Re: Floating point in pango

[Behdad Esfahbod <behdad behdad org>]

On Wed, 2006-07-12 at 08:47 +0200, Murray Cumming wrote:
> > Hi;
> >
> > On Tue, 2006-07-11 at 12:04 +0300, Jorn Baayen wrote:
> >> >
> >> > True.  That's because cairo's public API uses floating point.  Do you
> >> > have any idea how Pango can do better here?
> >>
> >> No :(
> >>
> >
> > Neither that nice but;
> >
> >  - Have cairo expose a new alternate fixed point API that pango-cairo
> >    makes use of ( openGL API does a similar thing ). Internally cairo
> >    is mostly fixed point I believe.
> 
> Is this something that we can do with just a typedef?

Not without a C++ compiler.  But that may be feasible still.  We use
floats like others do, add, multiply, sin(), cos(), and add & multiply
won't work straight on fixed.


> I don't think we should be afraid of adding an --enable-fixed-point=yes or
> --enable-embedded-api=yes build option so that the API is slightly
> different on some platforms. Backwards ABI compatibility isn't a big
> concern. Dependant software can then #ifdef where necessary to adapt its
> build to the alternative API.

Agreed.  At some point I started making the 16.16 fixed split in cairo
configurable, but didn't finish the patch.  That helps here too.

-- 
behdad
http://behdad.org/

"Commandment Three says Do Not Kill, Amendment Two says Blood Will Spill"
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