATE] [ft-devel] Another round of (additional) analysis on libre fonts.

Hin-Tak Leung htl10 at users.sourceforge.net
Thu Nov 10 09:37:06 UTC 2016


--------------------------------------------
On Thu, 10/11/16, werner at lemberg.at <werner at lemberg.at> wrote:

> >
 - Apple's version of truetype spec has a little extra
 sentence
 >   saying
 "Setting the loop variable to zero is an error". 
 So this
 >   check is added. 
 A surprising large number of libre fonts do that.
 
> Sorry to say, but this Apple
 addition is nonsense.  Allowing a zero
 loop
 variable is *extremely* useful for programmatically
 created
 bytecode.  For example, hinting
 created by ttfautohint uses that all
 the
 time.  It doesn't do any harm (the loop is simply
 skipped), and it
 works with all hinting
 engines used today, AFAIK.  I strongly
 recommend to disable this warning.


Apple's version of the truetype spec has that extra sentence. I assume it is later since the Microsoft word version linked from Microsoft's web site is 2008 and in a few other ways seems briefer/older. Since I am not making a release any time soon either way, I guess it is just a note for people who might be using git HEAD [which is b66] to ignore it. (and there is one other thing I like to not be in git HEAD also - some noise about twilight zone - please ignore much of those too). b66 was pushed out to github untested. As I said, it takes about 9 hours to run the basic single-size test... and then much human time to compare it with the last 6000 reports... FontVal 2.0 went through about 3 or 4 rounds of such from b51 onwards to b54.

Hin-Tak 


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