Re: GtkCanvas requirements?

[Emmanuele Bassi <ebassi gmail com>]

On Tue, 2007-04-24 at 00:19 +0100, Damon Chaplin wrote:
>  
> > thinking 'in these days of 64-bit machines' would basically screw up all
> > of the people working on getting GTK+ to work on small devices which -
> > surprise! - have no FPU, hence perform like shit with doubles and
> > floats. in Clutter, for instance, most of the operations are done using
> > fixed point algebra and transforming doubles in the public API into
> > 16.16 or 21.11 fixed point numbers internally; we also expose a fixed
> > point API to avoid using doubles altogether. is this hard? yes. is it
> > necessary? yes. should it be a part of the initial design and
> > implementation? hell, yes. because history teach us that starting with
> > "well, we have 64-bit machines nowadays, what's a double going to do" is
> > the perfect way to hit the wall of performance regressions.
> > 
> > cairo and pango developers and contributors went all the lengths to
> > reduce the floating point usage in their libraries; we shouldn't screw
> > the developers on embedded devices *again*.
> 
> But the cairo API already uses doubles, for coordinates and
> transformations.

I'm not saying that cairo API exposes fixed point values; neither I'm
saying that a GtkCanvas should expose a fixed point API (albeit we went
down this road in Clutter and we will see where that leads). all I'm
saying is that people should not think that the canvas should be design
or targeted for desktop boxes; instead, we avoid screwing up people in
the embedded world. we've been there, we've seen what happens. that's
the only point I was trying to make. really. :-)

ciao,
 Emmanuele.

-- 
Emmanuele Bassi,  E: ebassi gmail com
W: http://www.emmanuelebassi.net
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