[poppler] TrueType "post" table format 2.8?

[mpsuzuki at hiroshima-u.ac.jp]

Hi,

Recently I was trying to add a feature to obtain a
TrueType glyph name for a glyph specified by GID,
for CIDFontType2 instance. Now I think it's almost
useless because most embedded TrueType fonts are
embedded without post table, but I found a strange
code in FoFiTrueType.cc.

  1353  void FoFiTrueType::readPostTable() {
  1354    GooString *name;
  1355    int tablePos, postFmt, stringIdx, stringPos;
  1356    int i, j, n, m;
  1357  
  1358    if ((i = seekTable("post")) < 0) {
  1359      return;
  1360    }
  ....
  1366    if (postFmt == 0x00010000) {
  1367      nameToGID = new GooHash(gTrue);
  ....
  1371    } else if (postFmt == 0x00020000) {
  1372      nameToGID = new GooHash(gTrue);
  ....
  1409    } else if (postFmt == 0x00028000) {
  1410      nameToGID = new GooHash(gTrue);
  1411      for (i = 0; i < nGlyphs; ++i) {
  1412        j = getU8(tablePos + 32 + i, &parsedOk);
  1413        if (!parsedOk) {
  1414          return;
  1415        }
  1416        if (j < 258) {
  1417          nameToGID->removeInt(macGlyphNames[j]);
  1418          nameToGID->add(new GooString(macGlyphNames[j]), i);
  1419        }
  1420      }
  1421    }
  1422  }

This code looks like as if designed to support "post"
table format version 1.0, 2.0 and 2.8. The version 2.8
is unknown for me. According to latest OpenType spec:

  http://www.microsoft.com/typography/otspec/post.htm

There are 1.0, 2.0, 2.5 and 3.0, there's no 2.8.
And, the implementation for 2.8 looks as if it was intended
to support 2.5.

# BTW, post 3.0 is just used to declare "there is no
# PostScript glyph names in this font", so there is
# no need to support post 3.0 in future poppler/xpdf.

If anybody has an example of TrueType font including
post table with version 0x00028000, please let me know
about its detail.

I'm afraid poppler maintainer don't know why 2.8 was used,
because this part had already existed in the initial version
of poppler. In addition, current xpdf (3.02) uses 2.8 too.
I will write to derekn, the original author of xpdf.

Regards,
mpsuzuki