Re: Private Use Area

Eric:

> >I believe these have just been
> >codepoints used for internal purposes by GDI
> >
> And Netscape
>
<http://lxr.mozilla.org/seamonkey/source/intl/ctl/src/thaiShaper/thai-x.c>
> and ICU
> <http://oss.software.ibm.com/cvs/icu/icu/source/layout/ThaiShaping.cpp>,
> and probably FreeType/Gnome...

I looked at the Mozilla code. To the extent that I understand C (which,
admittedly is only to a limited degree), I see 8-bit values used for
presentation forms. For instance, in

502     else if (is_char_type (cluster[0], SpltTailCons) &&
503              is_char_type (cluster[1], BelowVowel|BelowDiac)) {
504         glyph_lists[0] = PANGO_MOZ_MAKE_GLYPH (tailcutcons (ucs2tis
(cluster[0]), shaping_table));
505         glyph_lists[1] = PANGO_MOZ_MAKE_GLYPH (ucs2tis (cluster[1]));


the Unicode codepoints are converted to TIS before being passed to the
tailcutcons and PANGO_MOZ_MAKE_GLYPH macros, and there's a lookup into
ThaiShapeTable, which is working in an 8-bit codespace (even if 16- or
32-bit datatypes are being passed around, the values are all 0xA0..0xFF).
So, I don't see reference to PUA codepoints. But then, I also don't know
how Pango is getting from these character codes to glyph IDs, and perhaps
somewhere along the way it's assuming U+F7xx code points in a Unicode cmap
table.



- Peter


---------------------------------------------------------------------------
Peter Constable

Non-Roman Script Initiative, SIL International
7500 W. Camp Wisdom Rd., Dallas, TX 75236, USA
Tel: +1 972 708 7485