[cairo] Re: adding a new curve type to cairo

[Jeff Smith]

--- Jeff Smith <whydoubt at yahoo.com> wrote:
> --- Niki Spahiev <niki.spahiev at gmail.com> wrote:
> > Carl Worth wrote:
> > > poorly approximated with individual cubic B�ziers, (even the common
> > > approach of 4 cubic B�ziers per circle is poor, so cairo_arc does
> > > better than that when necessary).
> > 
> > Any info on how poor it is?
> 
> http://cgafaq.info/wiki/Bezier_Circle.  I am pretty sure the formula is correct, as I
> calculated it independently once upon a time.  The accuracy stated I cannot vouch for.

I found a program I wrote once to calculate the accuracy.  I calculated it with higher
precision than that given on the page I just cited.  The most inaccurate point is off by
0.027253% of the radius.  This occurs at +/-19.02 degrees from each of (0, 90, 180, 270)
degrees. 

 -- Jeff Smith


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