[cairo] Backwards glyphs?

[Ian Britten]

Hi all,
I'm working on getting text rendered by Cairo (PDF) in our framework,
and have noticed that the rendered glyphs are coming out backwards,
and was wondering if anyone had seen this before (and hopefully knew
how to fix it!)

I don't think I'm doing anything too unusual to cause this:
- Creating a PDF surface
- Configuring a Cartesian (lower-left origin) world transform on it.
When drawing a glyph, I just:
- cairo_set_font_size()
- cairo_set_source_rgba()
- cairo_show_glyphs()
   [I'm not even setting a specific face, and still see this behaviour]

Generally, everything is working as expected with my rendering.
Lines, polygons, and images all draw correctly.  Even for the glyphs,
they're at the correct position, with the specified size, colour, etc.
It's just that the individual glyphs are backwards... :(

Note that the text is simple Latin characters, drawn one glyph at a
time.  There's no Arabic/Hebrew/R-to-L issues with the text I'm
rendering.

Am I expected to muck about with cairo_set_font_matrix(), even for
simple rendering?  I was hoping just setting the size+position would
result in the correct output...

I can post screenshots, the PDF, source code, etc, if anyone wants
any more details.

Thanks for any info/suggestions!
Ian