Re: [ft-devel] Freetype-devel Digest, Vol 146, Issue 8

[Werner LEMBERG]

> The prep table seems to be trash.

Yep.

> Can another OS uses it?

Certainly not.  Trash is trash :-)

> > I find a 'problematic' font in which all the glyphs are
> > unloadable, they all cause Invalid_Opcode error(error code:
> > 0x80). The loading flag is FT_LOAD_DEFAULT.
> >
> > Please check it. Thank you.

BTW, you can check such issues by yourself.

. Get a recent version of `ttx' and try to decompile it.  For your
  font it aborts with a failed assertion, which is already a good
  indicator that your font is broken[*].

. Compile FreeType with debugging support and say

    FT2_DEBUG=any:7 ftview yourfont.ttf &> yourfont.log

  and quit immediately with pressing the `q' key.  You can then see

    Executing `prep' table.
    TT_RunIns: Limiting total number of loops in LOOPCALL to 2560
    TT_RunIns: Limiting total number of backward jumps to 2560
      000000 MSIRP[0]   #
      000001 SRP2       #
      000002 AlignRP    #
      000003 INS_$AF    #
      interpretation failed with error code 0x80
      failed (error code 0x80)

  right of the `#' sign you normally find the opcode arguments – as
  you can see, there aren't any arguments; this is why Hin-Tak's
  FontVal program emits so many error messages.


    Werner


[*] I would prefer a more civilized message from ttx, but I'm too lazy
    to open a fonttools issue :-)