CGAL users discussion list

[Efi Fogel <>]

On 5 January 2018 at 00:54, xoru <> wrote:

I have 2 polygons. outer and hole inside outer.

 

Polygon_2 outer ;

 

outer.push_back( Point(-1,-1) ) ;

outer.push_back( Point(0,-12) ) ;

outer.push_back( Point(1,-1) ) ;

outer.push_back( Point(12,0) ) ;

outer.push_back( Point(1,1) ) ;

outer.push_back( Point(0,12) ) ;

outer.push_back( Point(-1,1) ) ;

outer.push_back( Point(-12,0) ) ;

 

Polygon_2 hole ;

 

hole.push_back( Point(-1,0) ) ;

hole.push_back( Point(0,1 ) ) ;

hole.push_back( Point(1,0 ) ) ;

hole.push_back( Point(0,-1) ) ;

 

 

Polygon_with_holes poly( outer ) ;

 

poly.add_hole( hole ) ;

 

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1. How I can create poly variable without initialization.

 Polygon_with_holes poly;

You cannot

and how add outer to poly?

is any poly.add_outer function?

Briefly looking at it, I think these functions can and should be added.

Until we do it, you have 2 options:

1. Construct a new polygon with holes when you need to add an outer boundary.

2. Introduce a new template that has these missing functions and refer to this new template of yours in Gps_segment_traits_2.h (you can simply replace the included file Polygon_with_holes_2.h with your newly introduced file.)

 

2. How I can clear all point from poly. all outer and all holes?

poly.clear() or similar?

Yes