AmandaLind wrote:

This is the last time I bump this in hope of help...

You should be a little more patient, I read the list every day and search for Polygon in the subject line.

namespace gtl = boost::polygon; using namespace boost::polygon::operators; using namespace gtl;

//lets construct the two polygons typedef gtl::polygon_data Polygon; typedef gtl::polygon_traits::point_type Point;

Both polygon_data and polygon_traits are templates, so the above code doesn't appear legal. You need to specify the coordinate type for polygon data and the polygon type for polygon traits. ...

Polygon poly1; gtl::set_points(poly1, pts1, pts1+numcorners1);

...

Polygon poly2; gtl::set_points(poly2, pts2, pts2+numcorners2);

using namespace boost::polygon::operators;

Polygon poly3; poly3 = poly1 & poly2;

The above code should not compile because the result of a boolean AND between two polygons can be zero, one or many polygons. It must be stored to a model of polygon set concept. The polygon_data assignment operator should not accept the operator template produced by &.

Point pts3[poly3.size()];

//how does one use iterators ?! std::vector<point_data<int> >::iterator itr ; itr= poly3.begin(); int index=0 for(itr; itr != ploy3.end(); ++itr) { pts3(index)=*itr; index++; }

They are just like stl iterators (in fact they are std::vector iterators in this case.) Just do: std::vector pts; Pts.insert(pts.end(), poly3.begin(), poly3.end()); However, you need extra code before you get to that point. Try typedef std::vector PolySet; typedef boost::polygon::polygon_data<int> Poly; typedef boost::polygon::polygon_traits<Poly>::point_type Point; Poly poly1, poly2; gtl::set_points(poly1, pts1, pts1+numcorners1); gtl::set_points(poly2, pts2, pts2+numcorners2); PolySet polys; using namespace boost::polygon::operators; boost::polygon::assign(polys, poly1 & poly2); for(std::size_t i = 0; i < polys.size(); ++i) { std::vector<Point> pts; pts.insert(pts.end(), polys[i].begin(), polys[i].end()); //do whatever you wanted with the points } I wrote the above code off the top of my head, so don't be too alarmed if it doesn't compile for some reason. Use the example code and look at the unit test code as well as the tutorial code to see usage of the library. Regards, Luke

AmandaLind wrote:

Luke, Thank you for your response !

I don't understand your comment on the first block of code, mostly because I don't see Coordinate type or Polygon type in the example you provided at the end.

~Amanda

int is coordinate type and Poly is polygon type. Coordinate type and polygon type are the names of the template parameters for polygon_data and polygon_traits templates. I substitute int and Poly in my example at the end when I instantiate those templates. Regards, Luke

I ask the first part because Point pts2[numcorners2]; for (int index=0; index<numcorners2; index++) { pts2[index]=gtl::construct<Point>(rotated_corners2[index].x*1000, rotated_corners2[index].y*1000); //mult by 1000 because it rounds to integers. } is throwing an error since Point is not "Plain Old Data" and numcorners2, though a const int, is a variable. -- View this message in context: http://boost.2283326.n4.nabble.com/Polygon-accessing-Points-Data-tp3446015p3... Sent from the Boost - Users mailing list archive at Nabble.com.

HxH wrote:

Hi, Luke and Amanda I am kind of having the problem with the polygon. When I do the & (AND) operation of two polygons, the points in resulted polygon are not correct. Do you any ideas?? I have a post in the forum called Logic operation in boost polygon.

Thank you so much!

I have replied to your post. You are most welcome, Luke