[cairo] Engaging 64 bit precision

[Richard Procter]

Hi there,

I'd like to use a 64 bit type in cairo's path calculations and at  
least 30 bits of fractional precision. This looks tantalizingly  
possible going by the defines in cairo-fixed-type-private.h.

Has anyone already done this or have any pointers on how to go about it?

I see there's a warning that CAIRO_FIXED_BITS "must be 32" as the  
tesselator makes assumptions about the fixed type, however I don't  
believe I'm using it as I am using/abusing cairo only for its clean  
path construction API and python bindings (having pdf debug output in  
development has also been very handy, too).

many thanks,
Richard.