Re: [Chicken-users] Computational geometry for chicken?

[Matthew Welland]

I definitely need only a very small subset of what CGAL can do. For now at 
least I need 2D polygon operations. I'm not familiar with how a quad tree is 
used in polygon operations. Do you have a reference? I see lots of very 
interesting stuff on quad trees (although quite a bit of it is pay to read) 
and they look very useful.

For comparison here is a description of how one implementation of polygon 
operations was done: 

http://boolean.klaasholwerda.nl/bool.html#document

Matt
-=-

On Sunday 08 November 2009 10:24:20 pm Ivan Raikov wrote:
> Hello,
>
>    Are you really sure that you need a library that is as general as
> CGAL?  Perhaps you should start by defining the exact requirements of
> the application you are interested in, and that should guide you in
> determining what kind of data structures and algorithms you need. For
> example, if all you are interested in is union and intersection of 2D
> objects, a quad-tree [1] might be sufficient, and I would not be
> surprised if there is a functional quad-tree implementation available
> online. So defining your requirements first might save you some labor.
>
>   -Ivan
>
> [1] http://en.wikipedia.org/wiki/Quadtree
>
> Matthew Welland <address@hidden> writes:
> > I don't see anything in the eggs list that does the trick so ....
> >
> > I need some basic polygon computational geometry operations, namely;
> > AND, OR, XOR, NOT. Any suggestions how to go about this? I have some
> > slow, incomplete and buggy code I wrote a long time ago that I could
> > resurrect and slap into shape but I think a proper egg accessing a C
> > library would be a better solution.
> >
> > I'm guessing the right answer is to eggify http://www.cgal.org/ but
> > that looks like a daunting task.
> >
> > Suggestions, insights and pointers appreciated.
> >
> > Free book on the subject for anyone interested:
> >
> > http://www.freetechbooks.com/computational-geometry-methods-and-
> > applications-t557.html