[geos-devel] QD (Quad-Double) Approach to Robustness

[strk at refractions.net]

On Wed, Jun 14, 2006 at 11:40:00AM -0700, Martin Davis wrote:
> > > In any case, I'm not sure that JTS uses FP equals for 
> > anything other 
> > > than checking whether two points are *exactly* the same.  So this 
> > > should be portable, I assume.
> 
> I think you're misreading what I said.  I meant that JTS uses == (via
> equals2D) to test whether the *value* of two coordinates is exactly the
> same.  Pointers don't enter into it.
> 
> You absolutely should NOT try to replace those equality tests with
> "approximately equals".  Approx equals may have a place in some of the
> algorithms, but this needs to be carefully evaluated on a case-by-case
> basis.

Ok, so back to original problem: do you obtain a successful result
with JTS against the XML test I attached ?
GEOS is successfull or not depending on wheter or not Coordinate
copy constructor and/or assignment operator is inlined.

--strk;