Using the Symbol font with pango

[Timothée Lecomte <timothee lecomte ens fr>]

Dear Pango specialists,

I am writing a rendering terminal for gnuplot, a scientific plotter. I
use Cairo for drawing, and Pango to manage text. I would like to use the
Symbol font with its conventionnal mapping, as it is the common way to
display mathematic characters under gnuplot currently.

However, if I simply choose the Symbol font and try to draw the
characters, I don't get the desired output. Under Linux (gtk2.8, pango
1.10.1, cairo 1.0.2), I get expected Symbol output for characters for up
to 128 (ie greek characters) and default font for others, and under
Windows (pango 1.10.1, cairo 1.0.2) I don't get any Symbol output but
default font.

I understand that Pango is based on unicode, and that the Symbol font
doesn't respect unicode. I would be pleased to have help regarding this.

As far as I understand, I could write something like a conversion
function to replace iso-8859-1 characters (usual input from gnuplot) by
corresponding unicode characters using a map like the one provided here :
http://www.unicode.org/Public/MAPPINGS/VENDORS/APPLE/SYMBOL.TXT

Another solution could be to use a custom PangoFcDecoder, but I must
admit that I don't understand everything about it. Moreover, if it's
based on Fontconfig, will it also work under Windows ?

Is there a more straightforward solution ?

Thanks for your help !

Timothée Lecomte