libgd + symbol fonts [was Re: Universal enhanced text mode!]

[Ethan M. <merritt@u.washington.edu>]

Just an update.

I added this code to CVS back in November, with a caveat that full
support for symbol fonts in the png/jpeg terminal required a patch
for libgd.

I am delighted to report that Tom Boutell has added the patch into
libgd. As of version 2.0.21 (now available for download) both the
Microsoft symbol.ttf and the Adobe Symbol fonts are handled correctly,
and "just work" from gnuplot.  Actually any Adobe custom-encoded
font should work, not just Symbol. Apple fonts should work also,
but I haven't tested them.



iso-8859-xx encodings
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D

A related relatively minor problem remains, however, in that
there is currently no mechanism for translating the requested
character encoding from gnuplot through libgd to the font libraries.

libgd's own native font (default if you don't specify one) happens
to be iso-8859-2.   When you request a specific TTF font you=20
get iso-8859-1 so far as I can tell, but I am not sure if this is
guaranteed. =20

There is a mechanism for requesting 8-bit unicode, Shift-JIS, or big5=20
characters, however. So in principal gnuplot could  convert strings
to unicode if it wants characters not in iso-8859-1, but that
sounds like too much work.  I may see if I can further hack
libgd itself to know more about character encodings in some future
release.

--=20
Ethan A Merritt       merritt@u.washington.edu
Biomolecular Structure Center Box 357742
University of Washington, Seattle, WA 98195