[XeTeX] Finding out if a font supports a particular Unicode character and using it

[Michiel Kamermans]

Peter, (and everyone else reading this thread I suppose),

as of yesterday I found I needed a way to determine whether a font 
contains a certain glyph in PHP, and it turns out there is no such 
functionality available anywhere, at all, using any utility or extension 
that PHP understands, so I just decided to take the plunge and write a 
TTF/OTF file parser, instead of trying to find ways to glue fontforge 
and PHP together. The result is certainly good enough for my own needs 
(namely, it correcly parses a ttf/otf file's byte layout and navigates 
through the tables to see if the glyph is in the 'Unicode BMP (UCS-2)' 
subtable of the 'cmap' table), but perhaps this approach is also helpful 
for you and others.

The code is pretty vanilla, and should port ridiculously easily to 
Python. Relying on FontForge for full table checking is of course very 
nice, but if all you need is to check if a glyph is in a file's 
"standard" Unicode BMP cmap, this script might be a nice and quick solution.

I put the file on 
http://pomax.nihongoresources.com/downloads/fonttest.php.txt with a .txt 
extension, just download and rename to plain .php for the functional script.

- Mike "Pomax" Kamermans
nihongoresources.com