Re: [boost] [GGL] Can't seem to use equals on multi_polygons

Subject: Re: [boost] [GGL] Can't seem to use equals on multi_polygons
From: Kef Schecter (furrykef_at_[hidden])
Date: 2010-01-21 10:27:35

> Intersections are enhanced in that new version. However, they should
> still be oriented clockwise in this version (the definitions from your
> first samples are counter-clockwise (so it was useful them being there
> :-) ).

Wait... my coordinates were counter-clockwise? I'm confused... are they 
supposed to be specified in (y, x) order instead of (x, y)? I assumed 
they were (x, y), in which case the coordinates would be clockwise: 
right, down, left, up.

> Is GGL running fine using CodeWarrior?

For the most part, yes. There were a couple of hacks I had to make:
* I had to change cartesian_distance::operator<< to use a plain ol' 
ostream instead of a basic_ostream<Char, Traits>. CodeWarrior didn't 
like the use of a template there, apparently. Using a plain ostream is 
fine for the purposes of my program -- in fact, the final program will 
use no streams at all. (Somebody on IRC suggested an alternative 
solution that might allow for the template, but I haven't tried it yet.)

* I applied the same hack to dsv_manipulator::operator<<.

There is also another problem I've just discovered:
* get_not_intersecting_holes<polygon_tag>::apply (from 
ggl/algorithms/overlay/assemble.hpp) does not compile correctly. I 
thought maybe the code I'm using doesn't need it anyway, but I tested it 
and it seems I thought wrong. This is the part it chokes on:

         typename boost::range_const_iterator
                 <
                     typename interior_type<Polygon>::type
                 >::type rit = boost::begin(interior_rings(polygon));
         std::vector<bool>::const_iterator iit = boost::begin(intersecting);

This yields this error message:

Error   : illegal implicit conversion from 
'std::__bit_iterator<Metrowerks::__bitvec_deleter<std::allocator<bool>>, 
false>' to
'std::__convert_iterator<std::__implicit_convert<const bool *, 
std::__bit_iterator<Metrowerks::__bitvec_deleter<std::allocator<bool>>, 
true>>>'

- Kef