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[Andreas Fabri <>]

You are right.

I fixed the example:  https://github.com/afabri/cgal/blob/SVD-inscribed_circle-GF/Segment_Delaunay_graph_2/examples/Segment_Delaunay_graph_2/sdg-inscribed-circle.cpp

You can also see some input files in the directory data/

But again, there is room for improvement.

Best,

Andreas

On 3/12/2024 12:54 AM, Bob Bill ( via cgal-discuss Mailing List) wrote:

Hello,

I tried your snippet (thanks a lot!) on the following polygon (it's the square [-1,0]x[-1,0], I've attached a mwe):

boundary_polygon.push_back(Point_2(-1., -1.));

boundary_polygon.push_back(Point_2(-0.5, -1));

boundary_polygon.push_back(Point_2(0., -1.));

boundary_polygon.push_back(Point_2(0., -0.5));

boundary_polygon.push_back(Point_2(0., 0.));

boundary_polygon.push_back(Point_2(-0.5, 0.));

boundary_polygon.push_back(Point_2(-1., 0));

boundary_polygon.push_back(Point_2(-1., -0.5));

and it gives as result 0 instead of 0.5. After debugging, I realised the check:

if (fit->vertex(0)->site().is_segment() &&

fit->vertex(1)->site().is_segment() &&

fit->vertex(2)->site().is_segment()))

is always false for this example, but I can't see the reason why it fails. Is there an obvious fix for this?

Best,

Bob

Il lunedì 11 marzo 2024 alle ore 15:37:01 CET, Andreas Fabri ha scritto:

Hello,

The idea is here :  https://gist.github.com/afabri/da5f00ff59eaadad3f00a7873670b897

There is place for improvement as the test if the point is inside the polygon is each time O(n log n).

This should evolve in a function provided by the library, but maybe this is better than nothing for you.

Best,

Andreas

On 3/9/2024 12:58 PM, Bob Bill ( via cgal-discuss Mailing List) wrote:

Hi,

I've been trying for a while to compute **the radius** of the inscribed circle of a general polygonal shape in CGAL. As suggested in another post, I should compute the segment Voronoi diagram. 

                                    Unfortunately, I am not
                                      able to understand how to compute
                                      the "segment voronoi diagram" in
                                      CGAL. Is  Segment_Delaunay_graph_2 the
                                      right class?
                                     
                                    Moreover, once I have the
                                      Voronoi diagram, how can I compute
                                      such a radius? Is there any code
                                      snippet already available for such
                                      a task? 
                                    
                                    
                                    
                                    
                                    Best regards,
                                    Bob
                                  
                                
                              
                            
                          
                        
                      
                    
                  
                  
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Andreas Fabri, PhD
Chief Officer, GeometryFactory
Editor, The CGAL Project
                  
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Editor, The CGAL Project