SDG: Add an example for inscribed circle of polygon

Segment_Delaunay_graph_2/examples/Segment_Delaunay_graph_2/CMakeLists.txt

@@ -13,6 +13,7 @@ create_single_source_cgal_program("sdg-filtered-traits.cpp")
 create_single_source_cgal_program("sdg-info-set.cpp")
 create_single_source_cgal_program("sdg-red-blue-info.cpp")
 create_single_source_cgal_program("sdg-voronoi-edges.cpp")
+create_single_source_cgal_program("sdg-inscribed-circle.cpp")
 
 find_package(LEDA QUIET)
 if(CGAL_Core_FOUND OR LEDA_FOUND)

Segment_Delaunay_graph_2/examples/Segment_Delaunay_graph_2/sdg-inscribed-circle.cpp

@@ -0,0 +1,59 @@
+// standard includes
+#include <iostream>
+#include <fstream>
+#include <cassert>
+#include <string>
+
+// define the kernel
+#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
+
+typedef CGAL::Exact_predicates_inexact_constructions_kernel Kernel;
+typedef Kernel::Segment_2 Segment_2;
+typedef Kernel::Line_2 Line_2;
+typedef Kernel::Point_2 Point_2;
+
+#include <CGAL/Polygon_2.h>
+#include <CGAL/IO/WKT.h>
+
+typedef CGAL::Polygon_with_holes_2<Kernel> Polygon_with_holes;
+
+// typedefs for the traits and the algorithm
+#include <CGAL/Segment_Delaunay_graph_traits_2.h>
+#include <CGAL/Segment_Delaunay_graph_2.h>
+
+typedef CGAL::Segment_Delaunay_graph_traits_2<Kernel>  Gt;
+typedef CGAL::Segment_Delaunay_graph_2<Gt>             SDG2;
+
+
+int main()
+{
+  std::ifstream ifs("data/polygon.wkt");
+  assert( ifs );
+
+  Polygon_with_holes pwh;
+  CGAL::IO::read_polygon_WKT(ifs, pwh);
+
+  const auto boundary_polygon = pwh.outer_boundary();
+
+  SDG2          sdg;
+
+  sdg.insert_segments(boundary_polygon.edges_begin(), boundary_polygon.edges_end());
+
+  double sd = 0;
+  SDG2::Finite_faces_iterator fit = sdg.finite_faces_begin();
+  for(; fit !=  sdg.finite_faces_end(); ++fit){
+    if(fit->vertex(0)->site().is_segment() && fit->vertex(1)->site().is_segment()  && fit->vertex(2)->site().is_segment()){
+      Segment_2 s0 = fit->vertex(0)->site().segment();
+
+
+      Point_2 p = sdg.primal(fit);
+      std::cout << p << std::endl;
+      if (boundary_polygon.bounded_side(p) == CGAL::ON_BOUNDED_SIDE) {
+          double point_segment_sqdist = CGAL::squared_distance(p, s0);
+          sd = std::max(point_segment_sqdist, sd);
+      }
+    }
+  }
+  std::cout << "radius of largest inscribed circle: " << sqrt(sd) << std::endl;
+  return 0;
+}